1. Recreational Physical Activity and Outcomes After Breast Cancer in Women at High Familial Risk
- Author
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Kehm, RD, MacInnis, RJ, John, EM, Liao, Y, Kurian, AW, Genkinger, JM, Knight, JA, Colonna, S, Chung, WK, Milne, R, Zeinomar, N, Dite, GS, Southey, MC, Giles, GG, Mclachlan, S-A, Whitaker, KD, Friedlander, ML, Weideman, PC, Glendon, G, Nesci, S, Investigators, K, Phillips, K-A, Andrulis, IL, Buys, SS, Daly, MB, Hopper, JL, Terry, MB, Kehm, RD, MacInnis, RJ, John, EM, Liao, Y, Kurian, AW, Genkinger, JM, Knight, JA, Colonna, S, Chung, WK, Milne, R, Zeinomar, N, Dite, GS, Southey, MC, Giles, GG, Mclachlan, S-A, Whitaker, KD, Friedlander, ML, Weideman, PC, Glendon, G, Nesci, S, Investigators, K, Phillips, K-A, Andrulis, IL, Buys, SS, Daly, MB, Hopper, JL, and Terry, MB
- Abstract
BACKGROUND: Recreational physical activity (RPA) is associated with improved survival after breast cancer (BC) in average-risk women, but evidence is limited for women who are at increased familial risk because of a BC family history or BRCA1 and BRCA2 pathogenic variants (BRCA1/2 PVs). METHODS: We estimated associations of RPA (self-reported average hours per week within 3 years of BC diagnosis) with all-cause mortality and second BC events (recurrence or new primary) after first invasive BC in women in the Prospective Family Study Cohort (n = 4610, diagnosed 1993-2011, aged 22-79 years at diagnosis). We fitted Cox proportional hazards regression models adjusted for age at diagnosis, demographics, and lifestyle factors. We tested for multiplicative interactions (Wald test statistic for cross-product terms) and additive interactions (relative excess risk due to interaction) by age at diagnosis, body mass index, estrogen receptor status, stage at diagnosis, BRCA1/2 PVs, and familial risk score estimated from multigenerational pedigree data. Statistical tests were 2-sided. RESULTS: We observed 1212 deaths and 473 second BC events over a median follow-up from study enrollment of 11.0 and 10.5 years, respectively. After adjusting for covariates, RPA (any vs none) was associated with lower all-cause mortality of 16.1% (95% confidence interval [CI] = 2.4% to 27.9%) overall, 11.8% (95% CI = -3.6% to 24.9%) in women without BRCA1/2 PVs, and 47.5% (95% CI = 17.4% to 66.6%) in women with BRCA1/2 PVs (RPA*BRCA1/2 multiplicative interaction P = .005; relative excess risk due to interaction = 0.87, 95% CI = 0.01 to 1.74). RPA was not associated with risk of second BC events. CONCLUSION: Findings support that RPA is associated with lower all-cause mortality in women with BC, particularly in women with BRCA1/2 PVs.
- Published
- 2021