lifestyle intervention study in adjuvant treatment of early breast cancer

Conditions: Breast Cancer

Summary: the primary objective of this trial is to evaluate the effect of the addition of a 2 year, centrally delivered individualized, telephone-based lifestyle intervention focusing on weight management to a mailed educational intervention on disease free survival in post-menopausal women with early stage breast cancer (hormone receptor positive), bmi ≥24-\<40 kg/m2, who are receiving standard letrozole adjuvant therapy.

the primary objective of this trial is to evaluate the effect of the addition of a 2 year, centrally delivered individualized, telephone-based lifestyle intervention focusing on weight management to a mailed educational intervention on disease free survival in post-menopausal women with early stage breast cancer (hormone receptor positive), bmi ≥24-\<40 kg/m2, who are receiving standard letrozole adjuvant therapy. the telephone intervention will involve 19 phone calls, as well as mailings and a participant manual; women will be asked to lose up to 10% of their weight by reducing their caloric and fat intake (by 500-1000 kcal/day, 20% calories fat) and increasing their moderate physical activity (to 150-200 minutes/week). secondary outcomes include overall survival, distant disease-free survival, weight change, health-related quality of life (hrqol), selected non-cancer medical events and biologic factors (notably insulin). approximately 2,150 women will be enrolled; follow-up will continue until target event rates have been met (anticipated 4-6 years after completion of the intervention). this sample size will provide 80% power (type 1 error 0.05 2-tailed) to detect a hazard ratio (hr) for dfs of 0.74-0.76 in the weight loss intervention arm.

Eligibility criteria:
inclusion criteria: * post-menopausal woman with a diagnosis of invasive breast cancer (t1-3,pn0-2,m0) for which definitive surgery was performed during the previous 36 months. * on adjuvant hormonal therapy with letrozole at time of randomization (either as initial adjuvant hormonal therapy or after a switch from tamoxifen or other hormonal therapy). * bmi ≥ 24 kg/m2. * medical, surgical or radiation oncologist agrees to subject participation in a diet and physical activity program. exclusion criteria: * life expectancy less than five years. * self-reported inability to walk at least 2 blocks (at any pace). * insulin requiring diabetes (telephone directed diet and physical activity changes would be difficult in this population without close coordination with the treating physician). non-insulin requiring diabetics are eligible for the study. * serious digestive and/or absorptive problems, including inflammatory bowel disease and chronic diarrhea that preclude adherence to the study diet. * cardiovascular, respiratory or musculoskeletal disease or joint problems that preclude moderate physical activity. moderate arthritis that does not preclude physical activity is not a reason for ineligibility. * psychiatric disorders or conditions that, in the opinion of the investigator, would preclude participation in the study intervention (e.g. untreated major depression or psychosis, substance abuse, severe personality disorder). * patients on aromatase inhibitors other than letrozole at study entry. * known recurrence of breast cancer (local, regional or distant) at any time prior to study entry. * history of other malignancies except: adequately treated non-melanoma skin cancer, curatively treated in situ carcinoma of the cervix, or other solid tumours curatively treated with no evidence of disease for ≥ 5 years. prior in situ cancer of the breast is not a reason for exclusion. * patients not fluent in either english or french (spoken and written). * patient unwilling or unable to provide informed consent.

Keywords: lifestyle intervention breast cancer adjuvant letrozole weight loss bmi post-menopausal estrogen receptor positive progesterone receptor positive