Histological and Immunohistochemical Characteristics for Hereditary Breast Cancer Risk in a Cohort of Brazilian Women

Abstract Objective The study aimed to characterize the clinical, histological, and immunohistochemical profile of women with invasive breast cancer, according to the risk for Hereditary Predisposition Breast and Ovarian Cancer Syndrome in a Brazilian population. Methods This is a retrospective study performed from a hospital-based cohort of 522 women, diagnosed with breast cancer treated at an oncology referral center in the Southeast region of Brazil, between 2014 and 2016. Results Among the 430 women diagnosed with invasive breast cancer who composed the study population, 127 (29.5%) were classified as at increased risk for hereditary predisposition to breast and ovarian cancer syndrome. There was a lower level of education in patients at increased risk (34.6%) when compared with those at usual risk (46.0%). Regarding tumor characteristics, women at increased risk had higher percentages of the disease diagnosed at an advanced stage (32.3%), and with tumors > 2cm (63.0%), with increased prevalence for both characteristics, when compared with those at usual risk. Furthermore, we found higher percentages of HG3 (43.3%) and Ki-67 ≥ 25% (64.6%) in women at increased risk, with prevalence being about twice as high in this group. The presence of triple-negative tumors was observed as 25.2% in women at increased risk and 6.0% in women at usual risk, with the prevalence of absence of biomarkers being 2.5 times higher among women in the increased risk group. Conclusion From the clinical criteria routinely used in the diagnosis of breast cancer, the care practice of genetic counseling for patients at increased risk of hereditary breast cancer in contexts such as Brazil is still scarce.

【摘要 研究目的】本研究旨在针对巴西人群中，依据遗传性乳腺癌-卵巢癌综合征（Hereditary Predisposition Breast and Ovarian Cancer Syndrome）风险分层的浸润性乳腺癌女性患者，明确其临床、组织学及免疫组化特征。
【研究方法】本研究为回顾性医院队列研究，纳入2014年至2016年间在巴西东南部某肿瘤转诊中心接受治疗的522名乳腺癌确诊女性患者。
【研究结果】本研究最终纳入的研究人群为430名浸润性乳腺癌确诊女性，其中127例（29.5%）被归类为遗传性乳腺癌-卵巢癌综合征高风险人群。与普通风险人群相比，高风险人群的受教育程度偏低（高风险组低学历占比34.6%，普通风险组为46.0%）。在肿瘤特征方面，高风险组患者的晚期诊断比例（32.3%）及肿瘤直径＞2cm的比例（63.0%）均高于普通风险组，两项特征的患病率均更高。此外，高风险组的组织学分级Ⅲ级（HG3）患者占比（43.3%）及Ki-67指数≥25%的患者占比（64.6%）均更高，该组的两项指标患病率约为普通风险组的2倍。三阴性乳腺癌（triple-negative tumors）在高风险组中的占比为25.2%，普通风险组仅为6.0%；高风险组缺乏生物标志物的患病率是普通风险组的2.5倍。
【研究结论】基于乳腺癌诊断中常规使用的临床标准，在巴西这类地区，针对遗传性乳腺癌高风险人群的遗传咨询服务实践仍较为匮乏。