As the rapid development of endoscopic techniques and the application of endoscopy with biopsy in early gastric cancer has become the primary means of inspection, but also common in early diagnosis of gastric cancer gold standard. Gastroscope gastroscopy particular operational flexibility, clear imaging, and biopsy and cell brush biopsy, while the photography and video, the qualitative location of gastric cancer diagnosis rate of 95% or more. Diagnosis of early gastric cancer using endoscopy requires careful observation station operator membrane lesions, where there are local erythema, inexpensive bad, save martyrs, who teaches film should be rough biopsy biopsy biopsy, stressed that multiple lesions, with lesions more biopsy guarantee biopsy depth, attention to the first biopsy forceps, etc., if necessary, repeat the examination, biopsy combined with cell brush biopsy can improve the diagnostic rate of foci. In recent years, there have been some special methods and gene level gastroscopy examination, the diagnosis of early gastric cancer to improve the level of great value.
Since 80% of asymptomatic patients with early gastric cancer or symptoms of neuron specific, some of the symptoms of acid-suppressing drugs can be applied mitigation, coupled with X ray contrast imaging and endoscopy in the diagnosis of early gastric cancer still have a false negative (about 5% – 10%), since the issue of early gastric cancer was still not high, accounting for the same period of early gastric cancer in China the ratio is 5% or so.
(1) gastric cancer early diagnosis of common endoscopic ultrasound
The past 10 years to develop endoscopic ultrasound technique can show the structure of normal gastric wall layers 5, 7 or 9 layer sonographic layer, which in determining the depth of tumor invasion and lymph node metastasis has great value, and for the selection of the number of early gastric cancer endoscopic resection of a reference film. Japan reported that the overall accuracy rate of 80% or more. Endoscopic ultrasound in early gastric cancer showed the disorder of the stomach hierarchy, showing stalk membrane rupture, gastric wall thickening, but also found that lymph node metastasis. Kanazawa University, Japan, researchers recently three-dimensional endoscopic ultrasonography (3-D EUS) of early gastric cancer for good imaging, to assess the depth of invasion. They have selected a total of 69 visible lesions of early gastric cancer in 67 patients in vivo studies, while 30 patients in which surgical resection specimens in vitro, and compared with histopathologic biopsy results showed that the rapid evaluation of three-dimensional EUS lesions in vivo and in vitro, in vivo studies ,3-DEUS assess the accuracy of the depth of tumor invasion was 87%, that the three-dimensional evaluation of endoscopic ultrasonography in the diagnosis of early gastric cancer invasion and extent of the primary methods;
(2) magnifying endoscopy
High-resolution image bundles development and application of magnifying endoscopy, the gastric membrane fine structure can be significant for the identification of benign and malignant lesions and determined to provide a powerful means to further improve the diagnosis of gastric cancer. Through magnification, according to the form of gastric pits and the arrangement of clinical manifestations can be divided into A, B, C, D4 type. Benign lesions showed regular arrangement, and with changes in the degree of malignancy, showed irregular arrangement of fine form and structure of the disorder until it is destroyed. Magnifying endoscopy combined pigment dyeing but also help improve the early gastric cancer in particular, the diagnosis of small gastric cancer. The researchers found that magnification endoscopy gastric membrane need to observe the fine structure of teaching and microvessel model, a small depression, the depression of different sizes, irregular blood vessels to support depression and irregular surface structure is the characteristics of early gastric cancer, differentiated type early gastric cancer Common small depression (88%), undifferentiated type is relatively rare (50%). Analysis of frame type and fine capillary structure on the surface of young families with 0.1% of early gastric cancer with magnifying endoscopy in the importance of observation.
(3) chromoendoscopy
Education membrane staining in vivo to improve gastric cancer diagnosis and accurate visual positioning of the biopsy has an important significance and malignant lesions of the blue, blue-colored plastic toluene rate of 90% or more. 1mm difficult to identify the naked eye on the early diagnosis of gastric cancer is particularly assisted by direct spraying pigment stain, to diagnose gastric cancer is quite necessary.
(4) early diagnosis of common cancer diagnosed in the molecular biology
The molecular biology of early gastric cancer reported more changes, but the current diagnostic sensitivity and specificity are not satisfactory candle. Obvious gastric cancer susceptibility of individuals, such susceptibility polymorphisms in vivo on some basic skills, including the Valley off the glutathione S transferase, cytochrome P450, DNA mismatch repair genes, these genes are present collectively referred to as gastric cancer susceptibility genes. Tumor suppressor gene p53, p16, oncogene c-met, telomerase, cyclin D, E, DNA microsatellite instability and so the detection of precancerous lesions and early gastric cancer monitoring has some value, and can help determine the prognosis of gastric cancer. Telomerase activation is considered to be an early event in gastric cancer.