Past recreational physical activity, body size, and all-cause mortality following breast cancer diagnosis: results from the Breast Cancer Family Registry.
Few studies have considered the joint association of body mass index (BMI) and physical activity, two modifiable factors, with all-cause mortality after breast cancer diagnosis. Women diagnosed with invasive breast cancer (n = 4,153) between 1991 and 2000 were enrolled in the Breast Cancer Family Registry through population-based sampling in Northern California, USA; Ontario, Canada; and Melbourne and Sydney, Australia. During a median follow-up of 7.8 years, 725 deaths occurred. Baseline questionnaires assessed moderate and vigorous recreational physical activity and BMI prior to diagnosis. Associations with all-cause mortality were assessed using Cox proportional hazards regression, adjusting for established prognostic factors. Compared with no physical activity, any recreational activity during the 3 years prior to diagnosis was associated with a 34% lower risk of death [hazard ratio (HR) = 0.66, 95% confidence interval (CI): 0.51-0.85] for women with estrogen receptor (ER)-positive tumors, but not those with ER-negative tumors; this association did not appear to differ by race/ethnicity or BMI. Lifetime physical activity was not associated with all-cause mortality. BMI was positively associated with all-cause mortality for women diagnosed at age > or =50 years with ER-positive tumors (compared with normal-weight women, HR for overweight = 1.39, 95% CI: 0.90-2.15; HR for obese = 1.77, 95% CI: 1.11-2.82). BMI associations did not appear to differ by race/ethnicity. Our findings suggest that physical activity and BMI exert independent effects on overall mortality after breast cancer.
Northern California Cancer Center, 2201 Walnut Ave, Suite 300, Fremont, CA 94536, USA. Theresa.keegan@nccc.org
Theresa H M
TH
Keegan
Roger L
RL
Milne
Irene L
IL
Andrulis
Ellen T
ET
Chang
Meera
M
Sangaramoorthy
Kelly-Anne
KA
Phillips
Graham G
GG
Giles
Pamela J
PJ
Goodwin
Carmel
C
Apicella
John L
JL
Hopper
Alice S
AS
Whittemore
Esther M
EM
John
D000293:Adolescent; D000328:Adult; D001315:Australia / Q000453:epidemiology; D015992:Body Mass Index; D049628:Body Size; D001943:Breast Neoplasms / Q000175:diagnosis / Q000235:genetics / Q000401:mortality* / Q000503:physiopathology; D002140:California / Q000453:epidemiology; D002648:Child; D015444:Exercise; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D016013:Likelihood Functions; D008875:Middle Aged; D009864:Ontario / Q000453:epidemiology; D010375:Pedigree; D011379:Prognosis; D016016:Proportional Hazards Models; D011960:Receptors, Estrogen / Q000032:analysis; D011998:Recreation; D012042:Registries; D018570:Risk Assessment; D012307:Risk Factors; D011795:Surveys and Questionnaires; D013997:Time Factors; D055815:Young Adult
D011960:Receptors, Estrogen