Are there any special considerations when treating a patient with anal cancer who has poorly managed HIV/AIDS?

In the early days of AIDS, prior to the development of HAART, standard chemoradiation ("Nigro") was very poorly tolerated, and it was necessary to omit or dose-reudce the mitomycin, and many patients could not tolerate the full dose of radiation, stopping treatment early because of toxicity. Outcomes were quite poor. This all changed with HAART, and multiple publications have shown that patients with well controlled HIV, as seen by a low or undectetable viral titer and an adequate CD4 count, tolerate chemoradiation essentially as well as patients without HIV.

My approach when seeing a patient with poorly manged HIV/AIDS and anal cancer is to refer to Infectious Disease to treat the HIV. With poorly controlled disease, the toxicity of treatm...

While there are some conflicting data, I think the evidence points to treating patients who have well controlled HIV the same as their HIV-negative counterparts. Multiple reports suggest no difference in oncologic outcomes or toxicity based on presence of HIV infection and management with HAART (PMID: 24608297, 28049602).

I absolutely agree with @Dr. First Last that poorly controlled HIV patients should be first managed by an Infectious Disease specialist and then once medically optimized they should receive chemoradiation.