Female breast cancer survivors who adhered to a 12-month weight-loss intervention program that used telephone-based counseling were able to lose an average of 7.6% of body weight, but a similarly clinically meaningful mark was not met by colorectal cancer survivors, according to findings from a phase 2 feasibility study published in Obesity.
“A growing body of observational data suggests that higher BMI at diagnosis and following treatment is associated with poorer prognosis for breast cancer and possibly for colorectal cancer,” Heather Greenlee, PhD, adjunct associate professor of clinical epidemiology at the Mailman School of Public Health, Columbia University, and colleagues wrote. “It is problematic to use observational data to examine the effects of postdiagnosis changes in weight on cancer outcomes, as few people effectively achieve and maintain weight loss following a cancer diagnosis, and it is difficult to distinguish between unintentional and intentional weight loss.”
Fifty women with BMI greater than 25 kg/m2 were recruited from nine medical centers in the U.S. from August 2012 to June 2014. Twenty-six were breast cancer survivors (mean age, 57.3 years; mean BMI, 37.2 kg/m2), and 24 were survivors of colorectal cancer (mean age, 64.4 years; mean BMI, 31.8 kg/m2).
Each participant was given a pedometer to record physical activity levels as well as a 12-month gym membership. In addition, during the 12-month study, each participant received 14 40-minute behavioral counseling sessions via telephone.
Participants were asked to increase physical activity by taking part in 30-minute exercise programs at least three times per week while walking at an elevated pace 60 minutes per week. Participants were also given a dietary goal of reducing caloric intake by 500 kcal per day along with eating fruits and vegetables. Follow-up examinations were conducted at 6 and 12 months after enrollment.
At the end of the study, the researchers reported an average weight loss of 7.6% for breast cancer survivors (95% CI, –3.9 to 19.2). The breast cancer survivors also decreased caloric intake by 502 kcal per day and increased physical activity time to 242 minutes per week. For those who adhered to the dietary goal (n = 14), average weight loss was 8.9% (95% CI, –3.7% to 21.5), and for those who adhered to the exercise goal (n = 7), the average weight loss was 9.9% (95% CI, –4.7 to 24.6).
In the colorectal cancer survivor group, the researchers found an average weight loss of 2.5% (95% CI, –8.2 to 13.3). An average decrease in caloric intake of 452 kcal per day and an average increase in physical activity of 70 minutes per week were also reported. Average weight loss for the 15 participants who adhered to the dietary goal was 1.8% (95% CI, –9.8 to 13.4). Only four participants in this group adhered to the exercise goal, and they averaged 4.8% weight loss (95% CI, –8.2 to 17.9).
“Compared to [breast cancer] survivors, it was more difficult to recruit [colorectal cancer] survivors, as they were older, had more uncontrolled comorbidities and were less likely to have overweight and as there were fewer numbers of patients available to be screened,” the researchers wrote. “This difference may have been due to underlying differences in patient clinical characteristics … or to differences in patient preferences.” – by Phil Neuffer
Disclosures: The authors report no relevant financial disclosures.