Department of Surgery, Iwakuni Clinical Center, Yamaguchi, Japan.
Department of Gastroenterological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, 700-8558, Okayama, Japan.
Breast Cancer. 2019 May;26(3):359-364. doi: 10.1007/s12282-018-0931-z. Epub 2018 Nov 16.
Lynch syndrome (LS) is a predominantly inherited syndrome caused by a pathological germline mutation in one of the mismatch repair (MMR) genes. Whether breast cancer (BC) is one of the LS-associated tumors is controversial. The aim of this retrospective cohort study was to evaluate the clinical features of BC in Japanese patients with LS.
Of 38 mutation carriers, 4 females with BC were examined in this study.
Two of the four patients had multiple BC. Their median age at the diagnosis of BC was 63 (range, 47-84) years. The TNM (6th revision) stages of the six BCs were as follows: stage I, 33% (2/6); stage IIA, 50% (3/6); and stage IIB, 17% (1/6). Histological examination revealed four scirrhous, one papillotubular, and one medullary carcinoma. The positive ratios for estrogen receptor (ER), progesterone receptor (PgR), and human epidermal growth receptor 2 (HER2) were 83.3% (5/6), 83.3% (5/6), and 16.7% (1/6), respectively. Two of the three specimens showed MSI-H and one showed MSS. These MSI-H BCs had tumor-infiltrating lymphocytes. Two of the three specimens showed an absence of MLH1 and PMS2 proteins on immunohistochemistry. The cumulative risks for a person with LS to develop BC were 4.35% at the age of 50 years, 8.70% at 60 years, and 21.5% at 70 years.
Our study results showed BC in Japanese females with LS to be an MSI-H tumor, which was ER and PgR positive and HER2 negative.
林奇综合征（LS）主要是由错配修复（MMR）基因之一的病理性种系突变引起的遗传性综合征。乳腺癌（BC）是否为 LS 相关肿瘤之一存在争议。本回顾性队列研究的目的是评估日本 LS 患者的 BC 临床特征。
在 38 名突变携带者中，本研究检查了 4 名患有 BC 的女性。
4 名患者中有 2 名患有多发性 BC。BC 的诊断中位年龄为 63 岁（范围，47-84 岁）。6 例 BC 的 TNM（第 6 版）分期如下：Ⅰ期，33%（2/6）；ⅡA 期，50%（3/6）；ⅡB 期，17%（1/6）。组织学检查显示 4 例硬癌、1 例乳管内乳头状癌和 1 例髓样癌。雌激素受体（ER）、孕激素受体（PgR）和人表皮生长因子受体 2（HER2）的阳性率分别为 83.3%（5/6）、83.3%（5/6）和 16.7%（1/6）。3 个标本中的 2 个显示 MSI-H，1 个显示 MSS。这些 MSI-H BC 有肿瘤浸润淋巴细胞。3 个标本中有 2 个免疫组化显示 MLH1 和 PMS2 蛋白缺失。LS 患者发生 BC 的累积风险在 50 岁时为 4.35%，60 岁时为 8.70%，70 岁时为 21.5%。
我们的研究结果表明，日本 LS 女性的 BC 是一种 MSI-H 肿瘤，ER 和 PgR 阳性，HER2 阴性。
