Women with a normally low cancer risk are twice as likely to develop breast cancer if they used permanent hair dyes, according to a federally funded study scheduled for publication next year.
The study is the first major research effort to establish a link between permanent hair coloring, used by an estimated 30 million women in the United States, and breast cancer, the leading cause of death among American women. It is scheduled to be published early next year in the Journal of the National Cancer Institute.
Last year the National Cancer Institute announced that its studies on laboratory animals showed that those fed large amounts of hair dye developed throid and skin tumors. The agency warned that the studies indicated potential cancer danger to women who might absorb cancer-causing chemicals from the dyes through their scalps.
The latest study and its conclusions wee sharply criticized yesterday by a medical spokesman for the hair-dye industry.
Dr. John Corbett, chairman of the hair color technical committee of the Cosmetic, Toiletry and Fragrance Association, said yesterday that the study covered too few research subjects to be meaningful.
"I don't think they have anything there at all other than a beautiful manipulation of numbers," said Corbett, a vice president of the Clairol Corp., a major hair-dye manufacturer.
Dr. Roy E. Shore, an assistant professor of environmental medicine at the New York University Medical Center and the head of the six-person research team that did the study, acknowledged that his group's research sample was small. "It was rather marginal," Shore said yesterday. "But within the limits of the sample the evidence is positive and that is the significant factor. Our findings certainly suggest the need for a larger study."
Shore's research team interviewed 129 breast-cancer patients and 193 women who had not developed the disease. The researchers said they found that breast tumors were more likely t develop among hair-dye users who would otherwise be considered "at lower natural risk for breast cancer." The cancers appeared about 10 years after the dyes were used.
Shore yesterday said the women in the low-risk group included those who had no close relative with breast cancer, were married and had their first child at an early age, were premenopausal,had no thyroid problems or miscarriages, and smoked cigarettes.
In its study the research team made no mention of any specific brand of hair dye used by the women. The researchers also did not mention which ingredients in the days may have been responsible for the development of breast cancer.
But they noted that other studies have shown that chemical amines in hair dyes have been shown to have been absorbed through the skin of research animals. "Carcinogenic activity at remote body sites in humans is therefore a distinct possibility," the study said.
The hair-dye industry - a $280 million annual business in the United States - has drawn considerable attention since the NCI's findings were released last year. The Environmental Defense Fund, which has been pressing for closer federal inspection of hair-dye ingredients, said yesterday that the latest study appeared to support earlier federal animal studies linking cancer and hair colorings.
"Currently there is no mandatory safety testing of cosmetic ingredients," a spokesman for the environmental group said. "This situation needs to be changed."