Prevention of Liver Metastases of Colorectal Carcinoma

Abstract

Liver metastases are present on initial diagnosis of large-bowel cancer in 25%–30% of patients [2]. After curative resection of colorectal primary tumors, the liver again is the most frequent site of relapse in 40%–50% [4 18]. Once liver metastases have developed, the prognosis is poor, with an expected median survival time of 6–9 months [2, 14], the extent of the tumor being the most important prognostic factor [22]. A great deal of work has been done to determine the factors that influence development of liver metastases. There is evidence that tumor cells embolize into the portal venous system via the invaded mesenteric veins and enter the liver. In 1957, Dukes [7] found evidence of venous spread in 17% of operative rectal cancer specimens. Fisher and Turnbull [8] discovered tumor cells in the mesenteric venous blood of 32% of colorectal carcinoma patients at surgery. They suggested that manipulation of the tumor may force malignant cells into the circulation and they initiated the so-called “no touch-isolation” technique. This led to a significant reduction of the incidence of liver metastases at 2 years and an increased survival at 5 years, compared with historical controls [21]. In a recently closed prospective randomized trial on 231 patients, Wiggers et al. [23] found 19 recurrences and 8 tumor-related deaths in the conventionally resected group. Of the recurrences, 12 were liver metastases, 6 were recurrences elsewhere, and 1 was a new colon carcinoma. In the no-touch isolation group 13 recurrences and 4 tumor-related deaths were observed. Seven recurrences were liver metastases; 6 were recurrences elsewhere. The average time of discovering liver metastases was 8 months (range 6–18 months) in the conventional group and 15 months (range 6–28 months) in the no-touch group. The recurrence rate in this trial is relatively low and the follow-up too short for definitive conclusions.