HIV and malignancy – An update on treatments

Kaposi's sarcoma (KS) and non-Hodgkins Lymphoma (NHL) remain the most common malignancies associated with HIV infection. Although AIDS defining, rates of cervical cancer have not increased. Although modest, rates of Hodgkins disease, testicular cancer and SCC of the mouth and anus appear increased. The use of highly active antiretrovirals (HAART), especially protease inhibitors has seen dramatic decrease in the incidence of new AIDS diagnoses including KS but not NHL. Reasons for this discrepancy are not immediately apparent. The full impact and place of antiretrovirals is still not fully appreciated and deserves more study. Use of HAART together with anticancer therapies should improve outcomes and has become standard in the treatment of HIV patients (pts).

In the treatment of KS, therapies still vary according to the immune status of the patient. While spontaneous remissions may occur with HAART, most patients with established KS require specific therapy as well. Topical therapies (radiation, cryotherapy, intralesional injection,) remain the main treatments for limited cutaneous lesions. For those with extensive disease, systemic interferon is useful in pts with good CD4 cell counts (>300), while the liposomal-encapsulated anthracyclines have become the treatments of choice for pts with low counts. The recognition of the role of HHV8 in the aetiology of KS may allow preventative treatment strategies in the future. A number of biological modifying agents such retinoids, thalidomide and anti-angiogenesis factors are under further investigation after initial encouraging results.

NHL accounts for an increasing proportion of new and secondary AIDS diagnoses. If early reports of its incidence persisting despite HAART hold true it will become the major cause of AIDS. Although there have been a number of insights into its causation the aetiology remains complex and still poorly understood. The recognition of EBV in the causation of over 50% of these cancers has not led to any clinically significant therapeutic interventions. Combination chemotherapy remains the best available treatment with most centres now reporting complete remission rates >50% and 10-20% pts surviving beyond 2 years from treatment. These results may improve with concomitant use of HAART. Measures to modify biological response e.g. vaccination to prevent/modify latent EBV infection remain attractive but more basic knowledge is needed.

Prevention and early intervention strategies are the best way to control cervical and anal intra-epthelial neoplasia and cancer.