The tendency of colonic carcinoma to metastasize is best assessed by:

Ans. is 'c' i.e. depth of penetration of bowel wallSchwartz writes "Regional lymph node involvement is the most common form of spread of colorectal carcinoma and usually proceeds distant metastasis or the development of carcinomatosis, the T stage (depth of invasion) is the single most significant predictor of lymph node spread."From the above given lines 1 depth of penetration of bowel wall appears to be predictor of distant metastases as well.CEA level is a marker for recurrence of colorectal ca after surgical resection.Though its preoperative levels has some prognostic significance, it is not a predictor for distant metastasis.* CEA level is used to follow up post-operative cases of colorectal cancer, for early detection of recurrence.