| A case-control study was conducted among patients attending a screening center in New York City to investigate the relationship between hair dye use and breast cancer. The study group consisted of 398 breast cancer cases identified at the screening center between 1977 and 1981, and 790 randomly selected control women screened during the same period. Subjects were interviewed by telephone to obtain information on known risk factors for breast cancer along with a complete history of hair dye use detailing type of dye, color, duration, frequency, and temporal periods of use. There was a substantial amount of hair dye exposure in the study group: 77% had used hair dye at least once, 38% at least 100 times. However, no increased risk of breast cancer was found among hair dye users, and there was no evidence of a trend in risk with increasing hair dye usage. These results were the same whether all past exposures were considered or only exposures in the distant past (i.e., prior to ten years before disease). Breast cancer risk did not increase with increasing intensity of exposure, as measured by frequency of use or darkness of color. No effect was seen for different types or colors of dye, or for use during different periods of reproductive life. The results of this study, taken in conjunction with the findings of other epidemiological studies, do not implicate hair dyes as a cause of human breast cancer at the exposure levels associated with hair dyeing. |
