Screening for colorectal cancer aims for early detection and the removal of precancerous lesions in sporadic colorectal cancer developing in patients older than 50 years. Complete flexible colonoscopy is the gold standard in early detection of colorectal neoplasias. It shows the highest sensitivity and specificity. Two case-control studies demonstrated a 66–90 % reduction in colorectal cancer incidence by flexible colonoscopy. Negative colonoscopy should be repeated after a period of 10 years.

The protective effect of flexible sigmoidoscopy for distal neoplasms seems to last 6–10 years. However, a study of nearly 10,000 patients showed a 0.8 % detection rate for distal adenomas or carcinomas 3 years after negative sigmoidoscopy. The recommend control interval for sigmoidoscopy without pathological findings is 5 years.

The second recommended screening method is fecal occult blood testing (FOBT). The sensitivity of FOBT for confirmed colorectal cancer is 50 % and for polyps is around 10 %. The predictive value of a positive test averages 10 % for cancer. Any (single) positive test result must be followed by complete flexible colonoscopy. The efficacy of FOBT was demonstrated in four large, randomized trials in which colorectal cancer mortality was reduced by 25 % in individuals participating in an annual screening program. Biennial testing is less effective. FOBT is unnecessary in individuals participating in an regular colonoscopy screening program.

Randomized trials have demonstrated that some immunologic FOBTs are superior regarding the detection rate of advanced neoplasias compared with guaiac FOBT. The studies show some immunologic FOBTs (e.g., OC-Sensor) afford the same specificity (>90 %) but higher sensitivity.

The Advisory Committee on Cancer Prevention in the European Union suggested in 1999 that screening programs for colorectal cancer should use FOBT. Colonoscopy should be used to follow-up on positive findings. Screening should be offered to men and women aged 50 to approximately 74 years, with an interval of 1–2 years.

Persons with increased risk for colorectal cancer due to certain predispositions comprise the following three groups:

First-degree relatives of patients with colorectal cancer are at increased risk of developing colorectal cancer. If an index patient older than 60 years develops cancer, the risk of developing cancer is only minimally increased for his or her relatives.

In patients with a family history of colorectal cancer or adenomatous polyps, advise screening colonoscopy beginning at age 40 years or 10 years younger than the youngest age at the diagnosis in the family. Screening should be repeated at 5-year intervals. This protocol should followed in two groups of patients:

These screening recommendations must be considered provisional, as mortality-reduction studies are not yet available.

Colorectal cancer mortality is lower in patients with FAP who have been screened than in those who present with symptoms. Genetic testing should be performed at age 10 years; if a genetic mutation can be excluded, no further special screening is required. Annual colonoscopy from age 10–12 years should be advised in:

In patients with attenuated FAP, treatment should be based on age, the number of polyps, and the histopathological findings. Colonoscopy should be performed annually throughout the patient’s life if colectomy is not indicated. In persons from a family with attenuated FAP, the first colonoscopy should be at age 15 years; if there are no findings, the next colonoscopy should be performed in 5 years. From age 20 years, colonoscopy is recommend annually.

Colonoscopy can reduce risk and mortality from colorectal cancer in families fulfilling the Amsterdam criteria for HNPCC. Genetic testing for HNPCC should be offered to first-degree relatives of persons with a known inherited MMR gene mutation. Among persons with a genetic or clinical diagnosis of HNPCC, yearly or biennial colonoscopy should start at age 20–25 years or 10 years earlier than the youngest age at diagnosis of colorectal cancer in the family.

History of Adenomatous Polyps (see Chap. 8.1)

In patients with a history of colorectal cancer, if synchronous neoplasm is excluded at the time of resection with curative intent, subsequent colonoscopy should be performed 2 and 5 years after surgery and every 5 years thereafter.

Colonoscopy with systematic four-quadrant biopsies at 10-cm intervals should be performed in patients with inflammatory bowel disease/ulcerative colitis presenting as long-standing pancolitis (>8 years) or left-sided inflammatory colitis (>15 years). If intraepithelial neoplasia is detected and confirmed, colectomy is indicated. No general recommendation can be given for patients with Crohn’s disease.

No randomized controlled trials have studied surveillance colonoscopy in patients with ulcerative colitis or Crohn’s colitis. A meta-analysis of case-control studies showed a reduction in the risk of colorectal cancer mortality in patients with ulcerative colitis following a surveillance program.

The majority of patients present with alteration in bowel habit, frank rectal bleeding, or anemia as a result of occult bleeding. Symptoms such as intermittent abdominal pain, nausea, and vomiting are often secondary to partial obstruction or peritoneal dissemination. Patients may occasionally notice a palpable mass, which is more common in right-sided colon cancer.

Intestinal obstruction is most commonly associated with cancer of the sigmoid colon. This may lead to acute colonic perforation if the ileocecal valve is competent. If the valve is incompetent, presentation is less dramatic, with increasing constipation and abdominal distension noticed over many days, ending in a typical symptomatic ileus.

Perforation of colon cancer may be acute or chronic. It may occur at the site of the tumor or more proximal in the distended part of the colon. Perforation may extend into the retroperitoneum, bladder, or genital tract, with fistula formation.

Diagnosis is established by colonoscopy and biopsy. The precise location of the neoplasm must be documented and the base of any suspicious polyp tattooed at the time of snare excision. Careful clinical examination for regional lymphatic and distant metastatic disease should be performed.

To exclude liver metastasis, ultrasonography or multislice computed tomography (CT) are the imaging techniques with highest sensitivity (63–86 % and 75–83 %, respectively) and best specificity (98 % and 98 %, respectively). CT has advantages in assigning metastases to anatomic structures such as liver veins, hilar vessels, and the caval vein, which is necessary to estimate resectability. However, magnetic resonance imaging is the optimal tool to evaluate the extent of liver metastasis. To exclude synchronous malignancies, the entire large bowel should be examined if the lumen is not obstructed. If colonoscopy is not possible or complementary information is required, virtual colonography (based on CT or magnetic resonance tomography) or radiography with water-soluble contrast (if there is a risk of perforation) is mandatory.

History, including family history (Amsterdam and Bethesda criteria)

Physical examination

Elevated levels of serum carcinoembryonic antigen (CEA) that do not normalize after surgical resection imply persistent disease and the need for further evaluation. A postoperative increase in CEA during follow-up indicates a potential recurrence. A liver chemistry panel should also be performed.