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 haematological malignancies and premalignancies, we investigated patient and disease characteristics, subsequent haematological malignancy, and survival in 4651 people diagnosed with MGUS 2005-2019. The 5-year net (relative) survival (disease-specific estimate of the probability of survival) of MGUS patients was 87.8% (95% Confidence Interval 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 haematological malignancies was also higher in males than females (8.8% versus 5.3%; P.