Abstract P6-11-03: Characteristics and survival outcomes of HIV-positive breast cancer patients: A systematic review and meta-analysis
Authors: Brandão Mariana , Bruzzone Marco , Franzoi Maria Alice , De Angelis Claudia , Eiger Daniel , Caparica Rafael , Piccart-Gebhart Martine , Buisseret Laurence , Ceppi Marcello , de Azambuja Evandro , Lambertini Matteo 
Published: March 2020

Abstract
Background: The number of people living with HIV is increasing worldwide thanks to the use of effective antiretroviral therapy. As these individuals get older, their risk of being diagnosed with cancer increases, including non-AIDS defining cancers such as breast cancer (BC). Most reports reveal that HIV+ patients (pts) with BC tend to be younger than HIV-uninfected (HIV-) pts. However, epidemiological data is yet conflicting regarding tumor stage at diagnosis, distribution of BC subtypes and overall survival (OS) of HIV+ pts as compared to HIV- pts. This meta-analysis aims to assess differences of baseline clinicopathological characteristics and OS of HIV+ vs HIV- BC pts.
Methods: We performed a systematic review using MEDLINE, Scielo, and conference abstracts up to June 10, 2019, with no language restrictions. Cohort studies and consecutive series comparing baseline characteristics (age, stage at diagnosis or BC subtypes) and/or OS of HIV+ vs HIV- BC pts were included. BC subtypes were defined according to 2 classifications: 1) “classic” immunohistochemical (IHC) subtypes (ER+/HER2-; HER2+; triple-negative BC); 2) surrogate intrinsic subtypes as per the St. Gallen Consensus (luminal A-like, luminal B-like, HER2-enriched and basal-like). Summary risk estimates (pooled mean ratios [pMR] and odds ratios [pOR]) and 95% confidence intervals (CI) were calculated using random effects models. OS data were pooled as hazard ratios (HR) and 95% CI and modeled using a random effects model. The main endpoints were age (as a continuous variable), stage at diagnosis (early [0-II] vs late [III-IV]), distribution of BC subtypes and OS (using both adjusted and unadjusted HR). Subgroup analysis of each endpoint was performed according to region of the world.
Results: A total of 16 studies (4 from North America and 12 from Sub-Saharan Africa [SSA]) published from 2005-2019 were included in this meta-analysis (with 1,764 HIV+ and 1,330,122 HIV- pts). HIV+ pts were younger than HIV- pts (pooled mean age of 41.1 vs 50.5 years, respectively; pMR 0.82, 95% CI 0.76-0.90, p &lt; 0.001) and had a 45% increased risk of presenting with late stage disease (pOR 1.45, 95% CI 1.25-1.68, p &lt; 0.001). There were no differences regarding distribution of BC subtypes, both by the “classic” IHC or by the St. Gallen classification. Overall, HIV+ pts had a 91% increased risk of dying as compared to HIV- pts (adjusted HR for OS: 1.91, 95% CI 1.06-3.45, p = 0.031 and unadjusted HR for OS: HR 1.47, 95% CI 1.10-1.95, p = 0.008). Subgroup analysis of OS according to region of the world showed that, in North America, HIV+ pts had a significantly increased risk of dying as compared to HIV- pts (adjusted HR 2.96, 95% CI 1.06-8.25, p = 0.038). In SSA, the increased mortality risk among HIV+ pts was also significant (adjusted HR 1.59, 95% CI 1.26-2.00, p &lt; 0.001). Sensitivity analysis showed similar findings.
Conclusion: This meta-analysis provides for the first time a comprehensive comparison of baseline characteristics and survival outcomes between HIV+ vs HIV- BC pts. Our results consistently demonstrate that HIV+ pts are diagnosed with BC at a younger age and at a more advanced stage. Additionally, even after adjusting for known prognostic factors, HIV+ pts have a worse OS as compared to HIV- pts, not only in developing countries (SSA) but also and particularly in developed countries (North America). There were no apparent differences in terms of distribution of BC subtypes. These results should raise the awareness of clinicians and policy makers regarding the detection and survival gap among HIV+ BC pts. This underserved population should be the focus of more research efforts, in order to better understand the reasons behind these disparities, which can be related to the HIV infection itself, to a more aggressive BC biology, and/or to a lower access to timely diagnosis and effective treatment.
Citation Format: Mariana Brandão, Marco Bruzzone, Maria Alice Franzoi, Claudia De Angelis, Daniel Eiger, Rafael Caparica, Martine Piccart-Gebhart, Laurence Buisseret, Marcello Ceppi, Evandro de Azambuja, Matteo Lambertini. Characteristics and survival outcomes of HIV-positive breast cancer patients: A systematic review and meta-analysis [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-11-03.