Treatment outcomes in an institutional cohort of female patients with anal SCC undergoing definitive chemoradiation.

Abstract

Background: Anal cancer represented 0.3% of diagnosed cancers globally in 2018,1 with incidence rising in women. Most are squamous cell carcinomas (SCC) and highly associated with human papilloma virus (HPV) infection. Most patients present with localised disease amenable to curative intent chemoradiation. Few patient series with large numbers are reported. Method(s): After ethics approval, a retrospective chart review was performed on adult patients with localised anal SCC treated with definitive chemoradiation atMonash Health between 2009 and 2020. Toxicity was gauged from documentation in medical notes. Result(s): A total of 67 patients were identified; 54 were female and analysed further; 46 having sufficient documentation of toxicity. Median age at diagnosis was 63 years (range: 45-85); median followup was 79 months (1-133). Staging at diagnosis was: T1-2N0: 36%; T3-4N0: 15% and TanyN1 35%. Fourteen patients had documented HPV aetiology, and 13 patients a history of HPV-associated conditions. Median time between diagnosis and treatment commencement was 44 days (14-92). Short-term toxicity included skin reaction (50%), anorectal pain (50%), diarrhoea (39%), nausea/vomiting (30%), mucositis (26%), dysuria (11%) and febrile neutropenia (11%). Severity was grade 3 or 4 in 30%. Long-term toxicities included faecal urgency (19%) and incontinence (15%), diarrhoea (14%), vaginal stenosis (11%) and anorectal pain (8%). PET at 3 and/or 6 months post chemoradiation was utilised in 93% of evaluable patients; 77% had a complete metabolic response (CMR), 20% partial metabolic response and 3% progressive disease. Disease recurrence occurred in 8 patients; only 1 involved distant metastatic disease.Of those with recurrent disease, only 1 patient achieved CMR within 6 months of definitive treatment completion. Conclusion(s): This study provides one of the largest reported series of female patients diagnosed with anal SCC undergoing definitive chemoradiation. Limitations include small numbers and retrospective methodology, however for rare cancers analysis of real-life practice is particularly informative.