Colon Cancer

Cancer of the large bowel is the second most frequent malignant tumor in Europe with an increasing tendency. It is a cancer of Western civilization and is strongly connected to our eating habits, especially the high percentage of red meat in our food (beef, pork, mutton). The demographic development with increasing age of the population also plays an important role. In addition to that an inherited genetic defect, which causes colon cancer, runs in certain families.

Biology differentiates between two types of carcinoma: One is the classical polyp-carcinoma (more than 90%) and the other is a so called “de novo” carcinoma (flat lesions without benign precursors). Polyp carcinoma develops from an initially benign polyp or adenoma which slowly undergoes malignant change. This adenoma-carcinoma sequence is the base for our prophylactic approach to prevent colon cancer: colonoscopy. By regular colonoscopy, starting at the age of 50, a great majority of these polyps can be detected in time and be removed. 

Symptoms of colon cancer are mostly very discrete. Changes in the habit of bowel movement and blood in the stool are the most important complaints. Pain or signs of bowel obstruction occur late in the course of the disease. This underlines the importance of colonoscopy for early detection of polyps and cancers.

Diagnostic work on colon cancer consists mainly of colonoscopy and taking biopsies from the tumor. This also determines the localization of the tumor. Additional investigations like sonography, CT-scans and MRI help to detect local spread of the tumor and metastases.

The operation depends on the localization of the tumor and its lymphatic drainage. Based on careful studies of lymph vessels and lymph nodes of the colon the exact way of tumor spread has been determined. This led to internationally accepted resection standards for colon cancer. The pictures below demonstrate the extent of resection for certain tumor localizations. see figure

When compared with other tumors of the digestive tract colon cancer has a rather favorable prognosis. In the early stages (stage I and II) cure is almost always possible. But even in the later stage (stage III) chances for cure are quite good, especially if we do not only rely on surgery alone but add a (mild) chemotherapy after the operation. The presence or absence of lymph nodes infiltrated by the cancer (the nodes are completely removed at the operation and examined by the pathologist) tells us whether postoperative (adjuvant) chemo therapy is necessary. 

From a functional point of view the resection of 30-60 cm of large bowel is not a problem. The rest of the (shortened) bowel takes over the functions of absorbing water and electrolytes within a few days or weeks and the patients carry on with normal lives. In extreme situations the whole large bowel can be removed preserving function. In this case additional technical tricks are necessary to ensure normal bowel movement and normal life. see figure