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Updated: Mar 21, 2026
Immunoglobulin Gene Sequence Analysis In Chronic Lymphocytic Leukemia: From Patient Material To Sequence Interpretation
Published on: November 26, 2018
[Chronic lymphocytic leukemia in Iceland from 2003 to 2013: Incidence, presentation and diagnosis]
Insights
The incidence of chronic lymphocytic leukemia (CLL) in Iceland mirrors Western countries, with most patients showing elevated lymphocyte counts before diagnosis. Improved cancer registry data is needed, especially for flow cytometry diagnoses.
Area of Science:
- Hematology
- Oncology
- Epidemiology
Background:
- Chronic lymphocytic leukemia (CLL) is a B-cell malignancy with monoclonal B-cell lymphocytosis (MBL) as a precursor.
- CLL is typically indolent and often incidentally diagnosed.
- Limited data exists on CLL in Iceland, including incidence, diagnosis, and MBL prevalence.
Purpose of the Study:
- To determine the incidence and characteristics of CLL in Iceland from 2003-2013.
- To investigate diagnostic methods, symptoms, and survival rates for CLL patients in Iceland.
- To assess the prevalence of elevated lymphocyte counts preceding CLL diagnosis.
Main Methods:
- Retrospective descriptive study of 161 CLL patients diagnosed in Iceland (2003-2013).
- Data sourced from the Icelandic Cancer Registry and hospital records.
- Analysis included patient demographics, symptoms, diagnosis, treatment, and survival data.
Main Results:
- The incidence of CLL was 4.55/100,000, with a mean age at diagnosis of 70.9 years.
- 44.4% of patients presented with symptoms; 33.3% received chemotherapy.
- 85.9% of patients had elevated lymphocyte counts prior to CLL diagnosis; 5-year survival was 70%.
Conclusions:
- CLL incidence in Iceland is comparable to other Western nations.
- Cancer registry data requires improvement, particularly for flow cytometry-based diagnoses.
- A significant proportion of CLL cases exhibit preceding elevated lymphocyte counts.
Introduction:
Chronic lymphocytic leukemia (CLL) is characterized by the proliferation of monoclonal B-lymphocytes. MBL (monoclonal B-cell lymphocytosis) is considered a precursor state of the disease. Although CLL is incurable it is an indolent disorder and often detected incidentally on routine blood counts. Until now little information has been available on CLL in Iceland, including the incidence, diagnosis, symptoms or MBL precursor state.
Material And Methods:
This is a retrospective, descriptive study including CLL patients diagnosed in Iceland over the years 2003-2013. Registries of patients with a CLL diagnosis were obtained from the Icelandic Cancer Registry, Landspitali National University Hospital and the Medical Center in Mjódd. Medical records were reviewed for information on symptoms, diagnosis and treatment. Survival data and causes of death were obtained from national registries.
Results:
The number of patients diagnosed with CLL over the study period was 161 (109 males, 52 females). The calculated incidence was 4.55/100,000, and the age-standardized incidence was 3.00/100,000. Mean age at diagnosis was 70.9 years (range 35-96 years). The Icelandic Cancer Registry lacked information on 28 patients (17.4%). The initial diagnosis of CLL was obtained exclusively with flow cytometry in 47.2% of cases. Symptoms were present at diagnosis in 67 of 151 patients (44.4%). One third of the group received chemotherapy and the average time to treatment was 1.3 years. Five-year survival was 70% and median survival was 9.4 years. Elevated lymphocyte counts (≥4,0x109/L) in peripheral blood prior (0.1 to 13.4 years) to diagnosis of CLL was identified in 85 of 99 CLL patients (85.9%).
Conclusion:
The incidence of CLL in Iceland is similar to other Western countries. The registration of CLL cases in the Icelandic Cancer Registry must be improved, especially in cases where diagnosis is based solely on flow cytometry. Elevated lymphocyte counts were present in a large proportion of cases prior to the diagnosis of CLL.
Key Words:
Chronic lymphocytic leukemia, CLL, monoclonal B-cell lymphocytosis, MBL, incidence, diagnosis. Correspondence: Anna Margret Halldorsdottir, annamha@landspitali.is.
