What do we consider cancer of the rectum?

Rectal cancer constitutes one third of all colorectal cancers, representing the cancer with the second highest incidence and the second cause of cancer death in the western society [1, 2]. An estimated 100,000 new cases of rectal cancer are diagnosed each year in Europe. The incidence is increasing, mainly due to earlier detection and increasing age of the population, as the highest incidence of rectal cancer is found in the sixth and seventh decades. High incidence rates are found especially in western world populations, i.e. Western Europe, North America and Australia. This can probably be explained by a combination of factors, including dietary patterns with high amounts of red meat, obesity and smoking [3]. The United States is the only country with significantly decreasing incidence rates in both males and females in the most recent time period, which largely reflects detection and removal of precancerous lesions through colorectal cancer screening [4]. Next to dietary and lifestyle factors, risk factors for rectal cancer include inflammatory bowel disease and primary sclerosing cholangitis. Also, genetic predisposition plays a role; however, rectal cancer most commonly occurs sporadically and is inherited in only 5% of the cases. Five-year survival rate of rectal cancer is about 60% and depends to a large extent on disease stage at diagnosis [5].