REVIEW OF: Rahman T et al, J Clin Psychopharmacol 2022;42(1):7–16

STUDY TYPE: Observational study

When we select antipsychotic medications for our patients, we typically consider adverse effects like extrapyramidal symptoms, weight gain, and diabetes. But what about the risk of cancer?

A large observational study (n=540,737) evaluated the risk of breast cancer in US women (aged 18–64 years) taking antipsychotic drugs. When compared with women taking anticonvulsants and/or lithium, the risk of breast cancer in women on antipsychotic medications was 35% higher. For women taking highly prolactin-elevating antipsychotics (eg, haloperidol, paliperidone, and risperidone) and moderately prolactin-elevating antipsychotics (eg, lurasidone and olanzapine), the risks were even higher at 62% and 54%, respectively.

On the other hand, antipsychotics that produced mild or no prolactin elevation (eg, aripiprazole, clozapine, quetiapine, and ziprasidone) were not associated with an increased risk of breast cancer.

When analyses were stratified by age (18–50 years vs 51–64 years), the study found the risk of breast cancer was much higher in younger women using moderately prolactin-elevating antipsychotics compared with older women on these medications (90% vs 40%).

Carlat Take

For female patients and particularly for younger patients at elevated risk of breast cancer, use antipsychotics that produce little or no prolactin elevation whenever possible. If a female patient takes a prolactin-elevating agent like risperidone or haloperidol, monitor serum prolactin levels and mitigate hyperprolactinemia by switching antipsychotics, decreasing medication doses, and/or adding a partial dopamine agonist like aripiprazole. For more on hyperprolactinemia, see CHPR, Jul/Aug/Sept 2022.