Younger CLL Patients Are Less Common, and Have Favorable Survival

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[3335] Younger Patients with CLL/SLL Are Less Frequent and Have

Favorable Survival in a Canadian Population Based Study: The Manitoba

Cohort. Session Type: Poster Session, Board #564-III

Versha Banerji, Alain Demers, B. ston, Marshall W. Pitz,

Zoanne Nugent, Carmen Morales, Salah Mahmud, Donna Hewitt, Spencer B.

Gibson, D. Seftel Haematology/Oncology, CancerCare Manitoba,

Winnipeg, MB, Canada; Internal Medicine, University of Manitoba,

Winnipeg, MB, Canada; Community Health Sciences, University of

Manitoba, Winnipeg, MB, Canada; Immunology Pathology, University of

Manitoba, Winnipeg, MB, Canada; Manitoba Insitute of Cell Biology,

Winnipeg, MB, Canada; Epidemiology and Cancer Registry, CancerCare

Manitoba, Winnipeg, MB, Canada

Background: Detailed population-based clinical characteristics and

outcomes of chronic lymphocytic leukemia (CLL) and small lymphocytic

leukemia (SLL) are scarce. We have previously demonstrated in the

province of Manitoba that by combining population-based sources of a

cancer registry and a centralized flow cytometry database, the

incidence of CLL/SLL is much higher than previously reported.

We have now examined the clinical characteristics of this large and

well defined patient group.

We hypothesized that the clinical features of these patients (pts) may

differ from previous studies where data was obtained from referral

centers.

Methods: All pts from the Manitoba Cancer Registry with ICD codes 9 10

for CLL or SLL from 01/01/1998 to 12/31/2003 were identified. Pts from

the flow cytometry database during this time period with a diagnosis

of CLL/SLL were also identified. A retrospective electronic chart

review was conducted. The two databases were compared and analyzed.

Results: 715 pts with CLL were identified. 358 pts were identified

from the cancer registry alone, 136 pts by the flow cytometry

database, and 221 pts in both datasets. Overall, the age-adjusted

annual incidence rate of CLL/SLL in Manitoba was 10.5/105 (95% C.I.

9.4-12.7/105).

Median age of all pts was 72yrs (19-101). Only 71 pts (9.9%) were aged

<55 and 212 pts (29.6) were <65. The Male: Female ratio was identical

in the age<55 and >55 categories (1.33).

Median follow-up of living pts is 6.6 years (range 2.0-8.0). The

regression model was used to evaluate the significance of prognostic

factors including age at diagnosis and gender. Older cases (>55 years)

had significantly higher risk of dying (HR: 4.0, 95%CI: 1.23-13.1)

than younger pts. Women had a slightly lower risk of dying (HR: 0.78,

95%CI: 0.40-1.50) than men.

For the 136 pts for whom accurate Rai staging was available, estimated

median survival has not been reached in stage 0 patients, while it was

7.2 years in stage I-II cases and 4.5 years in stage III-IV patients.

Cause specific mortality and complete survival according to Rai stage

for all pts will be presented at the meeting.

Conclusions: In this population-based CLL/SLL cohort, clinical

presentation and outcomes appear to differ from previously reported

studies. Specifically, (1) there are fewer younger pts, (2) the male:

female ratio is similar amongst all ages, (3) older pts have a

significantly poorer survival, (4) pts with advanced Rai stages appear

to live longer than previously reported. This has important

implications for treatment and counseling of pts, as well as for

resource allocation for this common hematological malignancy.