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.