Cyclooxygenase-2 inhibition in colon experimental carcinogenesis.

BACKGROUND: An overexpression of cyclooxygenase-2 (COX-2) has been seen in colon tumors; therefore, COX-2 specific inhibitors may be used as preventive agents. The aim of this study was to investigate the effect of both selective and non-selective COX-2 inhibitors on the incidence of colonic tumors in a model of chemical carcinogenesis in the rat. DESIGN: Experimental study with 65 male Sprague-Dawley rats randomly assigned to one of four groups: (a) control (n = 20), with chemical carcinogenesis using 1-2 dimethylhydrazine (1-2 DMH); (b) acetylsalicylic acid (ASA) (n = 15), with chemical carcinogenesis and the addition of ASA at 30 mg/kg; (c) low-dose rofecoxib (n = 15), with chemical carcinogenesis and the addition of rofecoxib at a dose of 1.2 mg/kg; (d) high-dose rofecoxib (n = 15), with carcinogenesis and the addition of rofecoxib at 3 mg/kg. Carcinogenic induction was performed with 1-2 DMH at a weekly dose of 25 mg/kg for 18 weeks. The main parameter evaluated was percentage of neoplastic colonic tissue, which relates tumor surface area to colon surface area. RESULTS: Rofecoxib at a dose of 3 mg/kg significantly reduced chemical colon carcinogenesis in rats (p < 0.01). Rofecoxib in lower doses had the same effect on adenomas (p < 0.05) with no effect on adenocarcinomas. Rofecoxib reduced COX-2 expression in tumoral tissue from adenomas and adenocarcinomas (p < 0.01). CONCLUSIONS: Rofecoxib prevents chemical colon carcinogenesis in the rat, with a reduction of tumoral colonic percentage in adenocarcinomas and tumoral COX-2 expression.

Liver resection in metastatic colorectal cancer: a multidisciplinary approach.

AIM: To analyze qualitative short-time results of a new program for multidisciplinary liver evaluation in complex cases of liver metastasis from colorectal cancer. PATIENTS AND METHODS: 40 clinical consecutive evaluations with liver metastasis assessed for major liver resection by a multidisciplinary specialist committee. Complementary explorations performed included CT and ultrasounds, and MRI or PET for doubtful cases. Liver resection was made in a single operation or two-stage hepatectomy, or combined with other techniques. RESULTS: Postoperative mortality at 30 days was 4%. Complications occurred in 28%, with surgical wound infection being most frequent (20%); 16.6% of resections were transfused, with a mean volume of 1000 ml. Two patients needed reoperation -one for an intraperitoneal abscess and one for bile-duct stenosis. Percentage of global relapse was 36%, with 26% of relapses out of the liver. Actuarial survival at one year follow-up was 90%, and 82% at two years; 64% of patients remain free of disease two years after the operation. CONCLUSIONS: Programs for liver resection for colorectal cancer metastasis may be implemented by multidisciplinary teams of recent setup. There is a need to evaluate own results and then compare them with a standard of quality previously reported.