title: Risk of non-hematologic cancer in individuals with high-count monoclonal B-cell lymphocytosis.
abstract: It is unknown whether individuals with monoclonal B-cell lymphocytosis (MBL) are at risk for adverse outcomes associated with chronic lymphocytic leukemia (CLL), such as the risk of non-hematologic cancer. We identified all locally residing individuals diagnosed with high-count MBL at Mayo Clinic between 1999 and 2009 and compared their rates of non-hematologic cancer with that of patients with CLL and two control cohorts: general medicine patients and patients who underwent clinical evaluation with flow cytometry but who had no hematologic malignancy. After excluding individuals with prior cancers, there were 107 high-count MBL cases, 132 CLL cases, 589 clinic controls and 482 flow cytometry controls. With 4.6 years median follow-up, 14 (13%) individuals with high-count MBL, 21 (4%) clinic controls (comparison MBL P<0.0001), 18 (4%) flow controls (comparison MBL P=0.0001) and 16 (12%) CLL patients (comparison MBL P=0.82) developed non-hematologic cancer. On multivariable Cox regression analysis, individuals with high-count MBL had higher risk of non-hematologic cancer compared with flow controls (hazard ratio (HR)=2.36; P=0.04) and borderline higher risk compared with clinic controls (HR=2.00; P=0.07). Patients with high-count MBL appear to be at increased risk for non-hematologic cancer, further reinforcing that high-count MBL has a distinct clinical phenotype despite low risk of progression to CLL.
authors: University of South Dakota Sanford School of Medicine, Vermillion, SD, USA.|Avera Medical Group Oncology and Hematology, Sioux, SD, USA.
authors: B M
authors: BM
authors: Solomon
authors: Mayo Clinic Department of Health Sciences Research, Rochester, MN, USA.
authors: K G
authors: KG
authors: Chaffee
authors: Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
authors: J
authors: J
authors: Moreira
authors: Mayo Clinic Department of Medicine, Rochester, MN, USA.|Division of Hematology, Mayo Clinic, Rochester, MN, USA.
authors: S M
authors: SM
authors: Schwager
authors: Mayo Clinic Department of Health Sciences Research, Rochester, MN, USA.
authors: J R
authors: JR
authors: Cerhan
authors: Mayo Clinic Department of Medicine, Rochester, MN, USA.|Division of Hematology, Mayo Clinic, Rochester, MN, USA.
authors: T G
authors: TG
authors: Call
authors: Mayo Clinic Department of Medicine, Rochester, MN, USA.|Division of Hematology, Mayo Clinic, Rochester, MN, USA.
authors: N E
authors: NE
authors: Kay
authors: Mayo Clinic Department of Health Sciences Research, Rochester, MN, USA.
authors: S L
authors: SL
authors: Slager
authors: Mayo Clinic Department of Medicine, Rochester, MN, USA.|Division of Hematology, Mayo Clinic, Rochester, MN, USA.
authors: T D
authors: TD
authors: Shanafelt
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001402:B-Lymphocytes; D005260:Female; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000150:complications; D008218:Lymphocytosis / Q000150:complications*; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000209:etiology*; D016016:Proportional Hazards Models; D012306:Risk