Objective: To study the incidence pattern of cancer in Bahrain and compare the data with those of the world and Gulf Cooperation Council countries (GCC). Design: Retrospective Study. Setting: Pathology Department, Salmaniya Medical Complex, Bahrain. Method: Confirmed malignancies diagnosed in Bahraini patients between 1952 and 2004 in the histopathology and hematology departments of all government and private hospitals and clinics of Bahrain. Result: The overall age standardized rate (ASR) of cancer in Bahrain is 70.15/100,000. At 78.12 and 62.50, the male and female ASRs in Bahrain are less by 22.3% and 36.9% than the 100.5 and 99.1 GCC incidences and by 62.7% and 61.3 than the 209.6 and 161.7/100,000 world data respectively. Bahrain male ASR is lower than the 157.0, 132.6 and 99.1/100,000 of Qatar, Kuwait and Oman; it is higher than the 70.1 and 66.1 of the United Arab Emirates, and Saudi Arabia, wheras the female rate is similar to the 62.9 of Saudi Arabia but lower than the 165.2, 236.7, and 81.9 of Qatar, Kuwait, Oman and United Arab Emirates respectively. The age and gender distribution pattern of cancer patients in Bahrain and the frequency orders of the 10 most common cancers are also different from those of the GCC countries. The annual incidence rate in Bahrain increased from 12.05 during 1952-1964 to 73.6/100,00 during 1995-2004 with cross-over pattern during 1995-2004 whereby the annual male incidence rates, which were consistently higher than those of female prior to 1995, became consistently lower. Conclusion: Cancer pattern in Bahrain is different from that of Gulf Cooperation countries thus disputing a proposed hypothesis that people living along the shores of this region have common environmental, epidemiologic and population characteristics, and would therefore have a common expression of disease pattern including cancer. The unique characteristics specific to each country would determine the pattern of cancer.
