A telephone-based lifestyle intervention can have a significant effect on weight loss in overweight breast cancer survivors, according to a study that also highlights the dilemmas of funding large lifestyle trials with definitive mortality endpoints.
Mean weight loss at 6 months was greater in women who received telephone-based coaching and were mailed health information vs. women who received mailed information only (5.3% vs. 0.7%; P less than .001), investigators reported online June 16 in the Journal of Clinical Oncology. The study was part of the multicenter LISA(Lifestyle Intervention Study in Adjuvant Treatment of Early Breast Cancer) trial.
At 24 months the weight loss still compared favorably in the intervention group (3.6% loss vs. 0.4% in the mail-only group; P less than .001), reported Dr. Pamela J. Goodwin of the Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, and her associates (J. Clin. Oncol. 2014 June 16 [doi: 10.1200/JCO.2013.53.1517].
But will losing weight improve breast cancer outcomes?
The original aim of LISA was to examine the effect of weight loss on disease-free survival, but patient accrual was terminated early (at 338 of the 2,150 planned participants), because of a loss of funding from sponsor Novartis Pharmaceuticals, leaving that question unanswered.
Patients were eligible to participate in the study if they had been diagnosed in the last 36 months, had a body mass index of 24 kg/m2 or higher, and were receiving letrozole for hormone receptor–positive breast cancer. Study participants were randomly assigned to receive general health information by mail, or to a lifestyle intervention where they received weight loss advice by telephone in addition to the health information by mail.
The telephone-based lifestyle intervention included a dietary goal (500-1,000 kcal per day deficit) and a physical activity goal (150-200 minutes of moderate-intensity physical activity per week) to achieve weight loss.
"Our results support the use of telephone-based delivery of weight-loss interventions in patients with breast cancer, and they suggest that our approach will be generally effective in postmenopausal patients receiving an aromatase inhibitor," the investigators concluded.
The results, combined with the recognition that obesity is associated with poor breast cancer outcomes, provide support for a randomized trial using a telephone-based weight-loss intervention that is adequately powered to detect clinically important effects on breast cancer outcomes, they said.
While the findings add to a growing body of evidence supporting the benefits of weight-loss interventions in overweight breast cancer survivors, questions remain regarding the effect of weight loss on breast cancer recurrence and mortality, said Melinda L. Irwin, Ph.D., M.P.H., in an accompanying editorial (J. Clin. Oncol. 2014 June 16 [doi: 10.1200/JCO.2014.56.4583]).
"How can important lifestyle trials with definitive mortality end points best be funded?" asked Dr. Irwin of Yale University, New Haven, Conn. She suggested that pharmaceutical companies be required to include a lifestyle intervention arm in drug trials.
"Given that pharmaceutical companies primarily fund therapeutic trials, with little incentive to fund lifestyle interventions, and given the scarcity of funding from government agencies for large-scale long-term trials of lifestyle interventions with disease-free survival endpoints, another option may be to require pharmaceutical companies to include lifestyle interventions as an active comparison arm to drug trials, especially in cases when drug options provide modest benefit, or uptake or adherence to particular medications [is] low," she said.
The study was funded by Novartis Pharmaceuticals. Dr. Goodwin and Dr. Irwin reported no disclosures. Two coauthors disclosed honoraria or research funding from Novartis and other companies.