This single-arm prospective study evaluated the safety and efficacy of temporarily holding maintenance endocrine therapy for mostly stage I-II breast cancer in order to attempt pregnancy for women 42 and younger (n=516). Remarkably 74% became pregnant and 64% experienced a live birth. The rate of breast cancer recurrence at 3 years was 9% among both subjects as well as a matched external control group. | Partridge, N Engl J Med 2023