Antipsychotic drugs usage may contribute to development of breast cancer

China: A new study published in Epidemiology and Psychiatric Sciences shows that the prolactin-raising effects of certain drugs may be responsible for the modest link between antipsychotic usage and breast cancer.

Despite claims that antipsychotic usage in women increases the incidence of breast cancer, the available research is still ambiguous. As a result, this study was carried out by Janice Ching Nam Leung and colleagues to investigate the observational data already present in the literature and establish this hypothesized link.

The key findings of this study are summarized below:

1. Ultimately, nine observational studies were considered for review (N = 2 031 380) and seven for meta-analysis (N = 1 557 013), comprising five cohorts and four case-control studies.

2. All of the studies that were included received good marks (seven to nine stars). Antipsychotic usage was found to be significantly associated with breast cancer in six studies.

3. The link was higher when a greater degree of antipsychotic use, such as longer duration, was operationalized as the exposure.

4. A moderate relationship between the use of antipsychotics and breast cancer was shown by the pooled estimates of HRs retrieved from cohort studies and ORs from case-control studies, which were respectively 1.39 and 1.37.

In conclusion, antipsychotic usage was shown to be somewhat associated with breast cancer, with a more pronounced connection seen with prolactin-stimulating drugs and higher antipsychotic exposure levels. For a well-balanced clinical management choice, this risk, along with other known related adverse events, should be assessed against the anticipated therapeutic results.

Reference: 

Leung, J. C. N., Ng, D. W. Y., Chu, R. Y. K., Chan, E. W. W., Huang, L., Lum, D. H., Chan, E. W. Y., Smith, D. J., Wong, I. C. K., & Lai, F. T. T. (2022). Association of antipsychotic use with breast cancer: a systematic review and meta-analysis of observational studies with over 2 million individuals. Epidemiology and Psychiatric Sciences, 31(e61), e61. https://doi.org/10.1017/S2045796022000476