Leukaemia and multiple myeloma in the Maltese Islands - a ten year study

Abstract

An epidemiological study of haematological malignancies presents unique difficulties due to the diversity of these disorders and variation in the criteria used to diagnose and record them. Descriptive epidemiological studies categorise these diseases according to the International Classification of Disease which unfortunately has changed every decade. Major conceptual advances, such as the association between the myeloid dysplasia group of diseases and the myeloid leukeamias, have not been adopted into the classification. The published statistics for leukaemia and multiple myeloma are influenced not only by variation of definition but also by problems of registration and quality of case ascertainment. Such problems are particularly important when international comparisons are made. The relative rarity of these disorders has meant that epidemiological analyses have been few. The leukaemias and multiple myelomas account for approximately 3% of all malignancies worldwide and locally. The specific types of leukaemias differ widely in their epidemiological characteristics. Reports indicate an increasing incidence of the more indolent forms of leukaemia and of multiple myeloma in certain regions of the world. Reports indicate an increasing incidence of the more indolent forms of leukaemia and of multiple myeloma in certain regions of the world. This has been variously attributed to increasing case ascertainment, notably in the elderly population, changes in disease classification and to a true increase in the disease. This study aims to quantify the incidence of these diseases in the Maltese population during the last ten years (1985 - 1994), identify any changing trends and determine the survival of patients suffering from them. Although a ten year study period was chosen, the small size of the local population imposes inevitable difficulties in obtaining large sample sizes. However, we have worked within these constraints and statistically validated our results where possible.