According to a study, using antipsychotic medications increases your chance of breast cancer.
In the world’s first systematic review and meta-analysis of observational studies involving over 2 million people, a research team from the Center for Safe Medication Practice and Research (CSMPR), Department of Pharmacology and Pharmacy, LKS Faculty of Medicine, The University of Hong Kong (HKUMed) estimated a moderate association between antipsychotic use and breast cancer by over 30%. This emphasises how crucial it is to weigh the risks and benefits before prescribing antipsychotics to high-risk individuals.
Epidemiology and Psychiatric Sciences has published the findings. Patients with a variety of mental conditions, such as schizophrenia, bipolar disorder, major depressive disorder, and dementia, are frequently given antipsychotic medications.
Antipsychotic usage is thought to be at least partially responsible for the elevated risk of breast cancer in people with schizophrenia and bipolar illness, as has been regularly observed. Among the potential causes include antipsychotic-induced hyperprolactinemia, antipsychotic-mediated weight gain, and antipsychotic-users’ worsening lifestyles.
The evidence of the aforementioned link is still not conclusive due to the complex mechanism and several interrelated risk variables. Determining the relationship between antipsychotic usage and breast cancer required a systematic review and meta-analysis, which was carried out by CSMPR researchers. For the review and the meta-analysis, nine observational studies with nearly 2 million adults were incorporated. The Newcastle-Ottawa Scale, a standardised tool for evaluating study quality, gave each of these studies a high quality rating (seven to nine stars).
According to this research, six out of the nine studies indicated a connection between using antipsychotic drugs and a higher risk of breast cancer. The meta-analysis calculated a moderately favourable correlation between antipsychotic usage and an enhanced risk of more than 30%. The degree of antipsychotic exposure, such as a longer length of usage, is linked to a higher risk of breast cancer, particularly for antipsychotics with prolactin-elevating effects, according to some reviewed data. A significant increase in risk was observed among those exposed for at least five years by approximately 60%, according to a major Finnish case-control study that used electronic health records to compare those exposed for longer periods of time to those exposed for less time.
“With the increasingly prevalent use of antipsychotics worldwide, including off-label use, we believe a comprehensive clinical assessment should be made for patients based on the overall safety profile of antipsychotics before prescription,” commented Dr. Francisco Lai Tsz-tsun, Research Assistant Professor of the Department of Pharmacology and Pharmacy, HKUMed, the corresponding author of this study.
Hyperprolactinemia and other potential side effects of antipsychotics, such as central obesity, diabetes, and cardiovascular disease, may help to explain the increased risk of breast cancer. According to the results of this study, patients who have breast cancer risk factors should ideally avoid antipsychotics with known prolactin-elevating effects. Before administering prolactin-elevating antipsychotics, appropriate counselling is required, and prolactin level monitoring may be an option. Antipsychotic-induced hyperprolactinemia must be treated quickly.
This study underlines the possibility that breast cancer could be an uncommon but possible side event of antipsychotic drugs, despite significant limitations including unmeasured confounding effects.
Parvathy Sukumaran 
