High dose antipsychotic users at increased risk of breast cancer
China: According to a research paper published in Frontiers in Oncology, researchers have concluded that those exposed to antipsychotics at higher doses are at greater risk of breast cancer, and their use increases the mortality in breast cancer patients. This is the first meta-analysis suggesting that primary care providers should consider the screening of antipsychotic users for breast cancer more frequently.
Antipsychotic users are people with schizophrenia, depression, bipolar disorder, post-traumatic stress disorder and obsessive-compulsive disorder. The association of antipsychotics with breast cancer remains controversial. There needs to be more data on this.
Zheng Gao and colleagues conducted a study to investigate the relationship between antipsychotics and breast cancer.
The study summary includes:
- The researchers did a systematic review and meta-analysis of 11 studies with almost 1,499,001 participants.
- The data was collected from Scopus, Embase, Web of Science, PubMed, Cochrane Library, and Hebei Medical University Library.
- There were six retrospective cohort studies, one prospective cohort study, and four case-control studies.
- The primary outcome of the study was breast cancer.
- R version 4.1.2 was used to perform a meta-analysis.
- Antipsychotic use (vs non-users) was associated with an overall 23% increase in breast cancer risk with an OR of 1.23.
- High-dose groups were at high risk for breast cancer compared to the low-dose groups in 2 separate studies. The risk increased by 39% in one study having OR 1.39, and by 33%, having OR 1.33, in another study.
- Antipsychotic use (vs nonuse) increased the risk for all-cause mortality by 54 %, having OR 1.54.
- No difference in risk was observed between atypical (olanzapine) versus typical ( haloperidol) antipsychotics having OR 1.23.
- Between prolactin-increasing versus prolactin-sparing antipsychotics, there was no difference in the risk involved with OR, 1.13.
To conclude, this meta-analysis found that antipsychotics are an independent risk factor for breast cancer. High doses pose more risks than low doses. There is a higher risk for all-cause mortality in users with breast cancer.
The researchers said oncologists should consider more aggressive breast cancer treatment of women who receive antipsychotics and who already have breast cancer.
The limitations of the study include all 11 studies were observational, 4 were case-control designs, a weaker form of evidence and High heterogeneity across studies.
Reference:
Gao Z, Xi Y, Shi H, Ni J, Xu W, Zhang K. Antipsychotic exposure is an independent risk factor for breast cancer: A systematic review of epidemiological evidence. Front Oncol. 2022 Dec 15;12:993367. DOI: 10.3389/fonc.2022.993367. PMID: 36591471; PMCID: PMC9798228.
