Definitive Intensity-Modulated Chemoradiation for Anal Squamous Cell Carcinoma: Outcomes and Toxicity of 428 Patients Treated at a Single Institution

Abstract

Background Although intensity-modulated radiation therapy (IMRT) is considered the standard of care for the treatment of squamous cell carcinoma of the anus (SCCA), few large series have reported oncologic outcomes and toxicities. In this retrospective report, we aim to describe outcomes and toxicities after IMRT-based chemoradiation (CRT) for the treatment of SCCA, evaluate the impact of dose escalation (>54 Gy), and compare concurrent fluoropyrimidine in combination with either mitomycin or with cisplatin as chemosensitizers. Methods Patients treated at The University of Texas MD Anderson Cancer Center between January 1, 2003 and December 31, 2018 with IMRT-based CRT were included. Median time to locoregional recurrence, time to colostomy, and overall survival were estimated using the Kaplan–Meier method. Results A total of 428 patients were included; median follow-up was 4.4 years. Three hundred and thirty-four patients (78.0%) were treated with concurrent cisplatin and fluoropyrimidine, and 160 (37.4%) with >54 Gy. Two- and 5-year freedom from locoregional failure, freedom from colostomy failure, and overall survival were 86.5% and 81.2%, respectively, 90.0% and 88.3%, respectively, and 93.6% and 85.8%, respectively. Neither dose escalation nor mitomycin-based concurrent chemotherapy resulted in improved outcomes. Mitomycin-based concurrent chemotherapy was associated with in approximately 2.5 times increased grade 3 or greater acute toxicity. Radiation dose >54 Gy was associated with approximately 2.6 times increased Grade 3 or greater chronic toxicity. Conclusions Our results suggest IMRT-based CRT with concurrent fluoropyrimidine and cisplatin is a safe and feasible option for patient with SCCA and may cause less acute toxicity. The role for radiation dose escalation is unclear and requires further study.

High-tailored Anal Canal Radiotherapy (HIT-ART): Outcomes of a 10-Year Single Center Clinical Experience

“…These data suggest the importance of identifying strategies for better OARs preservation and late toxicities management. As several aspects of long-term function and quality of life (QoL) have been identified as factors to be investigated (e.g., sleep disorders) (34), anal cancer specific QoL questionnaires are being developed and validated and should be administered to patients over the course of follow-up visits (35)(36)(37). Unfortunately, our study lacks patient reported outcomes measures (PROMs), especially in terms of fecal continence; the opportunity to investigate this aspect, together with sexual function and sleep disorders is certainly interesting and challenging in the context of dose escalation strategy.…”

Anal Carcinoma, Version 2.2023, NCCN Clinical Practice Guidelines in Oncology

“…158 For older patients or those who are unlikely to tolerate mitomycin, the optimal chemotherapy regimen remains uncertain. Some NCCN Panel members have used a combination of weekly cisplatin and daily 5-FU on days of RT 159 for chemoRT in localized anal cancer. Other potential strategies for this patient population may include capecitabine 1 RT or RT alone (without chemotherapy).…”

Long-Term Patient-Reported Dyspareunia After Definitive Chemoradiation for Anal Cancer: Using the Anterior Vaginal Wall as an Organ-at-Risk to Define an Actionable Dosimetric Goal

“…This treatment achieves high rates of local control and good overall survival outcomes with an estimated 5-year freedom from local failure of 81.2% and 5-year overall survival of 85.8%. 1 However, radiation to the pelvis can lead to significant acute and permanent side effects that impair patient quality of life (QOL). 2 , 3 , 4 …”