Skip to main content

04-05-2024 | Breast Cancer | Brief Report

Disparities in PI3K/mTOR inhibitor use, toxicities, and outcomes among patients with metastatic breast cancer

Authors: Claire Sathe, Melissa K. Accordino, David DeStephano, Mansi Shah, Jason D. Wright, Dawn L. Hershman

Published in: Breast Cancer Research and Treatment

Login to get access



Novel agents such as PI3K and mTOR inhibitors (PI3K/mTORi) have expanded treatment options in metastatic breast cancer (MBC). Nevertheless, mortality rates remain disproportionately high for Black patients and patients with lower socioeconomic status. Furthermore, clinical trials for these novel agents lacked diversity, so their toxicity profile in minority populations is uncertain.


We conducted a retrospective analysis of EHR-derived data from the Flatiron Health Database for patients with HR+, HER2− MBC. Multivariable logistic regression was used to evaluate factors associated with PI3K/mTORi use and toxicity outcomes.


A total of 9169 patients with MBC were included in our analysis, of which 1780 (19.4%) received a PI3K/mTORi. We estimated the conditional total effect of insurance through Medicaid, and found lower odds of use of PI3K/mTORi among patients on Medicaid compared to those with commercial insurance (OR 0.73, 95% CI 0.54–0.99, p = 0.049). Odds of PI3K/mTORi use were higher for patients treated at an academic center (OR 1.28, CI 1.06–1.55, p = 0.01). Modeled as a controlled direct effect, Black/African American (Black/AA) race had no impact on odds of PI3K/mTOR use. Black/AA patients had twice the odds of developing hyperglycemia on PI3K/mTORi compared to White patients (OR 2.02, CI 1.24–3.39, p < 0.01).


This analysis of real-world data suggests that the use of PI3K/mTORi is influenced by socioeconomic factors. We also found racial disparities in toxicity outcomes, with Black/AA patients having twice the risk of hyperglycemia. Our findings call for greater efforts to ensure access to novel treatments and improve their tolerability in diverse populations.
Available only for authorised users
Disparities in PI3K/mTOR inhibitor use, toxicities, and outcomes among patients with metastatic breast cancer
Claire Sathe
Melissa K. Accordino
David DeStephano
Mansi Shah
Jason D. Wright
Dawn L. Hershman
Publication date
Springer US
Published in
Breast Cancer Research and Treatment
Print ISSN: 0167-6806
Electronic ISSN: 1573-7217
Live Webinar | 01-10-2024 | 12:30 (CEST)

Recent advances in the use of CAR T-cell therapies in relapsed/refractory diffuse large B-cell lymphoma and follicular lymphoma

Live: Tuesday 1st October 2024, 12:30-14:00 (CEST)

In this live webinar, Professor Martin Dreyling and an esteemed, international panel of CAR-T experts will discuss the very latest data on the safety, efficacy and clinical impact of CAR T-cell therapies in the treatment of r/r DLBCL and r/r FL, as presented at ASH 2023, EU CAR-T 2024, and EHA 2024. 

Please note, this webinar is not intended for healthcare professionals based in the US and UK.

Sponsored by: Novartis Pharma AG

Chaired by: Prof. Martin Dreyling
Developed by: Springer Healthcare