Breast cancers arising in high mammographic density tissue harbor tumor-promoting immune profiles

Abstract

Epidemiological studies have shown that high mammographic density (HMD) is a strong risk factor for breast cancer (BC) and is associated with poor prognosis. Although tumors from women with low (LMD) and HMD are genetically similar, HMD has a worse prognosis. We explored whether differences in the immune tumor microenvironment could explain the poorer outcomes. BC data were predominantly obtained from Lifepool, a population-based cohort of over 55,000 Australian women within the screening program. We identified 670 cases of invasive BC with pathology reports, family cancer history, and matched MD data to evaluate the clinico-pathological features of BC across MD quintiles. Tumour tissue was ..