Disparities in the treatment and outcomes of lung cancer among HIV-infected people in Texas.

Abstract

6070 Background: HIV-infected (HIV+) people are at elevated risk for lung cancer and have higher mortality following lung cancer diagnosis than uninfected (HIV-) individuals. The disparity in survival is partly due to advanced stage at diagnosis, but it is unclear whether HIV+ people with lung cancer are less likely to receive cancer treatment, which could worsen survival. Methods: We included adults ≥ 18 years of age with lung cancer reported to the Texas cancer registry (N=156,930). HIV status was determined by linkage with the enhanced Texas HIV/AIDS Reporting System. We compared HIV+ and HIV- lung cancer cases with respect to demographic and clinical characteristics. For non-small cell lung cancer (NSCLC) cases, we identified predictors of cancer treatment (surgery, radiation, and chemotherapy) using logistic regression. We used Cox regression to evaluate the effects of HIV and treatment on lung cancer-specific mortality. Results: Compared with HIV- lung cancer cases (N=156,593), HIV+ lung cancer cases (N=337) were more likely to be young, non-Hispanic black, male, and to have distant stage disease (53.7% vs. 44.4%). HIV+ cases were less likely to receive cancer treatment than HIV- cases (60.3% vs. 77.5%; odds ratio 0.39, 95%CI 0.30-0.52 after adjustment for diagnosis year, age, sex, race, stage, and histologic subtype). In Cox models adjusted for these variables, both HIV infection (hazard ratio [HR] 1.34, 95%CI 1.15-1.56) and lack of cancer treatment (HR 1.69, 95%CI 1.66-1.72) were associated with higher lung cancer-specific mortality. After adjustment for cancer treatment, the association between HIV and lung cancer mortality was attenuated (HR 1.25, 95%CI 1.06-1.47). The association between HIV and lung cancer-specific mortality was stronger among untreated lung cancer cases (HR 1.32, 95%CI 1.01-1.72) than treated cases (adjusted HR 1.16, 95%CI 0.94-1.43; p-interaction=0.34). Conclusions: In this population-based study, HIV+ people with NSCLC were less likely to be treated for lung cancer than their HIV- counterparts. This lack of treatment may be partly responsible for higher cancer-related mortality in HIV+ cases. Further investigation is needed to understand disparities in cancer treatment for HIV+ people.