Five common examinations for colon cancer

Colon cancer ranks third among gastrointestinal tumors. Statistics show that the number of new cases of colorectal cancer in my country reaches 130,000 per year, and the number is increasing at an average annual rate of 4%. China has become one of the areas with a high incidence of colorectal cancer. The prevention, diagnosis, and efficacy evaluation of colon cancer all require examinations. So, what are the common examinations for colon cancer?

Carcinoembryonic antigen (CEA) test

CEA is a tumor marker of the digestive system, and its elevation can be seen in a variety of tumors. Therefore, CEA does not have specific diagnostic value and is not suitable as a colon cancer screening item. However, serum CEA levels are inversely proportional to the degree of tumor differentiation in colon cancer and are significantly correlated with the stage, which is helpful in auxiliary diagnosis, efficacy judgment, and prognosis estimation.

Barium enema examination

As a basic imaging method for colon cancer, barium enema examination is mainly used to show intracavitary lesions and longitudinal invasion. It can also observe whether the mucosal folds in the lesion area are damaged and the morphological and dynamic changes of the gastrointestinal tract. Due to its low price, barium enema examination is still a simple, effective, economical and practical diagnostic method for colon cancer examination.

Colonoscopy

For patients clinically suspected of low-lying colorectal cancer, digital rectal examination and sigmoidoscopy should be used first. These two methods can detect at least 60% of lesions in low-lying colorectal cancer within 25 cm from the anus, while for colon cancer more than 20 cm from the anus, fiber colonoscopy is the most reliable examination method. It can not only confirm the nature of lesions that cannot be determined by barium enema, but also detect small lesions that are missed by barium enema.

CT

The main advantage of CT in the diagnosis of colon cancer is that it can show the location, size, morphology of the tumor, invasion of surrounding tissues, lymph node involvement, and metastasis to distant organs. In recent years, with the development of CT imaging technology, the sensitivity and specificity of CT in detecting tiny lesions have greatly increased, playing an important role in preoperative staging and postoperative monitoring of colon cancer.

Ultrasonography

Ultrasound diagnosis is simple and easy. It can display the various layers of the intestinal wall of colon cancer, determine the degree of tumor invasion and lymph node involvement, and has become an important examination method in the preoperative staging of colon cancer.