Most Antipsychotics May Increase the Risk of Breast Cancer in Women with Schizophrenia: Study

Woman taking certain antipsychotics for an extended period of time to treat schizophrenia may be at a significantly increased risk of developing breast cancer, according to the findings of a new study.

In a report published late last month in the medical journal The Lancet, Finnish researchers established a strong relationship between the use of prolactin-increasing antipsychotics prescribed to treat women with schizophrenia and the development of lobular adenocarcinoma, which is a form of breast cancer.

Antipsychotic medications have become widely used across the medical community to treat those with schizophrenia, bipolar disorder, ADHD, depression and Alzheimer’s disease.

Researchers used a nationwide Finnish registry to review patient data on 30,785 women diagnosed with schizophrenia who were prescribed antipsychotics between 1972 and 2014, and compared the rate of breast cancer diagnosis to a control group of 5,339 patients prescribed antipsychotics without a schizophrenia diagnosis.

According to their findings, 1,069 woman diagnosed with schizophrenia who were prescribed either typical or atypical antipsychotics developed breast cancer between January 1, 2000, and December 31, 2017, compared to a statistically lower rate of those in the control group.

Researchers determined women with schizophrenia taking prolactin-increasing antipsychotics for five years or more were most associated with the development of lobular adenocarcinoma, which is a type of breast cancer that begins in the milk-producing glands (lobules) of the breast. Less than five years of being prescribed prolactin-increasing or prolactin-sparing antipsychotics were not associated with an increased risk of breast cancer development.

However, the study found prolactin-sparing antipsychotics, including clozapine, Seroquel, and Abilify did not show any significant sign of breast cancer risk throughout a five year span of use.

Researchers warned that long-term exposure to prolactin-increasing antipsychotics is significantly associated with increased odds of breast cancer, and that prescribing doctors should closely monitor patients for hyperprolactinemia.

While antipsychotics have become increasingly popular, past studies have shown antipsychtic drugs have serious potential side effects, including reduced alertness, decreased blood pressure, increased risk of diabetes and heart disease, and even movement disorders that resemble those seen in Parkinson’s.

In January 2019, a study published in the medical journal JAMA Psychiatry, found children and young adults taking antipsychotic faced an increased risk of sudden death from cardiovascular or metabolic causes.

A 2016 study published in the May issue of JAMA Neurology found the mortality rates of patients with Parkinson’s disease who took antipsychotics were much higher compared with matched patients. The study highlighted the risks many nursing home residents face from being given antipsychotics as a form of chemical restraint.