Male sex adversely impacts survival and myeloid malignancy risk in MGUS: a real-world population-based study

Monoclonal gammopathy of undetermined significance (MGUS) is a common plasma cell disorder with well described risks of progression to myeloma and lymphoplasmacytic lymphoma. Using data from an established UK population-based cohort of hematological malignancies and premalignancies, we investigated patient and disease characteristics, subsequent hematological malignancy, and survival in 4,651 people diagnosed with MGUS between 2005 and 2019. The 5-year net (relative) survival (disease-specific estimate of the probability of survival) for MGUS patients was 87.8% (95% confidence interval [CI]: 85.9-89.7), with males (83.8%; 95% CI: 81.0-86.6) more affected than females (92.2%; 95% CI: 89.7-94.7). The proportion of subsequent hematological malignancies was also higher in males than females (8.8% vs. 5.3%; P