Factors associated with weight gain in women with breast cancer during adjuvant chemotherapy
Creators: name: Kutynec, Cheri Lee
Publisher: name: University of British Columbia
Year: 2009

description: Breast cancer is second to lung cancer as the leading cause of cancer deaths for Canadian women, and is responsible for the greatest number of years of life lost. Most women with newly diagnosed early stage disease will be offered surgery and adjuvant chemotherapy or radiation therapy as curative treatment. Although chemotherapy will be an important part of these patients' care, the tendency for breast cancer patients to gain weight with some forms of adjuvant chemotherapy has been reported over the past two decades. In addition to the body image concerns and possible health risks related to weight gain, an association between increased weight and earlier disease recurrence has been reported. The main purpose of this prospective study was to determine if weight gain occurs in premenopausal women who receive adjuvant chemotherapy using Adriamycin and cyclophosphamide (AC) or radiation therapy, from baseline to completion of treatment at 12 weeks. A secondary purpose was to measure the major factors associated with energy balance, including energy intake, resting energy expenditure (REE) and physical activity. Body composition was also measured, using dual energy x-ray absorptiometry (DEXA), to describe the total and regional changes in lean and fat mass. Nineteen women completed the study, including nine women treated with four 21-day cycles of chemotherapy, and 10 women treated with radiation therapy who served as a comparison group. Statistical analysis using repeated measures ANOVA revealed that women in both groups had no weight change, from pre- to post-treatment. There were however significant changes in body composition for both treatment groups. All women in the study experienced a decrease in total lean mass (p=0.05) and lean mass in the leg region (p=0.02), an increase in percent body fat (p=0.04), and a trend for a gain in fat mass in the trunk region (p=0.08). In addition, there was a significant difference in the pattern of change in bone mass between groups from pre- to post-treatment (p=0.04). Women treated with chemotherapy tended to decrease bone mass (/?=0.14), whereas there was a tendency for women treated with radiation therapy to increase bone mass, from pre- to post-treatment (p=0.\5). There were no statistically significant differences between groups in any of the factors associated with energy balance. There were however trends for an increase in total energy expenditure (p=0.08) in both groups, and for a different pattern of change in carbohydrate intake between groups from pre- to post-treatment (/&gt;=0.08). Women treated with chemotherapy tended to decrease carbohydrate intake, whereas there was a tendency for women treated with radiation therapy to increase carbohydrate intake, from pre- to post-treatment. Overall, the results of the study suggest that a shorter chemotherapy regimen using AC which uses a fewer number of antineoplastic agents and number of treatments than most protocols does not result in weight gain in premenopausal women with early stage breast cancer. Future research is recommended to investigate the loss of lean body mass in all women, with emphasis on more precise methods to measure physical activity, such as doubly labeled water. Furthermore, the tendency for bone loss in women treated with chemotherapy who experienced treatment-induced menopause requires further study to determine if there are any long-term consequences.