Antipsychotic Use and Risk of Breast Cancer in Women With Severe Mental Illness: Replication of a Nationwide Nested Case-Control Database Study

Marco Solmi; Markku Lähteenvuo; Antti Tanskanen; Olivier Corbeil; Ellenor Mittendorfer-Rutz; Christoph U Correll; Jari Tiihonen; Heidi Taipale

doi:10.1093/schbul/sbae058

Antipsychotic Use and Risk of Breast Cancer in Women With Severe Mental Illness: Replication of a Nationwide Nested Case-Control Database Study

Schizophr Bull. 2024 Apr 30:sbae058. doi: 10.1093/schbul/sbae058. Online ahead of print.

Authors

Marco Solmi^{1

2

3

4

5}, Markku Lähteenvuo⁶, Antti Tanskanen^{6

7

8}, Olivier Corbeil^{9

10}, Ellenor Mittendorfer-Rutz⁷, Christoph U Correll^{5

11

12}, Jari Tiihonen^{6

7

8}, Heidi Taipale^{6

7

8}

Affiliations

¹ Department of Psychiatry, University of Ottawa, Ontario, Canada.
² SCIENCES LAB, Department of Mental Health, The Ottawa Hospital, Ontario, Canada.
³ Ottawa Hospital Research Institute (OHRI), Clinical Epidemiology Program, University of Ottawa, Ontario, Canada.
⁴ School of Epidemiology and Public Health, Faculty of Medicine, University of Ottawa, Ontario, Canada.
⁵ Department of Child and Adolescent Psychiatry, Charité Universitätsmedizin, Berlin, Germany.
⁶ Department of Forensic Psychiatry, University of Eastern Finland, Niuvanniemi Hospital, Kuopio, Finland.
⁷ Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
⁸ Center for Psychiatry Research, Stockholm City Council, Stockholm, Sweden.
⁹ Faculty of Pharmacy, Université Laval, Quebec, Canada.
¹⁰ Department of Pharmacy, Quebec Mental Health University Institute, Quebec, Canada.
¹¹ Department of Psychiatry, The Zucker Hillside Hospital, Glen Oaks, NY.
¹² Department of Psychiatry and Molecular Medicine, Donald and Barbara School of Medicine at Hofstra/Northwell, Hempstead, NY.

PMID: 38687213
DOI: 10.1093/schbul/sbae058

Abstract

Background and hypothesis: Breast cancer is more prevalent in women with severe mental illness than in the general population, and use of prolactin-increasing antipsychotics may be a contributing factor.

Study design: A nested case-control study was conducted using the Swedish nationwide registers (inpatient/outpatient care, sickness absence, disability pension, prescribed drugs, cancers). All women aged 18-85 years with schizophrenia/schizoaffective/other nonaffective psychotic disorder/bipolar disorder and breast cancer (cases) were matched for age, primary psychiatric diagnosis, and disease duration with five women without cancer (controls). The association between cumulative exposure to prolactin-increasing/prolactin-sparing antipsychotics and breast cancer was analyzed using conditional logistic regression, adjusted for comorbidities and co-medications.

Study results: Among 132 061 women, 1642 (1.24%) developed breast cancer between 2010 and 2021, at a mean age of 63.3 ± 11.8 years. Compared with 8173 matched controls, the odds of breast cancer increased in women with prior exposure to prolactin-increasing antipsychotics for 1-4 years (adjusted odds ratio [aOR] = 1.20, 95% confidence interval [CI] = 1.03-1.41), and for ≥ 5 years (aOR = 1.47, 95%CI = 1.26-1.71). There were no increased or decreased odds of breast cancer with exposure to prolactin-sparing antipsychotics of either 1-4 years (aOR = 1.17, 95%CI = 0.98-1.40) or ≥5 years (aOR = 0.99, 95%CI = 0.78-1.26). The results were consistent across all sensitivity analyses (ie, according to different age groups, cancer types, and primary psychiatric diagnosis).

Conclusions: Although causality remains uncertain, exposure to prolactin-elevating antipsychotics for ≥ 1 year was associated with increased odds of breast cancer in women with severe mental illness. When prescribing antipsychotics, a shared decision-making process should consider individual risk factors for breast cancer.

Keywords: bipolar disorder; hyperprolactinemia; prolactin; psychiatry; psychotic disorder; schizoaffective disorder.

Abstract

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