男性乳腺癌预防性对侧乳房切除？ / 四六文摘

　　男性乳腺癌大约仅占全部乳腺癌病例的1%，因此关注如何治疗这些患者的临床研究极少，男性乳腺癌的治疗也主要参照女性乳腺癌。不过，越来越多研究发现男性乳腺癌与女性乳腺癌的流行病学特征、肿瘤学特征和预后因素有所不同。现有指南建议，对于对侧乳腺癌风险较高的患者，例如乳腺癌易感基因突变或有家族史的患者，应该考虑预防性对侧乳房切除术。一些文献报告了美国女性的预防性对侧乳房切除术率显著增加，但是对生存的影响仍然存在争议。对于可切除乳腺癌的男性，主要选择单侧乳房切除术，其次为保乳手术和预防性对侧乳房切除术。近年来，人们注意到男性乳腺癌越来越多采用预防性对侧乳房切除术，但是几乎没有现成证据可以评估其对该独特人群生存的影响。目前仍然缺乏针对男性单侧乳腺浸润癌的预防性对侧乳房切除术指南，故亟需有质量的生存获益证据证。

　　2021年9月23日，施普林格自然旗下《乳腺癌研究与治疗》在线发表复旦大学附属肿瘤医院杨银龙、潘梁威、邵志敏等学者的大数据分析报告，探讨了近18年来男性I～III期单侧乳腺癌预防性对侧乳房切除术的变化趋势和生存获益。

　　该研究对美国国家癌症研究所（NCI）监测流行病学最终结果（SEER）数据库1998～2016年的数据进行检索，确定I～III期单侧乳腺癌男性共计5118例，其中接受预防性对侧乳房切除术209例（4.1%）。通过考克兰-阿米蒂奇趋势检验，对研究期间预防性对侧乳房切除术率进行比较。通过逻辑回归模型，对预防性对侧乳房切除术的预测因素进行检验。通过生存时间曲线，对首次诊断单侧乳腺癌患者接受预防性对侧乳房切除术或单侧乳房切除术的生存结局进行分析。通过单因素和多因素比例风险回归回归分析，对预防性对侧乳房切除术和单侧乳房切除术的总生存和乳腺癌相关生存进行比较。通过倾向评分匹配，对基线特征进行平衡。

　　结果发现，接受预防性对侧乳房切除术的男性比例显著增加（P<0.0001）

1998年：1.7%
2016年：6.3%

　　预防性对侧乳房切除术显著相关因素：

患者年龄较小
诊断年份较近
肿瘤分级较高
肿瘤体积较小

　　其中首次诊断单侧乳腺癌患者3566例，中位随访65个月，预防性对侧乳房切除术与单侧乳房切除术相比：

任何原因致死亡风险较低（风险比：0.58，95%置信区间：0.37～0.89，P=0.022）
乳腺癌所致死亡风险相似（风险比：0.57，95%置信区间：0.29～1.11，P=0.153）

　　通过倾向评分匹配对患者年龄、诊断年份、种族、婚姻、医保、肿瘤分级、组织学、肿瘤大小、淋巴结、雌激素受体、孕激素受体、放化疗等基线特征进行平衡后，预防性对侧乳房切除术与单侧乳房切除术相比：

任何原因致死亡风险相似（风险比：0.83，95%置信区间：0.46～1.52，P=0.553）
乳腺癌所致死亡风险相似（风险比：0.98，95%置信区间：0.39～2.47，P=0.970）

　　因此，该研究结果表明，男性乳腺癌患者预防性对侧乳房切除术率显著增加，尤其年轻患者。不过，预防性对侧乳房切除术与单侧乳房切除术相比，对男性乳腺癌并无生存获益，这表明应该对预防性对侧乳房切除术的决策进行充分讨论。

Breast Cancer Res Treat. 2021 Sep 23. Online ahead of print.

Trend and survival benefit of contralateral prophylactic mastectomy among men with stage I-III unilateral breast cancer in the USA, 1998-2016.

Yang Y, Pan L, Shao Z.

Fudan University Shanghai Cancer Center, Shanghai, China; Shanghai Medical College, Fudan University, Shanghai, China.

PURPOSE: Our study aimed to explore temporal trends and survival benefit of contralateral prophylactic mastectomy (CPM) in male breast cancer (MBC).

METHODS: Men with stage I-III unilateral breast cancer between 1998 and 2016 were identified from the surveillance, epidemiology, and end results (SEER). We compared CPM rate over the study period using the Cochrane-Armitage test for trend. Logistic regression model was used to test for factors predicting CPM. Survival analysis was conducted in patients who underwent CPM or unilateral mastectomy (UM) with a first diagnosis of unilateral breast cancer. Kaplan-Meier curve and univariate and multivariable Cox proportional hazards regression analyses were performed to compare overall survival (OS) and breast cancer-specific survival (BCSS) between CPM and UM groups. Propensity score matching was adopted to balance baseline characteristics.

RESULTS: 5118 MBC cases were included in the present study, with 4.1% (n = 209) patients underwent CPM. The proportion of men undergoing CPM increased from 1.7 in 1998 to 6.3% in 2016 (P < 0.0001). Young age, recent years of diagnosis, higher tumor grade and lower T stage were significantly associated with CPM. A cohort of 3566 patients were enrolled in survival analysis with a median follow-up of 65 months. CPM was associated with better OS (HR 0.58, 95% CI 0.37-0.89, P = 0.022) rather than BCSS (HR 0.57, 95% CI 0.29-1.11, P = 0.153) compared with UM. In propensity score-matched model, CPM was not an independent prognostic factor for OS (HR 0.83, 95% CI 0.46-1.52, P = 0.553) and BCSS (HR 0.98, 95% CI 0.39-2.47, P = 0.970).

CONCLUSION: Our study revealed a dramatic increase in CPM utilization among MBC, especially in young patients. However, CPM provides no survival benefit for MBC compared with UM, indicating the decision of CPM should be fully discussed.

KEYWORDS: Contralateral prophylactic mastectomy; Male breast cancer; SEER; Survival; Trend.

PMID: 34554371

DOI: 10.1007/s10549-021-06397-z