ANALYSIS OF HPV INFECTION AND IMMUNOHISTOCHEMICAL PROGNOSTIC BIOMARKERS IN SQUAMOUS CELL ANAL CANCER PATIENTS RECEIVING DEFINITIVE RADIOTHERAPY/CHEMORADIOTHERAPY
Project no. 22981 · Status: Kapanmış (Yayın bekleniyor) · 2021
Summary
<p><strong>Purpose/Objectives: </strong>Anal squamous cell carcinoma (SCC) with definitive radiotherapy (RT)/chemoradiotherapy (CRT) has a high rate of treatment success; however, resistance to treatment and recurrence rates cannot be ignored. Therefore, we aimed to identify the relationship between immunohistochemical (IHC) evaluation, treatment response, and prognosis.</p><p><strong>Materials/Methods: </strong>Forty-two patients with anal SCC treated with definitive RT/CRT in the Department of Radiation Oncology at Ege University School of Medicine (EUTF) between 2006 and 2020 were evaluated retrospectively. Detection of high-risk HPV-DNA and IHC analysis of p16, p53, and PD-L1 expression was performed from diagnostic formalin-fixed, paraffin-embedded (FFPE) biopsies.</p><p><strong>Results: </strong>A complete response to definitive RT/CRT was in 30 (71.4%) cases. Recurrence was observed in 16 (38.1%) cases, and 24 (57.1%) cases were alive. Thirty cases (%71.4) were HPV positive. A strong correlation was observed between HPV positivity and p16 positivity (p<0.001). HPV and p16 positivity status were substantially significant with complete response to treatment [p<0.001, p<0.001; respectively]. There was increased recurrence (p=0.006) and local-regional recurrence (p=0.014) with p53 positivity. Regarding PD-L1 analysis, CPS ≥ 1% was significantly correlated with HPV (p=0.036) and p16 (p=0.021) positivity. In addition, PD-L1 CPS ≥ 1% was related to negative local control (p=0.031). In univariate analysis, age [<65] (p=0.049), complete response (p=0.015), and HPV positivity (p=0.010) for 5-year overall survival; complete response (p=0.001), HPV positivity (p=0.025) and p53 negativity (p=0.010) for 5-year disease-free survival were found to be important prognostic factors. In multivariate analysis, age [<65] (p=0.010) and HPV positivity (p=0.002) for 5-year overall survival; complete response (p=0.007) and p53 negativity (p=0.038) for 5-year disease-free survival were found to be independent prognostic factors.</p><p><strong>Conclusions: </strong>Cases with HPV negative status and/or poor prognostic biomarkers should be identified at diagnosis. Thus, immunotherapy and radiosensitising agents can be combined with standard CRT, and better response and survival outcomes can be obtained.</p>