title: Recruitment strategies, design, and participant characteristics in a trial of weight-loss and metformin in breast cancer survivors.
abstract: Weight loss and metformin are hypothesized to improve breast cancer outcomes; however the joint impacts of these treatments have not been investigated. Reach for Health is a randomized trial using a 2 × 2 factorial design to investigate the effects of weight loss and metformin on biomarkers associated with breast cancer prognosis among overweight/obese postmenopausal breast cancer survivors. This paper describes the trial recruitment strategies, design, and baseline sample characteristics. Participants were randomized in equal numbers to (1) placebo, (2) metformin, (3) weight loss intervention and placebo, or (4) weight-loss intervention and metformin. The lifestyle intervention was a personalized, telephone-based program targeting a 7% weight-loss in the intervention arm. The metformin dose was 1500 mg/day. The duration of the intervention was 6 months. Main outcomes were biomarkers representing 3 metabolic systems putatively related to breast cancer mortality: glucoregulation, inflammation, and sex hormones. Between August 2011 and May 2015, we randomized 333 breast cancer survivors. Mass mailings from the California Cancer Registry were the most successful recruitment strategy with over 25,000 letters sent at a cost of $191 per randomized participant. At baseline, higher levels of obesity were significantly associated with worse sleep disturbance and impairment scores, lower levels of physical activity and higher levels of sedentary behavior, hypertension, hypercholesterolemia, and lower quality of life (p<0.05 for all). These results illustrate the health burden of obesity. Results of this trial will provide mechanistic data on biological pathways and circulating biomarkers associated with lifestyle and pharmacologic interventions to improve breast cancer prognosis.
authors.affiliation: Department of Family Medicine and Public Health, UC San Diego, La Jolla, CA, USA; Moores UC San Diego Cancer Center, UC San Diego, La Jolla, CA, USA. Electronic address: repatterson@ucsd.edu.
authors.forename: Ruth E
authors.initials: RE
authors.lastname: Patterson
authors.affiliation: Department of Family Medicine and Public Health, UC San Diego, La Jolla, CA, USA; Graduate School of Public Health, San Diego State University, San Diego, CA, USA.
authors.forename: Catherine R
authors.initials: CR
authors.lastname: Marinac
authors.affiliation: Department of Family Medicine and Public Health, UC San Diego, La Jolla, CA, USA; Moores UC San Diego Cancer Center, UC San Diego, La Jolla, CA, USA.
authors.forename: Loki
authors.initials: L
authors.lastname: Natarajan
authors.affiliation: Department of Family Medicine and Public Health, UC San Diego, La Jolla, CA, USA; Moores UC San Diego Cancer Center, UC San Diego, La Jolla, CA, USA.
authors.forename: Sheri J
authors.initials: SJ
authors.lastname: Hartman
authors.affiliation: Department of Kinesiology, University of Wisconsin, Madison, WI, USA.
authors.forename: Lisa
authors.initials: L
authors.lastname: Cadmus-Bertram
authors.affiliation: Moores UC San Diego Cancer Center, UC San Diego, La Jolla, CA, USA.
authors.forename: Shirley W
authors.initials: SW
authors.lastname: Flatt
authors.affiliation: Moores UC San Diego Cancer Center, UC San Diego, La Jolla, CA, USA.
authors.forename: Hongying
authors.initials: H
authors.lastname: Li
authors.affiliation: Moores UC San Diego Cancer Center, UC San Diego, La Jolla, CA, USA.
authors.forename: Barbara
authors.initials: B
authors.lastname: Parker
authors.affiliation: Moores UC San Diego Cancer Center, UC San Diego, La Jolla, CA, USA.
authors.forename: Jesica
authors.initials: J
authors.lastname: Oratowski-Coleman
authors.affiliation: Department of Family Medicine and Public Health, UC San Diego, La Jolla, CA, USA; Moores UC San Diego Cancer Center, UC San Diego, La Jolla, CA, USA.
authors.forename: Adriana
authors.initials: A
authors.lastname: Villaseñor
authors.affiliation: Department of Family Medicine and Public Health, UC San Diego, La Jolla, CA, USA.
authors.forename: Suneeta
authors.initials: S
authors.lastname: Godbole
authors.affiliation: Department of Family Medicine and Public Health, UC San Diego, La Jolla, CA, USA.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Kerr
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001786:Blood Glucose / Q000378:metabolism; D001943:Breast Neoplasms / Q000150:complications / Q000378:metabolism*; D002097:C-Reactive Protein / Q000378:metabolism; D004958:Estradiol / Q000378:metabolism; D015444:Exercise; D005260:Female; D000072936:Fitness Trackers; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D007328:Insulin / Q000378:metabolism; D007333:Insulin Resistance; D008687:Metformin / Q000627:therapeutic use*; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000378:metabolism / Q000628:therapy*; D050177:Overweight / Q000150:complications / Q000378:metabolism / Q000628:therapy; D018579:Patient Selection; D017698:Postmenopause; D011788:Quality of Life; D017741:Survivors; D013689:Telephone; D061217:Weight Reduction Programs / Q000379:methods*
chemical_list: D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007328:Insulin; D004958:Estradiol; D002097:C-Reactive Protein; D008687:Metformin
keywords: Breast cancer; Metformin; Survivorship; Trial; Weight loss