Antipsychotic drugs: pro-cancer or anti-cancer? A systematic review

Important data was recently published on the potential genotoxic or carcinogenic effects of antipsychotics, as well as on their cytotoxic properties on cancer cells, that must be considered by psychiatrists in the benefit/risk ratio of their prescriptions.

To answer whether or not antipsychotics, as a class or only some specific molecules, may influence cancer risk among treated patients. METHODS ELIGIBILITY CRITERIA: All studies (in vitro, animal studies and human studies) concerning effects of antipsychotic drugs on cancer development were included. The search paradigm [neoplasms AND (antipsychotic agents OR neuroleptic OR phenothiazine)] was applied to Medline (1966-present) and Web of Science (1975-present).

Ninety-three studies were included in the qualitative synthesis. Results can be summarized as follows: (1) patients with schizophrenia may be less likely to develop cancer than the general population, (2) antipsychotics as a class cannot be considered at the moment as at risk for cancer, even if some antipsychotics have shown carcinogenic properties among rodents, (3) phenothiazines seem to have antiproliferative properties that may be useful in multidrug augmentation strategies in various cancer treatments, but their bad tolerance may decrease usage amongst non-psychotic patients, and (4) clozapine appears to have a separate status given that this molecule shows antiproliferative effects implied in agranulocytosis as well as a potential increased risk for leukemia.

Benefit/risk ratio regarding cancer risk is in favor of treating patients with schizophrenia with antipsychotic drugs. The practicing clinician should be reassuring on the subject of cancer risk due to antipsychotic drugs.