很少有研究调查了传统乳腺癌(BC)危险因素患病率的非洲土著人群中分子亚型的危险因素异质性。遗传背景,与欧洲祖先人群相比,环境暴露显示出明显的差异。
我们对从5组公众中招募的838例经病理证实的BC病例进行了仅病例分析,基于信仰,2012年3月至2015年5月,肯尼亚各地的私人机构。关键标志物(ER,PR,HER2,EGFR,进行CK5-6和Ki67)以定义亚型。在诊断时通过问卷收集危险因素数据。多变量logistic回归模型用于确定BC危险因素与肿瘤分子亚型之间的关联。根据临床特征和危险因素进行调整。
初潮和首次怀孕的中位年龄分别为14岁和21岁,中位儿童数为3,每个儿童母乳喂养时间为62个月.管腔A的分子亚型分布,管腔B,HER2富集,三阴性(TN)乳腺癌占34.8%,35.8%,10.7%,和18.6%,分别。在调整协变量后,与ER阳性肿瘤患者相比,ER阴性患者更可能有更高的奇偶校验(OR=2.03,95%CI=(1.11,3.72),p=0.021,比较≥5至≤2名儿童)。与腔A肿瘤患者相比,管腔B患者更可能具有较低的产次(OR=0.45,95%CI=0.23,0.87,p=0.018,与≥5至≤2名儿童相比);HER2富集患者在绝经时更不可能肥胖(OR=0.36,95%CI=0.16,0.81,p=0.013)或年龄较大(OR=0.38,95%CI=0.15,0.997,p=0.049).身体质量指数(BMI),无论是整体或更年期状态,不同的ER状态没有显著差异。总的来说,不同亚型的累计或平均母乳喂养时间没有显著差异.
在肯尼亚,我们发现与均等相关的危险因素和ER状态之间的关联与欧洲血统人群的观察结果一致,但与BMI和母乳喂养的关联不同。需要在癌症病因学研究中纳入不同的人群,以制定针对人群和亚型的风险预测/预防策略。
Few studies have investigated risk factor heterogeneity by molecular subtypes in indigenous African populations where prevalence of traditional breast cancer (BC) risk factors, genetic background, and environmental exposures show marked differences compared to European ancestry populations.
We conducted a case-only analysis of 838 pathologically confirmed BC cases recruited from 5 groups of public, faith-based, and private institutions across Kenya between March 2012 to May 2015. Centralized pathology review and immunohistochemistry (IHC) for key markers (ER, PR, HER2, EGFR, CK5-6, and Ki67) was performed to define subtypes. Risk factor data was collected at time of diagnosis through a questionnaire. Multivariable polytomous logistic regression models were used to determine associations between BC risk factors and tumor molecular subtypes, adjusted for clinical characteristics and risk factors.
The median age at menarche and first pregnancy were 14 and 21 years, median number of children was 3, and breastfeeding duration was 62 months per child. Distribution of molecular subtypes for luminal A, luminal B, HER2-enriched, and triple negative (TN) breast cancers was 34.8%, 35.8%, 10.7%, and 18.6%, respectively. After adjusting for covariates, compared to patients with ER-positive tumors, ER-negative patients were more likely to have higher parity (OR = 2.03, 95% CI = (1.11, 3.72), p = 0.021, comparing ≥ 5 to ≤ 2 children). Compared to patients with luminal A tumors, luminal B patients were more likely to have lower parity (OR = 0.45, 95% CI = 0.23, 0.87, p = 0.018, comparing ≥ 5 to ≤ 2 children); HER2-enriched patients were less likely to be obese (OR = 0.36, 95% CI = 0.16, 0.81, p = 0.013) or older age at menopause (OR = 0.38, 95% CI = 0.15, 0.997, p = 0.049). Body mass index (BMI), either overall or by menopausal status, did not vary significantly by ER status. Overall, cumulative or average breastfeeding duration did not vary significantly across subtypes.
In Kenya, we found associations between parity-related risk factors and ER status consistent with observations in European ancestry populations, but differing associations with BMI and breastfeeding. Inclusion of diverse populations in cancer etiology studies is needed to develop population and subtype-specific risk prediction/prevention strategies.