Symptoms

In its early stages, colon cancer is in most cases completely asymptomatic. One sign is blood in the stool, which is usually not visible to the naked eye. Therefore, a test for this so-called occult blood in the stool can be done by the family doctor as a precautionary measure against colorectal cancer.

Mucus in the stool can also occur in colorectal cancer. If the tumor sits more in the direction of the rectum, very narrow stools are often formed, which are also called pencil or goat droppings stools. Changes in stool habits can be associated with this, for example alternating between diarrhea and constipation and flatulence.

These can cause more or less severe stomach pain. Colon cancer can also lead to the general symptoms that any malignant disease can cause. These include unwanted weight loss, fever, night sweats, general fatigue and a drop in performance.

Colorectal cancer is primarily a disease that occurs at an advanced age. On average, patients are about 65 years old when the initial diagnosis is made. 9 out of 10 cases of colon cancer are diagnosed at the age of >50.

The older one gets, the higher the probability of developing colon cancer. Rarely genetic syndromes like Lynch syndrome or Familial adenomatous polyposis coli are causative. Then people at a younger age are affected.

Diagnostics

Diagnosis of a patient with suspected colon cancer always includes a medical consultation and a physical examination. The doctor will ask the patient about his symptoms and will especially palpate his abdomen and lymph nodes for abnormalities. This also includes a digital-rectal examination (DRU), in which the patient’s rectum is palpated with a finger.

Tumors located there can then often already be palpated. A colonoscopy reveals benign and malignant changes in the intestinal mucosa. If a probable malignant lesion is actually found, a sample can be taken which can then be examined in the pathology department.

If it is indeed colon cancer, further examination methods will follow to determine the current status of the disease.This is the basis on which the patient can be treated. This includes an ultrasound of the liver to look for possible metastases of the colon cancer. The lungs are also checked for such metastases, usually by means of an X-ray. Imaging of the body using computer and/or magnetic resonance imaging shows whether metastases have settled elsewhere in the body and how far the tumor has grown into the intestinal walls and surrounding tissue. Lymph node metastases can also often be clearly delineated in this way.