title: Chronic lymphocytic leukaemia and small lymphocytic lymphoma: overview of the descriptive epidemiology.
abstract: The 2001 World Health Organization classification scheme considers B-cell chronic lymphocytic leukaemia (CLL) and small lymphocytic lymphoma (SLL) in an aggregate category (CLL/SLL) because of shared clinicopathological features. We have estimated age-adjusted incidence rates (IRs) of CLL and SLL in the population-based Surveillance, Epidemiology and End Results Program in the United States to analyse patterns of CLL and SLL separately and jointly. Age-standardized to the 2000 US population, overall IRs were 3.83 per 100 000 person-years for CLL (n = 15 676) and 1.31 for SLL (n = 5382) during 1993-2004. Incidence of the combined entity, CLL/SLL, was 90% higher among males compared to females, and the male:female IR ratio was significantly higher for CLL (1.98) than for SLL (1.67). CLL/SLL IRs were 25% and 77% lower among Blacks and Asian/Pacific Islanders, respectively, compared to Whites. A significant reporting delay was evident for CLL but not for SLL, so that CLL/SLL temporal trends must be interpreted cautiously. CLL and SLL IRs increased exponentially with age among all gender/race groups, with CLL IRs increasing more steeply with advancing age than SLL. Avenues of future research include assessment of delayed- and under-reporting to cancer registries and exploration of race, gender, and age effects in epidemiological studies.
authors.affiliation: Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, Department of Health and Human Services (DHHS), National Cancer Institute (NCI), National Institutes of Health (NIH), Bethesda, MD, USA. doresg@mail.nih.gov
authors.forename: Graça M
authors.initials: GM
authors.lastname: Dores
authors.forename: William F
authors.initials: WF
authors.lastname: Anderson
authors.forename: Rochelle E
authors.initials: RE
authors.lastname: Curtis
authors.forename: Ola
authors.initials: O
authors.lastname: Landgren
authors.forename: Evgenia
authors.initials: E
authors.lastname: Ostroumova
authors.forename: Elizabeth C
authors.initials: EC
authors.lastname: Bluhm
authors.forename: Charles S
authors.initials: CS
authors.lastname: Rabkin
authors.forename: Susan S
authors.initials: SS
authors.lastname: Devesa
authors.forename: Martha S
authors.initials: MS
authors.lastname: Linet
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D044466:Asian People / Q000706:statistics & numerical data; D044383:Black People / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D015994:Incidence; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000453:epidemiology* / Q000208:ethnology; D008297:Male; D008875:Middle Aged; D018426:SEER Program; D017678:Sex Distribution; D014481:United States / Q000453:epidemiology; D044465:White People / Q000706:statistics & numerical data; D001741:Black or African American