October is Breast Cancer Awareness Month. In the U.S., there are an estimated 3.8 million breast cancer survivors thanks to screening, early detection and effective treatments. Breast cancer is diagnosed in one of every eight American women sometime during their lifetime. Men also get breast cancer, but at much lower rates than women.

Occupational exposure risk factors for breast cancer include age, family history/genetics, breast density, menstrual cycle and reproductive history, low physical activity, being overweight/obese, having had hormone replacement therapy, past exposure to ionizing radiation and drinking alcohol. Potential occupational exposure risks associated with breast cancer have also been identified in a variety of industries and occupations.

This indicates that the bottom line for employers is to be familiar with cancer research findings linked to occupations, and to support the promotion of breast cancer awareness year-round as part of employee wellness outreach efforts. As always, it is incumbent on employers to take steps to ensure consistent use of the hierarchy of controls, including personal protection measures, to help prevent exposures to substances or environmental conditions that may be associated with the development of cancer or any other type of illness.

What We Know About Occupational Exposure Risks

Research on work-related breast cancer risks often results in recommendations for further study. This is partly attributed to the complex interconnections among contributing non-occupational factors. In addition, occupational cancer studies, in general, have historically focused more on men working in industries that have traditionally employed more men than women.

Occupational causes of breast cancer have long been the subject of scientific research. In the early 18th century, Bernardino Ramazzini, referred to as the father of occupational medicine, found breast cancer prevalence was higher among nuns than it was in the general population. (He associated this with their lifestyle, including celibacy.)

Exposure to endocrine-disrupting chemicals used in the production of many products and work in high-temperature environments have been the subject of evidence-based breast cancer studies. The American Cancer Society reports that links between breast cancer and genetics, lifestyle and environmental conditions are undergoing scientific investigation. Chemicals in the environment that have estrogen-like properties reportedly are of special interest.

Meanwhile, findings from ongoing research on associations between anti-depressants, fertility drugs, parabens and stress are not strong enough to say whether they are truly related to breast cancer; more research is needed, according to Susan G. Koman, a non-profit organization supporting breast cancer research and other prevention initiatives.

Research Notes

Here are three studies that help illustrate the nature of links between occupation and breast cancer:

• A 2023 review of Occupational Cancers Among Employed Women suggests that with the ratio of men to women in the workforce narrowing (refer to Department of Labor Women’s Bureau statistics), it’s possible that occupational exposure risks to hazardous agents, such as organic solvents, increasingly contributes to breast cancer incidence. However, most of the studies that were reviewed did not consider potential confounders such as reproductive history or hormone use. “Since the epidemiological research on occupational cancers in males has always been quantitatively superior to that reserved for females, we should expand our knowledge of occupational exposure risks among women both through future specific studies on this focus and through more complete analyses where data are already available,” the authors concluded.
• A longitudinal study of breast cancer among Taiwanese women in different occupations that was published in 2022 found “slightly significant” breast cancer risk in manufacturing; wholesale and retail trade; information and communication; financial and insurance activities; real estate; professional, scientific and technical activities; public administration, defense and social security; education; and human health and social work activities. Researchers recommended further investigation of “the possible risk factors among female workers in those industries with slightly higher incidence of breast cancer.”
• A 2020 literature review of 40 articles found “significant evidence” to support an association between breast cancer and exposure to some chemical products (certain pesticides, solvents and plastics), exposure to ionizing radiation and night-shift work, which disrupts the body’s circadian rhythm and may affect hormone production. However, researchers concluded that “most studies have difficulty establishing a causal relationship between these variables, pointing to the need for further investigation of these issues.”

Why Wait to Find Out?

Screening and early detection of breast cancer saves lives. Breast cancer cells may form a tumor that can be seen on an X-ray before it might be felt as a lump. When cancer is caught in an early stage, the five-year relative survival rate is 99 percent. Only 5-10 percent of people diagnosed with breast cancer have a family history of it. When there is a family history, testing may be recommended to identify or rule out a gene mutation.

It’s important to be vigilant. Monthly self-checks and periodic mammograms based on a woman’s age and health history are recommended. In men (read the Better Health Campaign for Men) and women, noticeable changes such as a lump in the breast or armpit, thickening or swelling, skin dimpling, or discharge, inversion of or pain in the nipple should be checked by a doctor.

After a diagnosis and during treatment, there are many local and online resources available for physical and emotional support. Employers can do their part by facilitating temporary job accommodations for an employee undergoing breast cancer treatment, for example, flexible schedules, remote work, modifying physically demanding tasks or providing ergonomic tools to help reduce upper body exertion. Giving survivors a chance to talk about ways breast cancer has affected their life can also be helpful. Here are some related resources:

• American Cancer Society
• Cancer Care Support Groups
• National Breast Cancer Foundation
• Job Accommodation Network

For a one-page Healthful Workplace breast cancer prevention and early detection handout for employees, please send a request to communications@workcare.com.