Non-Hodgkin's lymphoma (NHL) represents the seventh tumor group in frequency worldwide, with age adjusted incidence rates per 100,000 of 7.7 in men and 5.2 in women. In industrialized countries, NHL represents 149.000 newly diagnosed cases pre year and 167.000 in developing countries. In the last decades, incidence rates for NHL are increasing dramatically. The aim of this study was to determine the risk factors for NHL in the Eastern region of Saudi Arabia.
Methodology
A hospital-based case-control study was conducted. NHL cases were identified by using the National Cancer Registry for the years 1997 and 1998. Cases were also identified from the participating hospitals. Subjects admitted as in-patients or out-patients in the same hospital were served as controls.
Results
A total of 205 subjects (41 cases and 164 controls) were included in the analysis. A statistical significance of elevated risk for NHL was associated with female gender, black race, and agricultural workers. An elevated risk for NHL was associated with age group 41-60 years, age group 61 years and older, living in a rural area, receiving secondary or above of education, history of blood transfusion, history of human herpes simplex virus, history of hepatitis C virus, history of rheumatoid arthritis, use of cimetidine and other histamine H2 receptor antagonists, exposure to diagnostic x-rays, and use of dye and de-coloration types of hair-coloring products. A reduced risk for NHL was associated with age groups 20 years and younger, age group 21-40 years, brown and white races, receiving less than secondary level of education, smoking habit, and chemical and textile workers. No risk for NHL was associated with the use of henna type of hair-coloring products.
Conclusion
Most of these results were consistent with previous investigations. An additional study on a larger number of cases within more recent years would be supportive.