B-chronic lymphocytic leukaemia in Latvia: epidemiological aspects.

As in western Europe and the USA, chronic lymphocytic leukaemia (CLL) in Latvia is the most prevalent type of leukaemia. A total of 1509 newly diagnosed cases of B-cell chronic lymphocytic leukaemia entered the study, 440 of whom were followed up at the Latvian Haematology Centre. The main peculiarities of the study were: 1) the higher incidence of the disease in Latvia as compared with other regions of the former USSR and with western countries, 2) a lower male-to-female ratio than in most other countries and 3) a higher morbidity among the Latvian population in comparison with the Russian. A positive correlation between the disease stage and survival was confirmed, but no precise individual prognosis in an early stage of the disease was possible.