Women who are teachers, religion workers or librarians have a significantly greater chance of dying from breast cancer than homemakers or other women in nonprofessional occupations, according to a federal study to be released today.
The study, which has already prompted special campaigns from two major teachers' groups, is the first to link breast cancer deaths with occupation on a large scale.
Carol Hogfoss Rubin, an epidemiologist with the Centers for Disease Control and Prevention, said her findings do not indicate that the occupations themselves are causing breast cancer, but rather that other outside factors associated with them -- such as delayed childbearing -- may be to blame.
Studying 2.9 million death certificates from 1979 through 1987, Ms. Rubin and fellow researchers at the CDC and National Institute for Occupational Safety and Health (NIOSH) looked at those with breast cancer as a cause of death and then categorized them by occupation.
They found that professional women, overall, had higher rates of breast cancer death than nonprofessional women. Nuns, clergy women, teachers and librarians had the most elevated rates among white women. Their risk of dying from the disease was between 62 percent and 65 percent greater than women in the average population, the study said.
Also at higher risk -- in decreasing order -- were white counselors, mathematicians, computer scientists, secretaries, finance officers, pharmacists, supervisors, bank tellers, clerks, lawyers, judges, managers and administrators, and nurses.
The risk was especially pronounced for black professional women. The study found that black physicians, lawyers, judges and pharmacists were three to six times more likely than other women to die from the disease.
Yet in general, women in less professional jobs had a lower than average risk of dying from breast cancer, which annually kills about 46,000 American women.
Among those were homemakers, laborers, farmers, equipment cleaners and service industry workers, the study said.
One reason behind the overall findings, Ms. Rubin said, may be that women in higher professions "go to school; they're starting their families later than they would if they went straight into childbearing."
Previous breast cancer research has shown that delayed childbearing increases a woman's risk of getting the disease, probably because of hormonal factors.
It may also be true, Ms. Rubin said, that women in some professions, such as teaching, are getting fewer mammograms to detect early stage breast cancer than women in other groups.
Black women professionals, Ms. Rubin said, may have higher breast cancer death rates than white professionals because of "further delay of childbirth . . . We also know across the board that black women are diagnosed at a later stage of breast cancer and have less of a survival period than white women do."