Colorectal cancer in Saudi Arabia: incidence, survival, demographics and implications for national policies

BACKGROUND AND OBJECTIVES: The national data on colorectal cancer in Saudi Arabia has not been analyzed. The objective of this study is to describe the demographics, incidence and survival rates for colorectal cancer in Saudi Arabia for the period 1994-2010. DESIGN: Retrospective analysis of the Saudi Cancer Registry data for the period 1994-2010. SETTING: Data from the Saudi Cancer Registry was analyzed by stage at presentation (local, regional, distal, unknown) and survival rates were calculated using the Kaplan-Meier method. PATIENTS: From 9889 colorectal cancer cases, a sample of 549 (5.6%) patients was selected and their living status ascertained to assess survival. RESULTS: Colorectal cancer has been the most common cancer among men and the third commonest among women since 2002 in Saudi Arabia. There has been a slight predominance among men with an average ratio of 116: 100 over the years (range: 99: 100-132: 100). The overall age-standardized rate (ASR) approached a plateau of 9.6/100 000 in 2010. The incidence of the disease has been highest in the capital, Riyadh, where it reached 14.5/100 000 in 2010. Median age at presentation has been stable at around 60 years (95% confidence Interval (CI): 57-61 years) for men and 55 years (95% CI: 53-58 years) for women. Distant metastasis was diagnosed in 28.4% of patients at the time of presentation and rectal cancer represented 41% of all colorectal cancers diagnosed in 2010. The overall 5-year survival was 44.6% for the period 1994-2004. The ASR for all age groups below 45 years of age was lower than that for the United States. LIMITATIONS: The study was retrospective with a possibility of bias from inaccurate staging of patients, and inaccurate survival information and patient demographics due to the underdeveloped census system prior to 2001. Survival data for the period 2005-2010 are lacking. CONCLUSION: Colorectal cancer presents at a younger age in Saudis, especially in women. This has a major implication for decisions about the threshold age for screening. The ASR has increased, but is still much lower than in developed countries. The lower overall 5-year survival compared with developed countries is due to lack of screening, a higher proportion of advanced stage cancer at presentation, lack of specialized care outside the major cities and a higher proportion of rectal cancer cases.