Colorectal Cancer Diagnosis

Colorectal Cancer Diagnosis include Laboratory examination such as Fecal occult blood test, Rectal mucus T antigen test, Serum carcinoembryonic antigen determination and Fiber colonoscopy, X-ray, Cytology and biopsy examination, B ultrasonic, CT, magnetic resonance imaging and more.

1. Laboratory examination:
In addition to diagnosis for Colorectal cancer with routine analysis of blood to known whether anemia, use other various tests include fecal occult blood test, colorectal cancer biomarker detection. These is important significance for confirm the diagnosis of early colorectal cancer.

1) Fecal occult blood test: colorectal cancer as a result of erosion due to mucosal ulceration and bleeding of varying degrees, so they can make use of simple occult blood test for monitoring colorectal cancer. Occult blood test will be early color method for the chemical, commonly used reagents for the joint aniline or fat, such as guaiacol, in recent years have been gradually more specific immune reagents replaced occult blood. However, due to occult blood test and it can not distinguish between cancer and non-cancerous bleeding, it is currently used for colorectal cancer as a large-scale population census means of screening. but also a small number of early cancer was missed due to false-negative results.

2) Rectal mucus T antigen test: also known as galactose oxidase test to detect colorectal cancer and precancerous lesions of specific markers easy way, as long as the digital rectal James put in a special solution applied paper film or slide on by galactose oxidase Schiff reagent reaction and color, can determine whether the intestinal mucosa of patients with T antigen expression. by the clinical and survey to verify the method of detection of colorectal cancer have a higher sensitivity and specificity, will be used to in the census, and the immune occult blood test screening for colorectal cancer have a complementary effect, but also there are some false positive and false negative rate.

3) Serum carcinoembryonic antigen (CEA) determination: the majority of patients with colorectal cancer often elevated serum CEA level, more than 50μg/ml. However, the specificity of the test is not strong, and in a number of non-digestive tract tumors and benign lesions, serum levels of can also be increased. In addition, CEA in the early adenomatous polyposis colon cancer and poor sensitivity, it will be used for early detection of colorectal cancer, the effect is not obvious.

2. Fiber colonoscopy:
Highly suspicious for clinical patients with colorectal cancer advocacy particularly in order to avoid the whole colonoscopy missed. Colonoscopy as a result of safe and reliable fiber can not only view the tumor size, shape, location, activity, and can visit small polyps or early cancer resection of suspicious lesions can be directed biopsy organizations mirror check, so this diagnosis of colorectal cancer is the most effective.

3. X-ray examination:
Can be found in the rectum or sigmoid colon mirror mirror can not look into the lesion, it is difficult for the service of fiber colonoscopy in patients with ileocecal particularly First of all, the diagnosis of colorectal cancer is also an effective means. Generally line barium enema examination, the main sign for the local deformation of mucosal , abnormal motility, intestinal stricture, filling defect, such as, for smaller, especially less than 2cm in diameter showed early cancer run into difficulties. the use of air-barium double imaging, the early colorectal cancer diagnosis will certainly help.

4. Cytology and biopsy examination:
Biopsy for the determination of early colorectal cancer, especially cancer and polyps and cancerous lesions will have a decisive significance of the differential diagnosis, it is clear not only the nature of the tumor, histological type and degree of malignancy, but also to determine prognosis and guide clinical treatment. Cytology Although high accuracy, but based on the more burdensome, it is not easy to obtain satisfactory specimens, the need to observe experienced doctors cytology, the clinical application of small, the current it is replaced by directly endoscopic brushing cytology smear for diagnosis.

5. Others test:
Such as B ultrasonography, CT tomography, magnetic resonance imaging, angiography, isotope scanning 99mTc lymph nodes for clinical diagnosis of colorectal cancer. Transrectal ultrasound scan can clearly show the scope of rectal tumor, size, depth and around the organization of the and rectum to distinguish the fine structure at all levels, inspection method is simple and can quickly provide images of the surgical options, postoperative follow-up of some help. CT examination of the understanding of the extent of tumor infiltration as well as outside the intestinal lymph nodes or liver metastasis of the importance of diagnosis of recurrence of rectal cancer more accurate.