Stage at diagnosis and stage-specific survival of breast cancer in Latin America and the Caribbean: A systematic review and meta-analysis.

Lívia Lovato Pires De Lemos,Mariangela Leal Cherchiglia,Paulo Henrique Ribeiro Fernandes Almeida,Augusto Afonso Guerra,Mirian Carvalho De Souza,Brian Godman,Daniela Pena Moreira,Stéphane Verguet,Hajo Zeeb

doi:10.1371/journal.pone.0224012

Abstract

BackgroundFemale breast cancer is the most common cancer in Latin American and Caribbean (LAC) countries and is the leading cause of cancer deaths. The high mortality-to-incidence ratio in the regions is associated with mainly the high proportion of advanced stage diagnosis, and also to inadequate access to health care. In this study we aimed to systematically review the proportion of advanced stage (III-IV) at diagnosis (pas) and the five-year stage-specific survival estimates of breast cancer in LAC countries.MethodsWe searched MEDLINE, Embase, and LILACS (Latin American and Caribbean Health Science Literature) to identify studies, in any language, indexed before Nov 5, 2018. We also conducted manual search by reviewing citations of papers found. pas was summarized by random effects model meta-analysis, and meta-regression analysis to identify sources of variation. Stage-specific survival probabilities were described as provided by study authors, as it was not possible to conduct meta-analysis. PROSPERO CRD42017052493.ResultsFor pas we included 63 studies, 13 of which population-based, from 22 countries comprising 221,255 women diagnosed from 1966 to 2017. The distribution of patients by stage varied greatly in LAC (pas 40.8%, 95%CI 37.0% to 44.6%; I2 = 99%; p<0.0001). The heterogeneity was not explained by any variable included in the meta-regression. There was no difference in pas among the Caribbean (pas 43.0%, 95%CI 33.1% to 53.6%), Central America (pas 47.0%, 95%CI 40.4% to 53.8%) and South America (pas 37.7%, 95%CI 33.1% to 42.5%) regions. For 5-year stage-specific survival we included 37 studies, comprising 28,988 women from ten countries. Seven of these studies were included also for pas. Since we were unable to adjust for age, comparability between countries and regions was hampered, and as expected, the results varied widely from study to study.ConclusionsLAC countries should look to address concerns with early detection and diagnosis of breast cancer, and wherever viable implement screening programs and to provide timely treatment.

Highlights

In 2018, of the 18 million new cancer cases diagnosed, female breast cancer was the second most frequent, corresponding to 11% of all cancer cases
The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
We evaluated three domains: selection bias, information bias, and other factors related to stage at diagnosis/survival analysis, such as age and tumor grade, with more value given to selection and information bias items

Summary

Introduction

In 2018, of the 18 million new cancer cases diagnosed, female breast cancer was the second most frequent, corresponding to 11% of all cancer cases. In Latin America and the Caribbean (LAC) breast cancer was the most common and the leading cause of cancer related death among women [1]. This pattern was observed previously [2] and is likely to continue in the coming decades. Despite most LAC countries being classified as upper-middle or high-income by the World Bank [4], social inequality and disparities are is still high in the region [5] This corroborates the relative high mortality-to-incidence ratio of breast cancer observed, as the relationship between low socioeconomic status and poor breast cancer outcomes is well-established [6]. In this study we aimed to systematically review the proportion of advanced stage (III-IV) at diagnosis (pas) and the five-year stage-specific survival estimates of breast cancer in LAC countries

Objectives

Results

Conclusion