HOW COLORECTAL CANCER SPREADS
Carcinoma In Situ
The earliest stage of colon cancer is called carcinoma in situ, which means “in place.” If you have carcinoma in situ, the cancer is limited (localized) to the glands in the mucosa. Carcinoma in situ does not have the ability to spread to lymph nodes or to other areas of the body, but it generally should be removed surgically.
In more advanced stages of colon cancer, called invasive carcinoma, the tumor penetrates into the colon wall. At this point, the cancer is positioned to spread to lymph nodes and to other organs in the pelvis and abdomen. This type of cancer needs to be removed as soon as possible, and you will be watched carefully for any sign of the cancer’s return.
Cancer cells that enter the lymph nodes can be carried to other parts of the body through the lymph system and form new tumors called metastases.
Most often, colon cancer spreads to the liver, but it can also spread to the ovaries, lungs, or brain. Colon cancer tends to spread to the liver first, because all of the blood from the colon drains to the liver before proceeding to the rest of the body.
The management of metastatic cancer is more difficult and can involve a combination of surgery and chemotherapy.