Prognostic factors of long-term outcomes after primary chemo-radiotherapy in non-metastatic anal squamous cell carcinoma: An international bicentric cohort.

person Soledad Iseas Oncology Unit, Gastroenterology Hospital “Dr. Carlos Bonorino Udaondo”, Buenos Aires, Argentina info_outline Soledad Iseas, Diego Martín Prost, Sarah Bouchereau, Mariano Golubicki, Juan Robbio, Ana Oviedo, Mariana Coraglio, Marcela Carballido, Mirta Kujaruk, Guillermo Mendez, Mario Edmundo Barugel, Enrique Roca, Louis Gros, Vincent de Parades, Nabil Baba-Hamed, Julien Adam, Martin C Abba, Eric Raymond

Authors person Soledad Iseas Oncology Unit, Gastroenterology Hospital “Dr. Carlos Bonorino Udaondo”, Buenos Aires, Argentina info_outline Soledad Iseas, Diego Martín Prost, Sarah Bouchereau, Mariano Golubicki, Juan Robbio, Ana Oviedo, Mariana Coraglio, Marcela Carballido, Mirta Kujaruk, Guillermo Mendez, Mario Edmundo Barugel, Enrique Roca, Louis Gros, Vincent de Parades, Nabil Baba-Hamed, Julien Adam, Martin C Abba, Eric Raymond Organizations Oncology Unit, Gastroenterology Hospital “Dr. Carlos Bonorino Udaondo”, Buenos Aires, Argentina, Medical Oncology Department, Paris-St Joseph Hospital, Paris, France, Oncology Unit, Gastroenterology Hospital “Dr. Carlos Bonorino Udaondo”, Ciudad Autónoma De Buenos Aires, Argentina, Oncology Unit, Hospital de Gastroenterología Carlos Bonorino Udaondo, Ciudad Autónoma De Buenos Aires, Argentina, oncology unit, Hospital de Gastroenterologia Carlos Bonorino Udaondo, Buenos Aires, Argentina, Proctology Unit, Gastroenterology Hospital “Dr. Carlos Bonorino Udaondo”, Buenos Aires, Argentina, Pathology Unit, Gastroenterology Hospital “Dr. Carlos Bonorino Udaondo”., Ciudad Autónoma De Buenos Aires, Argentina, Oncology Unit, Gastroenterology Hospital, Dr. Carlos Bonorino Udaondo, Buenos Aires, Argentina, Oncology Unit, Gastroenterology Hospital “Dr. Carlos Bonorino Udaondo”, Buenos Aires, Buenos Aires, Argentina, University Hospital of Lausanne, Lausanne, Switzerland, Proctology Unit, Paris-St Joseph Hospital, Paris, France, Pathology Unit Paris-St Joseph Hospital, Paris, France, Basic and Applied Immunological Research Center (CINIBA), School of Medical Sciences, National University of La Plata, La Plata, Argentina Abstract Disclosures Research Funding Other Foundation Foundation Nelia and Amadeo Barletta, NIH grant CA221208. Background: Anal squamous cell carcinoma (ASCC) is a rare malignancy with a rising incidence associated with Human papillomavirus (HPV) infection. Locally-advanced disease is associated with a 30% rate of treatment failure after standard chemoradiotherapy (CRT). We aimed to elucidate prognostic factors for ASCC after curative CRT. Methods: A retrospective multicenter study of 176 consecutive patients with ASCC having completed CRT treated between 2010 and 2017 at 2 centers. Complete response (CR), disease-free survival (DFS) and overall survival (OS) were analyzed by Kaplan–Meier estimates with log-rank tests. The hierarchical clustering on principal components (HCPC) method was employed in an unsupervised and multivariate approach. Results: CR rate was 68% and was predictive of DFS (p < 0.0001) and OS (p < 0.0001), where non-CR cases were associated shorter DFS (HR = 16.5, 95% CI 8.19-33.21) and OS (HR = 8.42, 95% CI 3.77–18.81) in univariate analysis. Median follow-up was 38 months, with 3-year DFS of 71%. Prognostic factors for DFS were cT1-T2 (p = 0.0001), N0 (p = 0.03), HIV-positive (p = 0.04), HIV-HPV coinfection (p = 0.02), and well-differentiated tumors (p = 0.03). Three-year OS was 81.6%. Female sex (p = 0.05), cT1-T2 (p = 0.019), and well-differentiated tumors (p = 0.003) were associated with better OS. This unsupervised analysis demonstrates clear segregation, identifying that poor prognosis clusters associated with shorter DFS (HR = 1.66, 95% CI = 1.21–2.27, p = 0.0012) were enriched with locally-advanced disease, anal canal location, HPV-HIV coinfection, and non-CR. Conclusions: In conclusion, our results reinforce the prognostic value of T stage, N stage, sex, differentiation status, tumor location, and HIV-HPV coinfection in ASCC after CRT.