Incidence of chronic lymphocytic leukemia in Olmsted County, Minnesota, 1935 through 1989, with emphasis on changes in initial stage at diagnosis

T. G. Call, R. L. Phyliky, P. Noel, Thomas Matthew Habermann, C. M. Beard, W. M. O'Fallon, L. T. Kurland

Research output: Contribution to journalArticle

70 Citations (Scopus)

Abstract

Objective: To determine whether the stage at the time of diagnosis of chronic lymphocytic leukemia (CLL) had changed during a 55-year period. Design: We conducted a study of the cohort of residents of Olmsted County, Minnesota, who had been diagnosed as having CLL during the period from 1935 through 1989. Material and Methods: By analysis of medical records, patients with CLL were characterized by Rai stage, absolute lymphocyte count, age at diagnosis, need for therapy, and reported cause of death in nonsurvivors. Trends for these variables were analyzed by decade throughout the study period. Results: The overall annual incidence rate of CLL per 100,000 population in Olmsted County increased from 2.6 in the 1935 through 1944 period to 5.4 in the 1975 through 1984 period; however, the increasing rate was found only for those 50 years of age or older and was especially dramatic for those 75 years old or older. Analysis of Rai stage over time demonstrated an increase in the proportion of cases diagnosed as Rai stage 0. In addition, the median absolute lymphocyte count decreased, the median time to initiation of therapy increased, and the median age of patients with Rai stage 0 CLL at the time of diagnosis increased over time. Overall, 54% of patients had received therapy for CLL by the time of last follow-up. Among the nonsurvivors, CLL was documented as the underlying or a contributing cause of death in 69%. Conclusion: The overall increase in CLL was thought to be due to enhanced methods of early diagnosis and improved health care for the elderly population. Thus, artifact may best explain the observed trend, although we cannot exclude the possibility of an actual increase in incidence rates over time.

Original languageEnglish (US)
Pages (from-to)323-328
Number of pages6
JournalMayo Clinic Proceedings
Volume69
Issue number4
StatePublished - 1994

Fingerprint

B-Cell Chronic Lymphocytic Leukemia
Incidence
Lymphocyte Count
Cause of Death
Artifacts
Population
Medical Records
Early Diagnosis
Cohort Studies
Therapeutics
Delivery of Health Care

ASJC Scopus subject areas

  • Medicine(all)

Cite this

Incidence of chronic lymphocytic leukemia in Olmsted County, Minnesota, 1935 through 1989, with emphasis on changes in initial stage at diagnosis. / Call, T. G.; Phyliky, R. L.; Noel, P.; Habermann, Thomas Matthew; Beard, C. M.; O'Fallon, W. M.; Kurland, L. T.

In: Mayo Clinic Proceedings, Vol. 69, No. 4, 1994, p. 323-328.

Research output: Contribution to journalArticle

Call, T. G. ; Phyliky, R. L. ; Noel, P. ; Habermann, Thomas Matthew ; Beard, C. M. ; O'Fallon, W. M. ; Kurland, L. T. / Incidence of chronic lymphocytic leukemia in Olmsted County, Minnesota, 1935 through 1989, with emphasis on changes in initial stage at diagnosis. In: Mayo Clinic Proceedings. 1994 ; Vol. 69, No. 4. pp. 323-328.
@article{8cd4ae9605ad4eed94d5754f6890b816,
title = "Incidence of chronic lymphocytic leukemia in Olmsted County, Minnesota, 1935 through 1989, with emphasis on changes in initial stage at diagnosis",
abstract = "Objective: To determine whether the stage at the time of diagnosis of chronic lymphocytic leukemia (CLL) had changed during a 55-year period. Design: We conducted a study of the cohort of residents of Olmsted County, Minnesota, who had been diagnosed as having CLL during the period from 1935 through 1989. Material and Methods: By analysis of medical records, patients with CLL were characterized by Rai stage, absolute lymphocyte count, age at diagnosis, need for therapy, and reported cause of death in nonsurvivors. Trends for these variables were analyzed by decade throughout the study period. Results: The overall annual incidence rate of CLL per 100,000 population in Olmsted County increased from 2.6 in the 1935 through 1944 period to 5.4 in the 1975 through 1984 period; however, the increasing rate was found only for those 50 years of age or older and was especially dramatic for those 75 years old or older. Analysis of Rai stage over time demonstrated an increase in the proportion of cases diagnosed as Rai stage 0. In addition, the median absolute lymphocyte count decreased, the median time to initiation of therapy increased, and the median age of patients with Rai stage 0 CLL at the time of diagnosis increased over time. Overall, 54{\%} of patients had received therapy for CLL by the time of last follow-up. Among the nonsurvivors, CLL was documented as the underlying or a contributing cause of death in 69{\%}. Conclusion: The overall increase in CLL was thought to be due to enhanced methods of early diagnosis and improved health care for the elderly population. Thus, artifact may best explain the observed trend, although we cannot exclude the possibility of an actual increase in incidence rates over time.",
author = "Call, {T. G.} and Phyliky, {R. L.} and P. Noel and Habermann, {Thomas Matthew} and Beard, {C. M.} and O'Fallon, {W. M.} and Kurland, {L. T.}",
year = "1994",
language = "English (US)",
volume = "69",
pages = "323--328",
journal = "Mayo Clinic Proceedings",
issn = "0025-6196",
publisher = "Elsevier Science",
number = "4",

}

TY - JOUR

T1 - Incidence of chronic lymphocytic leukemia in Olmsted County, Minnesota, 1935 through 1989, with emphasis on changes in initial stage at diagnosis

AU - Call, T. G.

AU - Phyliky, R. L.

AU - Noel, P.

AU - Habermann, Thomas Matthew

AU - Beard, C. M.

AU - O'Fallon, W. M.

AU - Kurland, L. T.

PY - 1994

Y1 - 1994

N2 - Objective: To determine whether the stage at the time of diagnosis of chronic lymphocytic leukemia (CLL) had changed during a 55-year period. Design: We conducted a study of the cohort of residents of Olmsted County, Minnesota, who had been diagnosed as having CLL during the period from 1935 through 1989. Material and Methods: By analysis of medical records, patients with CLL were characterized by Rai stage, absolute lymphocyte count, age at diagnosis, need for therapy, and reported cause of death in nonsurvivors. Trends for these variables were analyzed by decade throughout the study period. Results: The overall annual incidence rate of CLL per 100,000 population in Olmsted County increased from 2.6 in the 1935 through 1944 period to 5.4 in the 1975 through 1984 period; however, the increasing rate was found only for those 50 years of age or older and was especially dramatic for those 75 years old or older. Analysis of Rai stage over time demonstrated an increase in the proportion of cases diagnosed as Rai stage 0. In addition, the median absolute lymphocyte count decreased, the median time to initiation of therapy increased, and the median age of patients with Rai stage 0 CLL at the time of diagnosis increased over time. Overall, 54% of patients had received therapy for CLL by the time of last follow-up. Among the nonsurvivors, CLL was documented as the underlying or a contributing cause of death in 69%. Conclusion: The overall increase in CLL was thought to be due to enhanced methods of early diagnosis and improved health care for the elderly population. Thus, artifact may best explain the observed trend, although we cannot exclude the possibility of an actual increase in incidence rates over time.

AB - Objective: To determine whether the stage at the time of diagnosis of chronic lymphocytic leukemia (CLL) had changed during a 55-year period. Design: We conducted a study of the cohort of residents of Olmsted County, Minnesota, who had been diagnosed as having CLL during the period from 1935 through 1989. Material and Methods: By analysis of medical records, patients with CLL were characterized by Rai stage, absolute lymphocyte count, age at diagnosis, need for therapy, and reported cause of death in nonsurvivors. Trends for these variables were analyzed by decade throughout the study period. Results: The overall annual incidence rate of CLL per 100,000 population in Olmsted County increased from 2.6 in the 1935 through 1944 period to 5.4 in the 1975 through 1984 period; however, the increasing rate was found only for those 50 years of age or older and was especially dramatic for those 75 years old or older. Analysis of Rai stage over time demonstrated an increase in the proportion of cases diagnosed as Rai stage 0. In addition, the median absolute lymphocyte count decreased, the median time to initiation of therapy increased, and the median age of patients with Rai stage 0 CLL at the time of diagnosis increased over time. Overall, 54% of patients had received therapy for CLL by the time of last follow-up. Among the nonsurvivors, CLL was documented as the underlying or a contributing cause of death in 69%. Conclusion: The overall increase in CLL was thought to be due to enhanced methods of early diagnosis and improved health care for the elderly population. Thus, artifact may best explain the observed trend, although we cannot exclude the possibility of an actual increase in incidence rates over time.

UR - http://www.scopus.com/inward/record.url?scp=0028350529&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0028350529&partnerID=8YFLogxK

M3 - Article

C2 - 8170175

AN - SCOPUS:0028350529

VL - 69

SP - 323

EP - 328

JO - Mayo Clinic Proceedings

JF - Mayo Clinic Proceedings

SN - 0025-6196

IS - 4

ER -