Introduction Studies suggest that good social support is associated with a reduction in post-treatment complications in breast cancer. The aim of this study is to evaluate the association between pre-treatment social support and early complications after surgery (pain and subjective symptoms related to early oedema in the upper limbs) in women with breast cancer.

Methods Participants were women with breast cancer and that presented to the Brazilian National Cancer Institute between June 2009 and March 2010. MOS-SSS was used to assessment of social support before oncology treatment. Information about early post-operative complications were obtained by physical examination 30 days after surgery and collected in a standardised form. Bivariate analysis between dichotomous outcome and selected independent variables were conducted and RRs with 95% CIs were presented.

Results 181 eligible women were studied. Patients with good emotional and affective support had a 76% (95% CI 0.10 to 0.57) reduced risk and 62% (0.12 to 0.64) reduced risk of pain respectively. Better material support was associated with a 73% (0.11 to 0.623) reduction in the risk of pain. No significant association with early oedema was observed.

Conclusions Good social support was associated with reduced risk of post-operative complications in women undergoing treatment for breast cancer.