Adverse events in non-AIDS-defining cancer patients receiving chemotherapy and combined antiretroviral therapy.

Abstract

e12523 Background: From 1991 to 2005, the number of cases of non-AIDS defining cancers (NADC) rose from 3,192 to 10,059 in the USA. Studies have shown an improvement in survival for many HIV-associated malignancies in the post HAART era. Drug-drug interactions between HIV therapy and chemotherapy (CTX) are not well understood. HIV medications can inhibit or induce the cytochrome p450 system, modulating CTX clearance. To understand CTX-HIV medication interactions, we performed a retrospective analysis of all patients (pts) diagnosed with a solid NADC who took CTX with combined antiretroviral therapy (cART). Methods: 157 pts with solid NADC were identified via a computer search at County Hospital. Adverse events (AE) during CTX in pts taking cART were assessed by chart review and graded per the NCI Common Terminology Criteria. Statistics: A Fisher's exact test was used to examine the differences in AE incidence. Results: Patients who did not take cART in conjunction with, or did not require CTX, were excluded. The number of pts analyzed for anal cancer (n=25), lung carcinoma (n=9), breast (n=7), and head and neck carcinoma (HNSCC) (n=4) represents 94% of pts taking cART with CTX in our cohort. Interestingly, Forty-two pts (50%) never received cART during therapy. All pts with anal carcinoma were treated with mitomycin/5FU/radiotherapy. 46 % of the patients taking ritonavir-based cART (6 pts of 13) developed a G4 neutropenia versus 8% (1 pt of 12) taking non-ritonavir cART (p<0.07). Anemia all grades with ritonavir, 54%, versus non-ritonavir cART 16% (p<0.09). All grades neutropenia for lung carcinoma while taking ritonavir was 83% versus 33% while taking non-ritonavir cART. No other correlations were identified. In this cohort, 17 pts received platinum (37%), taxanes (n=5) (11%), anthracyclines (n=5) 11%, gemcitabine (n=2) (4%), and pemetrexed (n=1). No difference in AE was noted between any CTX class, AE, and cART. Conclusions: Ritonavirinduced a 38% increase in G4 neutropenia and anemia during treatment of anal carcinoma with mitomycin/5FU. More trials including HIV-associated cancer pts are needed to assess the role of cART when given in conjunction with CTX.