See M H, Bhoo-Pathy N, Jamaris S, Kiran A, Evans D G, Yip C H, Taib N A
Department of Surgery, Faculty of Medicine, University of Malaya, 50603, Lembah Pantai, Kuala Lumpur, Malaysia.
Faculty of Medicine, Julius Centre University of Malaya, University of Malaya, 50603, Lembah Pantai, Kuala Lumpur, Malaysia.
World J Surg. 2018 May;42(5):1270-1277. doi: 10.1007/s00268-017-4319-6.
The rate of contralateral risk-reducing mastectomy (CRRM) is increasing in the West with controversial evidence of improved survival in early breast cancer patients. Although uptake of CRRM in Asia appears low, the trends may rise, and there is currently an urgent need to provide evidence for informed decision-making in clinical practice. This study aims to determine the risk of contralateral breast cancer (CBC) and its associated factors in an Asian setting.
A total of 2937 newly diagnosed patients with stage I and stage II breast cancer in University Malaya Medical Centre between Jan 1993 to Dec 2012 were included in the study. Multinomial logistic regression analysis allowing death to compete with CBC as a study outcome was used; patients with unilateral breast cancer who were alive were taken as reference. A stepwise backward regression analysis including age at diagnosis, ethnicity, family history of breast cancer, TNM stage, hormonal receptor status, HER2 status, chemotherapy, radiotherapy, and hormone therapy was conducted.
Fifty women developed CBC, over a median follow-up of 6 years. The 5- and 10-year cumulative risk of contralateral breast cancer was 1.0% (95% CI 0.6-1.4%) and 2.8% (95% CI 2.0-3.6%), respectively. Young age at diagnosis of first cancer, positive family history, and stage I disease were independent predictors of CBC.
The current study suggests that the risk of CBC is very low in a Southeast Asian setting. Any recommendations or practice of CRRM should be reviewed with caution and patients must be counseled appropriately.
在西方，对侧预防性乳房切除术（CRRM）的实施率正在上升，但其对早期乳腺癌患者生存率的改善证据存在争议。尽管CRRM在亚洲的采用率似乎较低，但这一趋势可能会上升，目前迫切需要提供证据以支持临床实践中的明智决策。本研究旨在确定亚洲背景下对侧乳腺癌（CBC）的风险及其相关因素。
本研究纳入了1993年1月至2012年12月在马来亚大学医学中心新诊断的2937例I期和II期乳腺癌患者。采用多分类逻辑回归分析，将死亡作为与CBC竞争的研究结局；以单侧乳腺癌存活患者作为对照。进行逐步向后回归分析，纳入诊断时年龄、种族、乳腺癌家族史、TNM分期、激素受体状态、HER2状态、化疗、放疗和激素治疗等因素。
在中位随访6年期间，有50名女性发生了CBC。对侧乳腺癌的5年和10年累积风险分别为1.0%（95%CI 0.6-1.4%）和2.8%（95%CI 2.0-3.6%）。首次癌症诊断时年龄较小、家族史阳性和I期疾病是CBC的独立预测因素。
当前研究表明，在东南亚背景下CBC的风险非常低。任何关于CRRM的建议或实践都应谨慎审视，并且必须对患者进行适当的咨询。
