Estimating the prognosis of hepatic resection in patients with metastatic liver tumors from colorectal cancer with special concern for the timing of hepatectomy.

BACKGROUND: The effect of the time interval between colorectal and liver resection for metastatic lesions on the patient's survival remains controversial. Pretreatment classification for predicting the prognosis of this disease has not yet been reported.
METHODS: Nine clinical factors revealed by preoperative examinations, intraoperative screening before liver resection, and resection margin were examined in 304 patients who underwent hepatic resections for metastatic colorectal carcinoma. The patients were divided according to the timing of hepatectomy and both tumor number and maximum diameter to devise a staging system.
RESULTS: Tumor number and maximum tumor size were significant prognostic factors in the metachronous hepatectomy group, and resection margin was significant in the synchronous group. The following staging system was proposed: stage I, n < or = 3 and diameter < 5 cm in the metachronous hepatectomy group (n = 86); stage II, n < or = 3 and diameter > or = 5 cm in the metachronous hepatectomy group (n = 46); and stage III, n > or = 4 and diameter > 5 cm in the metachronous group and the synchronous hepatectomy group (n = 144).
CONCLUSIONS: The current study revealed that the factors that influenced the patient's prognosis were different between the synchronous and metachronous groups. It may be useful to develop a staging system that considers this difference.