Epidemiology of hairy cell leukemia in Iceland

INTRODUCTION

Hairy cell leukemia (HCL) is a rare B-cell lymphoproliferative disorder. Previous epidemiological studies have mainly focused on cases derived from single institutions or from localized cancer registries. This is the first study in which all cases diagnosed nationwide over a long period of time in a well defined population are analysed. We report the epidemiology of all HCL patients in Iceland, their clinical characteristics, treatment and follow-up.

PATIENTS AND METHODS

: All patients diagnosed with HCL in Iceland over a 20 year period, were included in this study. Data was collected retrospectively.

RESULTS

Sixteen patients, 13 males and three females were diagnosed with HCL in Iceland from 1981-2000, giving a mean incidence of 4.7/million/year (95% CI: 2.7-7.6) in the population 20 years and older. Eleven patients were treated with a purine analogue, 10 of whom achieved CR. One other patient obtained CR following splenectomy and IFN, giving a total CR rate of 69%. Three other patients (19%) obtained PR, giving a total response rate of 88%. One patient had a variant of HCL and did not respond to any therapy and one patient died of sepsis before any chemotherapy could be given. Six patients with HCL have died, one from complications of HCL. Three patients developed a second malignancy (19%).

CONCLUSIONS

The mean incidence of HCL in Iceland is 4.7/million/year. This is slighty higher than the reported incidence in England and Wales, although not significantly higher. The incidence is based on a nationwide information from a well defined stable and racially homogenous island population. Other results are in accordance with previously published studies.

[Elective splenectomies in Landspítalinn 1985-1994.]

OBJECTIVE

Splenectomy following trauma is well known and the consequences have been investigated thoroughly. Several splenic diseases are treated by simple splenectomy. Furthermore, it may be necessary to do a splenectomy in case of intraoperative splenic trauma. The aim of this study was to investigate the indications for splenectomy in these two groups of patients and to estimate the longterm results.

MATERIAL AND METHODS

We analysed all medical files of patients without history of splenic trauma but who nevertheless underwent splenectomy. We noted clinical features, laboratory findings, complications of the operation, volume of bloodloss and longterm results regarding the primary diagnosis.

RESULTS

In 1985-1994, 93 patients had splenectomy at the former noted occasions. We found medical files for 89 patients. Of them, 36 had disease of the spleen or diseases associated with it (group A) but 53 had no splenic disease (group B). In group A, a great variety of diseases led to splenectomies, idiopathic thrombocytopenic purpura being in the first place (28%) and non Hodgkin's lymphoma in the second place (12%). In group B the most common operation was a gastrectomy due to gastric cancer (30%) but in second place was an operation of the pancreas in connection with pancreas cancer (13%). The most common clinical indications for splenectomy in group A were thrombocytopenia (34%) and abdominal pain because of an enlarged spleen (23%). Intraoperative trauma (49%) of the spleen was the most common indication in group B. Before the operation, 13 patients got glucocorticoid steroids, nine patients received blood transfusions, and six patients got immunoglobulins, all in group A. There was less bloodloss and therefore a lower need for tranfusions in group A. Longterm results in group A, regarding primary disease, were good in 24 patients (67%), tolerable in three (8%), poor in four (11%) but uncertain in five (14%). Perioperative or postopertive complications were minimal. Often the results of splenectomies are good in patients with splenic diseases and these operations are quite safe.

CONCLUSIONS

Longterm results are strongly connected with the underlying disease. With greater attention and care we suppose the incidence of splenectomies could be lowered in patients without splenic disease.

Low iron-binding capacity as a risk factor for myocardial infarction

BACKGROUND

In a recent Finnish study, ferritin was suggested to be an independent risk factor for acute myocardial infarction. This study suggested that high levels of iron stores might thus be atherogenic and possibly explain partly the sex difference in the incidence of ischemic heart disease.

METHODS AND RESULTS

A randomly selected group (n = 2036), men and women aged 25 to 74 years, were examined between June and September 1983. All classic risk factors for coronary artery disease were measured as well as basic hematologic parameters and the parameters of iron metabolism, ie, iron, total iron-binding capacity (TIBC), and ferritin. During the follow-up for 8.5 years, 81 subjects experienced acute myocardial infarction (63 men and 18 women). The differences in the iron parameters between men and women were almost exclusively seen in ferritin values (198 micrograms/L in men and 91 micrograms/L in women), whereas small differences were seen in TIBC. The Cox proportional hazards model was used to estimate the contribution of independent variables to the risk of myocardial infarction. TIBC was found to be a strong independent negative risk factor in men (RR = 0.95; 95% CI, 0.92 to 0.98), whereas ferritin (RR = 0.999; 95% CI, 0.997 to 1.001) or other iron parameters had no significant predictive power. Each increase in TIBC of 1 mumol/L was associated with a 5.1% decrease in the risk of myocardial infarction. The classic major risk factors, ie, blood pressure, smoking, total cholesterol, and high-density lipoprotein, had significant independent correlation with myocardial infarction. When Cox multivariate analysis was carried out on both sexes combined, TIBC was still an independent negative risk factor, and the logarithmic transform of ferritin had a weak negative correlation but was not statistically significant. Sex was in this group still a very strong risk factor after taking into account all classic risk factors as well as the parameters of iron metabolism.

CONCLUSIONS

This study suggests that transferrin, measured as TIBC, is an independent negative risk factor for myocardial infarction. Other parameters of iron metabolism, including ferritin, were not found to contribute to the risk.

Prevalence of iron deficiency and iron overload in the adult Icelandic population

The aim of this cross-sectional study was to estimate the prevalence of iron deficiency and overload in the adult population in Iceland, a developed Scandinavian country. The study population consisted of 4240 individuals aged 25-74 years randomly selected from the national roster. Basic hematological, S-iron, S-total iron binding capacity (TIBC), and S-ferritin measurements were obtained on 2588 individuals (61.0%). The results indicated unusually large iron stores in the adult Icelandic population and significantly larger iron stores in the rural compared to the urban population. Iron deficiency was rare except in urban premenopausal women, where 1 in 4 showed evidence of iron deficiency and 3.2% had iron deficiency anemia. Seven patients with hereditary hemochromatosis were identified from a subgroup of 1887 subjects, resulting in a prevalence of 0.37%. Two of the hereditary hemochromatosis patients had been gastrectomized. Measures to improve the iron balance in urban premenopausal women cannot therefore include increased iron fortification of food but must be more directed towards the target group.