Investigating the Relationship between Schizophrenia and Incidence Risk of Breast Cancer: A Systematic Review and Meta-Analysis of Cohort Studies

Seyyed Muhammad  Mahdi Mahdavinoor; Saeed Kargar Soleimanabad; Amir-Hassan Bordbari; Aghil Mollaei; Leila Seddigh; Sorour Sarihi; Reihaneh  FirooziKhojastefar; Raziye Dehbozorgi; Sara Farhang

doi:10.18502/ijps.v19i4.16559

Seyyed Muhammad Mahdi Mahdavinoor Student Research Committee, Faculty of Allied Medical Sciences, Mazandaran University of Medical Sciences, Sari, Iran.
Saeed Kargar Soleimanabad Student Research Committee, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran.
Amir-Hassan Bordbari Student Research Committee, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran.
Aghil Mollaei Student Research Committee, Faculty of Health, Mazandaran University of Medical Sciences, Sari, Iran.
Leila Seddigh Department of Community Medicine, Tehran University of Medical Sciences, Tehran, Iran.
Sorour Sarihi Department of Human Nutrition and Hospitality Management, The University of Alabama, Tuscaloosa, Alabama, USA.
Reihaneh FirooziKhojastefar Department of Psychiatry, Roozbeh Hospital, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
Raziye Dehbozorgi Namazi Hospital, Shiraz University of Medical Sciences, Shiraz, Iran.
Sara Farhang University of Groningen, University Medical Center Groningen, University Center for Psychiatry, Rob Giel Research Center, Groningen, The Netherlands.

DOI: https://doi.org/10.18502/ijps.v19i4.16559

Keywords: Breast Cancer; Epidemiology; Meta-Analysis; Risk Factor; Schizophrenia

Abstract

Objective: Schizophrenia seems to have a complex association with various types of cancer, exerting a protective effect against some cancers while being a risk factor against some others. Therefore, we intended to conduct an updated systematic review and meta-analysis in order to examine the relationship between schizophrenia and the risk of breast cancer incidence.

Method: We did a systematic search of databases, namely Web of Science, Scopus, Embase, PubMed, and PsycINFO up to August 15, 2024. Screening and data extraction were performed independently. Data was analyzed using Stata16 software. We used the random effect model to pool the results, while the heterogeneity between studies was calculated using Cochran's Q test and (I²) index.

Results: We found 15 studies, among which 12 were included in this meta-analysis. The results indicated that the risk of breast cancer development is significantly increased in women with schizophrenia (SIR: 1.43, 95% CI: 1.08-1.85, P < 0.01; IRR: 1.19, 95% CI: 1.13-1.26, P < 0.01). Subgroup analysis revealed significant differences in the incidence of breast cancer rates among women with schizophrenia based on geographic location and duration of follow-up.

Conclusion: The results indicate that schizophrenia increases the risk of developing breast cancer. Therefore, taking preventive measures concerning breast cancer among women with schizophrenia is crucial. Additionally, regular screening programs should be implemented to ensure early diagnosis and treatment in case breast cancer is detected.