Understanding the impacts of cancer therapy, high temperature and poor air quality on heart and lung health in breast cancer survivors.

Breast cancer survivors are overburdened with therapy-related cardiovascular (CV) and respiratory/pulmonary (R/P) morbidity and mortality. However, there is variability in the degree of cardiopulmonary toxicity experienced by breast cancer survivors that cannot be fully explained by treatment, stage at diagnosis, and pre-existing conditions. This suggests that external factors, such as high temperature events and poor air quality, could predispose breast cancer survivors’ susceptibility to treatment-related toxicities. In this grant, we will identify how cardiopulmonary health risks among breast cancer survivors are impacted by the combination of their cancer therapies, prolonged high temperatures and air quality levels, by elucidating the underlying causes of variability in treatment toxicity and late-effects. Specifically, this proposal will address: a. Whether pre- and post-diagnosis exposures to prolonged high temperature or poor air quality (PM2.5, ozone, NO2 and wildfire smoke) predispose breast cancer survivors to greater CV and R/P toxicity from their treatments; b. How prolonged high temperatures and poor air quality influence survivors’ risks for CV and R/P events compared to individuals without cancer; and c. Which breast cancer survivors face the greatest health risks from these factors. To answer these questions, we will utilize a statewide Utah cohort of 21,835 breast cancer survivors and 65,503 cancer-free age- and sex-matched population controls identified using the Utah Population Database, an epidemiologic data resource that contains lifetime medical data and longitudinal residential histories. We will characterize chronic and acute exposures to high temperature and poor air quality (PM2.5, ozone, NO2 and wildfire smoke) for breast cancer survivors and cancer-free controls based on their residential history. We aim to: 1) Determine if pre-diagnosis, long-term exposure to prolonged high temperature and poor air quality are associated with CV and R/P health outcomes occurring while breast cancer survivors are on therapy. 2) Estimate the association of CV and R/P health outcomes and post-diagnosis, short-term exposure to high temperature and poor air quality from diagnosis onwards. 3) Identify differences in the effect of pre-diagnosis, long-term exposure to prolonged high temperature and poor air quality on the CV and R/P health outcomes between breast cancer survivors and a cancer-free cohort. Identifying whether prolonged high temperature and air quality levels exacerbate cancer treatment toxicities and identifying high-risk survivor subgroups will facilitate development of supportive care efforts to manage post-diagnosis health effects.