Department of Breast and Medical Oncology, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo, 162-8655, Japan.
Department of Breast and Endocrine Surgery, Hyogo Medical University, 1-1 Mukogawa-cho, Nishinomiya-shi, Hyogo, 663-8501, Japan.
Breast Cancer. 2022 Nov;29(6):985-992. doi: 10.1007/s12282-022-01378-6. Epub 2022 Jun 22.
Male breast cancer (MBC) is rare; however, its incidence is increasing. There have been no large-scale reports on the clinicopathological characteristics of MBC in Japan.
We investigated patients diagnosed with breast cancer in the Japanese National Clinical Database (NCD) between January 2012 and December 2018.
A total of 594,316 cases of breast cancer, including 3780 MBC (0.6%) and 590,536 female breast cancer (FBC) (99.4%), were evaluated. The median age at MBC and FBC diagnosis was 71 (45-86, 5-95%) and 60 years (39-83) (p < 0.001), respectively. MBC cases had a higher clinical stage than FBC cases: 7.4 vs. 13.3% stage 0, 37.2 vs. 44.3% stage I, 25.6 vs. 23.9% stage IIA, 8.8 vs. 8.4% stage IIB, 1.9 vs. 2.4% stage IIIA, 10.1 vs. 3.3% stage IIIB, and 1.1 vs. 1.3% stage IIIC (p < 0.001). Breast-conserving surgery was more frequent in FBC (14.6 vs. 46.7%, p = 0.02). Axillary lymph node dissection was more frequent in MBC cases (32.9 vs. 25.2%, p < 0.001). Estrogen receptor(ER)-positive disease was observed in 95.6% of MBC and 85.3% of FBC cases (p < 0.001). The HER2-positive disease rates were 9.5% and 15.7%, respectively (p < 0.001). Comorbidities were more frequent in MBC (57.3 vs. 32.8%) (p < 0.001). Chemotherapy was less common in MBC, while endocrine therapy use was similar in ER-positive MBC and FBC. Perioperative radiation therapy was performed in 14.3% and 44.3% of cases.
Japanese MBC had an older age of onset, were more likely to be hormone receptor-positive disease, and received less perioperative chemotherapy than FBC.
男性乳腺癌（MBC）较为罕见，但发病率呈上升趋势。目前尚无日本 MBC 临床病理特征的大规模报告。
我们调查了 2012 年 1 月至 2018 年 12 月期间在日本国家临床数据库（NCD）中诊断为乳腺癌的患者。
共评估了 594316 例乳腺癌病例，其中包括 3780 例 MBC（0.6%）和 590536 例女性乳腺癌（FBC）（99.4%）。MBC 和 FBC 诊断的中位年龄分别为 71 岁（45-86 岁，5-95 岁）和 60 岁（39-83 岁）（p<0.001）。MBC 病例的临床分期高于 FBC 病例：0 期为 7.4%比 13.3%，I 期为 37.2%比 44.3%，IIA 期为 25.6%比 23.9%，IIB 期为 8.8%比 8.4%，IIIA 期为 1.9%比 2.4%，IIIB 期为 10.1%比 3.3%，IIIC 期为 1.1%比 1.3%（p<0.001）。FBC 中保乳手术更为常见（14.6%比 46.7%，p=0.02）。MBC 病例腋窝淋巴结清扫更为常见（32.9%比 25.2%，p<0.001）。MBC 中雌激素受体（ER）阳性疾病占 95.6%，FBC 中占 85.3%（p<0.001）。HER2 阳性疾病率分别为 9.5%和 15.7%（p<0.001）。MBC 中合并症更为常见（57.3%比 32.8%）（p<0.001）。MBC 中化疗较少，而 ER 阳性 MBC 和 FBC 中内分泌治疗的使用相似。围手术期放疗在 14.3%和 44.3%的病例中进行。
日本 MBC 的发病年龄较大，更可能为激素受体阳性疾病，且围手术期化疗少于 FBC。
