Poor physical health predicts time to additional breast cancer events and mortality in breast cancer survivors.
BACKGROUND
Health-related quality of life has been hypothesized to predict time to additional breast cancer events and all-cause mortality in breast cancer survivors.


METHODS
Women with early-stage breast cancer (n=2967) completed the SF-36 (mental and physical health-related quality of life) and standardized psychosocial questionnaires to assess social support, optimism, hostility, and depression prior to randomization into a dietary trial. Cox regression was performed to assess whether these measures of quality of life and psychosocial functioning predicted time to additional breast cancer events and all-cause mortality; hazard ratios were the measure of association.


RESULTS
There were 492 additional breast cancer events and 301 deaths occurred over a median 7.3 years (range: 0.01-10.8 years) of follow-up. In multivariate models, poorer physical health was associated with both decreased time to additional breast cancer events and all-cause mortality (p trend=0.005 and 0.004, respectively), while greater hostility predicted additional breast cancer events only (p trend=0.03). None of the other psychosocial variables predicted either outcome. The hazard ratios comparing persons with poor (bottom two quintiles) to better (top three quintiles) physical health were 1.42 (95% CI: 1.16, 1.75) for decreased time to additional breast cancer events and 1.37 (95% CI: 1.08, 1.74) for all-cause mortality. Potentially modifiable factors associated with poor physical health included higher body mass index, lower physical activity, lower alcohol consumption, and more insomnia (p<0.05 for all).


CONCLUSIONS
Interventions to improve physical health should be tested as a means to increase time to additional breast cancer events and mortality among breast cancer survivors.
Saquib
Nazmus
N
Cancer Prevention and Control Program, Moores UCSD Cancer Center, University of California, San Diego, La Jolla, CA 92093-0901, USA.
Pierce
John P
JP
Saquib
Juliann
J
Flatt
Shirley W
SW
Natarajan
Loki
L
Bardwell
Wayne A
WA
Patterson
Ruth E
RE
Stefanick
Marcia L
ML
Thomson
Cynthia A
CA
Rock
Cheryl L
CL
Jones
Lovell A
LA
Gold
Ellen B
EB
Karanja
Njeri
N
Parker
Barbara A
BA
D000293:Adolescent; D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000145:classification / Q000401:mortality* / Q000473:pathology; D015331:Cohort Studies; D003863:Depression / Q000523:psychology; D005260:Female; D005500:Follow-Up Studies; D006304:Health Status; D006801:Humans; D008875:Middle Aged; D009043:Motor Activity; D009367:Neoplasm Staging; D016016:Proportional Hazards Models; D011788:Quality of Life; D012944:Social Support; D011795:Surveys and Questionnaires; D017741:Survivors / Q000523:psychology*; D013997:Time Factors; D055815:Young Adult