Women's College Research Institute, Women's College Hospital, Toronto, Ontario, Canada.
Women's Age Lab, Women's College Hospital, Toronto, Ontario, Canada.
JAMA Oncol. 2024 Sep 1;10(9):1228-1236. doi: 10.1001/jamaoncol.2024.2212.
The benefit of bilateral mastectomy for women with unilateral breast cancer in terms of deaths from breast cancer has not been shown.
To estimate the 20-year cumulative risk of breast cancer mortality among women with stage 0 to stage III unilateral breast cancer according to the type of initial surgery performed.
DESIGN, SETTINGS, AND PARTICIPANTS: This cohort study used the Surveillance, Epidemiology, and End Results (SEER) Program registry database to identify women with unilateral breast cancer (invasive and ductal carcinoma in situ) who were diagnosed from 2000 to 2019. Three closely matched cohorts of equal size were generated using 1:1:1 matching according to surgical approach. The cohorts were followed up for 20 years for contralateral breast cancer and for breast cancer mortality. The analysis compared the 20-year cumulative risk of breast cancer mortality for women treated with lumpectomy vs unilateral mastectomy vs bilateral mastectomy. Data were analyzed from October 2023 to February 2024.
Type of breast surgery performed (lumpectomy, unilateral mastectomy, or bilateral mastectomy).
Contralateral breast cancer or breast cancer mortality during the 20-year follow-up period among the groups treated with lumpectomy vs unilateral mastectomy vs bilateral mastectomy.
The study sample included 661 270 women with unilateral breast cancer (mean [SD] age, 58.7 [11.3] years). After matching, there were 36 028 women in each of the 3 treatment groups. During the 20-year follow-up, there were 766 contralateral breast cancers observed in the lumpectomy group, 728 contralateral breast cancers in the unilateral mastectomy group, and 97 contralateral cancers in the bilateral mastectomy group. The 20-year risk of contralateral breast cancer was 6.9% (95% CI, 6.1%-7.9%) in the lumpectomy-unilateral mastectomy group. The cumulative breast cancer mortality was 32.1% at 15 years after developing a contralateral cancer and was 14.5% for those who did not develop a contralateral cancer (hazard ratio, 4.00; 95% CI, 3.52-4.54, using contralateral breast cancer as a time-dependent covariate). Deaths from breast cancer totaled 3077 women (8.54%) in the lumpectomy group, 3269 women (9.07%) in the unilateral mastectomy group, and 3062 women (8.50%) in the bilateral mastectomy group.
This cohort study indicates that the risk of dying of breast cancer increases substantially after experiencing a contralateral breast cancer. Women with breast cancer treated with bilateral mastectomy had a greatly diminished risk of contralateral breast cancer; however, they experienced similar mortality rates as patients treated with lumpectomy or unilateral mastectomy.
对于单侧乳腺癌患者，双侧乳房切除术在降低乳腺癌死亡率方面的益处尚未得到证实。
根据初始手术类型，估计 0 期至 3 期单侧乳腺癌女性在 20 年内乳腺癌死亡的累积风险。
设计、环境和参与者：本队列研究使用监测、流行病学和最终结果（SEER）计划登记数据库，确定了 2000 年至 2019 年间被诊断为单侧乳腺癌（浸润性和导管原位癌）的女性。根据手术方法，使用 1:1:1 匹配生成了三个大小相等的紧密匹配队列。对每个队列进行了 20 年的随访，以观察对侧乳腺癌和乳腺癌死亡率。分析比较了接受保乳术与单侧乳房切除术与双侧乳房切除术的女性 20 年乳腺癌死亡的累积风险。数据分析于 2023 年 10 月至 2024 年 2 月进行。
所行乳房手术类型（保乳术、单侧乳房切除术或双侧乳房切除术）。
在接受保乳术、单侧乳房切除术和双侧乳房切除术治疗的组中，20 年随访期间对侧乳腺癌或乳腺癌死亡的情况。
研究样本包括 661270 名单侧乳腺癌女性（平均[标准差]年龄为 58.7[11.3]岁）。匹配后，每组各有 36028 名女性。在 20 年的随访期间，保乳术组观察到 766 例对侧乳腺癌，单侧乳房切除术组观察到 728 例对侧乳腺癌，双侧乳房切除术组观察到 97 例对侧癌症。保乳术-单侧乳房切除术组 20 年对侧乳腺癌风险为 6.9%（95%CI，6.1%-7.9%）。在发生对侧乳腺癌后 15 年，累积乳腺癌死亡率为 32.1%，未发生对侧乳腺癌的患者为 14.5%（风险比，4.00；95%CI，3.52-4.54，以对侧乳腺癌作为时间依赖性协变量）。保乳术组共有 3077 名（8.54%）女性死于乳腺癌，单侧乳房切除术组 3269 名（9.07%），双侧乳房切除术组 3062 名（8.50%）。
本队列研究表明，在发生对侧乳腺癌后，死于乳腺癌的风险会大大增加。接受双侧乳房切除术治疗的乳腺癌女性发生对侧乳腺癌的风险大大降低；然而，她们的死亡率与接受保乳术或单侧乳房切除术的患者相似。
