I. Overview
Gastric cancer is one of the most common malignant tumors in China, and the 2010 Health Statistical Yearbook shows that in 2005, the mortality rate of gastric cancer accounted for the 3rd place of malignant tumor mortality in China. The occurrence of gastric cancer is the result of the long-term effect of multiple factors. There are obvious regional differences in the incidence of gastric cancer in China, and environmental factors are dominant in the occurrence of gastric cancer, while host factors are subordinate. Some studies have shown that Helicobacter pylori (H, pylori) infection, diet, smoking and genetic susceptibility of the host are important factors affecting the occurrence of gastric cancer.
II. Treatment principles
The principle of comprehensive treatment should be adopted, that is, according to the pathological type and clinical stage of the tumor, combined with the general condition and functional status of the patient, the multidisciplinary team (MDT) model should be adopted to apply surgery, chemotherapy, radiotherapy and biologic targeting in a planned and rational manner to achieve radical or maximum control of the tumor, prolong the patient’s survival and improve the quality of life. The aim is to achieve radical or substantial tumor control, prolong patient’s survival and improve life quality.
1.For early stage gastric cancer without evidence of lymph node metastasis, endoscopic treatment or surgery can be considered according to the depth of tumor invasion, without adjuvant radiotherapy or chemotherapy after surgery.
2. Early gastric cancer with localized progressive stage or lymph node metastasis should be treated with comprehensive treatment mainly by surgery. Depending on the depth of tumor invasion and whether it is accompanied by lymph node metastasis, direct radical surgery or preoperative neoadjuvant chemotherapy can be considered before radical surgery. Adjuvant treatment plan (adjuvant chemotherapy and, if necessary, adjuvant chemoradiotherapy) should be decided according to the postoperative pathological stage for locally progressive gastric cancer that has been successfully performed radical surgery.
3. Recurrent/metastatic gastric cancer should be treated with a comprehensive treatment based on drug therapy, and local treatment such as palliative surgery, radiotherapy, interventional therapy, radiofrequency therapy should be given at the appropriate time, and the best supportive treatment such as pain relief, stent placement and nutritional support should also be actively given.
Third, chemotherapy (including targeted therapy)
It is divided into palliative chemotherapy, adjuvant chemotherapy and neoadjuvant chemotherapy, which should be strictly mastered for clinical indications and administered under the guidance of medical oncologists. Chemotherapy should be administered with full consideration of the patient’s disease stage, physical condition, adverse effects, quality of life and the patient’s wishes to avoid over-treatment or under-treatment. Timely assessment of chemotherapy efficacy, close monitoring and prevention of adverse reactions, and adjustment of drugs and/or doses as appropriate. Evaluate the efficacy according to the efficacy evaluation criteria or refer to WHO efficacy evaluation criteria for solid tumors. The evaluation criteria for adverse reactions should refer to NCI-CTC standards.
1.Palliative chemotherapy
The purpose is to relieve the clinical symptoms caused by tumor, improve the quality of life and prolong the survival. It is suitable for patients with good general condition and basically normal function of main organs after unresectable, recurrent or palliative resection.
Commonly used systemic chemotherapeutic agents include: 5-fluorouracil (5-FU), capecitabine, tigeo, cisplatin, epothilone, doxorubicin, paclitaxel, oxaliplatin, irinotecan, etc.
Chemotherapy regimens include two-drug combination or three-drug combination regimens. Two-drug regimens include: 5-FU/LV + cisplatin (FP), capecitabine + cisplatin, tegeo + cisplatin , capecitabine + oxaliplatin (XELOX), FOLFOX , capecitabine + paclitaxel, FOLFIRI, etc. Three-drug regimens are suitable for patients with advanced gastric cancer in good physical condition, and the commonly used ones include: ECF and its derivative regimens (EOX, ECX, EOF), DCF and its modified regimens, etc. For patients with poor physical status and advanced age, single-agent chemotherapy with oral fluorouracil analogs or paclitaxel analogs is considered.
For patients with advanced gastric cancer with positive HER-2 expression (immunohistochemical staining of ++++, or immunohistochemical staining of +++ and positive FISH test), the combination of molecular targeted therapy drug trastuzumab can be considered on the basis of chemotherapy.
2.Adjuvant chemotherapy
The targets of adjuvant chemotherapy include those with postoperative pathological stage Ib with lymph node metastasis, and those with postoperative pathological stage II or above. Adjuvant chemotherapy starts when the patient’s physical condition is basically normalized after surgery, and generally starts 3-4 weeks after surgery, and the combination chemotherapy is completed within 6 months, and the single drug chemotherapy should not exceed 1 year. The adjuvant chemotherapy regimen recommends a two-drug combination regimen of fluorouracil-based drugs combined with platinum. For those with clinicopathological stage Ib, poor physical condition, advanced age and intolerance of two-drug combination regimen, single-agent chemotherapy with oral fluorouracil is considered.
3.Neoadjuvant chemotherapy
For locally progressive gastric cancer without distant metastasis (T3/4, N+), neoadjuvant chemotherapy is recommended, and a two-drug or three-drug combination chemotherapy regimen should be used, and should not be applied as a single drug. ECF and its modified regimen are recommended for neoadjuvant chemotherapy of gastric cancer. The time limit of neoadjuvant chemotherapy generally does not exceed 3 months, and the efficacy should be evaluated in a timely manner and attention should be paid to the judgment of adverse effects to avoid additional surgical complications.
Postoperative adjuvant therapy should be based on preoperative staging and neoadjuvant chemotherapy efficacy, and the original regimen should be continued or adjusted according to patient’s tolerance if it is effective, or replaced if it is ineffective.
Follow-up
Patients with gastric cancer should be followed up regularly by monitoring symptoms, signs and adjuvant examinations. The purpose of follow-up is to monitor disease recurrence or treatment-related adverse effects, and to assess the improvement of nutritional status. Follow-up visits should include hematology, imaging, endoscopy and other examination items.
The frequency of follow-up is every 3-6 months for 3 years after treatment, every 6 months for 3-5 years, and once a year after 5 years. Endoscopy was performed once a year. For those who develop macrocytic anemia after total gastrectomy, vitamin B12 and folic acid should be supplemented.