Abstract 3597
Background
Anal squamous cell carcinoma (SCCA) is associated with E6 and E7 oncoproteins encoded by human papillomavirus (HPV) 16. Addition of Docetaxel to 5-Fluorouracil plus Cisplatin (DCF) induces favorable disease control and complete remission rate in recent clinical trials. Taking this observation into account, we decided to analyze the impact of DCF chemotherapy on adaptive immunity and immunosuppressive cells in SCCA.
Methods
Peripheral blood mononuclear cells from healthy donors and SCCA patients included in Epitopes-HPV01 and 02 studies were analyzed. The presence of T-cell responses after short term T-cell stimulation against HPV16-E6/E7 and TERT-antigens was measured by IFNγ-ELISpot. Immune checkpoint expression and immunosuppressive cells were monitored by flow cytometry.
Results
We first observed an enhanced HPV-specific T-cell response following DCF chemotherapy. Our investigations also suggest that TERT might be a relevant antigen in HPV-driven cancers. TERT-restricted CD4 Th1 were correlated to E6 responses and also enhanced following DCF treatment of SCCA patients. The distribution of T-cell exhaustion markers on peripheral T lymphocytes unraveled a drop of CD226 expression and the emergence of CD226-TIGIT+ T-cell subset. Monocytic-myeloid-derived-suppressor cells (M-MDSC) and regulatory T-cell (Treg) rates were increased. Treg levels and T-cell exhaustion markers did not influence clinical outcomes and frequencies of specific immune responses. M-MDSC levels monitored after DCF chemotherapy were correlated with progression free survival and antigen-specific T-cell response intensity and diversity.
Conclusions
DCF chemotherapy did not impair antigen-specific T-cell responses, supporting the potential interest to combine DCF chemotherapy with immunotherapies. Moreover, our study identifies post-therapy M-MDSC as a prognostic factor in SCCA patients.
Clinical trial identification
Epitopes-HPV01: NCT01845779 Epitopes-HPV02: NCT02402842.
Editorial acknowledgement
Legal entity responsible for the study
University Hospital of Besançon.
Funding
Besancon University Hospital, Ligue Contre le cancer Grand-Est and Association Nationale de la Recherche et de la Technologie.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
5218 - Elevated driver mutational burden or number of perturbed pathways and poor response to abiraterone or enzalutamide in metastatic castration-resistant prostate cancer
Presenter: Bram De Laere
Session: Poster Display session 3
Resources:
Abstract
2452 - High proportion of multiple KRAS mutations in circulating tumor DNA and tumor tissue of pancreatic ductal adenocarcinoma
Presenter: Min Kyeong Kim
Session: Poster Display session 3
Resources:
Abstract
3328 - Biological difference of tumor mutational burden (TMB) and microsatellite instability (MSI) status in patients (pts) with somatic vs. germline BRCA1/2-mutated advanced gastrointestinal (GI) cancers using cell-free DNA (cfDNA) sequencing analysis in the GOZILA study
Presenter: Yasuyuki Kawamoto
Session: Poster Display session 3
Resources:
Abstract
3022 - Cell-Free DNA to Detect Focal Versus Non-Focal MET Amplification in Metastatic Colorectal Cancer Patients: Combined Analysis from Japan and the United States
Presenter: Mishima Saori
Session: Poster Display session 3
Resources:
Abstract
2833 - Presence of circulating tumor DNA in surgically resected renal cell carcinoma is associated with advanced disease and poor patient prognosis
Presenter: Andres Correa
Session: Poster Display session 3
Resources:
Abstract
1376 - Combined genomic and epigenomic assessment of cell-free circulating tumor DNA (cfDNA) for cancer diagnosis and recurrence-risk assessment in early-stage lung cancer
Presenter: Junghee Lee
Session: Poster Display session 3
Resources:
Abstract
4050 - DEMo: a prospective evaluation of a prognostic clinico-molecular composite score in NSCLC patients treated with immunotherapy.
Presenter: Arsela Prelaj
Session: Poster Display session 3
Resources:
Abstract
4727 - Bespoke circulating tumor DNA (ctDNA) analysis as a predictive biomarker in solid tumor patients (pts) treated with single agent pembrolizumab (P)
Presenter: Cindy Yang
Session: Poster Display session 3
Resources:
Abstract
3662 - Dynamic changes in whole-genome cell-free DNA (cfDNA) to identify disease progression prior to imaging in advanced solid tumors
Presenter: Andrew Davis
Session: Poster Display session 3
Resources:
Abstract
3817 - Evaluation of Microsatellite Instability Testing Through cell-free DNA sequencing
Presenter: Shile Zhang
Session: Poster Display session 3
Resources:
Abstract