A typical hematological premalignant disease that is understudied in screening cohorts is monoclonal B-cell lymphocytosis (MBL). The size of the B-cell clone allows MBL to be divided into low-count (LC) and high-count (HC) varieties.
For a study, researchers performed an MBL screening using the Mayo Clinic Biobank and assessed its relationship with subsequent hematologic malignancy and overall survival (OS). They used cohorts for both the discovery and validation phases of the two-stage study design. Using an eight-color flow cytometry test, they checked for MBL. Hematological malignancies and deaths were extracted from medical data. With age and gender taken into account, they utilized Cox regression to assess relationships, estimate hazard ratios, and calculate 95% CIs.
The median follow-up for OS was 34.4 months, with 621 people dying during that period. They found 1,712 (17%) people with MBL (95% LC-MBL). The OS was not associated with LC-MBL patients (P =.78), but it was with HC-MBL patients (hazard ratio, 1.8; 95% CI, 1.1-3.1; P =.03). In the discovery cohort, 31 people with a median follow-up of 10.0 years acquired hematological cancers, with lymphoid malignancies accounting for two-thirds of those cases. In comparison to controls, MBL was linked to a 3.6-fold increased risk of hematological malignancy and a 7.7-fold increased risk of lymphoid malignancies (95% CI: 3.1-19.2; P< .001). 4.3-fold greater risk of lymphoid malignancies was linked to LC-MBL (95% CI, 1.4-12.7; P =.009), whereas the 74-fold increased risk was linked to HC-MBL (95% CI, 22-246; P< .001).
Although they found similar survival rates for those with and without LC-MBL in the large screening population, those with LC-MBL had a fourfold higher risk of lymphoid malignancies. There was growing evidence that the illness known as LC-MBL, which affected 8 to 10 million persons in the United States, had clinical repercussions.
