In 2012, the Department of Visceral Surgery of the Lausanne University Hospital CHUV implemented a dedicated high-resolution anoscopy (HRA) outpatient clinic for surveillance and follow-up purposes. This 10-year longitudinal study analyzed 537 patients (2214 visits) using a structured screening protocol. Dysplastic lesions were detected in 49% of patients, predominantly low-grade squamous intraepithelial lesions (LSILs, 74%). Among LSIL cases, 6% progressed to high-grade squamous intraepithelial lesions (HSILs) within 24 months, reaching 25% cumulative progression at 36 months. Of HSIL patients, 3% developed carcinoma in situ after 48 months. Notably, no invasive carcinoma was observed during the follow-up. Four patients diagnosed with squamous cell carcinoma at initial screening were treated with chemoradiotherapy, and one required salvage surgery. Independent risk factors for the presence of higher-stage precancerous lesions (≥HSILs) were the presence of high-risk HPV genotypes (OR 14.5, 95% CI 5–42.2, p < 0.001), detectable HIV viral load (OR 5.4, 95% CI 1.8–16.7, p = 0.003), and symptoms at the first screening visit (OR 3.2, 95% CI 1.1–9.9, p = 0.04). HIV-positive status was associated with a trend towards an increased risk of progression (OR 2.79, p = 0.073). These findings highlight the importance of systematic follow-up and early intervention in high-risk populations to prevent anal cancer progression.

Background: This study represents a follow-up analysis of the AnusGynecology (ANGY) study. Methods: This prospective, cross-sectional, single-center study recruited women for concomitant cervical and anal screening of HPV genotypes and cytology during a single appointment. All women with findings of either HPV or any type of dysplastic lesions on anal smears were offered follow-up in a specialized high-resolution anoscopy (HRA) outpatient clinic, representing the study cohort for this follow-up study. Results: Overall, 275 patients (mean age 42 ± 12) were included. Among them, 102 (37%) had cervical high-risk (HR) HPV. In total, HPV was (incidentally) revealed in 91 patients (33%) on anal smears, while any degree of anal squamous intraepithelial lesion (SIL) was found in 30 patients (11%), 6 if which were high-grade SIL (H-SIL). Furthermore, 10 out of 19 biopsies were positive (3 H-SIL lesions). Only half (48/91, 53%) of the women agreed to undergo the recommended specialized follow-up evaluation. Of them, 18 (38%) were diagnosed with dysplastic lesions (9 low grade (L-SIL) and 9 H-SIL, respectively) on biopsies, while the remaining visits revealed no abnormalities. Multivariable analysis revealed cervical HR-HPV infection (OR 4, 95% CI 2.2–7.5) and anal intercourse (OR 3.1, 95% CI 1.7–5.9) as independent risk factors for anal HR-HPV infection. Conclusions: Close follow-up of these women is hence strongly recommended.