Can Antipsychotic Drugs Increase Breast Cancer?

Researchers at Washington University School of Medicine in St. Louis have found that many commonly prescribed antipsychotic medications are associated with a significant increase in the risk of breast cancer. The new study looked at how the drugs affect levels of a hormone called prolactin. Increased levels of prolactin have been associated with breast cancer. Prolactin is an important hormone involved in puberty, pregnancy, and breastfeeding. However, many antipsychotics elevate prolactin levels and can produce side effects such as menstrual cycle irregularities, abnormal breast milk production, and abnormal breast tissue growth.

The researchers at Wash U Medicine tracked the medications provided to over half a million U.S. women.  The researchers found that many commonly prescribed older antipsychotic medications, and some newer ones, are associated with a significant increase in the risk of breast cancer. Antipsychotics are prescribed for a broad range of conditions, including depression, bipolar disorder, schizophrenia, dementia, and autism spectrum disorders.   This is the first study to compare newer antipsychotics to older drugs and to look at how the drugs affect levels of prolactin. The findings will be published in the February issue of the Journal of Clinical Psychopharmacology but are available online.

For more information:

Rahman T, Sahrmann JM, Olsen MA, Nickel KB, Miller JP, Ma C, Grucza RA. Risk of breast cancer with prolactin elevating antipsychotic drugs: an observational study of U.S. women (ages 18-64). Journal of Clinical Psychopharmacology. Published online Dec. 6, 2021.

This work was supported by an award from the Alvin J. Siteman Cancer Center; the National Cancer Institute and the National Center for Advancing Translational Sciences of the National Institutes of Health (NIH); the Taylor Family Institute for Innovative Psychiatric Research; and the Center for Brain Research in Mood Disorders. Grant numbers NCI CCSG P30CA091842, UL1 TR002345, R24 HS19455.

Washington University School of Medicine’s 1,700 faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children’s hospitals. The School of Medicine is a leader in medical research.