Cancer can spread through tissue, the lymph system, and the blood:
- Tissue. The cancer spreads from where it began by growing into nearby areas.
- Lymph system. The cancer spreads from where it began by getting into the lymph system. The cancer travels through the lymph vessels to other parts of the body.
- Blood. The cancer spreads from where it began by getting into the blood. The cancer travels through the blood vessels to other parts of the body.
Cancer may spread from where it began to other parts of the body.
When cancer spreads to another part of the body, it is called metastasis. Cancer cells break away from where they began (the primary tumor) and travel through the lymph system or blood.
- Lymph system. The cancer gets into the lymph system, travels through the lymph vessels, and forms a tumor (metastatic tumor) in another part of the body.
- Blood. The cancer gets into the blood, travels through the blood vessels, and forms a tumor (metastatic tumor) in another part of the body.
The metastatic tumor is the same type of cancer as the primary tumor. For example, if uterine sarcoma spreads to the lung, the cancer cells in the lung are actually uterine sarcoma cells. The disease is metastatic uterine sarcoma, not lung cancer.
The following stages are used for uterine sarcoma:
In stage I, cancer is found in the uterus only. Stage I is divided into stages IA and IB, based on how far the cancer has spread.
- Stage IA: Cancer is in the endometrium only or less than halfway through the myometrium (muscle layer of the uterus).
- Stage IB: Cancer has spread halfway or more into the myometrium.
In stage II, cancer has spread into connective tissue of the cervix, but has not spread outside the uterus.
In stage III, cancer has spread beyond the uterus and cervix, but has not spread beyond the pelvis. Stage III is divided into stages IIIA, IIIB, and IIIC, based on how far the cancer has spread within the pelvis.
- Stage IIIA: Cancer has spread to the outer layer of the uterus and/or to the fallopian tubes, ovaries, and ligaments of the uterus.
- Stage IIIB: Cancer has spread to the vagina or to the parametrium (connective tissue and fat around the uterus).
- Stage IIIC: Cancer has spread to lymph nodes in the pelvis and/or around the aorta (largest artery in the body, which carries blood away from the heart).