RESUMO
This study aimed to verify the prevalence of low social support (LSS) and associated factors in women submitted to breast cancer (BC) treatment. A cross-sectional study was carried out with 101 female residents of the municipality of Natal (Northeast Brazil), diagnosed with BC and submitted to oncological treatment. Data collection took place between July/2015 and May/2016 from medical records and individuals' interviews, and from the Medical Outcome Study-Social Support Survey. Descriptive, bivariate and multivariate statistics were carried out through Poisson's regression with robust variance and significance level 0.05. Prevalence of LSS in women with BC was 22.8% with confidence interval 14.6-39.94. Type of access to public services (p < .03), prevalence ratio (PR) 1.84 and negative self-rated health (p < .001), PR 4.47 were associated with LSS. These results were obtained after adjustments by the variables age and presence of chronic diseases. The associations established herein could have been mostly related to fragilities of the Brazilian health system, and can contribute to the planning of actions directed to the studied population.