RESUMEN

PURPOSE: Pseudomyxoma peritonei (PMP) is a rare and poorly understood malignant condition characterized by the accumulation of intra-abdominal mucin produced from peritoneal metastases. Currently, cytoreductive surgery remains the mainstay of treatment but disease recurrence and death after relapse frequently occur in patients with PMP. New therapeutic strategies are therefore urgently needed for these patients. EXPERIMENTAL DESIGN: A total of 120 PMP samples from 50 patients were processed to generate a collection of 50 patient-derived organoid (PDO) and xenograft (PDX) models. Whole exome sequencing, immunohistochemistry analyses, and in vitro and in vivo drug efficacy studies were performed. RESULTS: In this study, we have generated a collection of PMP preclinical models and identified druggable targets, including BRAFV600E, KRASG12C, and KRASG12D, that could also be detected in intra-abdominal mucin biopsies of patients with PMP using droplet digital PCR. Preclinical models preserved the histopathological markers from the original patient sample. The BRAFV600E inhibitor encorafenib reduced cell viability of BRAFV600E PMP-PDO models. Proof-of-concept in vivo experiments showed that a systemic treatment with encorafenib significantly reduced tumor growth and prolonged survival in subcutaneous and orthotopic BRAFV600E-PMP-PDX mouse models. CONCLUSIONS: Our study demonstrates for the first time that systemic targeted therapies can effectively control PMP tumors. BRAF signaling pathway inhibition represents a new therapeutic opportunity for patients with BRAFV600E PMP who have a poor prognosis. Importantly, our present data and collection of preclinical models pave the way for evaluating the efficacy of other systemic targeted therapies toward extending the promise of precision oncology to patients with PMP.

Asunto(s)

Terapia Molecular Dirigida , Neoplasias Peritoneales , Medicina de Precisión , Seudomixoma Peritoneal , Ensayos Antitumor por Modelo de Xenoinjerto , Seudomixoma Peritoneal/patología , Seudomixoma Peritoneal/tratamiento farmacológico , Seudomixoma Peritoneal/genética , Humanos , Animales , Ratones , Medicina de Precisión/métodos , Terapia Molecular Dirigida/métodos , Neoplasias Peritoneales/tratamiento farmacológico , Neoplasias Peritoneales/secundario , Neoplasias Peritoneales/genética , Neoplasias Peritoneales/patología , Proteínas Proto-Oncogénicas B-raf/genética , Proteínas Proto-Oncogénicas B-raf/antagonistas & inhibidores , Femenino , Masculino , Proteínas Proto-Oncogénicas p21(ras)/genética , Secuenciación del Exoma , Mutación , Línea Celular Tumoral , Organoides/efectos de los fármacos , Organoides/patología , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo

RESUMEN

Pseudomyxoma peritonei (PMP) is an indolent malignant syndrome. The standard treatment for PMP is cytoreductive surgery combined with intraperitoneal hyperthermic chemotherapy (CRS + HIPEC). However, the high recurrence rate and latent clinical symptoms and signs are major obstacles to further improving clinical outcomes. Moreover, patients in advanced stages receive little benefit from CRS + HIPEC due to widespread intraperitoneal metastases. Another challenge in PMP treatment involves the progressive sclerosis of PMP cell-secreted mucus, which is often increased due to activating mutations in the gene coding for guanine nucleotide-binding protein alpha subunit (GNAS). Consequently, the development of other PMP therapies is urgently needed. Several immune-related therapies have shown promise, including the use of bacterium-derived non-specific immunogenic agents, radio-immunotherapeutic agents, and tumor cell-derived neoantigens, but a well-recognized immunotherapy has not been established. In this review the roles of GNAS mutations in the promotion of mucin secretion and disease development are discussed. In addition, the immunologic features of the PMP microenvironment and immune-associated treatments are discussed to summarize the current understanding of key features of the disease and to facilitate the development of immunotherapies.

Asunto(s)

Inmunoterapia , Neoplasias Peritoneales , Seudomixoma Peritoneal , Microambiente Tumoral , Humanos , Seudomixoma Peritoneal/terapia , Seudomixoma Peritoneal/inmunología , Seudomixoma Peritoneal/genética , Seudomixoma Peritoneal/patología , Microambiente Tumoral/inmunología , Neoplasias Peritoneales/terapia , Neoplasias Peritoneales/inmunología , Neoplasias Peritoneales/genética , Inmunoterapia/métodos , Procedimientos Quirúrgicos de Citorreducción , Mutación , Quimioterapia Intraperitoneal Hipertérmica

RESUMEN

The study of circulating tumor DNA (ctDNA) plays a pivotal role in advancing precision oncology, providing valuable information for individualized patient care and contributing to the ongoing effort to improve cancer diagnosis, treatment, and management. However, its applicability in pseudomyxoma peritonei (PMP) remains unexplored. In this multicenter retrospective study involving 21 PMP patients, we investigated ctDNA presence in peripheral blood using three distinct methodologies. Despite mucinous tumor tissues exhibiting KRAS and GNAS mutations, ctDNA for these mutations was undetectable in blood samples. In this pilot study, circulating tumor DNA was not detected in blood when the tumor harbored mutations of known significance. In the future, a study with a larger sample size is needed to confirm these findings and to determine whether ctDNA could identify patients at risk for early recurrence and/or systemic metastases.

Asunto(s)

ADN Tumoral Circulante , Neoplasias Peritoneales , Seudomixoma Peritoneal , Humanos , Seudomixoma Peritoneal/genética , Seudomixoma Peritoneal/sangre , Seudomixoma Peritoneal/patología , Neoplasias Peritoneales/genética , Neoplasias Peritoneales/secundario , Neoplasias Peritoneales/sangre , ADN Tumoral Circulante/genética , ADN Tumoral Circulante/sangre , Estudios Retrospectivos , Femenino , Persona de Mediana Edad , Masculino , Anciano , Subunidades alfa de la Proteína de Unión al GTP Gs/genética , Cromograninas/genética , Mutación , Proteínas Proto-Oncogénicas p21(ras)/genética , Proyectos Piloto , Adulto

RESUMEN

INTRODUCTION: Pseudomyxoma peritonei (PMP) is a disease characterized by progressive accumulation of intraperitoneal mucinous ascites produced by neoplasms in the abdominal cavity. Since the prognosis of patients with PMP remains unsatisfactory, the development of effective therapeutic drug(s) is a matter of pressing concern. Genetic analyses of PMP have clarified the frequent activation of GNAS and/or KRAS. However, the involvement of global epigenetic alterations in PMPs has not been reported. METHODS: To clarify the genetic background of the 15 PMP tumors, we performed genetic analysis using AmpliSeq Cancer HotSpot Panel v2. We further investigated global DNA methylation in the 15 tumors and eight noncancerous colonic epithelial tissues using MethylationEPIC array BeadChip (Infinium 850k) containing a total of 865,918 probes. RESULTS: This is the first report of comprehensive DNA methylation profiles of PMPs in the world. We clarified that the 15 PMPs could be classified into at least two epigenotypes, unique methylation epigenotype (UME) and normal-like methylation epigenotype (NLME), and that genes associated with neuronal development and synaptic signaling may be involved in the development of PMPs. In addition, we identified a set of hypermethylation marker genes such as HOXD1 and TSPYL5 in the 15 PMPs. CONCLUSIONS: These findings may help the understanding of the molecular mechanism(s) of PMP and contribute to the development of therapeutic strategies for this life-threatening disease.

Asunto(s)

Neoplasias del Apéndice , Metilación de ADN , Seudomixoma Peritoneal , Humanos , Seudomixoma Peritoneal/genética , Seudomixoma Peritoneal/patología , Neoplasias del Apéndice/genética , Neoplasias del Apéndice/patología , Femenino , Masculino , Persona de Mediana Edad , Anciano , Neoplasias Peritoneales/genética , Epigénesis Genética , Estudio de Asociación del Genoma Completo , Adulto

RESUMEN

Epithelial-mesenchymal transition (EMT), angiogenesis, cell adhesion and extracellular matrix (ECM) interaction are essential for colorectal cancer (CRC) metastasis. Low grade mucinous neoplasia of the appendix (LAMN) and its advanced state low grade pseudomyxoma peritonei (lgPMP) show local aggressiveness with very limited metastatic potential as opposed to CRC. To better understand the underlying processes that foster or impede metastatic spread, we compared LAMN, lgPMP, and CRC with respect to their molecular profile with subsequent pathway analysis. LAMN, lgPMP and (mucinous) CRC cases were subjected to transcriptomic analysis utilizing Poly(A) RNA sequencing. Successfully sequenced cases (LAMN n = 10, 77%, lgPMP n = 13, 100% and CRC n = 8, 100%) were investigated using bioinformatic and statistical tests (differential expression analysis, hierarchical clustering, principal component analysis and gene set enrichment analysis). We identified a gene signature of 28 genes distinguishing LAMN, lgPMP and CRC neoplasias. Ontology analyses revealed that multiple pathways including EMT, ECM interaction and angiogenesis are differentially regulated. Fifty-three significantly differentially regulated gene sets were identified between lgPMP and CRC followed by CRC vs. LAMN (n = 21) and lgPMP vs. LAMN (n = 16). Unexpectedly, a substantial enrichment of the EMT gene set was observed in lgPMP vs. LAMN (FDR=0.011) and CRC (FDR=0.004). Typical EMT markers were significantly upregulated (Vimentin, TWIST1, N-Cadherin) or downregulated (E-Cadherin) in lgPMP. However, MMP1 and MMP3 levels, associated with EMT, ECM and metastasis, were considerably higher in CRC. We show that the different tumor biological behaviour and metastatic spread pattern of midgut malignancies is reflected in a different gene expression profile. We revealed a strong activation of the EMT program in non-metastasizing lgPMP vs. CRC. Hence, although EMT is considered a key step in hematogenous spread, successful EMT does not necessarily lead to hematogenous dissemination. This emphasizes the need for further pathway analyses and forms the basis for mechanistic and therapy-targeting research.

Asunto(s)

Neoplasias Colorrectales , Neoplasias Peritoneales , Seudomixoma Peritoneal , Humanos , Seudomixoma Peritoneal/genética , Transcriptoma , Neoplasias Colorrectales/patología , Transición Epitelial-Mesenquimal/genética , Neoplasias Peritoneales/genética , Neoplasias Peritoneales/patología , Perfilación de la Expresión Génica , Línea Celular Tumoral , Movimiento Celular

RESUMEN

Pseudomyxoma peritonei (PMP) is a rare malignant clinical syndrome with little known about the global mutation profile. In this study, whole-exome sequencing (WES) was performed in 49 appendiceal PMP to investigate mutation profiles and mutation signatures. A total of 4,020 somatic mutations were detected, with a median mutation number of 56 (1-402). Tumor mutation burden (TMB) was generally low (median 1.55 mutations/Mb, 0.12-11.26 mutations/Mb). Mutations were mainly enriched in the function of cancer-related axonogenesis, extracellular matrix-related processes, calcium signaling pathway, and cAMP signaling pathway. Mutations in FCGBP, RBFOX1, SPEG, RTK-RAS, PI3K-AKT, and focal adhesion pathways were associated with high-grade mucinous carcinoma peritonei. These findings revealed distinct mutation profile in appendiceal PMP. Ten mutation signatures were identified, dividing patients into mutation signature cluster (MSC) 1 (N = 28, 57.1%) and MSC 2 (N = 21, 42.9%) groups. MSC (P = 0.007) was one of the four independent factors associated with 3-year survival. TMB (P = 0.003) and microsatellite instability (P = 0.002) were independent factors associated with MSC 2 grouping. Taken together, our findings provided a broader view in the understanding of molecular pathologic mechanism in appendiceal PMP and may be critical to developing an individualized approach to appendiceal PMP treatment. IMPLICATIONS: This work describes exhaustive mutation profile of PMP based on WES data and derives ten mutation signatures, which divides patients into two clusters and serve as an independent prognostic factor associated with 3-year survival.

Asunto(s)

Neoplasias Peritoneales , Seudomixoma Peritoneal , Humanos , Seudomixoma Peritoneal/genética , Seudomixoma Peritoneal/patología , Neoplasias Peritoneales/genética , Neoplasias Peritoneales/patología , Secuenciación del Exoma , Fosfatidilinositol 3-Quinasas/genética , Mutación , Biomarcadores de Tumor/genética

RESUMEN

BACKGROUND: Appendiceal mucinous neoplasms (AMNs) with disseminated disease (pseudomyxoma peritonei) are heterogeneous tumors with variable clinicopathologic behavior. Despite the development of prognostic systems, objective biomarkers are needed to stratify patients. With the advent of next-generation sequencing (NGS), it remains unclear if molecular testing can improve the evaluation of disseminated AMN patients. METHODS: Targeted NGS was performed for 183 patients and correlated with clinicopathologic features to include American Joint Committee on Cancer/World Health Organization (AJCC/WHO) histologic grade, peritoneal cancer index (PCI), completeness of cytoreduction (CC) score, and overall survival (OS). RESULTS: Genomic alterations were identified for 179 (98%) disseminated AMNs. Excluding mitogen-activated protein kinase genes and GNAS due to their ubiquitous nature, collective genomic alterations in TP53, SMAD4, CDKN2A, and the mTOR genes were associated with older mean age, higher AJCC/WHO histologic grade, lymphovascular invasion, perineural invasion, regional lymph node metastasis, and lower mean PCI (p < 0.040). Patients harboring TP53, SMAD4, ATM, CDKN2A, and/or mTOR gene alterations were found to have lower OS rates of 55% at 5 years and 14% at 10 years, compared with 88% at 5 years and 88% at 10 years for patients without the aforementioned alterations (p < 0.001). Based on univariate and multivariate analyses, genomic alterations in TP53, SMAD4, ATM, CDKN2A, and/or the mTOR genes in disseminated AMNs were a negative prognostic factor for OS and independent of AJCC/WHO histologic grade, PCI, CC score, and hyperthermic intraperitoneal chemotherapy treatment (p = 0.006). CONCLUSIONS: Targeted NGS improves the prognostic assessment of patients with disseminated AMNs and identifies patients who may require increased surveillance and/or aggressive management.

Asunto(s)

Adenocarcinoma Mucinoso , Neoplasias del Apéndice , Neoplasias Peritoneales , Seudomixoma Peritoneal , Humanos , Seudomixoma Peritoneal/genética , Seudomixoma Peritoneal/terapia , Seudomixoma Peritoneal/metabolismo , Adenocarcinoma Mucinoso/genética , Adenocarcinoma Mucinoso/terapia , Neoplasias del Apéndice/genética , Neoplasias del Apéndice/terapia , Neoplasias Peritoneales/genética , Neoplasias Peritoneales/terapia , Neoplasias Peritoneales/patología , Secuenciación de Nucleótidos de Alto Rendimiento , Serina-Treonina Quinasas TOR/genética , Procedimientos Quirúrgicos de Citorreducción

Asunto(s)

Neoplasias del Apéndice , Neoplasias Peritoneales , Seudomixoma Peritoneal , Humanos , Seudomixoma Peritoneal/genética , Neoplasias del Apéndice/genética , Neoplasias Peritoneales/genética , Secuenciación de Nucleótidos de Alto Rendimiento

RESUMEN

Pseudomyxoma peritonei (PMP) is a rare, progressive, slowly growing neoplastic condition which is poorly understood, with a 5-year progression-free survival rate as low as 48%. PMP is most commonly caused by appendiceal mucinous neoplasms (AMN), and understanding their genetic biology and pathogenicity may allow for the development of better novel systemic treatments to target key deleterious mutations and the implicated pathways. The primary aim of this systematic review was to identify the genetic profile of histologically confirmed human PMP or AMN samples. The secondary aim was to identify whether genetic marks could be used to predict patient survival. Ovid EMBASE, Ovid MEDLINE, PubMed, and Web of Science were searched to identify studies investigating the genetic profile of histologically-confirmed human PMP or AMN samples. We review findings of 46 studies totalling 2181 tumour samples. The most frequently identified somatic gene mutations in patients with PMP included KRAS (38-100%), GNAS (17-100%), and TP53 (5-23%); however, there were conflicting results of their effect on survival. Three studies identified molecular subtypes based on gene expression profiles classifying patients into oncogene-enriched, immune-enriched, and mixed molecular subtypes with prognostic value. This review summarises the current literature surrounding genetic aberrations in PMP and AMNs and their potential utility for targeted therapy. Given the recent advances in clinical trials to directly target KRAS and GNAS mutations in other cancers, we propose a rationale to explore these mutations in future pre-clinical studies in PMP with a view for a future clinical trial.

Asunto(s)

Neoplasias del Apéndice , Neoplasias Peritoneales , Seudomixoma Peritoneal , Humanos , Seudomixoma Peritoneal/genética , Seudomixoma Peritoneal/patología , Neoplasias Peritoneales/genética , Neoplasias del Apéndice/genética , Neoplasias del Apéndice/patología , Perfil Genético , Proteínas Proto-Oncogénicas p21(ras)/genética

RESUMEN

BACKGROUND: Pseudomyxoma peritonei is a rare disease condition mainly caused by primary mucinous tumors from the appendix and rarely from the ovary, such as when mucinous ovarian tumors arise from within a teratoma. Molecular analyses of pseudomyxoma from the appendix showed that KRAS and GNAS pathogenic variants are common genetic features of pseudomyxoma peritonei. However, the origin of the tumors is difficult to be identified via genetic variants alone. This study presents a case of pseudomyxoma peritonei of ovarian origin, which was diagnosed by comprehensive genomic profiling with ploidy analysis in a series of primary, recurrent, and autopsy tumor specimens. CASE PRESENTATION: A 40-year-old woman was diagnosed with Stage IC2 mucinous ovarian tumor of borderline malignancy with mature cystic teratoma, upon clinical pathology. Immunohistochemical analysis suggested that the mucinous tumor was derived from the intestinal component of an ovarian teratoma. Three years later, intraperitoneal recurrence was detected, which subsequently progressed to pseudomyxoma peritonei. Genomic analysis detected KRAS (G12D), GNAS (R201C), and FBXW7 (R367*) variants in the primary tumor. In addition, the tumor showed aneuploidy with loss of heterozygosity (LOH) in all its chromosomes, which suggested that the primary ovarian tumor was derived from germ cells. Existence of one Barr body suggested the existence of uniparental disomy of the tumors throughout the genome, instead of a haploid genotype. All three pathogenic variants remained positive in the initial recurrent tumor, as well as in the paired DNA from the whole blood in pseudomyxoma peritonei. The pathogenic variant of KRAS (G12D) was also identified in the autopsy specimen of the appendix by droplet digital polymerase chain reaction. CONCLUSIONS: This study pathologically and genetically confirmed that the primary ovarian borderline tumor was derived from the intestinal component of an ovarian teratoma, and that the subsequent pseudomyxoma peritonei progressed from the primary ovarian tumor. Integrative genomic analysis was useful to identify cellular origin of tumors, as well as to precisely interpret the process of disease progression.

Asunto(s)

Neoplasias Ováricas , Neoplasias Peritoneales , Seudomixoma Peritoneal , Teratoma , Adulto , Femenino , Humanos , Neoplasias Ováricas/genética , Neoplasias Ováricas/patología , Neoplasias Peritoneales/genética , Neoplasias Peritoneales/patología , Proteínas Proto-Oncogénicas p21(ras)/genética , Seudomixoma Peritoneal/genética , Seudomixoma Peritoneal/patología , Teratoma/genética , Teratoma/patología

RESUMEN

Pseudomyxoma peritonei (PMP) is a rare disorder with unique pathological and genetic changes. Although several studies have reported the clinical features and mutational changes of PMP that originates from the appendix, few studies on PMP originating from the ovary have been reported due to its extreme rarity. In order to characterize the somatic mutational landscape and to investigate the prognosis predicting factors of ovary-originating PMP, we examined 830 cases of PMP and identified 16 patients with PMP that originated from the ovary. Whole-exome sequencing (WES) was performed on 12 cases using formalin-fixed, paraffin-embedded (FFPE) tissue samples. We found that 25% (3/12) of the patients carried mutations in cancer driver genes, including TP53, ATM and SETD2, and 16.7% (2/12) of the patients carried mutations in cancer driver genes, including ATRX, EP300, FGFR2, KRAS, NOCR1 and RB1. The MUC16 (58.33%), BSN (41.67%), PCNT (41.67%), PPP2R5A (41.67%), PRSS36 (41.67%), PTPRK (41.67%) and SBF1 (41.67%) genes presented the highest mutational frequencies. The PI3K-Akt signaling pathway, human papillomavirus infection pathway, cell skeleton, cell adhesion, and extracellular matrix and membrane proteins were the major pathways or functions that were affected. Patients were followed up to 174 months (median: 48.26 months). The 5-year OS rate for all patients was 71.2% and the median OS was not reached. PTPRK mutations, presurgical CA199 level, completeness of cytoreduction (CCR) and peritoneal cancer index (PCI) were identified as potential predictive factors for patient survival. In conclusion, the mutational landscape for ovary-originating PMP was revealed and exhibited unique features distinct from appendix-originating PMP. PTPRK, CA199, CCR and PCI may predict patient survival.

Asunto(s)

Secuenciación del Exoma/métodos , Predisposición Genética a la Enfermedad/genética , Mutación , Ovario/metabolismo , Neoplasias Peritoneales/genética , Seudomixoma Peritoneal/genética , Adulto , Anciano , Proteínas de la Ataxia Telangiectasia Mutada/genética , Femenino , N-Metiltransferasa de Histona-Lisina/genética , Humanos , Estimación de Kaplan-Meier , Persona de Mediana Edad , Ovario/patología , Neoplasias Peritoneales/metabolismo , Neoplasias Peritoneales/patología , Pronóstico , Seudomixoma Peritoneal/metabolismo , Seudomixoma Peritoneal/patología , Proteínas de Unión a Retinoblastoma/genética , Estudios Retrospectivos , Proteína p53 Supresora de Tumor/genética , Ubiquitina-Proteína Ligasas/genética

RESUMEN

PURPOSE: Pseudomyxoma peritonei (PMP) is a rare clinical malignancy syndrome characterized by the uncontrollable accumulation of copious mucinous ascites in the peritoneal cavity, resulting in "jelly belly". The mechanism of tumor progression and mucin hypersecretion remains largely unknown, but GNAS mutation is a promising contributor. This review is to systemically summarize the biological background and variant features of GNAS, as well as the impacts of GNAS mutations on mucin expression, tumor cell proliferation, clinical-pathological characteristics, and prognosis of PMP. METHODS: NCBI PubMed database (in English) and WAN FANG DATA (in Chinese) were used for literature search. And NCBI Gene and Protein databases, Ensembl Genome Browser, COSMIC, UniProt, and RCSB PDB database were used for gene and protein review. RESULTS: GNAS encodes guanine nucleotide-binding protein α subunit (Gsα). The mutation sites of GNAS mutation in PMP are relatively stable, usually at Chr20: 57,484,420 (base pair: C-G) and Chr20: 57,484,421 (base pair: G-C). Typical GNAS mutation results in the reduction of GTP enzyme activity in Gsα, causing failure to hydrolyze GTP and release phosphoric acid, and eventually the continuous binding of GTP to Gsα. The activated Gsα could thus continuously promote mucin secretion through stimulating the cAMP-PKA signaling pathway, which is a possible mechanism leading to elevated mucin secretion in PMP. CONCLUSION: GNAS mutation is one of the most important molecular biological features in PMP, with major functions to promote mucin hypersecretion.

Asunto(s)

Cromograninas/genética , Subunidades alfa de la Proteína de Unión al GTP Gs/genética , Mutación/genética , Neoplasias Peritoneales/genética , Seudomixoma Peritoneal/genética , Biomarcadores de Tumor/genética , Proliferación Celular/genética , Humanos , Mucinas/genética , Pronóstico , Transducción de Señal/genética

RESUMEN

BACKGROUND: Familial cases of appendiceal mucinous tumours (AMTs) are extremely rare and the underlying genetic aetiology uncertain. We identified potential predisposing germline genetic variants in a father and daughter with AMTs presenting with pseudomyxoma peritonei (PMP) and correlated these with regions of loss of heterozygosity (LOH) in the tumours. METHODS: Through germline whole exome sequencing, we identified novel heterozygous loss-of-function (LoF) (i.e. nonsense, frameshift and essential splice site mutations) and missense variants shared between father and daughter, and validated all LoF variants, and missense variants with a Combined Annotation Dependent Depletion (CADD) scaled score of ≥10. Genome-wide copy number analysis was performed on tumour tissue from both individuals to identify regions of LOH. RESULTS: Fifteen novel variants in 15 genes were shared by the father and daughter, including a nonsense mutation in REEP5. None of these germline variants were located in tumour regions of LOH shared by the father and daughter. Four genes (EXOG, RANBP2, RANBP6 and TNFRSF1B) harboured missense variants that fell in a region of LOH in the tumour from the father only, but none showed somatic loss of the wild type allele in the tumour. The REEP5 gene was sequenced in 23 individuals with presumed sporadic AMTs or PMP; no LoF or rare missense germline variants were identified. CONCLUSION: Germline exome sequencing of a father and daughter with AMTs identified novel candidate predisposing genes. Further studies are required to clarify the role of these genes in familial AMTs.

Asunto(s)

Adenocarcinoma Mucinoso/genética , Neoplasias del Apéndice/genética , Exoma , Mutación de Línea Germinal , Seudomixoma Peritoneal/genética , Adenocarcinoma Mucinoso/patología , Adulto , Anciano , Neoplasias del Apéndice/patología , Biomarcadores de Tumor/genética , Femenino , Estudios de Seguimiento , Humanos , Pérdida de Heterocigocidad , Masculino , Persona de Mediana Edad , Linaje , Pronóstico , Seudomixoma Peritoneal/patología , Secuenciación del Exoma

RESUMEN

BACKGROUND: Pseudomyxoma peritonei (PMP) is an extremely rare malignancy, characterized by extensive peritoneal implantation and colloidal ascites. This study was to explore the pathological prognostic factors of PMP. METHODS: Specimens from 155 PMP patients were analyzed by H&E and immunohistochemistry. Parameters included primary tumor location, histological grade, lymph node metastasis, tumor emboli in the blood and lymph vessels, perineural invasion, Ki67 labeling index, p53, mismatch repair (MMR) gene mutations, MUC1, MUC2, MUC5AC, and MUC6. Clinicopathological and follow-up data were subjected to univariate and multivariate analyses. RESULTS: The patients included 63.2% (n = 98) low-grade mucinous carcinoma peritonei, 31.6% (n = 49) high-grade mucinous carcinoma peritonei and 5.2% (n = 8) high-grade mucinous carcinoma peritonei with signet ring cells. There were 9.7% (n = 15) with lymph node metastasis; 11.6% (n = 18) with angiolymphatic invasion; 6.3% (n = 8) with defective MMR (dMMR); 35.5% (n = 55) with Ki67 labeling index ≥ 50%; 36.1% (n = 56) with p53 mutation. For PMP from appendiceal origin (n = 140), univariate analysis identified 10 potential prognostic factors. But Multivariate analysis identified only histologic grade was the independent prognostic factor for OS. Mortality risk of high-grade peritoneal mucinous carcinoma or high-grade peritoneal mucinous carcinoma with signet ring cells was 7.056 times (P < .0001, 95% CI: 2.701-18.435) or 27.224 times (P < .0001, 95% CI: 6.207-119.408), respectively, higher than low-grade. CONCLUSIONS: For PMP from the appendiceal origin, histological grade could be the only independent prognostic factor.

Asunto(s)

Neoplasias Peritoneales/patología , Seudomixoma Peritoneal/patología , Adulto , Anciano , Biomarcadores de Tumor/análisis , Biomarcadores de Tumor/genética , Reparación de la Incompatibilidad de ADN , Femenino , Humanos , Metástasis Linfática , Masculino , Persona de Mediana Edad , Mutación , Clasificación del Tumor , Células Neoplásicas Circulantes/patología , Neoplasias Peritoneales/química , Neoplasias Peritoneales/genética , Neoplasias Peritoneales/mortalidad , Seudomixoma Peritoneal/genética , Seudomixoma Peritoneal/metabolismo , Seudomixoma Peritoneal/mortalidad , Medición de Riesgo , Factores de Riesgo

RESUMEN

PURPOSE: The natural history and prognosis of appendiceal adenocarcinomas differ from those of adenocarcinomas arising in other large bowel sites. We aimed to compare the molecular profiles exhibited by appendiceal adenocarcinomas and colorectal cancers, or between the histopathologic subtypes of appendiceal adenocarcinoma. EXPERIMENTAL DESIGN: A total of 183 samples from appendiceal adenocarcinoma [46 adenocarcinoma, not otherwise specified (NOS), 66 pseudomyxoma peritonei (PMP), 44 mucinous adenocarcinoma (MU), and 27 signet ring cell carcinoma (SR)], 994 from right-sided colorectal cancer (R-CRC), and 1,080 from left-sided CRC (L-CRC) were analyzed by next-generation sequencing (NGS) and IHC markers. Microsatellite instability (MSI) and tumor mutational burden (TMB) were tested by NGS, and programmed death ligand 1 (PD-L1) by IHC. RESULTS: We observed high mutation rates in appendiceal adenocarcinoma samples for KRAS (55%), TP53 (40%), GNAS (31%), SMAD4 (16%), and APC (10%). Appendiceal adenocarcinoma exhibited higher mutation rates in KRAS and GNAS, and lower mutation rates in TP53, APC, and PIK3CA (6%) than colorectal cancers. PMP exhibited much higher mutation rates in KRAS (74%) and GNAS (63%), and much lower mutation rates in TP53 (23%), APC (2%), and PIK3CA (2%) than NOS. Alterations associated with immune checkpoint inhibitor response (MSI-high, TMB-high, PD-L1 expression) showed similar frequency in appendiceal adenocarcinoma compared with L-CRC, but not R-CRC, and those of NOS were higher than other subtypes of appendiceal adenocarcinoma and L-CRC. CONCLUSIONS: Molecular profiling of appendiceal adenocarcinoma revealed different molecular characteristics than noted in R-CRC and L-CRC, and molecular heterogeneity among the histopathologic subtypes of appendiceal adenocarcinoma. Our findings may be critical to developing an individualized approach to appendiceal adenocarcinoma treatment.

Asunto(s)

Adenocarcinoma/genética , Neoplasias del Apéndice/genética , Biomarcadores de Tumor/genética , Neoplasias Colorrectales/genética , Inestabilidad de Microsatélites , Mutación , Adenocarcinoma/patología , Adenocarcinoma Mucinoso/genética , Adenocarcinoma Mucinoso/patología , Neoplasias del Apéndice/patología , Cromograninas/genética , Neoplasias Colorrectales/patología , Femenino , Subunidades alfa de la Proteína de Unión al GTP Gs/genética , Perfilación de la Expresión Génica , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Humanos , Masculino , Proteínas Proto-Oncogénicas p21(ras)/genética , Seudomixoma Peritoneal/genética , Seudomixoma Peritoneal/patología , Estudios Retrospectivos

RESUMEN

We report a case of pseudomyxoma peritonei (PMP) arising in a 62-year-old male patient with Lynch syndrome (LS). The patient's medical history included an adenocarcinoma of the colon for which a right hemicolectomy was performed and a pancreatectomy due to an intraductal papillary mucinous neoplasm (IPMN) with invasive colloid carcinoma. It was considered that the PMP could be a metastasis of the earlier colonic or pancreatic carcinoma. The pancreatic carcinoma, colon carcinoma, and PMP tissues were examined, and immunohistochemical and molecular analyses were performed to determine the PMP origin. Histopathologic examination revealed morphological similarities with the pancreatic colloid carcinoma, and further immunohistochemical and molecular analyses, including a shared GNAS mutation, confirmed the pancreatic origin of the PMP. In conclusion, this is a unique case of a patient with LS presenting with PMP originating from an IPMN with invasive colloid carcinoma, several years after pancreatectomy. The present case has important diagnostic implications. The IPMN should be considered as a rare extracolonic manifestation of LS, and pancreatic carcinoma origin should be considered in patients presenting with PMP. This case report highlights the added value of molecular diagnostics in daily pathology practice.

Asunto(s)

Adenocarcinoma Mucinoso/cirugía , Neoplasias Colorrectales Hereditarias sin Poliposis/complicaciones , Pancreatectomía/métodos , Neoplasias Intraductales Pancreáticas/cirugía , Seudomixoma Peritoneal/diagnóstico , Adenocarcinoma Mucinoso/complicaciones , Cromograninas/genética , Diagnóstico Diferencial , Subunidades alfa de la Proteína de Unión al GTP Gs/genética , Humanos , Masculino , Persona de Mediana Edad , Mutación Missense , Pancreatectomía/efectos adversos , Neoplasias Intraductales Pancreáticas/complicaciones , Neoplasias Intraductales Pancreáticas/genética , Seudomixoma Peritoneal/etiología , Seudomixoma Peritoneal/genética

RESUMEN

Pseudomyxoma peritonei (PMP) is a clinical syndrome characterized by gross mucinous ascites originating from a disseminated intraperitoneal neoplasm. Although typically confined to the abdomen, mortality is high if untreated. Biomarkers, including genetic mutation profiles, may aid treatment selection and decision making. We applied whole-exome sequencing to five patients diagnosed with low-grade appendiceal mucinous neoplasms, using paired tumor and germline samples identify biomarkers. Multiple bioinformatic approaches were applied to these data to assess both somatic mutation profiles and loss of heterozygosity events. Mutation profiles of the tumors were consistent with deamination of methylcytosine being the prevailing mechanism. Pathogenic mutations were identified in both KRAS and GNAS in all samples, and further mutations in genes implicated in PMP, namely FGFR2, APC, SMAD2, and FAT4. No TP53 somatic mutations were identified, matching expectations for low-grade tumors. Four of five samples exhibited clonal loss of heterozygosity; these regions were further examined and found to contain genes harboring pathogenic somatic mutations in some samples. RNF43 was hereby implicated in the pathogenesis of PMP of appendiceal origin, having previously been found to increase sensitivity to Wnt signaling and to have involvement in similar mucinous tumors. In conclusion, we have investigated the mutation profile of PMP of appendiceal origin and provided the first report of RNF43 involvement in its progression.

Asunto(s)

Secuenciación del Exoma/métodos , Pérdida de Heterocigocidad/genética , Mutación/genética , Neoplasias Peritoneales/genética , Seudomixoma Peritoneal/genética , Adulto , Anciano , Biomarcadores de Tumor/metabolismo , Cromosomas Humanos Par 17/genética , Femenino , Frecuencia de los Genes/genética , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Peritoneales/diagnóstico , Neoplasias Peritoneales/patología , Seudomixoma Peritoneal/diagnóstico , Seudomixoma Peritoneal/patología

RESUMEN

OBJECTIVES: Pseudomyxoma peritonei (PMP) is a rare malignancy originating from the appendix, characterized by disseminated mucinous tumor implants on peritoneal surfaces. We examined the role of multiplatform molecular profiling to study biomarker-guided treatment strategies for this rare malignancy. METHODS: A total of 54 patients with appendix-derived PMP were included in the study. Tests included one or more of the following: gene sequencing (Sanger or next generation sequencing), protein expression (immunohistochemistry), and gene amplification (C/fluorescent in situ hybridization). RESULTS: Targeted sequencing of 47 genes detected variants in KRAS (81%), GNAS (74%), SMAD4 (16%), and ATM (16%). Mutations were found at low frequencies (n=1 to 2) in APC, BRAF, PIK3CA, MLH1, and TP53. GNAS and KRAS co-occurrence was found in 87%. Protein overexpression was found in epidermal growth factor receptor (83%), cyclooxygenase-2 (73%), cMET (63%), cKIT (58%), and platelet-derived growth factor receptor alpha (58%). Immune checkpoint expression was found in 36% (programmed cell death protein 1) and 18% (programmed death-ligand 1). Surrogate markers of cell proliferation were found at low rates (TLE3 23%, TOP2A 22%), consistent with the slow-growing biology of PMP. Phosophatase and tensin homolog was intact (wild type [100%]) and positive (immunohistochemistry [80%]). Patients exhibited stable microsatellite status and mismatch repair proficiency (93%). Importantly, multidrug resistance protein expression was elevated (100% BCRP, 94% MRP1, 88% PGP). Markers for gemcitabine (RRM1), fluorouracil (TS), oxaliplatin (ERCC1), and irinotecan (TOPO1) chemosensitivities were detected at favorable rates: 93%, 87%, 77% and 65%, respectively. CONCLUSIONS: Molecular profiling by multiple platforms identified potential therapies for the nontargetable KRAS-mutated population. The role of cMET-targeted therapeutics and immune checkpoint inhibitors merits further investigation. Biomarker-guided selection of cytotoxic chemotherapies may facilitate efficacy to systemic treatment.

Asunto(s)

Apéndice/patología , Biomarcadores de Tumor/genética , Perfilación de la Expresión Génica , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Mutación , Neoplasias Peritoneales/genética , Seudomixoma Peritoneal/genética , Anciano , Biomarcadores de Tumor/metabolismo , Femenino , Estudios de Seguimiento , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Selección de Paciente , Neoplasias Peritoneales/metabolismo , Neoplasias Peritoneales/patología , Neoplasias Peritoneales/terapia , Seudomixoma Peritoneal/metabolismo , Seudomixoma Peritoneal/patología , Seudomixoma Peritoneal/terapia

RESUMEN

Mucinous colorectal adenocarcinomas (MCAs) are clinically and morphologically distinct from nonmucinous colorectal cancers (CRCs), show a distinct spectrum of genetic alterations (higher KRAS mutations, lower p53, high MUC2), exhibit more aggressive behavior (more prone to peritoneal dissemination and lymph node involvement) and are associated with poorer response to chemotherapy with limited treatment options. Here, we report the effectiveness of combinatorial targeting of two KRAS-mediated parallel pathways in reducing MUC2 production and mucinous tumor growth in vitro and in vivo. By knockdown of mutant KRAS we show that, mutant KRAS (a) is necessary for MUC2 production in vitro and (b) synergistically engages PI3K/AKT and MEK/ERK pathways to maintain MUC2 expression in MCA cells. These results define a novel and a previously undescribed role for oncogenic KRAS in mucinous cancers. MCA cells were sensitive to MEK inhibition suggesting cellular dependence ('addiction') of KRAS-mutant MCA cells on hyperactivation of the MEK-driven pathway. Interestingly, MCA cells, though initially sensitive, were later resistant to PI3K single agent inhibition. Our studies suggest that this resistance involves dynamic rewiring of signaling circuits mediated through relief of RTK inhibition and MEK-ERK rebound activation. This resistance however, could be overcome by co-targeting of PI3K and MEK. Our studies thus provide a rational basis for MEK- and PI3K-targeted combination therapy for not only KRAS mutant MCA but also for other related mucinous neoplasms that overproduce MUC2 and have a high rate of KRAS mutations such as pseudomyxoma peritonei.

Asunto(s)

Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Quinasas de Proteína Quinasa Activadas por Mitógenos/metabolismo , Mutación , Neoplasias Peritoneales/tratamiento farmacológico , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas p21(ras)/genética , Seudomixoma Peritoneal/tratamiento farmacológico , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/patología , Activación Enzimática/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Terapia Molecular Dirigida , Mucina 2/genética , Mucinas/metabolismo , Neoplasias Peritoneales/genética , Neoplasias Peritoneales/metabolismo , Neoplasias Peritoneales/patología , Fosforilación/efectos de los fármacos , Seudomixoma Peritoneal/genética , Seudomixoma Peritoneal/metabolismo , Seudomixoma Peritoneal/patología

RESUMEN

BACKGROUND: Pseudomyxoma peritonei (PMP) is a rare disease with an estimated incidence of 1-2 cases per million individuals per year. PMP is characterized by the accumulation of abundant mucinous or gelatinous fluid derived from disseminated tumorous cells. Most of the tumorous cells are originated from rupture of appendiceal neoplasms, but some are from the metastasis of cancer of the colon, ovary, fallopian tube, urachus, colorectum, gallbladder, stomach, pancreas, lung and breast. Although frequent mutations in KRAS and/or GNAS genes have been reported, precise molecular mechanism underlying PMP remains to be elucidated. It is of note that mucinous tumour is one of the frequent histological features of colorectal cancer (CRC) in Lynch syndrome (LS), an autosomal dominantly inherited disease caused by a germline mutation of the DNA mismatch repair (MMR) genes including human mutL homolog 1 (MLH1), human mutS homolog 2 (MSH2), human mutS homolog 6 (MSH6), and postmeiotic segregation increased 2 (PMS2). Therefore, typical LS-associated tumours show mismatch repair instability. Although LS patients are most strongly predisposed to CRC, PMPs from mucinous CRC have not been reported in LS patients. CASE PRESENTATION: In this report, we report a case of PMP originating from an ovarian teratoma in a LS patient. The patient had surgical treatment of PMP arising from an ovarian teratoma at the age of 38 years, and later developed a transverse colon cancer at the age of 40. The patient's family history fulfilled the Amsterdam criteria, and genetic analysis of the peripheral leukocytes identified a germ line mutation in the MLH1 gene (MLH1 c.1546dupC p.Q516PfsX3). Interestingly, immunohistochemical staining showed that the expression of MLH1 was lost in the colon cancer as well as the ovarian teratoma. Consistent with the loss of MLH1 expression, both tumours showed high microsatellite instability (MSI-H). CONCLUSION: This case suggested that LS patients may develop various types of tumours including ovarian PMP, and that mismatch repair deficiency may play a role in the development of PMP derived from, at least, a part of ovarian teratomas.

Asunto(s)

Neoplasias Colorrectales Hereditarias sin Poliposis/complicaciones , Neoplasias Colorrectales Hereditarias sin Poliposis/diagnóstico , Neoplasias Ováricas/complicaciones , Neoplasias Ováricas/genética , Seudomixoma Peritoneal/complicaciones , Seudomixoma Peritoneal/genética , Teratoma/complicaciones , Teratoma/genética , Abdomen/diagnóstico por imagen , Adulto , Neoplasias del Colon/diagnóstico , Neoplasias del Colon/secundario , Neoplasias Colorrectales Hereditarias sin Poliposis/genética , ADN/química , ADN/aislamiento & purificación , ADN/metabolismo , Reparación de la Incompatibilidad de ADN , Femenino , Mutación de Línea Germinal , Humanos , Imagen por Resonancia Magnética , Inestabilidad de Microsatélites , Homólogo 1 de la Proteína MutL/genética , Neoplasias Ováricas/diagnóstico , Linaje , Seudomixoma Peritoneal/cirugía , Recurrencia , Teratoma/diagnóstico , Tomografía Computarizada por Rayos X