Colorectal cancer metastasis treatment

Editor(s)-in-Chief: C. Michael Gibson, M.S.,M.D. [mailto:mgibson@perfuse.org] Phone:617-632-7753; Elliot B. Tapper, M.D., Beth Israel Deaconess Medical Center

Overview
When colorectal cancer metastasizes, or travels to other parts of the body, there will be a different approach than a localized tumor.

Treatment of colorectal cancer metastasis to the liver
According to the American Cancer Society statistics in 2006 greater than 20% of patients present with metastatic (stage IV) colorectal cancer at the time of diagnosis, and up to 25% of this group will have isolated liver metastasis that is potentially resectable. Lesions which undergo curative resection have demonstrated 5-year survival outcomes now exceeding 50%.

Resectability of a liver met is determined using preoperative imaging studies (Ct or MRI), intraoperative ultrasound, and by direct palpation and visualization during resection. Lesions confined to the right lobe are amenable to en bloc removal with a right hepatectomy (liver resection) surgery. Smaller lesions of the central or left liver lobe may sometimes be resected in anatomic "segments", while large lesions of left hepatic lobe are resected by a procedure called hepatic trisegmentectomy. Treatment of lesions by smaller,non-anatomic "wedge" resections is associated with higher recurrence rates. Some lesions which are not initially amenable to surgical resection may become candidates if they have significant responses to preoperative chemotherapy or immunotherapy regimines. Lesions which are not amenable to surgical resection for cure can be treated with modalities including radio-frequency ablation (RFA), cryoablation, and chemoembolization.

Patients with colon cancer and metastatic disease to the liver may be treated in either a single surgery or in staged surgeries (with the colon tumor traditionally removed first) depending upon the fitness of the patient for prolonged surgery, the difficulty expected with the procedure with either the colon or liver resection, and the comfort of the surgery performing potentially complex hepatic surgery.

Poor prognostic factors of patients with liver metastasis include
 * Synchronous (diagnosed simultaneously) liver and primary colorectal tumors
 * A short time between detecting the primary cancer and subsequent development of liver mets
 * Multiple metastatic lesions
 * High blood levels of the tumor marker, carcino-embryonic antigen (CEA), in the patient prior to resection
 * Larger size metastatic lesions