RESUMEN
Undifferentiated Nasopharyngeal Carcinoma (UNPC) is associated with Epstein-Barr Virus (EBV) and characterized by an abundant immune infiltrate potentially influencing the prognosis. Thus, we retrospectively assessed the significance of immunosuppression in the UNPC microenvironment as prognostic biomarker of treatment failure in a non-endemic area, and monitored the variation of systemic EBV-specific immunity before and after chemoradiotherapy (CRT). DNA and RNA were extracted from diagnostic biopsies obtained by tumor and adjacent mucosa from 63 consecutive EBV+ UNPC patients who underwent radical CRT. Among these patients 11 relapsed within 2 years. The expression of the EBV-derived UNPC-specific BARF1 gene and several immune-related genes was monitored through quantitative RT-PCR and methylation-specific PCR analyses. Peripheral T cell responses against EBV and BARF1 were measured in 14 patients (7 relapses) through IFN-γ ELISPOT assay. We found significantly higher expression levels of BARF1, CD8, IFN-γ, IDO, PD-L1, and PD-1 in UNPC samples compared to healthy tissues. CD8 expression was significantly reduced in both tumor and healthy tissues in UNPC patients who relapsed within two years. We observed a hypomethylated FOXP3 intron 1 exclusively in relapsed UNPC patients. Finally, we noticed a significant decrease in EBV- and BARF1-specific T-cells after CRT only in relapsing patients. Our data suggest that a high level of immunosuppression (low CD8, hypomethylated FoxP3) in UNPC microenvironment may predict treatment failure and may allow an early identification of patients who could benefit from the addition of immune modulating strategies to improve first line CRT.
Asunto(s)
Antígenos CD8/inmunología , Resistencia a Antineoplásicos/inmunología , Factores de Transcripción Forkhead/inmunología , Carcinoma Nasofaríngeo/inmunología , Neoplasias Nasofaríngeas/inmunología , Tolerancia a Radiación/inmunología , Adolescente , Adulto , Anciano , Quimioradioterapia/métodos , Metilación de ADN , Infecciones por Virus de Epstein-Barr/complicaciones , Infecciones por Virus de Epstein-Barr/inmunología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Carcinoma Nasofaríngeo/terapia , Neoplasias Nasofaríngeas/terapia , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Microambiente Tumoral/inmunología , Proteínas Virales/inmunología , Adulto JovenRESUMEN
Human papillomavirus (HPV)-associated head and neck squamous cell carcinoma (HNSCC) is an entity with peculiar clinical and molecular characteristics, which mainly arises from the reticulated epithelium lining the crypts of the palatine tonsils and the base of the tongue. The only head and neck site with a definite etiological association between persistent high-risk (HR) HPV infection and development of SCC is the oropharynx. HPV-positive malignancies represent 5-20% of all HNSCCs and 40-90% of those arising from the oropharynx, with widely variable rates depending on the geographic area, population, relative prevalence of environment-related SCC and detection assay. HPV-16 is by far the most common HR HPV genotype detected in oropharyngeal SCC (OPSCC), and the only definitely carcinogenic genotype for the head and neck region. Patients with HPV-induced OPSCC are more likely to be middle-aged white men, non-smokers, non-drinkers or mild to moderate drinkers, with higher socioeconomic status and better performance status than subjects with HPV-unrelated SCC. HPV-induced HNSCCs are often described as non-keratinizing, poorly differentiated or basaloid carcinomas, and are diagnosed in earlier T-category with a trend for a more advanced N-category, with cystic degeneration, than the HPV-unrelated carcinomas. HPV positivity is associated with better response to treatment and modality-independent survival benefit. Treatment selection in HPV-related oropharyngeal carcinoma is becoming a critical issue, and although there is no evidence from randomized, controlled trials to support a treatment de-escalation in HPV-positive SCC, some investigators argue that intensive combined modality strategies may represent an overtreatment.