26 Jul 2024 • Bilateral mastectomy significantly reduced the risk of contralateral breast cancer but did not lower breast cancer mortality compared to lumpectomy or unilateral mastectomy.

• Analyzing outcomes for 661,270 women (36,028 per group) with unilateral breast cancer diagnosed from 2000 to 2019, the study found only 97 cases of contralateral cancer in the bilateral mastectomy group, versus 766 in the lumpectomy and 728 in the unilateral mastectomy groups. The 20-year risk of contralateral cancer was 6.9% for both lumpectomy and unilateral mastectomy.

• Mortality rates were similar across groups: 8.54% for lumpectomy, 9.07% for unilateral mastectomy, and 8.50% for bilateral mastectomy.

• Women with contralateral cancer had a 15-year mortality rate of 32.1%, significantly higher than 14.5% for those without.

Source:JAMA Oncology| Read full story