Patients with distant metastases from gastric cancer usually have a poor final outcome, with a 5-year survival rate typically less than 5%. For metastatic gastric cancer, physicians generally follow the following process for diagnosis and treatment.
Refinement of tests
Before treatment, patients usually undergo gastroscopy and imaging for characterization, localization, and staging of gastric cancer, in addition to possible biopsy of metastases, diagnostic laparoscopic exploration, and evaluation of abdominal lavage fluid.
- Gastroscopy and pathologic biopsy are the basis for confirming the diagnosis and treatment of gastric cancer.
- CT examination of the chest, abdomen, and pelvis is the basic means to determine the stage of gastric cancer before treatment.
- Magnetic resonance imaging (MRI), laparoscopic exploration, and positron emission computed tomography (PET-CT) can be used as alternative examinations when liver metastases, peritoneal metastases, and systemic metastases are suspected after CT examination.
What is the role of MRI in gastric cancer diagnosis and treatment?
Treatment
Chemotherapy
The National Comprehensive Cancer Network (NCCN) guidelines state that systemic chemotherapy remains the mainstay of treatment for advanced gastric cancer. Despite the availability of different chemotherapy regimens, approximately half of patients survive for only about 1 year after chemotherapy. Although there is no uniform standard for the choice of chemotherapy regimen, there is more agreement that multi-drug combinations improve overall survival and response rates than single-drug chemotherapy, although the incidence of toxic side effects is also relatively high with multi-drug combinations. Physicians will weigh the benefits and risks to choose the appropriate regimen.
Surgery
The primary goals of surgical resection include relief of serious complications such as obstruction, perforation, and bleeding, and improved patient outcomes. However, the value of surgical treatment in metastatic gastric cancer remains highly controversial due to the type and location of metastasis.
Radiotherapy
A large retrospective analysis of the National Cancer Institute’s Surveillance, Epidemiology, and End Results Database (SEER database) in 2012 showed that either surgery alone or radiotherapy alone improved survival relative to metastatic gastric cancer that had not received surgery or radiotherapy, and in particular that the effective combination of the two improved survival substantially. combined, can substantially improve survival.
More research is needed to provide an adequate basis for individualized treatment of the role of radiation therapy in metastatic gastric cancer and what types of metastatic gastric cancer are more amenable to radiation therapy.
Targeted therapy
In recent years, targeted therapy combined with chemotherapy has received increasing attention as a hot spot for individualized treatment of gastric cancer. The more commonly used targeted agents in metastatic gastric cancer are trastuzumab (Trastuzumab, trade name Herceptin), which targets HER2 (human epidermal growth factor receptor 2), and ramucirumab (Ramucirumab), which is an anti-angiogenic agent.
Follow-up visits
Follow-up visits are used to monitor disease recurrence or treatment-related adverse effects, assess nutritional improvement, and so on. The frequency of follow-up is usually every 3 months for the first 2 years after the end of treatment, and then every 6 months until 5 years after treatment.
Follow-up usually includes blood tests (including tumor markers), functional status score (PS), and possibly ultrasound or CT every 6 months and gastroscopy once a year. See your doctor if your symptoms get worse and if new symptoms develop.
Summary
For metastatic gastric cancer, physicians usually use a combination of treatment based on systemic chemotherapy, but there is no standardized treatment plan or sequence. Palliative surgery, radiation therapy, targeted therapy, and other treatments, when properly chosen, can also help prolong survival and improve quality of life. The treatment of metastatic gastric cancer is a process of multidisciplinary physicians’ cooperation. (Contributed by Wenbin Hou, Department of Gastrointestinal Oncology, The First Hospital of China Medical University)