Abstract
BACKGROUND: Squamous-cell carcinoma of the anal canal (SCCA) is a rare gastrointestinal malignancy, and its incidence is increasing among the aging population. This study aims to examine treatment efficacy and toxicity in elderly patients and to compare treatment outcomes between elderly and non-elderly patients to inform optimal management strategies for SCCA in older adults. PATIENTS AND METHODS: This retrospective study evaluates clinical outcomes in elderly (≥70 years) versus non-elderly (<70 years) patients with localized SCCA treated with definitive chemoradiotherapy or radiotherapy alone. The primary endpoints were overall survival (OS) and disease-free survival (DFS), whereas secondary endpoints were cancer-specific survival (CSS), complete response rates and grade 3 or 4 toxicity profiles. Statistical analyses were conducted using descriptive statistics, Kaplan-Meier methods, and Cox proportional hazards models. RESULTS: The study analyzed 269 patients. Elderly patients had a median age of 77.3 (range 70-83) years and presented with a higher burden of comorbidities and a lower prevalence of human immunodeficiency virus. No significant differences in treatment types or toxicity rates were observed between the groups. The median DFS for elderly patients was 103 months versus 128 months for non-elderly patients (P = 0.43). CSS rates were comparable, showing a rate of 83% at five years for the elderly compared with 85% for non-elderly patients (P = 0.74). Cox regression analyses revealed that cancer stage and treatment completion were significant predictors of DFS and OS. CONCLUSION: This study highlights that while elderly patients with SCCA experience similar survival outcomes to their younger counterparts, age-related factors and comorbidities require careful management to optimize treatment efficacy while minimizing toxicity.