RESUMEN

INTRODUCTION: Systemic inflammatory response (SIR) indicators are an emerging category of serum biomarkers with significant potential as prognostic and predictive factors in various types of cancers The primary focus of our study was to determine the prognostic value of the lymphocyte-to-monocyte ratio (LMR), platelet-to-albumin ratio (PLR) and platelet-to-albumin ratio (PAR) in evaluating the response to neoadjuvant treatment for patients with rectal cancer. MATERIALS AND METHODS: We included 99 consecutive patients with rectal cancer which were admitted for surgery in our institution after completing a standard neoadjuvant radio-chemotherapy regimen. Several hematologic parameters, including LMR, PAR and PLR, were calculated by collecting and analyzing blood samples preoperatively. Cases were divided into groups using ROC curve analysis to determine optimal cutoff values for each of the investigated parameters. Treatment response was assessed through histopathological analysis of the resected specimens. RESULTS: PLR values over 215.2 were correlated with the presence of lymph node metastasis. A similar correlation was observed between PAR values over 41.89 and lymph node positivity. A significant correlation was observed between the presence of tumor budding on histopathological analysis and high-PAR values. A statistically significant correlation between a high PLR and a good response to neoadjuvant treatment was determined. CONCLUSIONS: High PLR values may be associated with a more favorable treatment response to neoadjuvant radio-chemotherapy. A high PAR may be associated with unfavorable histopathological characteristics. Further studies on these readily available biomarkers are required in order to validate their clinical utility.

Asunto(s)

RESUMEN

BACKGROUND: The treatment of choice for patients with locally advanced cervical cancer (LACC) is definitive concurrent radio chemotherapy which consists of external beam radiotherapy (EBRT) and concurrent platinum-based chemotherapy (CCRT), with the possible addition of brachytherapy (BT). However, the benefits of adjuvant surgery after neoadjuvant treatments remain a debated issue and a still open question in the literature. This meta-analysis aims to provide an updated view on the controversial topic, focusing on comparing surgery after any adjuvant treatment and standard treatment. METHODS: Following the recommendations in the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement, the PubMed and Embase databases were systematically searched in April 2023 for early publications. No limitations on the country were applied. Only English articles were considered. The comparative studies containing data about disease-free survival (DFS) and/or overall survival (OS) were included in the meta-analysis. RESULTS: The CCRT + surgery group showed a significantly better DFS than CCRT (RR 0.69 [95% CI 0.58-0.81] p < 0.01) and a better OS (RR 0.70 [95% CI 0.55-0.89] p < 0.01). Nine studies comparing neoadjuvant chemotherapy (NACT) plus surgery and CCRT were also enrolled. The NACT + surgery group showed a significantly better DFS than CCRT (RR 0.66 [95% CI 0.45-0.97] p < 0.01) and a better OS (RR 0.56 [95% CI 0.38-0.83] p < 0.01). In the sub-analysis of three randomized control trials, the surgery group documented a non-significantly better DFS and OS than CCRT (OR 1.10 [95% CI 0.67-1.80] p = 0.72; I2 = 69% p = 0.72; OR 1.09 [95% CI 0.63-1.91] p = 0.75; I2 = 13% p = 0.32). CONCLUSION: The results provide updated findings about the efficacy of neoadjuvant treatments, indicating significantly improved DFS and OS in patients undergoing hysterectomy after CCRT or NACT compared with patients undergoing standard treatments.

RESUMEN

Background: For locally advanced rectal cancer, neoadjuvant therapy (NT) is an established element of therapy. Endoscopic vacuum therapy (EVT) has been a relevant treatment option for anastomotic leakage after rectal resection since 2008. The aim was to evaluate the influence of NT on the duration and success of EVT in anastomotic leakage after rectal resection for rectal cancer. Methods: This was a monocentric, retrospective cohort study including patients who underwent rectal resection with primary anastomosis because of histologically proven carcinoma of the rectum in the Department for General and Visceral Surgery of Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin over a period of ten years (2012 to 2022). Results: Overall, 243 patients were included, of which 47 patients (19.3%) suffered from anastomotic leakage grade B with consecutive EVT. A total of 29 (61.7%) patients received NT and 18 patients (38.3%) did not. The median duration of EVT until the removal of the sponge did not differ between patients with and without NT: 24.0 days (95% CI 6.44-41.56) versus 20.0 days (95% CI 17.03-22.97); p = 0.273. The median duration from insertion of EVT until complete healing was 74.0 days with NT (95% CI 10.07-137.93) versus 62.0 days without NT (95% CI 45.99-78.01); p = 0.490. Treatment failure-including early persistence and late onset of recurrent anastomotic leakage-was evident in 27.6% of patients with NT versus 27.8% without NT; p = 0.989. Ostomy was reversed in 19 patients (79.2%) with NT compared to 11 patients (68.8%) without NT; p = 0.456. Overall, continuity was restored in 75% of patients in the long term after EVT. Conclusion: This trial comprised-to our knowledge-the largest study cohort to analyze the outcome of EVT in anastomotic leakage after rectal resection for rectal cancer. We conclude that neoadjuvant therapy neither prolongs EVT nor the time to healing from anastomotic leakage. The rates of treatment failure of EVT and permanent ostomy were not higher when neoadjuvant therapy was used.

RESUMEN

Purpose: Clinical evidence suggests an association between comorbidities and outcome in patients with glioblastoma (GBM). We hypothesised that the internal carotid artery (ICA) calcium score could represent a promising prognostic biomarker in a competing risk analysis in patients diagnosed with GBM. Methods: We validated the use of the ICA calcium score as a surrogate marker of the coronary calcium score in 32 patients with lung cancer. Subsequently, we assessed the impact of the ICA calcium score on overall survival in GBM patients treated with radio-chemotherapy. Results: We analysed 50 GBM patients. At the univariate analysis, methyl-guanine-methyltransferase gene (MGMT) promoter methylation (p = 0.048), gross total tumour resection (p = 0.017), and calcium score (p = 0.011) were significant prognostic predictors in patients with GBM. These three variables also maintained statistical significance in the multivariate analysis. Conclusions: the ICA calcium score could be a promising prognostic biomarker in GBM patients.

RESUMEN

The treatment of superficial rectal cancers (local excision, or proctectomy with total mesorectal excision (TME) remains controversial. Endoscopy and endorectal ultrasonography are essential for the precise initial definition of these small cancers. During endoscopy, the depth of the lesion can be estimated using virtual chromoendoscopy with magnification, thereby aiding the assessment of the possibilities of local excision. Current international recommendations indicate completion proctectomy after wide local excision for cases where the pathologic examination reveals poorly-differentiated lesions, lymphovascular invasion, grade 2 or 3 tumor budding, and incomplete resection. But debate persists regarding whether the depth of submucosal invasion can accurately predict the risk of lymph node spread. Recent data from the literature suggest that the depth of submucosal invasion should no longer, by itself, be an indication for additional oncological surgery. Adjuvant radio-chemotherapy could be an alternative to completion proctectomy in patients with pT1 rectal cancer and unfavorable histopathological criteria. A Dutch randomized controlled trial is underway to validate this strategy.

Asunto(s)

RESUMEN

BACKGROUND: The PACIFIC study showed that after radio-chemotherapy, patients with NSCLC derived a benefit in PFS and OS when treated with durvalumab. This effect was limited to patients with a PD-L1 expression of >1%, partly because the outcome in the observational control arm was surprisingly favorable. Thus, it could be speculated that a lack of PD-L1 expression confers a favorable outcome for patients with stage III NSCLC. METHODS: Clinical data, PD-L1 expression, predictive blood markers, and the outcomes of 99 homogeneously treated patients with stage III NSCLC were retrospectively captured. Statistical analyses using the log rank test were performed. RESULTS: The median OS of patients with an expression of PD-L1 < 1% was 20 months (CI 10.5-29.5) and the median OS of patients with an expression of PD-L1 ≥ 1% was 28 months (CI 16.5-39.2) (p = 0.734). The median PFS of patients with an expression of PD-L1 < 1% was 9 months (CI 6.3-11.6) and the median PFS of patients with an expression of PD-L1 ≥ 1% was 12 months (CI 9.8-14.2) (p = 0.112). CONCLUSIONS: The assumption that the lack of PD-L1 expression represents a favorable prognostic factor after radio-chemotherapy vs. PD-L1 expression > 1% was not confirmed.

RESUMEN

Oncologists and applied mathematicians are interested in understanding the dynamics of cancer-immune interactions, mainly due to the unpredictable nature of tumour cell proliferation. In this regard, mathematical modelling offers a promising approach to comprehend this potentially harmful aspect of cancer biology. This paper presents a novel dynamical model that incorporates the interactions between tumour cells, healthy tissue cells, and immune-stimulated cells when subjected to simultaneous chemotherapy and radiotherapy for treatment. We analysed the equilibria and investigated their local stability behaviour. We also study transcritical, saddle-node, and Hopf bifurcations analytically and numerically. We derive the stability and direction conditions for periodic solutions. We identify conditions that lead to chaotic dynamics and rigorously demonstrate the existence of chaos. Furthermore, we formulated an optimal control problem that describes the dynamics of tumour-immune interactions, considering treatments such as radiotherapy and chemotherapy as control parameters. Our goal is to utilize optimal control theory to reduce the cost of radiotherapy and chemotherapy, minimize the harmful effects of medications on the body, and mitigate the burden of cancer cells by maintaining a sufficient population of healthy cells. Cost-effectiveness analysis is employed to identify the most economical strategy for reducing the disease burden. Additionally, we conduct a Latin hypercube sampling-based uncertainty analysis to observe the impact of parameter uncertainties on tumour growth, followed by a sensitivity analysis. Numerical simulations are presented to elucidate how dynamic behaviour of model is influenced by changes in system parameters. The numerical results validate the analytical findings and illustrate that a multi-therapeutic treatment plan can effectively reduce tumour burden within a given time frame of therapeutic intervention.

Asunto(s)

RESUMEN

BACKGROUND AND PURPOSE: Immunotherapy is actively explored in glioblastoma (GBM) to improve patient prognosis. Tumor-associated macrophages (TAMs) are abundant in GBM and harnessing their function for anti-tumor immunity is of interest. They are plastic cells that are influenced by the tumor microenvironment, by radio-chemotherapy and by their own phagocytic activity. Indeed, the engulfment of necrotic cells promotes pro-inflammatory (and anti-tumoral) functions while the engulfment of apoptotic cells promotes anti-inflammatory (and pro-tumoral) functions through efferocytosis. MATERIALS AND METHODS: To model the effect of radio-chemotherapy on the GBM microenvironment, we exposed human macrophages to supernatant of treated GBM cells in vitro. Macrophages were derived from human monocytes and GBM cells from patient-resected tumors. GBM cells were exposed to therapeutically relevant doses of irradiation and chemotherapy. Apoptosis and phagocytic activity were assessed by flow cytometry. RESULTS: The phagocytic activity of macrophages was increased, and it was correlated with the proportion of apoptotic GBM cells producing the supernatant. Whether uptake of apoptotic tumor cells could occur would depend upon the expression of efferocytosis-associated receptors. Indeed, we showed that efferocytosis-associated receptors, such as AXL, were upregulated. CONCLUSIONS AND PERSPECTIVES: We showed that macrophage phagocytic activity increased when exposed to supernatant from GBM cells treated by radio-chemotherapy. However, as efferocytosis-associated receptors were up-regulated, this effect could be deleterious for the anti-GBM immune response. We speculate that by inducing GBM cell apoptosis in parallel to an increase in efferocytosis receptor expression, the impact of radio-chemotherapy on phagocytic activity could promote anti-inflammatory and pro-tumoral TAM functions.

Asunto(s)

RESUMEN

Metal-based drugs currently dominate the field of chemotherapeutic agents; however, achieving the controlled activation of metal prodrugs remains a substantial challenge. Here, we propose a universal strategy for the radiation-triggered activation of metal prodrugs via nanosurface energy transfer (NSET). The core-shell nanoplatform (Ru-GNC) is composed of gold nanoclusters (GNC) and ruthenium (Ru)-containing organic-inorganic hybrid coatings. Upon X-ray irradiation, chemotherapeutic Ru (II) complexes were released in a controlled manner through a unique NSET process involving the transfer of photoelectron energy from the radiation-excited Ru-GNCs to the Ru-containing hybrid layer. In contrast to the traditional radiation-triggered activation of prodrugs, such an NSET-based system ensures that the reactive species in the tumor microenvironment are present in sufficient quantity and are not easily quenched. Additionally, ultrasmall Ru-GNCs preferably target mitochondria and profoundly disrupt the respiratory chain upon irradiation, leading to radiosensitization by generating abundant reactive oxygen species. Consequently, Ru-GNC-directed radiochemotherapy induces immunogenic cell death, resulting in significant therapeutic outcomes when combined with the programmed cell death-ligand 1 (PD-L1) checkpoint blockade. This NSET strategy represents a breakthrough in designing radiation-triggered nanoplatforms for metal-prodrug-mediated cancer treatment in an efficient and controllable manner.

Asunto(s)

RESUMEN

Precise delivery of radionuclides and anticancer drugs to tumor tissue is crucial to ensuring drug synergism and optimal therapeutic effects in radionuclide-based combination radio-chemotherapy. However, current codelivery vectors often rely on physical embedment/adsorption to load anticancer drugs, which lacks precise mechanisms for drug loading and release, resulting in unpredictable combination effects. Herein, a macrocyclic-albumin conjugate (MAC) that enables precise loading and controlled release of anticancer drugs is presented. By conjugating multiple macrocyclic hosts (sulfonate azocalix[4]arenes, SAC4A) to albumin molecules, the MAC facilitates the precise loading of anticancer drugs through host-guest interactions and site-specific labeling of radionuclides. Furthermore, the MAC degrades under hypoxic conditions, enabling the release of loaded drugs upon reaching tumor tissues. Through precise loading and targeted delivery of radionuclides and anticancer drugs, MAC achieves efficient cancer diagnosis and combined radio-chemotherapy in breast cancer cell (4T1)-bearing mice. Considering that SAC4A can load many anticancer drugs, MAC may provide a promising platform for effective combination radio-chemotherapy.

Asunto(s)

RESUMEN

BACKGROUND: Radio/chemotherapy and immune systems provide examples of hormesis, as tumours can be stimulated (or reduced) at low radio/chemical or antibody doses but inhibited (or stimulated) by high doses. METHODS: Interactions between effector cells, tumour cells and cytokines with pulsed radio/chemo-immunotherapy were modelled using a pulse differential system. RESULTS: Our results show that radio/chemotherapy (dose) response curves (RCRC) and/or immune response curves (IRC) or a combination of both, undergo homeostatic changes or catastrophic shifts revealing hormesis in many parameter regions. Some mixed response curves had multiple humps, posing challenges for interpretation of clinical trials and experimental design, due to a fuzzy region between an hormetic zone and the toxic threshold. Mixed response curves from two parameter bifurcation analyses demonstrated that low-dose radio/chemotherapy and strong immunotherapy counteract side-effects of radio/chemotherapy on effector cells and cytokines and stimulate effects of immunotherapy on tumour growth. The implications for clinical applications were confirmed by good fits to our model of RCRC and IRC data. CONCLUSIONS: The combination of low-dose radio/chemotherapy and high-dose immunotherapy is very effective for many solid tumours. The net benefit and synergistic effect of combined therapy is conducive to the treatment and inhibition of tumour cells.

Asunto(s)

RESUMEN

Anaplastic thyroid carcinoma is a rare and aggressive form of thyroid cancer that has a poor prognosis and a high mortality rate. It is characterized by rapid growth and invasion of nearby tissues. It typically presents as a rapidly growing goiter or nodule that is firm to the touch and firmly attached to the underlying structures. Case reports of unusual presentations of anaplastic thyroid carcinoma have been reported. The presentation of anaplastic thyroid carcinoma mimicking cervical tuberculosis is very unusual. We reported a case of a 65-year-old patient who had a left cervical swelling that had been evolving for 4 months, causing dysphagia. Initial imaging showed a necrotic mass in the left lobe of the thyroid, communicating with a second necrotic mass in the subcutaneous tissue that was fistulized to the skin and suggesting cervical tuberculosis. The mass was incised with pus and whitish material resembling caseous tuberculosis was discharged. Acid-fast bacilli (AFB) Polymerase chain reaction (PCR) was negative and biopsy revealed a nonspecific granulomatous lesion. Due to the growth of the mass and the presence of a permeation nodule, a second biopsy was performed, revealing anaplastic thyroid carcinoma. The patient was referred for radiochemotherapy due to tumor inoperability.

RESUMEN

BACKGROUND: A significant number of clinical trials must be prematurely discontinued due to recruitment failure, and only a small fraction publish results and a failure analysis. Based on our experience on conducting the NEOPA trial on neoadjuvant radiochemotherapy for resectable and borderline resectable pancreatic carcinoma (NCT01900327-funded by the German Federal Ministry of Education and Research-BMBF), we performed an analysis of potential reasons for recruitment failure and general problems in conducting clinical trials in Germany. METHODS: Systematic analysis of environmental factors, trial history, conducting and funding in the background of the published literature. RESULTS: The recruitment failure was based on various study-specific conceptional and local environmental aspects and in peculiarities of the German surgical study culture. General reservations against a neo-adjuvant study concept combined with game changing scientific progresses during the long-lasting planning and funding phase have led to a reduced interest in the trial design and recruitment. CONCLUSIONS: Trial planning and conducting should be focused, professionalized and financed on a national basis. Individual interests must be subordinated to reach the goal to perform more relevant and successful clinical trials in Germany. Bureaucratic processes must be further fastened between a trial idea and the start of a study.

RESUMEN

BACKGROUND: Unplanned early readmission (UER) within 30 days after hospital release is a negative prognostic marker for patients diagnosed with glioblastoma (GBM). This work analyzes the impact of UER on the effects of standard therapy modalities for GBM patients, including the extent of resection (EOR) and adjuvant therapy regimen. METHODS: Records were searched for patients with newly diagnosed GBM between 2014 and 2020 who were treated at our facility. Exclusion criteria were being aged below 18 years or missing data. An overall survival (OS) analysis (Kaplan-Meier estimate; Cox regression) was performed on various GBM patient sub-cohorts. RESULTS: A total of 276 patients were included in the study. UER occurred in 13.4% (n = 37) of all cases, significantly reduced median OS (5.7 vs. 14.5 months, p < 0.001 by logrank), and was associated with an increased hazard of mortality (hazard ratio 3.875, p < 0.001) in multivariate Cox regression when other clinical parameters were applied as confounders. The Kaplan-Meier analysis also showed that patients experiencing UER still benefitted from adjuvant radio-chemotherapy when compared to radiotherapy or no adjuvant therapy (p < 0.001 by logrank). A higher EOR did not improve OS in GBM patients with UER (p = 0.659). CONCLUSION: UER is negatively associated with survival in GBM patients. In contrast to EOR, adjuvant radio-chemotherapy was beneficial, even after UER.

RESUMEN

The identification of a biomarker that is response predictive could offer a solution for the stratification of the treatment of head and neck cancers (HNC) in the context of high recurrence rates, especially those associated with loco-regional failure. Delta (Δ) radiomics, a concept based on the variation of parameters extracted from medical imaging using artificial intelligence (AI) algorithms, demonstrates its potential as a predictive biomarker of treatment response in HNC. The concept of image-guided radiotherapy (IGRT), including computer tomography simulation (CT) and position control imaging with cone-beam-computed tomography (CBCT), now offers new perspectives for radiomics applied in radiotherapy. The use of Δ features of texture, shape, and size, both from the primary tumor and from the tumor-involved lymph nodes, demonstrates the best predictive accuracy. If, in the case of treatment response, promising Δ radiomics results could be obtained, even after 24 h from the start of treatment, for radiation-induced xerostomia, the evaluation of Δ radiomics in the middle of treatment could be recommended. The fused models (clinical and Δ radiomics) seem to offer benefits, both in comparison to the clinical model and to the radiomic model. The selection of patients who benefit from induction chemotherapy is underestimated in Δ radiomic studies and may be an unexplored territory with major potential. The advantage offered by "in house" simulation CT and CBCT favors the rapid implementation of Δ radiomics studies in radiotherapy departments. Positron emission tomography (PET)-CT Δ radiomics could guide the new concepts of dose escalation on radio-resistant sub-volumes based on radiobiological criteria, but also guide the "next level" of HNC adaptive radiotherapy (ART).

RESUMEN

BACKGROUND AND STUDY AIM: The incidence of wound infections after percutaneous endoscopic gastrostomy (PEG) varies widely in recent studies. The present study systematically investigates the underlying risk factors for the development of wound infections in a large cohort of patients over a long-term follow-up period. PATIENTS AND METHODS: A retrospective cohort study of patients undergoing PEG insertion using either the pull or push technique was conducted and patients followed up for 3 years. Tube-related wound infections were identified, and pathogens regularly cultured from wound swabs. Adjusted analysis was performed via univariate and multivariate logistic regression analysis. RESULTS: 616 patients were included in this study. A total of 25% percent of patients developed wound infections upon PEG tube insertion and 6.5% showed recurrent infections. Nicotine abuse (p = 0.01), previous ischemic stroke (p = 0.01) and head and neck cancer (p < 0.001) showed an increased risk for wound infection after PEG placement. Moreover, radio-chemotherapy was associated with the occurrence of wound infections (p < 0.001). Infection rates were similar between pull and push cohorts. The most common bacterial pathogen detected was Enterobacterales (19.2%). Staphylococcus aureus, Pseudomonas aeruginosa and enterococci were frequently detected in recurrent infection (14.2%, 11.4% and 9.6%, respectively). Antibiotic prophylaxis showed no effect on infection rates. CONCLUSIONS: Wound infections after PEG placement are common and occasionally occur as recurrent infections. There is potential for improvement in everyday clinical practice, particularly regarding antibiotic prophylaxis in accordance with guidelines.

RESUMEN

INTRODUCTION AND IMPORTANCE: Squamous cell carcinoma occurring in the rectum is a very rare malignancy. When encountered in the gastrointestinal tract, it usually involves the esophagus or the anal canal. The rare incidence of rectal squamous cell carcinomas has raised quite a few questions on the hypothetical etiologies and prognosis. CASE PRESENTATION: In this report, we present a case of a 73 years old woman who presented a rare case of squamous cell carcinoma, at 8 cm from the anal margin. CLINICAL DISCUSSION: Optimal treatment sequence of such an uncommon disease is yet to be standardized, surgery was the gold standard management for rectal squamous cell carcinoma, but exclusive chemoradiotherapy is slowly but surely supplanting it. CONCLUSION: This case allows us to engage in discussions over the uncommon location of the rectal SCC and its current treatment management. The exclusive chemoradiation therapy has given excellent results becoming the gold standard treatment of this rare entity.

RESUMEN

BACKGROUND/AIM: Radiotherapy for head-and-neck cancer is often associated with significant toxicities, which may cause emotional distress. We evaluated prevalence and risk factors for pre-treatment emotional problems in patients irradiated for head-and-neck cancer. PATIENTS AND METHODS: Twelve characteristics were retrospectively investigated in 213 patients for associations with emotional problems (worry, fear, sadness, depression, nervousness, loss of interest). After Bonferroni adjustment, p-values <0.0042 were regarded significant. RESULTS: At least one emotional problem was reported by 131 patients (61.5%). Specific prevalence for emotional problems ranged between 10% and 44%. Physical complaints showed significant associations with all six emotional problems (p<0.0001) and female sex with sadness (p=0.0013). Trends were found for associations between female sex and fear (p=0.0097), history of another tumor and sadness (p=0.043), worse performance status and nervousness (p=0.012), and cancer site (oropharynx/oral cavity) and nervousness (p=0.063). CONCLUSION: More than 60% of patients reported emotional distress prior to radiotherapy for head-and-neck cancer. Patients with risk factors likely require near-term psycho-oncological assistance.

Asunto(s)

RESUMEN

Artificial intelligence (AI) and in particular radiomics has opened new horizons by extracting data from medical imaging that could be used not only to improve diagnostic accuracy, but also to be included in predictive models contributing to treatment stratification of cancer. Head and neck cancers (HNC) are associated with higher recurrence rates, especially in advanced stages of disease. It is considered that approximately 50% of cases will evolve with loco-regional recurrence, even if they will benefit from a current standard treatment consisting of definitive chemo-radiotherapy. Radiotherapy, the cornerstone treatment in locally advanced HNC, could be delivered either by the simultaneous integrated boost (SIB) technique or by the sequential boost technique, the decision often being a subjective one. The principles of radiobiology could be the basis of an optimal decision between the two methods of radiation dose delivery, but the heterogeneity of HNC radio-sensitivity makes this approach difficult. Radiomics has demonstrated the ability to non-invasively predict radio-sensitivity and the risk of relapse in HNC. Tumor heterogeneity evaluated with radiomics, the inclusion of coarseness, entropy and other first order features extracted from gross tumor volume (GTV) in multivariate models could identify pre-treatment cases that will benefit from one of the approaches (SIB or sequential boost radio-chemotherapy) considered the current standard of care for locally advanced HNC. Computer tomography (CT) simulation and daily cone beam CT (CBCT) could be chosen as imaging source for radiomic analysis.

RESUMEN

BACKGROUND: Programmed death-ligand 1 (PD-L1) checkpoint inhibitors represent a mainstay of therapy in head and neck squamous cell cancer (HNSCC). However, little is known about the influence of combined therapy on PD-L1 expression. The study aims to gather evidence on this topic. METHODS: A systematic search was carried out in electronic databases Pubmed-MEDLINE and Embase to retrieve studies on the comparison of PD-L1 expression before and after conventional therapy. Data were extracted and a quantitative analysis with pooled odds ratios (ORs) was performed when applicable. RESULTS: Of 5688 items, 15 were finally included. Only a minority of studies assessed PD-L1 with the recommended combined positive score (CPS). The results are highly heterogeneous, with some studies reporting an increase in PD-L1 expression and others reporting a decrease. Three studies allowed for quantitative analysis and showed a pooled OR of 0.49 (CI 0.27-0.90). CONCLUSIONS: From the present evidence, a clear conclusion towards an increase or decrease in PD-L1 expression after combined therapy cannot be drawn, but even with few studies available, a trend towards an increase in expression in tumor cells at a cutoff of 1% can be noted in patients undergoing platinum-based therapy. Future studies will provide more robust data on the effect of combined therapy on PD-L1 expression.