The impact of weight gain during adjuvant chemotherapy on survival in breast cancer.

Objective: Weight gain can be detected during adjuvant chemotherapy in breast cancer patients, leading to administration of lower drug doses than planned and a decrease in long-term survival. In this study, the effect of weight gain on survival in breast cancer patients was investigated.

Material and methods: Breast cancer patients treated with adjuvant chemotherapy between May 2002 and May 2003 were prospectively included in the study. Patients treated with neoadjuvant chemotherapy or with chemotherapy for metastatic disease were excluded from the study. Data regarding patients' demographic, clinical and pathologic characteristics and chemotherapy protocols were recorded. Patients were grouped as those with weight gain less than or more than 3 kg, and those with a body mass index of less than or more than 30. The impact of weight gain on patients' disease-free and overall survival was investigated. Log-rank test and Cox regression analyses were utilized for survival analyses. P<0.05 value was accepted as statistically significant.

Results: Eighty-eight consecutive female patients with a median age of 46 (29-71) were included in the study. Patients received anthracycline based chemotherapy protocols. Weight gain was detected in 79 patients (89.8%), with more than 3 kg weight gain detected in 38 patients (43.2%). In a median follow-up time of 98 months (62-120), distant metastases were detected in 21 patients (23.9%), and 11 patients (12.5%) died. Mean disease-free survival of patients with a weight gain less than and more than 3 kg during chemotherapy was 89.1±3.9 and 84.7±4.2 months (p=0.007), whereas mean overall survival was 95.6±2.2 and 92.5±2.1 months (p=0.01), respectively. Mean disease-free survival of patients with a body mass index less than and more than 30 was 87.3±2.3 and 85.1±3.6 months (p=0.4), whereas mean overall survival was 94.2±2.3 and 92.1±1.1 months (p=0.35), respectively.

Conclusion: Weight gain during adjuvant chemotherapy has a negative effect on both disease-free and overall survival in patients with breast cancer.