Regional, racial, gender, and tumor biology disparities in breast cancer survival rates in Africa: A systematic review and meta-analysis

Abstract

BackgroundThe 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.MethodsWe 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.FindingsThere 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.ConclusionRegional, 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.

Breast cancer subtypes: implications for the treatment and survival of patients in Africa—a prospective cohort study from Mozambique

“…Despite the fact that we included patients from the three largest hospitals in Mozambique, detailed follow-up data were only available for patients treated at the MCH. Yet, this single-centre subcohort is similar to other African series in terms of young age at diagnosis, 40 high prevalence of HIV infection, 15 long delays between symptoms and diagnosis 41 and a large proportion of stage III/IV. 3 The limited staging options available (chest X-ray and abdominal ultrasound) may have led to an underestimation of the real incidence of stage IV disease, which may partly explain the low survival of our patients.…”

Coffee Consumption and Its Inverse Relationship with Gastric Cancer: An Ecological Study

“…Certain confounding factors such as diet, lifestyle (consumption of fruits, vegetables, red meat, salt, cigarettes, and alcohol, and physical activity), socioeconomic status, place of residence, race, health insurance, and Helicobacter pylori infection have been shown to play paramount roles in gastric cancer development [ 31 , 32 , 33 , 34 , 35 ]. Conversely, the data available for our ecological analysis were based on population-level information and were insufficient to propose a multilevel analysis.…”

Incidence, risk factors and outcomes of early postoperative hyperglycemia in surgical patients: a protocol for a systematic review and meta-analysis

“…When abstracts and subsequently included papers are not available in English, translators will be sought. Using the format of the standard data extraction form that has been validated and used somewhere, [19] we will extract the following information: first author, country in which the study was conducted, year of publication, study period, research methodology, total sample size using study level median age, year of publication, study level gender proportions, proportion of type 2 diabetes, mean body mass index, American Society of Anesthesiologists and type of surgical procedure and study limitations. Data will be extracted independently by two authors (JAL, AES).…”