Hematologic malignancies of primary bone marrow involvement: a decade's experience in Bahrain

INTRODUCTION: The data on the pattern of primary hematologic malignancies in Bahrain is sparse, although previously published studies suggested rising trends in their incidence. This study aimed to compare with regional and world data and identify any changing trends. METHODS: A retrospective cross-sectional chart analysis study was done on all cases of primary hematologic malignancies of bone marrow origin of Bahraini nationals presenting during the 10-year period from January 2005 to December 2014 at the sole oncology referral center in Bahrain during the study period. RESULTS: In a total of 272 cases, the primary hematologic malignancies in decreasing order of frequency with respective median ages at diagnosis were: acute myeloid leukemia (AML; 26.1%, 39 years), acute lymphoblastic leukemia (ALL; 22.8%, 9 years), multiple myeloma (MM, 16.2%, 57 years), chronic myeloid leukemia (CML, 14%, 39.5 years), myelodysplastic syndromes (MDS; 12.5%, 56 years) and chronic lymphocytic leukemia (CLL; 5.5%, 65 years). The overall crude annual incidence rate of these malignancies was 4.8/10(5) population. Age-specific incidence rates were found to increase dramatically with age, except for ALL, for which it peaked in the pediatric age group. The age-standardized incidence rates (ASIRs) per 10(5) per year were 1.47 (AML), 1.13 (MM), 0.93 (ALL), 0.85 (MDS), 0.81 (CML) and 0.44 (CLL). CONCLUSION: The pattern of primary hematologic malignancies in Bahrain shows unique features that distinguish it from trends reported in Eastern and Western world populations. Compared to previously published reports, ASIR trends decreased in CML and ALL but increased in MDS and MM.