The spread of the tumor is malignant tumor growth when a certain local direct spread and distant metastasis.
1. With the spread of tumor growth directly, showing invasive growth of tumor cells can destroy adjacent normal organs and tissues, such as advanced rectal cancer spread to the bladder and pelvis, advanced breast cancer invading the chest and rib bone.
2. Metastasis cancer cells can invade the lymphatic vessels, blood vessels and body cavities, it was taken at the continued growth of the original tumor formation and the same type of tumor.
The transfer of common ways are:
(1) lymph node metastasis: cancer cell invasion of lymphatic vessels after lymph flow reached with the regional lymph nodes, where the division, proliferation, the formation of lymph node metastasis. Can continue after the transfer to other lymph nodes or thoracic duct into the bloodstream, the blood secondary to metastasis.
(2) hematogenous metastasis: cancer cells after the invasion of blood vessels to reach far away from the organ with the blood flow to continue to grow and form metastases. Venous invasion of the system through the right heart to the lung tumor cells, the formation of lung metastasis, such as osteosarcoma, liver cancer such as lung metastases; invasive cancer cells in portal venous system may be the first to form liver metastases, hepatic vein and then transferred to the lungs; lung cancer cells of pulmonary vein into the left heart, arterial system and then transferred to the body organs such as brain, bone and so on.
The spread of the tumor (3) planting of transfer: The main tumor in the abdominal organs. Such as gastric perforation of gastric cancer, as the shedding of cancer cells by peritoneal seeding of ovarian serous surface of the same plant, such as the formation of metastasis.