Causal associations between schizophrenia and cancers risk: a Mendelian randomization study

Abstract

BackgroundPrevious observational studies have reported inconsistent findings regarding the incidence of cancer in patients with schizophrenia compared to the general population. The causal relationship between schizophrenia and cancer remains unclear and requires further investigation.ObjectiveTo investigate the causal relationship between schizophrenia and cancer.MethodsIn this study, a two-sample Mendelian randomization (MR) analysis was conducted using publicly available genome-wide association studies to determine the causal relationship. The effect estimates were calculated using the random-effects inverse-variance-weighted method.ResultsWe determined a causal relationship between genetic predisposition to schizophrenia and cancer, with schizophrenia increasing lung cancer (odds ratio (OR) = 1.0007; 95% confidence interval (CI), 1.0001-1.0013; p = 0.0192), thyroid cancer (OR = 1.5482; CI, 1.1112-2.1569; p =0.0098),colorectal cancer (OR = 1.0009; CI, 1.0001-1.0018; p = 0.0344), ovarian cancer (OR = 1.0770; CI, 1.0352-1.1203; p = 0.0002), breast cancer (OR = 1.0011; CI, 1.0001- 1.0022; p =0.0352) and reduced the risk of malignant neoplasm of the stomach (OR = 0.8502; CI, 0.7230-0.9998; p = 0.0496).ConclusionsThis study conducted a two-sample MR analysis and discovered a positive causal relationship between schizophrenia and breast, ovarian, thyroid, lung, and colorectal cancers. On the other hand, an inverse causal relationship was found between schizophrenia and malignant neoplasm of the stomach.

Commentary: Causal associations between schizophrenia and cancers risk: a Mendelian randomization study

“…This update prompts a reevaluation of the validity of the conclusions drawn in the article by Zhou et al. ( 1 ) regarding these types of cancer, as well as considering the possibility that alternative findings may arise upon replacement of the revised data.…”

“…However, the population included in the Cancer-related outcomes section of Zhou et al. ( 1 ) consists solely of individuals of European ancestry. The presence of diverse ethnicities in the exposure and outcome populations may introduce population stratification bias, potentially impacting the robustness of the study’s conclusions.…”

“…In this context, we read with interest the study ‘‘Causal associations between schizophrenia and cancers risk: a Mendelian randomization study’’ by Zhou et al. ( 1 ). To our knowledge, the article by Zhou et al.…”

“…To our knowledge, the article by Zhou et al. ( 1 ) is the most comprehensive current MR article assessing the causal relationship between schizophrenia and cancer risk. However, the trial appeared to suffer from some data issues as well as methodological biases.…”

“…In recent years, advancements in statistical methods and high-throughput sequencing technologies have enhanced the efficacy of Mendelian randomization (MR) in elucidating potential causal relationships between exposures and outcomes. In this context, we read with interest the study ''Causal associations between schizophrenia and cancers risk: a Mendelian randomization study'' by Zhou et al (1). To our knowledge, the article by Zhou et al (1) is the most comprehensive current MR article assessing the causal relationship between schizophrenia and cancer risk.…”