The effect of psychosocial factors on breast cancer outcome: a systematic review

INTRODUCTION: We sought to review the available evidence regarding the effect of psychosocial factors on the survival of breast cancer patients. METHODS: We systematically searched the PubMed and PsycINFO databases to identify relevant studies. RESULTS: We identified 31 studies examining the association of various psychosocial parameters with overall breast cancer survival/disease free survival and 6 studies examining whether psychological intervention influences the disease outcome. Of the 31 studies summarized in this overview, 25 (80.6%) showed a statistically significant association between at least one psychosocial variable and disease outcome. Parameters associated with better breast cancer prognosis are social support, marriage, and minimizing and denial, while depression and constraint of emotions are associated with decreased breast cancer survival; however, the role of these factors has not been verified in all studies. CONCLUSION: Most of the studies show a significant relationship between psychosocial factors and survival, but the actual psychosocial variables related to survival are not consistently measured across studies and the findings for many of the psychosocial variables with survival/recurrence are not consistent across studies. Thus, more research is warranted regarding the role of social support, marriage, minimizing and denial, depression and constraint of emotions on breast cancer survival.