Schizophrenia and Bone Marrow Malignancy - A Distinctive Prospect Capable of Reshaping the Future: A Nationwide Analysis

Abstract:

Background: The increased incidence of solid cancers in schizophrenia is well documented in literature. However, emerging evidence suggests an unusual phenomenon - schizophrenia being cured by bone marrow transplantation in bone marrow malignancies [BM malignancies]. It was also studied that long term use of clozapine and other antipsychotics increase the risk of BM malignancies. This raises multiple questions - Is there an association between schizophrenia and BM malignancies? Is there an immune element in the pathogenesis of schizophrenia? Is schizophrenia a paraneoplastic phenomenon? In this study, we tried to estimate the prevalence and impact of schizophrenia in BM malignancies using a national database.

Methods: The national inpatient sample database (2016-2020) was utilized for the study and ICD-10 codes were used to identify hospitalized patients with BM malignancies. We included patients with three main BM malignancies (multiple myeloma[MM], myeloproliferative neoplasm[MPN] and leukemia). This cohort was stratified for the prevalence of schizophrenia. Multivariate analysis assessed the influence of schizophrenia on mortality and resource utilization in hospitalized patients with BM malignancies.

Results: Out of 728, 825 hospitalized patients with MPN, 8750 had schizophrenia. Among 591,745 hospitalized patients with MM, 2360 had schizophrenia. 1,195,310 hospitalized leukemia patients were identified, of which 5900 had schizophrenia. Patients with schizophrenia were identified to be younger. Schizophrenia also had higher resource utilization in BM malignancies marked by increased length of stay and hospital cost, however there was a statistically significant increase in mortality only in leukemia patients with schizophrenia. [Table-1]

Conclusion: Our study reveals a higher prevalence of schizophrenia in hospitalizations with BM malignancies. It also concludes that schizophrenia portends worse outcomes in terms of mortality in leukemia patients and leads to a higher resource utilization in BM malignancies.

Clinical implications: A plausible explanation for these findings could be due to the chemotaxis of hematopoietic stem cells to the brain and secretion of bioactive molecules interfering with neurogenesis. Our study supports the existing hypothesis that schizophrenia may have an immune origin and targeting the inflammation with immunomodulators or bone marrow transplantation could potentially cure schizophrenia. This could lay the foundations for preeminent future research to study this association and revolutionize the management of schizophrenia in patients with BM malignancies.