San Antonio, TX—An interim analysis of a randomized clinical trial showed that a lifestyle intervention aimed at weight loss achieved approximately a 1-kg weight loss in patients with early breast cancer who received chemotherapy, whereas patients in the control group gained approximately 1 kg over the course of the study.
Although the lifestyle intervention had no effect on disease-free or overall survival in the main analysis of the study, an unplanned post-hoc exploratory analysis showed that patients who completed the 2-year lifestyle program had an absolute difference in weight loss of approximately 7 or 8 pounds and significantly improved disease-free and overall survival compared with patients who did not complete the program (P <.001 for both survival comparisons).
The rate of adherence to the lifestyle intervention program was relatively low, at approximately 50%. The results suggest that if more patients had adhered to or completed the program, there would have been a greater difference in outcomes in the overall analysis of the study.
“Although bias cannot be ruled out, the analysis among completers suggests significantly better disease-free survival of patients in the intervention arm versus the controls,” said lead investigator Wolfgang Janni, MD, Chair, Department of Obstetrics and Gynecology, University of Ulm, Germany, who presented these results at the 2018 San Antonio Breast Cancer Symposium (SABCS).
The study was embedded in the larger SUCCESS C trial, an open-label, multicenter, randomized controlled trial with a 2 × 2 factorial design that included 3643 patients. For the first randomization, the patients received treatment with either 3 cycles of epirubicin, fluorouracil, and cyclophosphamide followed by 3 cycles of docetaxel or 6 cycles of docetaxel plus cyclophosphamide. At the end of chemotherapy, they were rerandomized to the lifestyle intervention (structured telephone and mail-based lifestyle intervention program for weight loss by diet and physical exercise, N = 2292) or to a control group of 1146 patients who were given general health recommendations.
The lifestyle intervention designed to achieve weight loss consisted of 19 telephone contacts with trained lifestyle coaches who discussed motivational and behavioral issues with participants, a detailed workbook supplemented with mailings focused on weight management, newsletters, and up to 3 additional phone calls and mailings to discuss any problems that arose. The control arm received mail-based educational support after the completion of chemotherapy and at month 12, and 2 years of lifestyle information at regular intervals.
“This study adds to the volume of data showing that interventions can improve the psychology and physical status of breast cancer patients, and perhaps the cancer itself,” said SABCS Co-director C. Kent Osborne, MD, Director, Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX.
“It is difficult to implement these types of programs in medical practice because of issues for reimbursement and time factors,” he added.
“The lack of adherence in the study is probably a consequence of the large size and the lack of resources needed to give extra attention to patients in face-to-face encounters with oncologists. A healthcare system can’t pay for that kind of extra attention,” Dr Osborne noted.