Adjuvant Portal Infusion Chemotherapy in Colorectal Cancer

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 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 mesenteric veins and enter the liver. In 1957, Dukes [6] found evidence of venous spread in 17% of operative rectal cancer specimens. Fisher and Turnbull [7] 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 [21]. However, not all circulating cancer cells give rise to metastases. Several reports have shown that patients with malignant cells in the portal venous blood fare no worse than those without [15,17].