Search citation statements
Paper Sections
Citation Types
Year Published
Publication Types
Relationship
Authors
Journals
Even as breast cancer incidence and mortality have steadily increased throughout the low-and middle-income world, full descriptions of typical patient outcomes have been lacking. 1 Limenih et al 2 should be commended for preparing a comprehensive and carefully designed systematic review and meta-analysis summarizing overall survival patterns among patients with breast cancer living in sub-Saharan Africa (SSA), the world's poorest region. Synthesizing data from 49 studies, they estimate that the regionwide survival for patients newly diagnosed with breast cancer at 1 year is 79%; at 3 years, 56%; and at 5 years, 40%. They also demonstrate a pattern of improving survival over time and with increasing development. Estimated 5-year survival reached 46% to 47% in studies conducted after 2014 compared with just 24% to 26% in those conducted earlier. Five-year survival also steadily increased as countries moved up the ladder on the United Nations Development Programme's human development index (HDI), with estimates of 36% for countries with low HDI, 46% for those with middle HDI, and 54% for those with high HDI.Use of individual cohort study data yields a more complete picture of breast cancer survival in SSA than prior efforts that relied on more official datasets, such as national cancer registries. Less than half of SSA nations maintain a national cancer registry and participate in the African Cancer Registry Network, depriving researchers of a standardized and comprehensive source of local incidence and mortality data. 3 The CONCORD-3 study, for instance, only presented data from 3 SSA countries: South Africa, Nigeria, and Mauritius. 4 Even under the strict data standards applied by the CONCORD Working Group, national cancer registry data from SSA can also be incomplete and yield implausible results (eg, >95% 5-year survival for Nigerian women with breast cancer).The individual studies that Limenih et al 2 captured in their meta-analysis show a remarkable degree of heterogeneity, with the I 2 values from the 1-to 5-year survival estimates ranging from 94% to 96% and individual studies included in the 5-year survival meta-analysis reporting rates between 9% and 79%. Some of this heterogeneity could be artifactual, a byproduct of disparities in data and research quality. High-quality epidemiologic work with long-term participant follow-up is expensive and time-consuming. Even in the best of circumstances, reliance on medical record review alone leads to frequent loss to follow-up, and participants with poorer outcomes may account for a disproportionate share of missing data. It is encouraging that, while controlling for year and HDI, the authors found an association between higher-quality studies and longer survival. That finding provides some evidence against concerns that missing data and loss to follow-up have produced an overly optimistic picture of breast cancer survival in SSA. Such a range of outcomes is not necessarily surprising in a region comprising 46 countries with national per capita gross domestic produ...
Even as breast cancer incidence and mortality have steadily increased throughout the low-and middle-income world, full descriptions of typical patient outcomes have been lacking. 1 Limenih et al 2 should be commended for preparing a comprehensive and carefully designed systematic review and meta-analysis summarizing overall survival patterns among patients with breast cancer living in sub-Saharan Africa (SSA), the world's poorest region. Synthesizing data from 49 studies, they estimate that the regionwide survival for patients newly diagnosed with breast cancer at 1 year is 79%; at 3 years, 56%; and at 5 years, 40%. They also demonstrate a pattern of improving survival over time and with increasing development. Estimated 5-year survival reached 46% to 47% in studies conducted after 2014 compared with just 24% to 26% in those conducted earlier. Five-year survival also steadily increased as countries moved up the ladder on the United Nations Development Programme's human development index (HDI), with estimates of 36% for countries with low HDI, 46% for those with middle HDI, and 54% for those with high HDI.Use of individual cohort study data yields a more complete picture of breast cancer survival in SSA than prior efforts that relied on more official datasets, such as national cancer registries. Less than half of SSA nations maintain a national cancer registry and participate in the African Cancer Registry Network, depriving researchers of a standardized and comprehensive source of local incidence and mortality data. 3 The CONCORD-3 study, for instance, only presented data from 3 SSA countries: South Africa, Nigeria, and Mauritius. 4 Even under the strict data standards applied by the CONCORD Working Group, national cancer registry data from SSA can also be incomplete and yield implausible results (eg, >95% 5-year survival for Nigerian women with breast cancer).The individual studies that Limenih et al 2 captured in their meta-analysis show a remarkable degree of heterogeneity, with the I 2 values from the 1-to 5-year survival estimates ranging from 94% to 96% and individual studies included in the 5-year survival meta-analysis reporting rates between 9% and 79%. Some of this heterogeneity could be artifactual, a byproduct of disparities in data and research quality. High-quality epidemiologic work with long-term participant follow-up is expensive and time-consuming. Even in the best of circumstances, reliance on medical record review alone leads to frequent loss to follow-up, and participants with poorer outcomes may account for a disproportionate share of missing data. It is encouraging that, while controlling for year and HDI, the authors found an association between higher-quality studies and longer survival. That finding provides some evidence against concerns that missing data and loss to follow-up have produced an overly optimistic picture of breast cancer survival in SSA. Such a range of outcomes is not necessarily surprising in a region comprising 46 countries with national per capita gross domestic produ...
Blood lipids are associated with breast cancer. An increasing number of reports have attempted to explore the genetic connection between blood lipids and the risk of developing breast cancer. However, observational studies can be affected by confounding factors and reverse causation, which can compromise the reliability of the findings. We used univariate and multivariable two-sample mendelian randomization to explore the causal association between blood lipids and breast cancer. Summary-level data for lipid traits were obtained from the Africa Wits-INDEPTH partnership for Genomic Research (AWI-Gen) (N= 10,603, 58.5% of women). For breast cancer, we leveraged summary statistics from the most comprehensive Genome-wide Association Studies (GWAS) on breast cancer consisting of 18,034 cases and 22,104 controls of women of African ancestry. Our analysis suggests that genetically predicted triglycerides had a potential protective effect on breast carcinoma (OR = 0.73, 95% CI = 0.56, 0.95, FDR = 0.001). We found no evidence that genetically elevated levels of TC, HDL, and LDL may be associated with the risk of breast cancer TC (OR = 1.04; 95% CI, 0.93, 1.18; FDR = 0.029); HDL (OR = 1.29, 95% CI = 0.93, 1.79, FDR = 0.008); LDL (OR = 1.04, 95% CI = 0.90, 1.20, FDR = 0.036). Multivariate mendelian randomization analysis, which adjusted for the effects of TG, TC, LDL, and HDL, attenuated the observation of TG and breast cancer and also found no relationship between TC, HDL, LDL, and breast cancers. Furthermore, there was no evidence for a causal association between lipid traits and breast cancer subtypes. Our findings were robust in several sensitivity analyses. This study provides strong evidence that circulating TG may be associated with a decreased risk of breast cancer, while TC, LDL and HDL may not be related to the risk of breast cancer among African women.
Backgrounds Blood lipids are associated with breast cancer. An increasing number of reports have attempted to explore the genetic connection between blood lipids and the risk of developing breast cancer. However, observational studies can be affected by confounding factors and reverse causation, which can compromise the reliability of the findings. Methods We used univariate and multivariable two-sample mendelian randomization to explore the causal association between blood lipids and breast cancer. Summary-level data for lipid traits were obtained from the Africa Wits-INDEPTH partnership for Genomic Research (AWI-Gen) (N = 10,603, 58.5% of women). For breast cancer, we leveraged summary statistics from the most comprehensive Genome-wide Association Studies (GWAS) on breast cancer consisting of 18,034 cases and 22,104 controls of women of African ancestry. Results Our analysis suggests that genetically predicted triglycerides had a potential protective effect on breast carcinoma (OR = 0.73, 95% CI = 0.56, 0.95, FDR = 0.001). We found no evidence that genetically elevated levels of TC, HDL, and LDL may be associated with the risk of breast cancer TC (OR = 1.04; 95% CI, 0.93, 1.18; FDR = 0.029); HDL (OR = 1.29, 95% CI = 0.93, 1.79, FDR = 0.008); LDL (OR = 1.04, 95% CI = 0.90, 1.20, FDR = 0.036). Multivariate mendelian randomization analysis, which adjusted for the effects of TG, TC, LDL, and HDL, attenuated the observation of TG and breast cancer and also found no relationship between TC, HDL, LDL, and breast cancers. Furthermore, there was no evidence for a causal association between lipid traits and breast cancer subtypes. Our findings were robust in several sensitivity analyses. Conclusions This study provides strong evidence that circulating TG may be associated with a decreased risk of breast cancer, while TC, LDL and HDL may not be related to the risk of breast cancer among African women. Our findings align with both observational and MR studies conducted in European populations. However, in contrast to our results, some studies suggest that TG, LDL, and HDL may increase breast cancer risk in Europeans, indicating potential ethnic differences in the lipid profiles of breast cancer patients.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.