Key clinical point: Estrogen therapy with or without the concurrent use of adjuvant aromatase inhibitors (AI) or tamoxifen did not increase the risk for mortality in women with early hormone receptor-positive (HR+) breast cancer (BC).
Major finding: No association was observed between BC mortality risk and receipt of estrogen therapy concurrent with AI, tamoxifen, or both AI and tamoxifen, although estrogen therapy without concurrent AI or tamoxifen was associated with decreased BC mortality risk (adjusted odds ratio 0.61; 95% CI 0.43-0.87).
Study details: Findings are from a population-based nested case-control study including patients with HR+ BC who received local estrogen therapy or AI, tamoxifen, or AI and tamoxifen sequentially, of which 1262 women died due to BC and were matched to 12,620 alive control individuals.
Disclosures: This study was supported by Bröstcancerförbundet, Sweden,and ALF Funding Region Örebro County, Sweden. The authors declared no conflicts of interest.
Source: Sund M et al. Estrogen therapy after breast cancer diagnosis and breast cancer mortality risk. Breast Cancer Res Treat. 2023 (Feb 11). Doi: 10.1007/s10549-023-06871-w