Stomach cancer that has spread to other parts of the body is called metastatic gastric cancer. Metastatic gastric cancer may be treated with surgery, radiation therapy or chemotherapy. Radiation therapy is a treatment that uses high-energy x-rays or other particles to kill cancer cells and shrink tumors. Chemotherapy is a drug that causes cancer cells to die or stops them from growing. It is often used in combination with other cancer treatments.
The type of treatment that is right for you will depend on how advanced your disease is and what else your doctor recommends. You might be able to participate in a clinical trial that tests new ways to treat your cancer. If you are interested, ask your doctor about clinical trials for metastatic gastric cancer.
Treatment for metastatic gastric cancer can cause side effects. If you have side effects, talk to your doctor. Some side effects are more serious than others. For example, radiation therapy can cause hair loss and diarrhea. It can also cause a weakening of your immune system, which may make it easier for bacteria to grow and enter the bloodstream.
Metastatic gastric cancer usually metastasizes to the lungs, bone and nervous system. The liver is a less common site of metastasis. Compared with generic adenocarcinoma, adenocarcinomas with the histological subtypes signet ring and mucinous have different metastasis patterns. This suggests that the histological subtypes of adenocarcinoma influence their progression and treatment response. Two theories are commonly proposed to explain this: the “anatomical/mechanical” hypothesis and the “seed-and-soil” hypothesis.
In general, survival is poor in people with metastatic gastric cancer. In addition to T and N stages, and site of metastasis, survival differed remarkably by histological subtype, with a poorer prognosis in mucinous adenocarcinoma and a better one in signet ring adenocarcinoma. Survival was worse in men and in those with a bone or liver metastasis.
Several systemic treatments are available for metastatic gastric cancer, including the drugs paclitaxel, bevacizumab and erlotinib. Other promising agents include PD-1 inhibitors, HER-2 tyrosine kinase inhibitors and multikinase inhibitors. Molecular profiling (at least for HER-2-expression, microsatellite instability status, programmed cell death ligand 1 expression and Epstein-Barr virus) is recommended prior to the start of any systemic treatment in order to identify therapy-fit patients.
