Center for Neural Engineering, Department of Engineering, Science and Mechanics, The Pennsylvania State University, Pennsylvania, United States of America.
Department of Surgery, Penn State Hershey College of Medicine and Milton S. Hershey Medical Center, Hershey, Pennsylvania, United States of America.
PLoS One. 2019 Nov 21;14(11):e0225039. doi: 10.1371/journal.pone.0225039. eCollection 2019.
The survival rates from breast cancer in Africa are poor and yet the incidence rates are on the rise. In this study, we hypothesized that, in Africa, a continent with great disparities in socio-economic status, race, tumor biology, and cultural characteristics, the survival rates from breast cancer vary greatly based on region, tumor biology (hormone receptor), gender, and race. We aimed to conduct the first comprehensive systematic review and meta-analysis on region, gender, tumor-biology and race-specific 5-year breast cancer survival rates in Africa and compared them to 20-year survival trends in the United States.
We searched MEDLINE, EMBASE, and Cochrane Library to identify studies on breast cancer survival in African published before October 17, 2018. Pooled 5-year survival rates of breast cancer were estimated by random-effects models. We explored sources of heterogeneity through subgroup meta-analyses and meta-regression. Results were reported as absolute difference (AD) in percentages. We compared the survival rates of breast cancer in Africa and the United States.
There were 54 studies included, consisting of 18,970 breast cancer cases. There was substantial heterogeneity in the survival rates (mean 52.9%, range 7-91%, I2 = 99.1%; p for heterogeneity <0.0001). Meta-regression analyses suggested that age and gender-adjusted 5-year survival rates were lower in sub-Saharan Africa compared to north Africa (AD: -25.4%; 95% CI: -34.9 - -15.82%), and in predominantly black populations compared to predominantly non-black populations (AD: -25.9%; 95% CI: 35.40 - -16.43%). Survival rates were 10 percentage points higher in the female population compared to male, but the difference was not significant. Progesterone and estrogen receptor-positive breast cancer subtypes were positively associated with survival (r = 0.39, p = 0.08 and r = 0.24, p = 0.29 respectively), but triple-negative breast cancer was negatively associated with survival. Survival rates are increasing over time more in non-black Africans (55% in 2000 versus 65% in 2018) compared to black Africans (33% in 2000 versus 40% in 2018); but, the survival rates for Africans are still significantly lower when compared to black (76% in 2015) and white (90% in 2015) populations in the United States.
Regional, sub-regional, gender, and racial disparities exist, influencing the survival rates of breast cancer in Africa. Therefore, region and race-specific public health interventions coupled with prospective genetic studies are urgently needed to improve breast cancer survival in this region.
非洲的乳腺癌存活率很低，但发病率却在上升。在这项研究中，我们假设，在非洲这个社会经济地位、种族、肿瘤生物学和文化特征差异巨大的大陆上，乳腺癌的存活率因地区、肿瘤生物学（激素受体）、性别和种族的不同而有很大的差异。我们旨在对非洲的乳腺癌 5 年生存率进行首次全面的系统综述和荟萃分析，并将其与美国 20 年的生存趋势进行比较。
我们检索了 MEDLINE、EMBASE 和 Cochrane Library，以确定截至 2018 年 10 月 17 日之前在非洲发表的关于乳腺癌生存的研究。采用随机效应模型估计乳腺癌 5 年总生存率。我们通过亚组荟萃分析和荟萃回归来探讨异质性的来源。结果以百分比的绝对差异（AD）表示。我们比较了非洲和美国的乳腺癌生存率。
共纳入 54 项研究，包括 18970 例乳腺癌病例。生存率存在很大的异质性（平均 52.9%，范围 7-91%，I2=99.1%；p<0.0001）。荟萃回归分析表明，与北非相比，撒哈拉以南非洲地区的年龄和性别调整后 5 年生存率较低（AD：-25.4%；95%CI：-34.9%至-15.82%），与以非黑人为主要人口的地区相比，以黑人为主要人口的地区生存率较低（AD：-25.9%；95%CI：35.40%至-16.43%）。女性的生存率比男性高 10 个百分点，但差异无统计学意义。孕激素和雌激素受体阳性乳腺癌亚型与生存率呈正相关（r=0.39，p=0.08；r=0.24，p=0.29），但三阴性乳腺癌与生存率呈负相关。与 2000 年相比，2018 年非黑人非洲人的生存率呈上升趋势（55%上升至 65%），而黑人非洲人的生存率呈下降趋势（33%下降至 40%）；但是，与美国的黑人（2015 年 76%）和白人（2015 年 90%）相比，非洲人的生存率仍然显著较低。
区域、次区域、性别和种族差异存在，影响着非洲乳腺癌的生存率。因此，迫切需要针对特定地区和种族的公共卫生干预措施，并结合前瞻性的遗传研究，以提高该地区的乳腺癌生存率。
