Monoclonal Gammopathy Prevalence in Newly Diagnosed Prostate Cancer Patients: A Correlative Perspective Observational Study

Abstract

Background: While there have been limited reports suggesting a possible association between Monoclonal Gammopathy (MG) of Undetermined Significance (MGUS) and prostate cancer, a clear biological correlation has yet to be established. Methods: In this study, we aimed to investigate the incidence of MGUS in a cohort of 168 patients undergoing TRUSBx for suspected prostate cancer between September 2022 and December 2023. Results: Our findings revealed that the incidence of MGUS, identified by serum immunofixation or abnormal free light chain ratio, was significantly higher in this cohort than the anticipated global incidence (33.93% vs. 5%). Furthermore, the prevalence of MGUS was higher in patients with a Gleason Score (GS) exceeding 7 compared to those with GS6 or with ASAP/HG PIN (34.2% vs. 28% vs. 25%, respectively). A systematic univariate analysis of 42 clinical and biological variables identified fibrinogen levels, neutrophil-to-lymphocyte ratio, and the percentage of alpha2 band in serum protein electrophoresis as significantly associated with MGUS presence. Conclusions: These findings suggest that a systemic inflammatory status and a highest GS in these patients may increase the likelihood of detecting an MGUS. To our knowledge, this study is the first to suggest an association between prostate cancer and MG. Further and larger studies are required to confirm the increased prevalence of MGUS within this target population and to establish the clinical relevance of these precocious diagnoses.