Breast Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
Biostatistics Service, Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
Breast Cancer Res Treat. 2022 Jul;194(1):137-148. doi: 10.1007/s10549-022-06532-4. Epub 2022 Apr 29.
Lobular carcinoma in situ (LCIS) confers increased cancer risk in either breast, but it remains unclear if this population is at increased risk for bilateral breast cancer (BC) development. Here we report bilateral BC incidence among women with a history of LCIS.
Women with classic-type LCIS diagnosed from 1980 to 2017 who developed unilateral BC (UBC) or bilateral BC were identified. Bilateral BC was categorized as synchronous (bilateral BC diagnosed < 6 months apart; SBBC) or metachronous (bilateral BC diagnosed ≥ 6 months apart; MBBC). Five-year incidence rates of bilateral BC among this population were evaluated. Comparisons were made to identify factors associated with bilateral BC.
At 7 years' median follow-up, 249/1651 (15%) women with LCIS developed BC; 34 with bilateral BC (2%). There were no clinicopathologic feature differences between those with UBC and bilateral BC. SBBC occurred in 18 without significant differences versus UBC. Among 211 with UBC and a contralateral breast at risk, 16 developed MBBC at a median follow-up of 3 years. MBBC patients were less likely to receive endocrine therapy and more likely to receive chemotherapy versus UBC. Tumor histology was not associated with MBBC. Estimated 5-year MBBC risk was 6.4%. Index estrogen/progesterone receptor positivity and endocrine therapy were the only factors associated with MBBC risk.
Bilateral BC occurred in 2% of women with LCIS history at median follow-up of 7 years. Similar to the general BC population, a decrease in MBBC is seen among women with a history of LCIS who develop hormone receptor-positive disease and those who receive endocrine therapy, highlighting the protective effects of this treatment.
小叶原位癌（LCIS）会增加双侧乳腺癌（BC）的发病风险，但目前尚不清楚这一人群是否存在双侧乳腺癌发展的风险增加。本研究报告了有 LCIS 病史的女性发生双侧乳腺癌的发病率。
本研究纳入了 1980 年至 2017 年期间诊断为经典型 LCIS 且发生单侧 BC（UBC）或双侧 BC 的女性。双侧 BC 分为同步性（双侧 BC 在 6 个月内诊断；SBBC）或异时性（双侧 BC 在 6 个月以上诊断；MBBC）。评估了该人群中双侧 BC 的 5 年发病率，并比较了其与双侧 BC 相关的因素。
在中位随访 7 年时，1651 例 LCIS 患者中有 249 例（15%）发生了 BC，其中 34 例（2%）为双侧 BC。与 UBC 患者相比，双侧 BC 患者的临床病理特征无显著差异。SBBC 患者与 UBC 患者相比，无明显差异。在 211 例发生 UBC 且对侧乳房有风险的患者中，16 例在中位随访 3 年后发生了 MBBC。与 UBC 患者相比，MBBC 患者接受内分泌治疗的可能性较小，而接受化疗的可能性较大。肿瘤组织学与 MBBC 无相关性。MBBC 的估计 5 年风险为 6.4%。指数雌激素/孕激素受体阳性和内分泌治疗是与 MBBC 风险相关的唯一因素。
在中位随访 7 年后，有 LCIS 病史的女性中有 2%发生了双侧 BC。与一般 BC 人群相似，在发生激素受体阳性疾病和接受内分泌治疗的 LCIS 病史女性中，MBBC 的发生率有所下降，这突出了这种治疗的保护作用。
