Hairy cell leukemia in Hong Kong Chinese: a 12-year retrospective survey

Risk of active tuberculosis in migrants diagnosed with cancer: a retrospective cohort study in British Columbia, Canada

OBJECTIVES

To describe the association between types of cancer and active tuberculosis (TB) risk in migrants. Additionally, in order to better inform latent TB infection (LTBI) screening protocols, we assessed proportion of active TB cases potentially preventable through LTBI screening and treatment in migrants with cancer.

DESIGN

Population-based, retrospective cohort study.

SETTING

British Columbia (BC), Canada.

PARTICIPANTS

1 000 764 individuals who immigrated to Canada from 1985 to 2012 and established residency in BC at any point up to 2015.

PRIMARY AND SECONDARY OUTCOME MEASURES

Using linked health administrative databases and disease registries, data on demographics, comorbidities, cancer type, TB exposure and active TB diagnosis were extracted. Primary outcomes included: time to first active TB diagnoses, and risks of active TB following cancer diagnoses which were estimated using Cox extended hazard regression models. Potentially preventable TB was defined as active TB diagnosed >6 months postcancer diagnoses.

RESULTS

Active TB risk was increased in migrants with cancer ((HR (95% CI)) 2.5 (2.0 to 3.1)), after adjustment for age, sex, TB incidence in country of origin, immigration classification, contact status and comorbidities. Highest risk was observed with lung cancer (HR 11.2 (7.4 to 16.9)) and sarcoma (HR 8.1 (3.3 to 19.5)), followed by leukaemia (HR 5.6 (3.1 to 10.2)), lymphoma (HR 4.9 (2.7 to 8.7)) and gastrointestinal cancers (HR 2.7 (1.7 to 4.4)). The majority (65.9%) of active TB cases were diagnosed >6 months postcancer diagnosis.

CONCLUSION

Specific cancers increase active TB risk to varying degrees in the migrant population of BC, with approximately two-thirds of active TB cases identified as potentially preventable.

Identification of the BRAF V600E mutation in Japanese patients with hairy cell leukemia and related diseases using a quenching probe method

Hairy cell leukemia (HCL) is a rare B-cell lymphoid malignancy that is difficult to distinguish from other morphological variants. The frequency of HCL has not been determined accurately in Japan. Recent studies revealed that the BRAF V600E mutation is the causal genetic event in HCL. We assessed the BRAF mutation in Japanese patients with HCL and related diseases using the quenching probe (QP) method, a single-nucleotide polymorphism detection system, and evaluated the incidence rate of HCL among Japanese patients with chronic lymphocytic leukemia, and related diseases. We identified 18 cases (33.3%) harboring the BRAF mutation among 54 patients diagnosed with, or suspected of having HCL. Of BRAF V600E-positive patients, 7 were only detected using the QP method, not by direct sequencing, whereas 11 were positive using both tests. In a larger cohort of Japanese patients diagnosed with chronic lymphoid leukemia or related diseases, the frequency of HCL was 4%. Patients with the BRAF V600E mutation had a significantly higher frequency of neutropenia, thrombocytopenia, and elevated soluble interleukin-2 receptor and common B-cell surface markers than patients without the mutation. Our results confirm that BRAF V600E-positive HCL is a relatively rare disorder in the Japanese leukemia patient population.

Cerebral tuberculomas in a patient with hairy cell leukaemia treated with cladribine

A 67-year-old man was treated with cladribine for hairy cell leukaemia. A few weeks later, he presented with persistent headaches, intermittent hypoesthesia of the right upper limb and language impairment. Brain CT scan showed 3 contrast-enhancing lesions. MRI revealed infracentimetric nodular lesions with restricted diffusion. One of the lesions was surgically removed and tested positive for acid-fast bacilli. Moreover, Mycobacterium tuberculosis was confirmed by PCR. Antituberculous drugs were prescribed for 12 months, with complete resolution of neurological deficits. This case highlights the risk of mycobacterial infections associated with both hairy cell leukaemia and cladribine use, and the importance of screening and treatment of latent forms of tuberculosis in patients undergoing treatment with immunosuppressive drugs.

Epidemiology and environmental risk in hairy cell leukemia

Hairy cell leukaemia (HCL) is an orphan subtype of leukaemia which constitutes less than 2% of all leukaemia's, with an incidence of less than 1 per 100,000 persons per annum. Median age at presentation is 55 years and it is 3-4 times more frequent in males. It is also more frequently encountered in whites and less in Asians, Africans and Arabs. The epidemiologic data are multi-factorial and influenced by ethnicity and geographical factors. Other reported associations relate to some environmental exposures and possible occupational factors. Smoking appears to have an inverse correlation with the development of hairy cell leukaemia, while farming and exposure to pesticides, petroleum products, diesel and ionizing radiation have also been reported to be associated with an increased risk. National and international collaborative efforts are needed in order to undertake more extensive studies involving larger patient cohorts, aiming to determine the role of occupational and environmental risk factors in the development of this rare form of chronic leukaemia.

Classical hairy cell leukemia and its variant: a 17-year retrospective survey in Taiwan Chinese

BACKGROUND

Classical hairy cell leukemia (HCL-C) and its variant (HCL-V) are rare chronic B-cell lymphoproliferative disorders. Only a few reports in Chinese patients are available.

METHODS

We retrospectively reviewed 16 patients with HCL-C and HCL-V in Taiwan over a 17-year period.

RESULTS

Eight were HCL-C and 8 were HCL-V. All HCL accounted for 0.7% of all adult leukemias. Compared to HCL-V, HCL-C was characterized by profound leukopenia, monocytopenia, thrombocytopenia and fewer circulating hairy cells. One HCL-C and 2 HCL-V patients had second malignancies. Seven HCL-C patients achieved hematological remission after splenectomy (n = 1) or 2-chlorodeoxyadenosine (n = 6). Of the 8 HCL-V patients, 6 received splenic irradiation. Only one achieved complete remission and another had partial remission; relapse or disease progression was noted 13.4 or 25.7 months later, respectively. Two of three HCL-V patients who underwent splenectomy had stable disease. All patients with HCL-C were alive while 3 with HCL-V expired. Compared to HCL-C, HCL-V had a significantly shorter leukemia-free survival.

CONCLUSION

A relatively higher proportion of HCL-V in all HCL comparing to Westerners is observed. Second malignancies are common. With an inferior outcome and dismal response to most treatment, enrollment in a clinical trial should be considered for HCL-V.

Hairy cell leukaemia: a heterogeneous disease?

The US National Cancer Institute's Surveillance, Epidemiology and End Results program was used to develop aetiological clues for hairy cell leukaemia (HCL). Descriptive techniques (age-adjusted incidence trends, age-specific incidence rates (IR), and age distributions-at-diagnosis) were supplemented with mathematical models (two-component mixture, generalized linear regression, and age-period-cohort). There were 2856 cases of HCL diagnosed during 1978-2004 (IR 0.32/100,000 person-years). IRs were nearly 4-fold greater among men than women and more than 3-fold higher for Whites than Blacks. Temporal trends were stable over time. Age-specific IRs increased rapidly until approximately 40 years then rose at a slower pace. The age-specific IR curves reflected bimodal early- and late-onset age distributions-at-diagnosis (or density plots), with some variation by gender. Among both men and women, a two-component mixture model fitted the data better than a single density or cancer population. Age-period-cohort models confirmed statistically significant age-related effects after full adjustment for temporal trends (calendar-period and birth-cohort effects). In summary, age incidence patterns (rates and bimodal densities) suggested that HCL is a heterogeneous disease, consisting of at least two underlying subgroups and/or cancer populations by age-at-onset. Distinct early- and late-onset HCL populations may reflect different age-related causal pathways, risk factor profiles, and/or stem cells of origin.

High incidence of tuberculosis after alemtuzumab treatment in Hong Kong Chinese patients

Twenty-seven patients received the anti-CD52 monoclonal antibody alemtuzumab for hematologic malignancies and autoimmune cytopenias in a tuberculosis-endemic area. Seven patients developed mycobacterium tuberculosis (TB) infections (median: 4, 1-24, months from alemtuzumab). The actuarial 1- and 2-year incidence of TB was 31% and 45%. All patients had severe depression of lymphocyte counts subsequent to alemtuzumab treatment, and tuberculosis was extra-pulmonary in three cases. All seven patients had received prior chemotherapy/immunosuppression and tuberculosis had not occurred until alemtuzumab was administered. Patients receiving alemtuzumab in areas endemic for tuberculosis should have careful initial evaluation of TB exposure, so that prophylactic antibiotics might be administered. Tuberculosis reactivation should be considered for unexplained fever and symptoms after alemtuzumab treatment.

Combined treatment with splenectomy and cladribine in hairy cell leukemia in Taiwan: a clinicopathologic study of 5 cases

BACKGROUND

Hairy cell leukemia (HCL) is a rare B-cell lymphoid malignancy that is characterized by the presence of hairy cells in the peripheral blood and bone marrow, pancytopenia and various degrees of splenomegaly. Very few reports have explored the clinicopathologic features and treatment outcome of HCL in Taiwan.

METHODS

Of 33 patients with malignant lymphoma who underwent splenectomy over a 10-year period (1996-2005), 5 cases of HCL were retrospectively studied.

RESULTS

All cases presented with various degrees of splenomegaly. Pancytopenia was noted in 3 cases, and lymphadenopathy in 1. Typical hairy cells with positive tartrate-resistant acid phosphatase stain were noted in 2 cases. Only 3 cases could be diagnosed with HCL based solely on bone marrow findings. In contrast, all spleen specimens had characteristic pathologic features. All patients underwent splenectomy uneventfully, and cladribine was given at a median time of 2 months after splenectomy without significant side effects. Complete remission with durable response was documented in 4 patients (80%) with a median follow-up of 29 months (range, 4-96 months). The last patient experienced partial remission but was only followed up for 4 months.

CONCLUSION

For the HCL patients in this study, splenectomy had a role not only in improving cytopenia but in aiding diagnosis. Cladribine is safe and highly effective for Taiwanese patients and should be considered as first-line treatment for HCL.

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.