[Squamous cell anal carcinoma. What's next ?]

Abstract

Despite its status as a rare disease, the incidence of the squamous cell carcinoma of the anus (SCCA) is surging, especially in its metastatic form. In addition, the prognosis of initially localized diseases has not substantially changed since the 1970s with a recurrence rate of between 25-40 % after the chemoradiotherapy. The updated data from 115 patients included in the Epitopes-HPV01 and Epitopes-HPV02 trials, confirm the modified regimen of DCF (mDCF) as the treatment of choice for patients with advanced SCCA given the rate of sustained remissions and complete molecular responses observed. The carboplatin-paclitaxel regimen may be considered as an option for patients with contraindication to cisplatin or 5-FU. In chemo-refractory patients, the efficacy of anti-PD-1/PD-L1 in monotherapy is limited and only brings benefit to 10-20 % of patients, and its use cannot be generalized in the absence of an association potentiating its effectiveness. In order to better understand the immunological parameters associated with advanced SCCA, an analysis of peripheral immune responses was carried out in the Epitopes-HPV01 and 02 trials. It demonstrated the key role of CD4 Th1 specific responses of telomerase and M-MDSC as main prognostic factors for the therapeutic efficacy of DCF. Numerous combination trials are currently underway or will soon begin in localized SCCA, as well as in the first and second-line in the advanced stage. Finally, the detection of circulating tumor DNA of HPV oncoprotein E6 and E7 (HPVtc), especially by the "digital droplet PCR" technique, is highly sensitive and specific, and can be used in daily practice.

Keywords: Anal cancer; Biomarkers; Biomarqueurs; Cancer du canal anal; Chemotherapy; Chimiothérapie; Immune responses; Immunotherapy; Immunothérapie; Réponses immunitaires.