Purpose: Despite the benefits of diet and physical activity (PA) in improving breast cancer (BC) outcomes, few lifestyle interventions focus on Latina BC survivors who are at increased risk of cardiometabolic disorders, obesity and poor BC outcomes. We developed and tested the effectiveness of the culturally-tailored ¡Mi Vida Saludable! (My Healthy Life) in-person and/or electronic health (eHealth) program on improving diet and PA among Latina BC survivors. The program was developed in collaboration with community partners and used theory-based psychosocial determinants of behavior change. Methods: Latina BC survivors were post-treatment (endocrine therapy allowed) and consumed <5 daily servings of fruits/vegetables (F/V) and/or engaged in <150 minutes of moderate-to-vigorous PA (MVPA)/week. Women were randomized 1:1:1:1 in a 2x2 factorial design to: 1) 4 weekly in-person group sessions over 1 month + 11 months of eHealth health promotion messages (text messaging, eNewsletters, website), 2) in-person group sessions alone, 3) eHealth alone, or 4) control. Randomization was stratified by language preference and current use of endocrine therapy. All study activities were offered in Spanish and English. All participants received a Fitbit to self-monitor PA and a 30 min individual session on healthy lifestyle behaviors. Primary outcomes at 12 months were change in daily servings of targeted F/V and energy density (kcal/g of food). Secondary outcomes were change in min/week of MVPA, body mass index (BMI), and waist:hip ratio. One-way analysis of variance (ANOVA) examined main intervention effects (i.e., in-person group sessions, yes vs. no; eHealth, yes vs. no) from baseline to 12 months while controlling for stratification factors and baseline values. Two-way ANOVA compared differences between changes in the 4 arms. Results: Women (n=167) were randomized between January 2016 and September 2018. On average, women were 57±10 years old and 6±5 years post-diagnosis; 47% were on endocrine therapy and 83% were overweight/obese. Over 15 Latin American national backgrounds were represented. Retention at 12 months was 93.4%. At 12 months, main effect analyses showed in-person group sessions resulted in an increase of 0.78±2.8 servings/day of F/V (P=0.01) compared to control. Analyses comparing effects across the 4 arms showed increases in F/V in the in-person group session arm only (P=0.02). No other significant changes in F/V intake or energy density were observed. At 12 months, there were no significant changes in min/week of MVPA in any analyses. However, in main effect analyses, the control compared to eHealth increased in 79.9±422.0 min/week of moderate intensity exercise (P<0.01) and analyses comparing effects across the 4 arms, both in-person group sessions and the control showed increases (P=0.01). At 12 months, the in-person group sessions resulted in decreased BMI (0.48±1.3 kg/m2, P=0.04) and decreased waist circumference (3.4±7.7 cm, P=0.04) as compared to control. In analyses across the 4 arms, women in the in-person group sessions had greater decrease in waist:hip ratios (P=0.04). Conclusion: The 4-week culturally-tailored in-person ¡Mi Vida Saludable! diet and PA group sessions resulted in increased F/V intake, increased moderate physical activity, and improvements at 12 months in anthropometric measures in Latina BC survivors. Participation in the 11-month eHealth program did not result in changes in diet, PA, or anthropometric measures, despite similar content. Future studies need to continue to develop and test culturally relevant and scalable programs to promote and sustain long-term behavior change within at-risk patient populations, possibly focusing on group-based interventions.

Citation Format: Heather Greenlee, Margarita Santiago-Torres, Pamela Koch, Wei-Yann Tsai, Heewon L Gray, Adam M Brickman, Ann Ogden Gaffney, Martha Eddy, Cynthia A Thomson, Tracy E Crane, Naxielly Dominguez, Jhack Sepulveda, Amanda M. Marin-Chollom, Rachel Paul, Zaixing Shi, Kathleene T Ulanday, Hanjie Shen, Marisol Castellano, Yanette Fuentes, Katherine Crew, Kevin Kalinsky, Melissa Accordino, Meghna Trivedi, Bret Taback, Melissa Beauchemin, Fernando J Camacho, Daniel T Friedman, Isobel Contento, Dawn L. Hershman. A randomized, controlled, 2x2 factorial trial of a diet and physical activity intervention among Latina breast cancer survivors: ¡Mi Vida Saludable! study [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-10-07.