Changing trends of adult lymphoma in the Kingdom of Saudi Arabia - comparison of data sources.

BACKGROUND Lymphoma is one of the most common malignancies affecting the young Saudi population. This disease has diversified pathologies and clinical stages that necessitate well optimized clinical management. Regular updates of epidemiological behavior of lymphoma from various parts of the world are available but studies from the Kingdom of Saudi Arabia (KSA) in this field are not consistent. OBJECTIVES The aim of this study was to investigate the current trends in presentation and distribution of lymphoma with special reference to incidence and mortality, gender, age, histopathological subtypes, and clinical stages at King Faisal Specialist Hospital and Research Centre (KFSH and RC). MATERIALS AND METHODS Our study included lymphoma data from Saudi Cancer Registry, and relative comparison against KFSH and RC tumor registry data, Gulf country data and International Agency for Research on Cancer data. RESULTS Common tumors in the West (lung, colon, and prostate) were found to be much less frequent in KSA while leukemia, lymphoma and thyroid cancers were more common. Non-Hodgkin Lymphoma (NHL) ranked 3rd most common cancer with age-adjusted incidence of 6/100,000. Estimated age adjusted mortality was 4/100,000 in KSA. There was a peak rise in incidence of lymphoma in 1997-2007. Most common NHL was diffuse large B cell lymphoma at KFSH and RC. A total of 434 cases were diagnosed in 5 years with 55% of them at advanced stage and 35% demonstrating bulky disease and high risk. KFSH and RC registered 35% of Hodgkins and 21% of total NHL identified in entire Saudi Cancer Registry, 2009. CONCLUSIONS Results of this study are very unique, and reveal diverse trends. The findings provide valuable insights in the understanding of current epidemiological features of lymphoma in this part of the world.