Regional differences in the pattern of cancer are obvious in Saudi Arabia. From January 1987 to December 1995, 1106 new cases of cancer (642 males, 464 females) were seen at the King Fahd Specialist Hospital in Buraidah, AlQassim. Overall, lymphomas, non-Hodgkin's and Hodgkin's disease combined were the most common malignancy seen (15.10%), followed by esophageal carcinoma (7.77%). Thyroid cancer was the most common malignancy among females (12.50%), followed by breast cancer (9.48%). The majority of the patients were in the younger age group (77% were <50 years of age). Among the hematological malignancies, acute lymphoblastic leukemia was the most frequent type (36.23%). Lymphomas were the most common malignancy (66.12%) seen in the pediatric age group (0-14 years), followed by leukemias and brain tumors. The pattern of cancer in Al-Qassim is generally similar to other regions of Saudi Arabia, with few regional variations. Prominent among such variations is the high frequency of non-Hodgkin's lymphomas (NHL), esophageal and thyroid carcinomas. Ann Saudi Med 1997; 17(6):595-600. (1987)(1988)(1989)(1990)(1991)(1992)(1993)(1994)(1995). 1997; 17(6): 595-600 SS Akhtar, LM Reyes, Cancer in Al-Qassim, Saudi Arabia: A Retrospective StudyThe study of the geographical distribution of malignant tumors has greatly influenced our understanding of the cause of cancer. In Saudi Arabia, which is the largest country in the Middle East, regional variations in the prevalence of different cancers have been documented from data taken from the tertiary care centers.1 Pending the availability of results from the national cancer registry, information regarding the relative frequency of different tumors can be obtained from sources such as pathology and admissions departments of hospitals in different regions. 2The purpose of this study was to evaluate the pattern of cancer in the Al-Qassim region by analyzing data from the departments of Oncology and Pathology at King Fahd Specialist Hospital (KFSH) in Buraidah. Al-Qassim region has a total population of approximately 578,000.3 It is situated in the central region of Saudi Arabia, and the majority of the population are involved in either agriculture or trading. KFSH, a 570-bed hospital, is the regional referral center for cancer patients, where the majority of cancer patients are seen. Patients and MethodsAll histologically confirmed cases of malignant disease seen at KFSH from January 1987 to December 1995 were included in the study. All cases were indexed by medical record number, name, age, sex, nationality, site of tumor and histopathology. The tumor sites and morphology were coded according to the International Classification of Diseases. We studied the frequency by age and sex of different malignant tumors seen among these patients. The observed figures were compared to available data from other regions of Saudi Arabia and the Middle East. ResultsDuring the nine-year period (1987)(1988)(1989)(1990)(1991)(1992)(1993)(1994)(1995), 1106 cases of cancer were seen at KFSH. There we...