Survival rates of breast cancer and predictive factors: a hospital-based study from western Amazon area in Brazil / Sobrevida do câncer de mama e fatores preditivos: um estudo de base hospitalar do oeste amazônico, Brasil

ABSTRACT

Abstract Breast cancer survival in Latin America countries is below Central European countries. Hospital-based breast cancer survival studies in western Amazon, Brazil, are lacking. This article aims to estimate hospital-based breast cancer survival in Rio Branco, Acre, and predictor factors. Hospital-based cohort study of all women diagnosed with breast cancer (2007-2012) was proceeded. Information were obtained from medical reports, and follow-up was until 2013. One-, 2- and 5- years breast cancer specific-survival were estimated by Kaplan-Meier method. Crude and adjusted Harzards Ratios (HR) were estimated by proportional Cox regression model. One-, 2-, and 5-year overall breast cancer survival were 95.5%, 83.7%, and 87.3% respectively. Surgery combined to radiotherapy significantly affected 1-, 2-, and 5-year survival (99%, 94%, and 90.6%, respectively) as compared to other treatments (77%,57.1%, and 37.5%, respectively). Comparing to surgery combined to radiotherapy treatment, surgery alone increased the risk of death, independently of age and stage (HR = 7.23;95%CI2.29-22.83). In Rio Branco, Acre, 5-year breast cancer survival is similar to more developed areas in Brazil. Surgery combined to radiotherapy was independently associated to a lower risk of death as compared to surgery alone and other treatment.

RESUMO

Resumo Na América Latina, a sobrevida de 5 anos do câncer de mama está abaixo dos países da Europa central. Não há estudos de sobrevida de câncer de mama de base hospitalar no oeste da Amazônia brasileira. O objetivo deste artigo é estimar a sobrevida hospitalar de câncer de mama e fatores associados em Rio Branco, Acre. Estudo de coorte de base hospitalar com todos os casos de câncer de mama diagnosticados em Rio Branco (2007-2012). As informações foram obtidas de prontuários. As sobrevidas específicas para câncer de mama foram estimadas para 1, 2, e 5 anos pelo método de Kaplan Meier. As hazards ratios (HR) brutas e ajustadas foram estimadas pela regressão proporcional de Cox. As sobrevidas globais em 1, 2 e 5 anos foram respectivamente 95,5%, 83,7%e 87,3%. A cirurgia combinada à radioterapia afetou significativamente a sobrevida em 1, 2 e 5 anos (99%, 94% e 90,6%, respectivamente) quando comparadas a outros tratamentos (77%, 57,1% e 37,5%, respectivamente). Comparadas à cirurgia combinada, as mulheres submetidas à cirurgia isolada apresentaram maior risco de óbito, independentemente da idade e estadiamento (HR = 7,23; 95%CI2,29-22,83). Em Rio Branco, Acre, a sobrevida em 5 anos para câncer de mama foi elevada. A cirurgia combinada à radioterapia foi independentemente associada ao menor risco de óbito.