Risk of Breast and Uterine Cancers Deemed Higher for Calif. Teachers

California teachers appear to have a 51% higher rate of breast cancer and a 72% higher rate of uterine cancer than women in the general population, according to a study by California scientists. The teachers have lower rates of lung and cervical cancers.

But the profession of teaching is very unlikely to be the cause, said Dr. Ronald K. Ross, chair of preventive medicine at USC and one of the study’s researchers. Instead, the study--which has been tracking the health of more than 133,000 female active or retired public school teachers since 1995--revealed lifestyle factors that could explain the bulk of the difference.

Teachers were more likely to take hormones at menopause, less likely to have children and started their families, on average, several years later in life, according to the study, published in the journal Cancer Causes & Control. These factors are known to increase the risk of breast and endometrial cancers because they increase lifetime exposure to the hormone estrogen.

Female teachers are also less likely to smoke, lowering their risk of lung cancer, and more likely to have regular checkups, reducing their risk of cervical cancer. The women had a 34% lower risk of lung cancer and a 47% lower risk of cervical cancer, the study found.