Prognostic and Predictive Clinicopathologic Factors of Squamous Anal Canal Cancer in HIV-Positive and HIV-Negative Patients: Does HAART Influence Outcomes?

Background: The incidence of squamous cell carcinoma (SCC) of the anal canal has been rising over the past decades, especially in patients infected with human immunodeficiency virus (HIV). Despite the advent of potent multidrug regimens to treat HIV-termed highly active antiretroviral therapy (HAART), anal SCC rates have not declined, and the impact of HAART on anal SCC remains controversial.
Aim: The purpose of this study was to define outcomes of anal SCC treatment in HIV-positive and HIV-negative patients.
Methods and Materials: A retrospective single-institution analysis was performed on all patients with anal SCC treated at the Johns Hopkins Hospital between 1991 and 2010. The primary outcomes measured were 5-year overall survival (5-year OS), median survival, and relapse rates.
Results: Our search identified 93 patients with anal SCC. Patients had a mean age of 54 years; 37.6% were male, and 21.5% were HIV-positive. Median follow-up was 28 months. Relapse occurred in 16.1% of patients. Median time to relapse was 20 months. Relapse rates were slightly higher with HIV-positive versus negative patients (30.0 vs. 12.3%) but did not reach statistical significance (p = 0.06). Among HIV-positive patients, those who relapsed were more likely to be on HAART than those who did not relapse (83.3 vs. 14.3%, p = 0.007). 5-year OS was 58.9% for the total group of patients with no significant difference between those who relapsed versus those who did not (76.2 vs. 54.5%, p = 0.20). No survival difference was seen between HIV-positive and negative patients. Survival was associated with AJCC stage in all patients.
Conclusion: In our small series, HIV infection was not associated with a significantly higher relapse rate or worse 5-year OS among patients with anal SCC. HAART was associated with a higher rate of relapse in HIV-positive patients. AJCC staging predicted survival in both relapsed and non-relapsed patients regardless of HIV status.