There are three main ways of cancer metastasis, 1) through blood metastasis, cancer cells are transferred to distal organs through blood circulation system, such as liver, lung, brain adrenal gland, bone, etc. 2) lymphatic metastasis, cancer cells enter the lymphatic system of the whole body and transfer to lymphatic tissues of the whole body, such as breast cancer transferring to axillary lymph nodes, stomach cancer transferring to supraclavicular lymph nodes, etc. 3) disseminated metastasis, just like seeds spread to For example, stomach cancer can spread to abdominal cavity, pelvis, etc. Direct spread of cancer cells is also more important.