An intact immune system appears to be critical to tolerating anal cancer treatment. A study from Emory University also found that HIV+ patients with CD4<200 did worse with anal cancer treatment (43). Of 17 HIV+ patients with anal cancer documented at Emory from 1994-2004,

only those with CD4<200 were unable to complete treatment (43). Antiretroviral drugs play a key role in controlling Inhibitors,research,lifescience,medical the HIV virus and helping bolster CD4 counts. Therapy for HIV changed dramatically in the mid 1990s with the implementation of HAART (highly active anti retroviral therapy). HAART therapy includes a combination of protease inhibitors (discovered/designed in 1995) and non nucleosidase reverse transcriptase inhibitors (1996). Widespread use of HAART came around 1999-2000. Papers discussing the use of HAART to aid in anal cancer treatment are thus limited. Hoffman et al (1999) at UCSF suggested that one patient in their cohort of 17 who initially Inhibitors,research,lifescience,medical had a CD4 count less than 200 tolerated the standard of care treatment for anal cancer due to the addition of a protease inhibitor which bolstered the CD4 count to greater than 200 (42). A later study done by Stadler et al (UT Southwestern 2004) demonstrated a trend toward improved efficacy of anal cancer treatment in HIV+ AIDS patient treated with HAART (44). Stadler et al (2004) Inhibitors,research,lifescience,medical compared outcomes in patients treated

for anal cancer preHAART and post HAART (44). The UT Southwestern study differs from the other studies in that the chemotherapy used was 5FU/cisplatin instead of 5FU/MMC. Inhibitors,research,lifescience,medical The RT dose was similar at 54 Gy. In this study all patients had AIDS at time

of diagnosis. Overall, 14 patients were analyzed, including 6 pre HAART and 8 on HAART. Stadler et al (2004) suggested a trend towards better treatment tolerability and outcome in patients treated with HAART. 2 year OS in patients on HAART was 67% vs. 17% in the pre-HAART era. 1yr and 3 yr mortality pre HAART was only 12% and 40% respectively compared to 67% and 80% for patients on HAART. The success of definitive treatment for HIV+ patients on HAART seems to Inhibitors,research,lifescience,medical fare the same as HIV negative patients in the randomized Chlormezanone control BMN 673 trials. Moreover there was more toxicity in the preHAART patients (60%) compared to the HAART treated patients (50%) (44). It suggests that the HAART and increased CD4 count help patients tolerate treatment. Recent single institutional studies have shown that as long as HIV+ patients can tolerate the standard of care treatment for anal cancer and do not have AIDS (i.e. CD4<200), the efficacy and durability of treatment is similar to immunocompetent patients. A group from Paris (Blazy et al 2005) reported on a cohort of 9 HIV+ men all on HAART treated with chemoradiation (45). They found no correlation between CD4 count and toxicity. Clinical outcome was similar to immunocompetent historical controls (45). Yet another single institutional study from St.