Prognostic role of HPV integration status and molecular profile in advanced anal carcinoma: An ancillary study to the epitopes-HPV02 trial.

Squamous Cell Carcinoma of the Anal canal (SCCA) is a rare disease associated with a Human Papillomavirus (HPV) infection in most cases, predominantly the HPV16 genotype. About 15% of SCCA are diagnosed in metastatic stage and some will relapse after initial chemoradiotherapy (CRT). Treatment of patients by Docetaxel, Cisplatin and 5-fluorouracil (DCF) has been recently shown to improve their complete remission and progression-free survival. The aim of this retrospective study was to explore the impact of HPV infection, HPV DNA integration, TERT promoter mutational status and somatic mutations of oncogenes on both progression-free (PFS) and overall survivals (OS) of patients treated by DCF. Samples obtained from 49 patients included in the Epitopes-HPV02 clinical trial, diagnosed with metastatic or non-resectable local recurrent SCCA treated by DCF, were used for analyses. Median PFS and OS were not associated with HPV status. Patients with episomal HPV had an improved PFS compared with SCCA patients with integrated HPV genome (p=0.07). TERT promoter mutations were rarely observed and did not specifically distribute in a subset of SCCA and did not impact DCF efficacy. Among the 42 genes investigated, few gene alterations were observed, and were in majority amplifications (68.4%), but none were significantly correlated to PFS. As no biomarker is significantly associated with patients' survival, it prompts us to include every patient failing CRT or with metastatic disease in DCF strategy.

Longitudinal follow-up of HPV16 sequence after cervical infection: Low intrahost variation and no correlation with clinical evolution.

Human papillomavirus (HPV) 16 exhibits different variants that may differ in their carcinogenic risk. To identify some high-risk variants, we sequenced and compared HPV16 whole genomes obtained from a longitudinal cohort of 34 HPV16-infected women who had either spontaneously cleared their infection (clearance group or "C"), or developed cervical high-grade lesions following a viral persistence (group persistence or "P"). Phylogenetic analysis of paired samples obtained at the beginning (C0 or P0) and at the end (C2 or P2) of the follow-up (median intervals between C0-C2 and between P0-P2 were 16 and 36.5 months, respectively) revealed a low genetic variability within the host compared to the genetic interhost diversity. By comparing our HPV16 sequences to a reference sequence, we observed 301 different substitutions, more often transitions (60.9%) than transversions (39.1%), that occurred throughout the viral genome, but with a low frequency in E6 and E7 oncogenes (10 and 9 substitutions), suggesting a high conservation of these genes. Deletions and insertions were mostly observed in intergenic regions of the virus. The only significant substitution found between the subgroups C2 and P2 was observed in the L2 gene (L330F), with an unclear biological relevance. Our results suggest a low longitudinal intrahost evolution of HPV16 sequences and no correlation between genetic variations and clinical evolution.

Clinical Validity of HPV Circulating Tumor DNA in Advanced Anal Carcinoma: An Ancillary Study to the Epitopes-HPV02 Trial.

PURPOSE: Human papillomavirus (HPV) is found in 90% of squamous cell carcinomas of the anal canal (SCCA). We investigated the clinical validity of HPV circulating tumor DNA (ctDNA) detection in patients enrolled in the Epitopes-HPV02 trial that demonstrated the efficacy of docetaxel, cisplatin, and 5-FU as first-line chemotherapy in advanced SCCA. EXPERIMENTAL DESIGN: According to the protocol, serum samples were collected before chemotherapy and on completion of chemotherapy. HPV16 ctDNA was quantified by droplet digital PCR (ddPCR) and correlated with prospectively registered patient characteristics and outcomes. A landmark was set at the time of chemotherapy completion for postchemotherapy progression-free survival (PFS) analyses. RESULTS: Among 57 patients with HPV16-related advanced SCCA, HPV ctDNA was detected in 91.1% (95% confidence interval, 81.1-96.2) of baseline samples. Baseline HPV ctDNA levels were not associated with any patient characteristics; baseline ctDNA level below the cutoff obtained by AUC (area under the curve) was associated with a longer PFS (HR = 2.1; P = 0.04). Among the 36 patients who completed 5 months of chemotherapy, residual HPV ctDNA was detected after chemotherapy in 38.9% of patients. Residual HPV ctDNA detected at chemotherapy completion was associated with shorter postchemotherapy PFS (median PFS 3.4 months vs. not reached; HR = 5.5; P < 0.001) and a reduction of 1-year overall survival rate (OR = 7.0; P = 0.02). CONCLUSIONS: This prospective study in advanced SCCA demonstrated a significant prognostic impact of HPV ctDNA level before first-line chemotherapy and HPV ctDNA negativity after chemotherapy completion. With a limited cost and short turnaround, this assay is a promising tool to optimize the therapeutic management of SCCA.See related commentary by Morris, p. 2030.