Complementary and alternative medicine use and breast cancer prognosis: a pooled analysis of four population-based studies of breast cancer survivors.
BACKGROUND
Complementary and alternative medicine (CAM) use is common among breast cancer survivors, but little is known about its impact on survival.


METHODS
We pooled data from four studies conducted in Hawaii in 1994-2003 and linked to the Hawaii Tumor Registry to obtain long-term follow-up information. The effect of CAM use on the risk of breast cancer-specific death was evaluated using Cox regression.


RESULTS
The analysis included 1443 women with a median follow-up of 11.8 years who had a primary diagnosis of in situ and invasive breast cancer. The majority were Japanese American (36.4%), followed by white (26.9%), Native Hawaiian (15.9%), other (10.6%), and Filipino (10.3%). CAM use was highest in Native Hawaiians (60.7%) and lowest in Japanese American (47.8%) women. Overall, any use of CAM was not associated with the risk of breast cancer-specific death (hazard ratio [HR] 1.47, confidence interval [CI] 0.91-2.36) or all-cause death (HR 0.82, 95% CI 0.63-1.06). However, energy medicine was associated with an increased risk of breast cancer-specific death (HR 3.19, 95% CI 1.06-8.52). When evaluating CAM use within ethnic subgroups, Filipino women who used CAM were at increased risk of breast cancer death (HR 6.84, 95% CI 1.23-38.19).


CONCLUSIONS
Our findings suggest that, overall, CAM is not associated with breast cancer-specific death but that the effects of specific CAM modalities and possible differences by ethnicity should be considered in future studies.
University of Hawaii Cancer Center, Department of Epidemiology, Honolulu, Hawaii 96813, USA. rweise@cc.hawaii.edu
Rayna Kim
RK
Matsuno
Ian S
IS
Pagano
Gertraud
G
Maskarinec
Brian F
BF
Issell
Carolyn C
CC
Gotay
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000208:ethnology / Q000401:mortality / Q000628:therapy*; D002423:Cause of Death; D000529:Complementary Therapies / Q000706:statistics & numerical data*; D016001:Confidence Intervals; D005006:Ethnicity; D005260:Female; D005500:Follow-Up Studies; D006254:Hawaii / Q000453:epidemiology; D006306:Health Surveys; D006801:Humans; D008875:Middle Aged; D010342:Patient Acceptance of Health Care / Q000208:ethnology*; D011159:Population Surveillance; D015995:Prevalence; D011379:Prognosis; D016016:Proportional Hazards Models; D011788:Quality of Life / Q000523:psychology; D012042:Registries; D012044:Regression Analysis; D012307:Risk Factors; D011795:Surveys and Questionnaires; D017741:Survivors