Because more effective control of HIV infection has become possible, patients are living longer and are being affected by types of cancers that are not directly induced by HIV. A growing number of reports from around the world now indicate that other malignant tumors, including Hodgkin lymphoma (HL), nonmelanomatous skin cancers, lung cancer, germ cell tumors, myeloid or lymphoid leukemias, multiple myeloma, renal cell carcinoma, head and neck cancer, brain tumors, squamous tumor of the conjunctiva, and leiomyosarcoma in pediatric patients, are occurring in HIV-infected individuals.
Rates of other non–AIDS-defining cancers appear to be increasing among HIV-infected individuals. In an Australian cancer database, 196 cases of non–AIDS-defining cancers were noted in 13,067 individuals (1.5%), including 8,351 notified with HIV infection and 8,118 registered with AIDS. Because HIV-infected individuals are surviving longer with currently available combination anti-HIV drugs, clinicians should anticipate seeing the development of more tumors in these patients. Greater vigilance for these tumors is warranted.
These non–AIDS-defining cancers are generally treated with the same stage-adjusted strategies as would be used in individuals not infected with HIV.
Sidebar: Because HIV infection has yielded to better therapies, unrelated tumors occurring in infected individuals raise the question of tolerance to and efficacy of otherwise standard therapies in this setting. To some degree, the concern is fueled by in vitro studies, such as a recent report that demonstrated heightened sensitivity of HIV-infected T lymphocytes to damage from radiation, but the in vivo data are not uniformly supportive (Baeyens A et al: Int J Radiat Biol 86:584-592, 2010).
Sidebar: Researchers in Japan concluded that damage to the skin and mucosa, including stomatitis and diarrhea, tended to occur after low-dose radiation therapy; however, no severe acute adverse effects were seen in other organs, such as the brain, lung, and bone. Acute adverse effects often occurred earlier in HIV-positive patients and became severe more frequently than in the general population, especially disorders of the mucosa, which tended to arise rapidly. It was shown that radiation therapy is safe when it is performed carefully and that it is a very useful treatment for cancer in HIV-positive patients (Kaminuma T et al: J Radiat Res 51:749-753, 2010).
Studies showing a possible increased incidence of HL in HIV-infected individuals have been reported from Europe, Australia, and the United States. The most common histologic types are mixed cellularity and lymphocyte-depleted. Male predominance, a higher prevalence of B symptoms, and more extranodal disease on presentation are the main characteristics of HL in HIV-infected patients.
Chemotherapy is recommended for this group of patients, because of the high proportion of stage III or IV disease. Standard treatments include doxorubicin(Drug information on doxorubicin), bleomycin, vinblastine, and dacarbazine(Drug information on dacarbazine) (ABVD) or ABVD alternating with vincristine mechlorethamine (Mustargen), vincristine, procarbazine(Drug information on procarbazine) (Matulane), and prednisone(Drug information on prednisone) (MOPP). More recently, early results with bleomycin(Drug information on bleomycin), etoposide(Drug information on etoposide), doxorubicin, cyclophosphamide(Drug information on cyclophosphamide), vincristine, procarbazine, and prednisone (BEACOPP) and the Stanford V regimen (mechlorethamine, doxorubicin, vinblastine(Drug information on vinblastine), vincristine, bleomycin, etoposide, and prednisone) look promising.
As in the general population, basal cell carcinoma is more common than squamous cell carcinoma in the setting of HIV infection. The risk factors for the development of these tumors are the same as in the general population: namely, fair skin, history of sun exposure, and family history.
Patients with HIV infection appear to have a higher relative risk of developing lung cancer than do age-matched controls (relative risk = 4.5; 95% confidence interval, 4.2 to 4.8). These tumors tend to present at later stages than do tumors with a similar histologic distribution in the general population.
Cases of aggressive leiomyosarcoma developing in HIV-positive children have been reported. Leiomyosarcoma is a rare tumor, occurring in fewer than two cases per 10 million non–HIV-infected children. However, a much higher than expected frequency of leiomyosarcoma has been reported in HIV-infected children. Visceral sites (eg, the lungs, spleen, and GI tract) are commonly involved.