RESUMEN
INTRODUCTION: Anal squamous cell carcinoma (ASCC) is a rare malignancy with rising incidence rates. Risk factors include human immunodeficiency virus (HIV) infection, high-risk sexual activity and HPV-related genitourinary dysplasia/neoplasia. There is an overlap between high-risk patients and those attending HIV Medicine/Sexual Health (HMSH) services. We hypothesised that HMSH involvement may facilitate earlier referral to colorectal surgeons, with better outcomes. METHODS: Retrospective review of all ASCC and anal intraepithelial neoplasia (AIN) treated at a tertiary-referral hospital with a dedicated HMSH clinic between 2000 and 2018. Comparative analysis was performed of demographics, management and outcomes between HMSH and non-HMSH patients. RESULTS: One hundred and nine patients had anal pathology, eighty-five with ASCC (78%) and twenty-four with AIN (22%). Seventy (64%) were male. Median (range) age at ASCC diagnosis was 51 years (26-88). Thirty-six percent of all patients attended HMSH services, 28% were HIV positive, and 41% of males were men-who-have-sex-with-men (MSM). Eighty-one ASCC patients (97.5%) were treated with curative intent. Sixty-seven (80%) had primary chemoradiation therapy. Fifteen (17.5%) had primary surgical excision. Twelve (14%) developed recurrent disease. Ultimately, seven required salvage APR. Overall 3-year survival (3YS) was 76%. HMSH patients were significantly younger at ASCC diagnosis (p < 0.001), with a higher prevalence of HIV, HPV and MSM. HMSH attenders also tended to be diagnosed at earlier stages, were less likely to develop recurrence and achieved better overall outcomes, with a superior overall 3YS than non-HMSH patients (92% vs 72%, p = 0.037). CONCLUSION: ASCC incidence is increasing worldwide. The HMSH cohort has emerged as a distinct subpopulation of younger, high-risk, male patients. Collaboration between HMSH and colorectal surgeons offers an opportunity for risk reduction strategies and earlier intervention.