A total of 98 patients with gastric cancer diagnosed by postoperative pathology admitted to our hospital from October 2017 to May 2019 were selected as the subjects, including 63 males and 35 females, aged from 27 to 69 years old, with an average of 47.62 ± 17.16 years old. TNM staging: 29 in stage I, 37 in stage II, 21 in stage III, 11 in stage IV; lymph node metastasis: 58 had metastasis and 40 had no metastasis.
(1) Meeting the diagnostic criteria for gastric cancer in the Guidelines for the Standardized Diagnosis and Treatment of Gastric Cancer; (2) having no surgery or radiotherapy before the examination; (3) all being diagnosed with gastric cancer by biopsy pathology; (4) the patients and their families being informed and agreed to the study.
(1) Having diseases combined, such as endocrine system disease, immune system disease, blood system disease, and other diseases that may interfere with the detection of tumor markers; (2) patients having incomplete case data. The study was approved by the Ethics Committee of our hospital and informed consent was given by the patients and their families.
The GE Optima 660 64 Slice CT scanner was adopted. The patients fasted for 8 h before the examination, and received an intramuscular injection of 20 mg anisodamine (Fujian Sanai Pharmaceutical Co., Ltd., Guoyao Zhunzi H35020158) 10−20 min before the examination, and 800−1000 mL of drinking water to fill the gastric cavity. The patients were scanned in a supine, side or prone position, scanning from the top of the right diaphragm to the diaphragmatic crest, including the whole abdomen and pelvic cavity. Eighty milliliters of iopromide (Bayer Schering Pharma AG, Germany, Guoyao Zhunzi: J20130157) was injected into the patient’s elbow vein through a high-pressure syringe at a flow rate of 3.5 mL/s. After 30 s of injection of contrast agent, enhanced arterial scanning was performed, scanning from the esophagus, abdomen to whole stomach. After 60 s of injection of contrast agent, intravenous scanning was performed to observe the location of the lesion, its organs around and the distal metastasis, etc. The scanning parameters were as follows: voltage 120 kV, current 250 mA, layer thickness 5 mm, spacing 5 mm, and pitch 1.625 mm.
Olympus Gastrointestinal Videoscope GIF-HQ290 was adopted. The patients fasted for 8 hours before the examination. In order to avoid reflex vomiting during the examination, 5~10 min before the examination, the patients took dyclonine hydrochloride mucilage orally (Yangtze River Pharmaceutical Group, Guoyao Zhunzi H20041523) to anesthetize the throat, took the mouth gag, and kept the left side lying. The gastrointestinal endoscope was then used to enter the mouth, pass through the trachea and esophagus, and then reach the inside of the stomach to observe and diagnose the internal tissues. Lesions with hard texture, solitary erosion or crater shape observed under gastroscopy were collected for biopsy. In case the lesion had a diameter of ≤ 1.0 cm, then all samples were taken; or the lesion > 1.0 cm, then the selected sampling shall be completed.
Gastric mucosa specimens of all patients were collected through endoscopy, fixed with 3.7% neutral formaldehyde solution, routinely dehydrated, embedded in paraffin, cut into slices of 4 μm, baked and dewaxed. Immunohistochemistry was used to detect Her-2 expression in gastric cancer tissues. The kit was purchased from Shanghai Huzhen Biological Technology Co., Ltd. The MaxVision two-step method was used for dyeing. The color development reagent DAB solution was added, lasted for 1 to 2 min, dyed with hematoxylin, dehydrated, and sealed with neutral transparent gum. Phosphate-buffered saline (PBS) was used instead of the primary antibody, as a negative control group. Cell membrane showing brown-yellow granular precipitation was taken as the judgement criteria. For no or < 10% cells having staining, expressed as 0; for ≥ 10% cells having slight staining, expressed as +; for ≥ 10% cells having weak staining, expressed as ++; for ≥ 10% cells having medium to intensive staining, expressed as +++. (0) and (+) indicated low expression, that was, Her-2 was negative; (++) and (+++) indicated overexpression, that was, Her-2 was positive.
Tumor marker detection
Before surgery, 6 mL of the venous blood in the morning under the fasting state of the patient was collected, centrifuged at 1500 r/min for 15 min, and the supernatant was taken. ELISA was adopted to detect tumor markers, including carcinoembryonic antigen (CEA), carbohydrate antigen 242 (CA242), carbohydrate antigen 724 (CA724), and carbohydrate antigen 199 (CA199). All kits were purchased from Shanghai Huzhen Biotechnology Co., Ltd. The positive standards for CEA, CA242, CA724, and CA199 were > 5 ng/mL, > 25 U/mL, > 6.9 U/mL, and > 35 U/mL, respectively.
ROC curve of factors causing gastric cancer
Ninety-eight patients suffering from gastric cancer and 98 normal adults were statistically analyzed for their diet, BMI, family genetic history, and type A blood.
The examination results of all patients were read by two attending radiologists; in case of any dissension, it shall be adopted after consultation.
All patients with gastric cancer were classified into, according to the TNM staging , I, II, III, and IV; and the materials regarding the gender, age, tumor size, lesion location, and lymph node metastasis was collected. The sensitivity, specificity, and accuracy of single detection by gastroscopy, MSCT, HER-2, or tumor marker, and their combination of all patients were observed for comparation. According to AJCC TNM Staging System for Gastric Cancer 2016, T1: tumor invades the muscularis mucosae or submucosa; tumor invades the muscularis propria; T3: tumor penetrates the subserosal connective tissue without invasion of the visceral peritoneum or adjacent structures; tumor invades the serosa or adjacent structures.
Criteria for the positive result of comprehensive detection
Gastroscope, MSCT, Her-2, CEA, CA242, CA724, and CA199 were combined for the detection of gastric cancer. If two of the above results were positive, the comprehensive result was positive; otherwise, it was negative.
SPSS 23.0 software was used for statistical analysis of all data. Measurement data was expressed as mean ± standard deviation (‾x ± s). Counting data was expressed in percentage (%). χ2 test was for comparison between the 2 groups, and pathological results were taken as the gold standard. Differences in the accuracy of single MSCT, gastroscopy, immunohistochemical marker HER-2, tumor marker, and combined examination in the evaluation of clinical staging of gastric cancer were analyzed, and P < 0.05 was considered statistically significant.
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