Radio-chemotherapy in anal cancer: Institutional experience at a large radiation oncology center in Chile

Aim: In this article the aim is to provide a concise narrative review and inform the institutional experience at a referral center in Chile with the use of radio-chemotherapy in anal cancer. Background: Cancer of the anus and anal canal is mainly a loco-regional disease. For years the standard of care has been concomitant radio-chemotherapy, which permits organ preservation and better local control than alternative surgical procedures. Materials and methods: A retrospective analysis of 44 patients treated between 2002 and 2010 was performed. Local recurrence, distant recurrence and overall survival were analyzed with the Kaplan-Meier method. Relevant groups where compared with the log-rank test and univariate analysis were done with the Cox proportional hazards model. Results: Median follow-up of the cohort was 56 months, with a minimum follow-up of at least 24 months. There was a significant difference between clinical stages in disease free survival (log-rank trend p< 0.001), and a significant difference in overall survival (OS) when comparing clinical stages that were grouped in stage I-IIIa and IIIB (log-rank p= 0.001). On univariate analysis, age older than 60, having received full treatment and dose above 45. Gy were all significantly related to OS (p< 0.05). An overall survival of 45% and disease free survival of 45% at 5 years were found in our series. Conclusions: Our findings show that results at the Instituto de Radiomedicina in Chile are comparable to published literature. Dismal results in stage IIIb cases indicate much work remains in therapies to achieve loco-regional control in locally advanced cases.