Hairy Cell Leukemia: Retrospective Analysis of Demographic Data and Outcome of 203 Patients from 12 Medical Centers in Israel.

BACKGROUND/AIM: In this retrospective study, we summarized the national Israeli experience with hairy cell leukemia (HCL) in a large cohort of patients with a long follow-up. PATIENTS AND METHODS: Demographic data, and relevant laboratory and clinical parameters were analyzed, emphasizing the outcome after first-line treatment with cladribine. RESULTS: Data on 203 patients was collected from 12 medical centers during 1985-2015. Mean and median follow-up were 7.5 years and 5.18 years (interquartile range=0.1-40 years), and 5- and 10-year survival were 96% and 90.62%, respectively. The median age of diagnosis was 55.5 years for Jews and 49 years for Arabs (p=0.021), and most patients were males (81.77%); 52.2% were Ashkenazi Jews, 36.1% Sephardic Jews and 11.7% were Arab, Druze or other ethnicity. Cladribine was given to 159 patients (80.7%%) and most (62%) received intravenous (i.v.) and 38% received subcutaneous (s.c.) therapy. Overall survival and time to next treatment were not significantly different between the two schedules (i.v., s.c.). In univariate analysis of a variety of factors, only age >65 years had a negative impact on outcome, with shorter overall survival. It is of interest that Arab patients with HCL were diagnosed at an earlier age, but had a similar clinical course and outcome to both Ashkenazi and Sephardic Jews.

Hairy cell leukemia-related disorders consistently show low CD27 expression.

In Japan, typical hairy cell leukemia (HCL) is rare, and HCL-Japanese variant (HCL-JV) is more common. Hairy B-cell lymphoproliferative disorder (HBLD) is another unusual disorder of polyclonal B-lymphocytosis of hairy cell appearance. In the present study, we analyzed the clinical features of 3 patients with HCL, 3 with HCL-JV, and 3 with HBLD. All HBLD patients had the DRB1*04 allele. As compared with other B-cell lymphoproliferative disorders, CD27 expression on B cells was significantly lower in all patients, ranging from 0.3% to 23.4%. Our results suggest that low CD27 expression may be a distinct feature of these HCL-related disorders.

Second cancer incidence and cause-specific mortality among 3104 patients with hairy cell leukemia: a population-based study.

BACKGROUND: The introduction of new treatments for hairy cell leukemia has resulted in improved patient survival but also engendered increasing concern about the possibility of excess second cancers. The available evidence is conflicting, with most risk estimates based on sparse numbers. To our knowledge, no study has evaluated cause-specific mortality in patients with hairy cell leukemia. METHODS: We quantified second cancer incidence and cause-specific mortality among 3104 two-month survivors of hairy cell leukemia who were reported to 16 population-based registries in the Surveillance, Epidemiology and End Results (SEER) Program between 1973 and 2002. Standardized incidence ratios (SIRs) and standardized mortality ratios (SMRs) were used to quantify the risk of second cancers and causes of death, respectively. The cumulative probability of a second cancer among survivors of hairy cell leukemia was calculated using a competing risk model. All statistical tests were two-sided. RESULTS: Mean follow-up of hairy cell leukemia survivors was 6.5 years (range, 2 months-29.3 years). Second cancer risk was statistically significantly elevated (SIR = 1.24, 95% confidence interval [CI] = 1.11 to 1.37) compared with the general population. Survivors had statistically significantly higher risks of Hodgkin lymphoma (SIR = 6.61, 95% CI = 2.13 to 15.42), non-Hodgkin lymphoma (SIR = 5.03, 95% CI = 3.77 to 6.58), and thyroid cancer (SIR = 3.56, 95% CI = 1.30 to 7.74) and a lower risk of lung cancer (SIR = 0.63, 95% CI = 0.42 to 0.90). The cumulative probability of all second cancers was estimated to be 31.9% (95% CI = 26.2 to 37.6) 25 years after hairy cell leukemia diagnosis. Among 10,000 hairy cell leukemia patients, a total excess of about 34 cancers, including 21 non-Hodgkin lymphomas, 2 Hodgkin lymphomas, and 7 solid tumors (including 2 thyroid cancers), might be observed per year. Deaths due to solid tumors were not elevated compared with the general population (SMR = 0.9), and there were statistically significant deficits in mortality due to both cardiovascular (SMR = 0.67, 95% CI = 0.56 to 0.80) and cerebrovascular (SMR = 0.61, 95% CI = 0.38 to 0.93) disease. CONCLUSIONS: Patients with hairy cell leukemia are at increased risk of Hodgkin lymphoma, non-Hodgkin lymphoma, and thyroid cancer. The decrease in lung cancer incidence and smoking-associated vascular mortality may reflect an inverse association of tobacco use with hairy cell leukemia. Future studies should address the roles of immunologic impairment inherent to hairy cell leukemia, treatment modalities, and other factors as codeterminants of morbidity and mortality in hairy cell leukemia survivors.

A population-based study of hairy cell leukemia in Israel.

OBJECTIVES: Few population-based data exist on the incidence and prognosis of hairy cell leukemia (HCL). Our objectives were to study the effect of socio-demographic factors on this rare disease and the risk of second malignancies occurring in HCL patients. METHODS: We measured crude and age-adjusted incidence rates of HCL based on reporting to the Israel Cancer Registry (ICR) 1991-2001. Using Kaplan-Meier and multivariate analysis, we assessed survival by gender, ethnicity and geographic region. We ascertained additional primary tumors reported in this population and calculated standardized incidence ratios (SIRs) for tumors reported after the diagnosis of HCL. RESULTS: The ICR registered 147 cases of HCL among males and 34 in females between 1991 and 2001. Age-adjusted incidence rates were 1.62/10(6)/yr for women and 7.97/10(6)/yr for men, with rates 1.5 times higher in Jewish than in non-Jewish (mainly Arab) men. Mean overall survival also differed by ethnicity. In a multivariate model, increasing age at diagnosis (P < 0.001), as well as Arab origin (P = 0.008) were associated with poorer survival but gender did not significantly affect the survival after controlling for age and ethnicity. Other primary malignancies were reported in 20 (11%) individuals, with a predominance of genito-urinary tumors (65%) among males. Secondary genito-urinary tumors were significantly increased above the expected population rates (SIR 3.23, 95% confidence interval: 1.39-6.36, P = 0.008). CONCLUSIONS: In the Israeli population, age and ethnicity were associated with prognosis of HCL. Variations in disease characteristics, stage of disease at diagnosis or differential access to treatment may contribute to these findings. Patients with HCL appear to be at increased risk for genito-urinary malignancies.

Epidemiology of hairy cell leukemia in Los Angeles County.

The descriptive epidemiological characteristics of hairy cell leukemia (HCL), a rare chronic lymphoproliferative disorder, were examined by using incidence data collected from 1972 to 1987 by the Cancer Surveillance Program, the population-based cancer registry for Los Angeles County. During the study period, 208 incident cases of histologically confirmed HCL were diagnosed. HCL comprised 2% of all leukemias diagnosed in Los Angeles County during the study period. HCL risk was concentrated in white males; there were few black and Asian patients for analysis. Overall, the age-adjusted incidence rate of HCL for men (2.9/million population) was 4.8 times greater than that for women (0.6/million population). Using data from all cancer patients diagnosed during the study period, Jewish men had significantly greater risk of HCL than Protestant men (odds ratio (OR) = 3.0, P less than 0.0001); there was no significant variation in risk of HCL by religion for women. For men, the OR was significantly elevated for professional and technical workers (OR = 2.1, P = 0.001); within this category of occupations, risk was significantly elevated for engineers (OR = 3.3, P less than 0.0001) and university faculty and school teachers (OR = 4.0, P = 0.0008). HCL patients were more than twice as likely to have multiple primary cancer diagnoses as other cancer patients. Since the majority of the other primary cancer diagnoses occurred prior to (greater than 1 year) or concurrent with (less than or equal to 1 year) the HCL diagnosis, this greater frequency of multiple primaries in HCL patients may be due to impaired immune function.