Use of hair dyes by patients with breast cancer: a case-control study.

The recent finding that many permanent and semipermanent hair dyes are strongly mutagenic in a laboratory test, together with the fact that single female hair-dressers had higher than expected death rates from breast-cancer in 1959-63, prompted a study into the use of hair dyes by patients with breast cancer and by matched controls. There was no difference between the patients and their controls in their use of hair dyes. There were also no significant differences between the two groups when the analysis was confinedto women who had used dyes over four years and over nine years before diagnosis. The only significant findings were a higher proportion of past or present smokers among women aged over 50 who used hair dyes and an association between hair dyes use and age at first pregnancy. Further epidemiological studies are clearly needed in view of the mutagenicity found in the Ames test, and the fact th & several human carcinogens are also mutagenic according to this test.