New research finds a surprising link between high-status occupations among American women in the 1970s and later episodes of breast cancer.

A group of feminist trailblazers—women professionals in the 1970s—may be paying a high price for breaking the mold: An increased risk of breast cancer.

“We find that women who were in professional and managerial occupations in 1975, at age 36, had a substantially higher risk of a breast cancer diagnosis up to age 72, compared to housewives and lower-status occupations,” writes a research team led by Penn State sociologist Tetyana Pudrovska.

The researchers, writing in the journal Social Science and Medicine, cite a combination of factors for this disturbing finding, the largest of which appears to be chronic stress. Asserting authority can be emotionally and physically taxing—especially in the face of gender-based resistance.

The study used data from the Wisconsin Longitudinal Study, focusing on 3,682 white women who were born in 1939 and tracked between 1957 and 2011. Of that group, 297 reported suffering from breast cancer at some point.

"Chronic stress may have been an important long-term link between higher-status jobs in young adulthood and the risk of breast cancer.”

The researchers found women who worked as professionals in 1975 had a 72 to 122 percent higher risk of a breast cancer diagnosis than housewives and women in lower-status occupations. Women who worked as managers that year had a risk 57 to 89 percent higher.

Those figures are particularly striking in that higher social status is usually associated with better health. Why has that not held true for this group of women?

The researchers believe 20 percent of their elevated risk can be attributed to “estrogen-related” reasons, including “their later age at first birth, more regular alcohol use, higher use of hormone replacement therapy, and later menopause.”

A bigger factor, they believe, is workplace stress. They note that chronically-elevated levels of steroid hormones such as cortisol can “promote mammary cell proliferation” and increase “the risk of malignant transformations.”

“Exercising job authority was particularly stressful for women in the context of gender inequality embedded in the occupational structure of the 1960s and 1970s, when women in managerial positions often faced prejudice, tokenism, discrimination, social isolation, and resistance from subordinates, colleagues, and superiors,” they write. “This chronic stress may have been an important long-term link between higher-status jobs in young adulthood and the risk of breast cancer.”

They go on to note that, in the 1970s, “Professional women were predominantly employed in ‘caring’ occupations, mostly teaching and nursing.” These lines of work, they add, often require “emotional suppression” and result in “emotional exhaustion”—high-stress states which have been linked to elevated cortisol levels.

Unfortunately, the Wisconsin study did not collect information on health-related behaviors in 1975; such data would indicate how the women were coping with stress, and perhaps give further clues to the causes of their long-term health issues. Also, the sample contained no black or Hispanic women, who in many cases were simultaneously dealing with stress related to racism.

Arguably the most intriguing question the study leaves unanswered, however, is: Are its results unique to this generation? Or will they hold true for women professionals and managers who came of age in later decades?

“Our findings may be most relevant to women born in the first half of the 20th century,” the researchers write. But they add that “because of the persistence of gender inequality and dominant gender beliefs,” there’s a good chance the disturbing pattern they identified will hold true for women born during the baby boom and beyond.