Colorectal Cancer

A polyp is an elevation above mucosal surface, and the majority of colorectal polyps are adenomas with malignant potential. Polyps range in size from a few millimeters to 10 cm diameter. Adenomas occur in about 10% of the populations in the Western World but are rare elsewhere in the world. Genetic and environmental factors have been implicated. They may be single or multiple and in the polyposis syndromes hundreds may be found.

Polyps rarely produce symptoms and most are diagnosed on x-ray or on colonoscopy performed for other reasons. Once a polyp has been found it is usually removed endoscopically. Larger polyps should be removed for histological confirmation. Further polyps may develop and continuous surveillance is necessary. The frequency with which invasive carcinoma occurs in adenomas increases with the size of the polyp and most if not all colonic carcinomas originate as adenomas.
A report in 1995 by Malaysian Society of Gastroenterology & Hepatology, College of Surgeons of Malaysia, Academy of Medicine, Malaysia in 1995 on the Screening for Colorectal Cancer in Malaysia, documented that Colorectal Cancer is the third commonest cause of cancer deaths in Malaysia. Data from the Ministry of Health of Malaysia confirms an increase in Colorectal Cancer admission rates from 8.1% in 1987 to 11.9% in 1995 (MOH 1995)
According to the 2nd Report of the National Cancer Registry on cancer incidence in Malaysia 2003, colon and rectal cancer, each on their own ranked among the ten most common cancers in Malaysia. When taken together colorectal cancer would accou8nt for 14.2% of male cancers making it the commonest cancer among men, and the third most common cancer among women comprising 10.1% of female cancers. The incidence of colorectal cancers combined is 20.8 per 100,000 for males and 12.9 per 100,00 for females.
Genetics, experimental and epidemiological data suggest that colorectal cancer develops from complex interactions between inherited susceptibility and environmental factors. The current hypothesis is that adenomatous polyps are the precursors of the vast majority of colorectal cancers. Thus measures that can detect and reduce the prevalence of these adenomatous polyps can reduce the risk of colorectal cancer.