Breast Cancer Incidence and Mortality in LGBTQ+ Populations Compared With Cisgender Heterosexual Individuals: A Comparative Epidemiologic Synthesis

Document Type

Conference Proceeding

Publication Date

6-2026

Publication Title

Journal of Clinical Oncology

Abstract

Background: Breast cancer incidence and mortality by sexual orientation and gender identity remain poorly characterized. We aimed to systematically review comparative studies in LGBTQ+ populations versus cisgender heterosexual comparators. Methods: We conducted a PRISMA 2020–guided systematic review evaluated breast cancer incidence and mortality in LGBTQ+ populations versus cisgender heterosexual comparators. PubMed, Embase, and Scopus were searched from inception to January 2026. Population-based cohort, registry, and health system studies reporting comparative incidence or mortality were eligible. Two reviewers independently screened records. Of 189 records, 105 were excluded at title/abstract, 84 underwent full-text review, and 8 studies were included. Due to heterogeneity in SOGI ascertainment, comparators, and effect measures, results were synthesized qualitatively. Results: Among transgender populations, breast cancer incidence varied by reference group. In a nationwide cohort, trans women had higher incidence vs cis men (SIR 46.7) but lower vs cis women (SIR 0.3), while trans men showed the inverse pattern (vs cis women SIR 0.2; vs cis men SIR 58.9). In a U.S. health system cohort, incidence was similar for FTM vs cis women (0.4% vs 0.5%) but higher for MTF vs cis men (0.2% vs 0.004%). Among sexual minority women, incidence did not differ from heterosexual women in UK Biobank (HR 0.63–0.93) or Nurses’ Health Study (aIRR 1.19; 95% CI, 0.92–1.53). Mortality data were sparse; one national linkage found higher breast cancer–specific mortality in same-sex partnered women (HR 3.24; 95% CI, 1.01–10.37). Conclusions: Breast cancer incidence in transgender populations is comparator-dependent: trans women have higher incidence vs cis men but lower vs cis women, with the inverse pattern in trans men; incidence among sexual minority women is similar to heterosexual women.

Volume

44

Issue

16 Suppl

First Page

1118

Comments

American Society of Clinical Oncology (ASCO) Annual Meeting, May 29 - June 2, 2026, Chicago, IL

Last Page

1118

DOI

10.1200/JCO.2026.44.16_suppl.1118

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