Changes in the characteristics of Colorectal Cancer in the last 15 years

Background: The incidence of colorectal cancer (CRC) increased in the last years in Western-countries and Hungary, and the disease starts to develop in an earlier age group. In general 70% of CRC is localised in the left colon and rectum, but recent studies suggest an increasing trend of right-sided tumours. Aims: to investigate the prevalence of CRC, and to examine distribution of the gender, age and location over a 15-year period in our academic centre. Methods: a retrospective review of endoscopic and histologic records of patients with CRC between 1998 and 2013 every three years has been performed. Results: Over a 15 years period (examined years were 1998, 2001, 2004, 2007, 2010 and 2013) a total of 9708 patients underwent colonoscopy. CRC was diagnosed in 3% (n = 303) of all patients. The rate of CRC increased significantly from 1998 to 2013 (2.48% and 3.57%, respectively p < 0.05), which represents an increase of 14%. The mean age of CRC patients at the time of their diagnosis was 67.5 years over the examined time period, however, a stepwise decrease from 2001 to 2013 was observed (73 to 66 years, respectively, p < 0.05). CRC was mainly detected in 70 – 80 years old patients in 1998 – 2001, while in 2013 the main age group was 60 – 70 years. The overall rate of right-sided CRC was around 30%, its prevalence increased from 1998 to 2007 (29% and 44%, respectively, p < 0.05). The rate of right-sided CRC in females was significantly higher than in men (p < 0.05), except in 2013 (female-male rates: 25 – 19% in 1998; 29 – 10% in 2001; 16 – 14% in 2004; 26 – 21% in 2007; 24 – 16 in 2010, and 9 – 14% in 2013). The prevalence of rectum tumours showed a 3% increase in the left-sided tumour subgroup during the detailed study of localization. Conclusion: The prevalence of CRC increased significantly over a 15-year period in our high-volume academic endoscopic centre between 1998 and 2013. We confirm a significant decrease in the average age of onset. We demonstrate a significant increase in the prevalence of right-sided tumors, especially in female patients.