Safely interrupt endocrine therapy after breast cancer due to desire to conceive?

In selected women with a history of early hormone receptor-positive breast cancer, temporary discontinuation of endocrine therapy due to a desire to become pregnant did not increase the short-term risk of breast cancer, compared to an outpatient control cohort. Further follow-up is needed to verify long-term safety.

The positive study evaluated the temporary discontinuation of adjuvant endocrine therapy due to the desire to conceive in young women with a history of breast cancer. were eligible to participate if they were 42 years of age or younger; had stage I, II, or III disease; received adjuvant endocrine therapy for 18 to 30 months; And he wanted to get pregnant. The primary endpoint was the number of breast cancer events (defined as similar or localized invasive disease, distant recurrence, or contralateral invasive breast cancer) during follow-up. Results in this district cohort were compared with those in an external control group consisting of women who had met the inclusion criteria for this study.

The mean age of the 516 participants was 37 years, the median time from breast cancer diagnosis to inclusion was 29 months, and 93.4% had stage I or II disease. Of the 497 women followed for pregnancies, 368 (74.0%) had at least one pregnancy and 317 (63.8%) had at least one delivery. A total of 365 children were born. After a follow-up of 1638 patients (median follow-up: 41 months), 44 patients developed breast cancer, which did not pass the safety threshold (46 events). The 3-year incidence of breast cancer was 8.9% (95% CI 6.3–11.6) in the cut-out group and 9.2% (95% CI 7.6–10.8) in the control group.

source:

Partridge AH, Niman SM, Ruggeri M, et al. Interrupting endocrine therapy to try to conceive after breast cancer. Engel J Med. 2023; 388: 1645-56.