Colorectal Polyps

Colorectal polyps are a common finding during any diagnostic or screening evaluation of the colon. Polyps can be broadly classified into neoplastic (adenomatous) or non-neoplastic. The latter category of polyps includes hamartomas, hyperplastic polyps, mucosal polyps, lymphoid hyperplasia, and inflammatory polyps. These are usually considered benign with minimal to no risk of progression to cancer. Distinguishing between these subgroups based on endoscopic or radiographic features is not reliable and requires histologic evaluation. Furthermore, clinical insignificance cannot be entirely applied to nonneoplastic polyps. Many of the polyposis syndromes (see below) are associated with polyps of nonneoplastic histology. Cleary, these syndromes need to be clinically recognized because of the associated risk of colon cancer as well as malignancies in other gastrointestinal (GI) sites and extra-intestinal organs. When to suspect a polyposis syndrome depends on the number and distribution of polyps, other clinical features compatible with a syndrome, and familial clustering of cancers as discussed in later sections.

Adenomas are the most common colorectal polyp accounting for up to 75% of polyps. Overall prevalence of adenomas in the United States is about 40 to 50% (Young and Macrae, 2003). Large adenomas tend to be found more frequently in the distal colon; this distribution parallels that of colorectal cancers (CRCs). Several lines of evidence suggest an adenoma-to-carcinoma sequence. This includes not only epidemiologic evidence, but also molecular and morphologic studies that correlate histologic progression of polyps with accumulation of genetic mutations in certain genes. Furthermore, family studies have shown clustering of adenomas and CRCs. About 30% of adenomas appear to have a hereditary basis. A family history of colon adenomas and/or CRC increases an individual's risk of colon cancer (Johns and Houlston, 2001). One of the best characterized hereditary CRC syndromes, familial adenomatous polyposis (FAP) (see below), is associated with thousands of colonic adenomas and a subsequent 100% lifetime risk of CRC.

Because of the association with colon cancer, treatment of adenomas and future surveillance for recurrent adenomas are central aspects of colon cancer prevention. Strong evidence exists that removal of adenomas is associated with a decreased incidence of subsequent advanced adenomas and colorectal carcinoma (Winawer et al, 1993). Therefore, after diagnosis and removal of adenomas, a major question is when and how often to repeat endoscopic surveillance to remove recurrent polyps. Surveillance can discover new adenomas as well as adenomas that were potentially missed on prior colonoscopy. The National Polyp Study showed that the incidence of advanced neoplasia (polyps at least 1 cm in size, or with high grade dysplasia or invasive cancer) with postpolypectomy surveillance at 1 and 3 years was the same as those who underwent surveillance at 3 years only (Winawer et al, 1993). Thus, 3-year follow-up is recommended after the discovery and removal of advanced adenomas. Predictors of adenoma recurrence include multiple adenomas (at least 3), villous architecture, large adenomas, and age (Winawer et al, 1993; Van Stolk et al, 1998).

Several groups have published surveillance strategies. A panel of experts in several fields, including gastroenterology, surgery, and oncology, combined with representatives form the US Multisociety Task Force on Colorectal Cancer, collectively called the Gastroenterology Consortium Panel, recently published recommendations for adenoma surveillance (Winawer et al, 2003). Patients with advanced (a 1 cm, villous architecture or high-grade dysplasia) or multiple adenomas (a 3) should undergo surveillance colonoscopy in 3 years. Those with 1 or 2 small (< 1cm) tubular adenomas should have a follow-up colonoscopy in 5 years. If the first 3-year follow-up colonoscopy shows no polyps or only 1 to 2 small adenomas are found, then repeat colonoscopy can be extended to 5 years. Although these guidelines provide reasonable timeframes for surveillance, modifications to the intervals should be considered in certain clinical situations, taking into account the number and degree of individual risk factors. Colonoscopy is the recommended surveillance strategy as double-contrast barium enema has been shown to be less effective (Winawer et al, 2000).

Constipation Prescription

Constipation Prescription

Did you ever think feeling angry and irritable could be a symptom of constipation? A horrible fullness and pressing sharp pains against the bladders can’t help but affect your mood. Sometimes you just want everyone to leave you alone and sleep to escape the pain. It is virtually impossible to be constipated and keep a sunny disposition. Follow the steps in this guide to alleviate constipation and lead a happier healthy life.

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