Abstract: Objective To investigate the influence of weight changes during adjuvant therapy on the prognosis of breast cancer patients after operation.
Methods The clinical data of 186 cases with breast cancer were collected. According to the weight change during adjuvant therapy, 186 patients were divided into 3 groups: weight loss group, weight stable group and weight gain group. The clinicopathological characteristics were analyzed among groups. Log-rank test and Cox proportional hazard model analysis were preformed to make univariate and multivariate analysis on diseasefree survival（DFS）. Results Weight change was associated with age，body mass index，radiotherapy，clinical stage，smoking and gastrointestinal reaction. Univariate analysis showed that weight change was associated with DFS and Cox proportional hazard model analysis showed that during adjuvant therapy weight gain was an independent prognostic factor associated with poorer clinical outcomes in breast cancer patients（χ2=12.107，P=0.002）. Conclusion Weight change during adjuvant therapy was an independent negative prognostic factor for DFS in breast cancer patients. Therefore, maintaining normal weight may contribute to the prevention of breast cancer.