The impact of HIV and CD4 count stratification on all cause mortality for adenocarcinoma and squamous cell lung cancers in the antiretroviral therapy era: Analysis of National Veterans Affairs and Kaiser Permanente Northern cohorts.

8070 Background: Since the widespread introduction of antiretroviral therapy (ART), people living with HIV (PWH) have experienced substantially decreased morbidity and mortality. However, PWH are at higher risk for lung cancer and have decreased cancer survival rates compared to people without HIV (PWoH). Few studies have evaluated histology-specific lung cancer survival by stage and HIV immune control. Methods: A retrospective cohort study was conducted with newly diagnosed non-small cell lung cancer (NSCLC), including PWH with PWoH, identified between 2008 and 2020 from the US Department of Veterans Affairs and Kaiser Permanente, California. Adjusted hazard ratios for 5-year survival by CD4 count (≥ 500 cells/mm 3 , <500 cells/mm 3 , ref: PwOH) were estimated using Cox models stratified by subtype (adenocarcinoma, squamous) and TNM (I, II/III, IV) stage. Results: This cohort consisted of 562 PWH (53% adenocarcinoma, 33% squamous cell) and 91,370 PWoH (52% adenocarcinoma, 33% squamous cell, 15% not specified). The PWH cohort tended to be younger (62 vs. 69 years), male (97% vs. 83%), and non-Hispanic Black race (48% vs. 14%), compared to PWoH. Among PWH, 41% had CD4 ≥500 cells/mm 3 , 59% had CD4 <500 cells/mm 3 . The median survival in years for PWoH, PWH CD4 count ≥500 cell/mm 3 and <500 cells/mm 3 were: 2.4 ±0.10, 2.3 ± 0.17, 2.0±0.17, respectively for adenocarcinoma, and 2.1±0.01, 2.3±0.21, 1.6±0.17 respectively for squamous cell carcinoma. The table shows the adjusted HR for all-cause mortality for Adenocarcinoma and Squamous Cell Carcinoma comparing PWH ≥500 and PWH<500 to PWoH (as reference) stratified by stage. Conclusions: Although it is well known that low CD counts (<200) are associated with poor cancer outcomes, higher CD4 counts (CD<500) at the time of lung cancer diagnosis may still play a role in the treatment outcomes of NSCLC. PWH who have CD4 counts ≥500 appear to have similar survival compared to PWoH, but CD4<500, those with (vs. without) HIV have higher rates of mortality for both adenocarcinoma and squamous cell histologies. Adjusted hazard ratios (HR)* with 95% confidence intervals (CI) for 5-year all-cause-mortality associated with HIV by CD4 count (reference: PWoH), across Adenocarcinoma and Squamous Cell Cancer histology and baseline cancer stage. Table: see text