3. Outcome of excision of early invasive squamous carcinomas of the anal canal and perianus

Abstract

Background: Combined modality therapy (CMT) is the standard of care for anal canal (AC) squamous cell carcinoma (SCCA); excision is reserved for small perianal (PA) cancers. Increasingly, asymptomatic, superficially invasive SCCAs (SISCCA) are identified during high-resolution anoscopy (HRA). For AC- and PA-SISCCA, the Lower Anogenital Squamous Terminology Project’s proposed definition is an excised tumour with clear margins, depth of invasion <3 mm, and horizontal extent <7 mm. We report our experience with surgical excision alone of early invasive SCCA (EISCCA), defined as AC- or PA-SISCCA and >SISCCA, but with clear margins. Methods: EISCCA were excised sparing the anal sphincter and anal high-grade squamous intraepithelial lesions (HSIL) were ablated. Those with margins positive for SCCA were referred for CMT. HRA was performed every 4 months; recurrent HSIL/EISCCA was ablated or excised. Patients were referred for CMT if cancer could not be excised without compromising the sphincter. Results: EISCCA was excised in 81 patients: 68 men and 13 women, 57 HIV-infected and 24 HIV-uninfected. Median age was 52 years (range: 33–79). Patients were followed for a median of 43 months (range: 2–230) following excision. Excision of EISCCA was successful in 73 (90%) patients. Eight (10%) required CMT (4 developed inguinal node recurrences, including 2 with systemic metastases). There was no statistically significant difference in outcome by location (AC v. PA EISCCA), HIV status or sex (P > 0.05). Conclusions: Excision of EISCCA, including AC tumours, produces an excellent outcome, sparing most patients CMT, including those with HIV infection.