Interval period tumor progression: Does delayed hepatectomy detect occult metastases in synchronous colorectal liver metastases?

Background Rapid remnant liver recurrence in patients with synchronous colorectal liver metastases (CRLM) is occasionally experienced after simultaneous colorectal and liver resection. We evaluated the tumor progression during interval periods to determine whether delayed hepatic resection detects occult metastases. Methods One hundred thirty-seven patients underwent hepatectomy for synchronous CRLM. Up to 2003, 116 patients underwent simultaneous colorectal and hepatic resection. From 2004 onward, we identified 21 patients undergoing delayed hepatectomy for synchronous CRLM. The tumor progression during interval was determined by a dynamic computed tomography scan. Results Median/mean interval between the two evaluations prior to the first and second surgery was 2/2.4 months. The median/mean number of metastases detected at each evaluation was 2/3.3 and 3/4.6, respectively. Nine of the 21 (43%) patients had new detectable metastatic lesions after reevaluation. For 11 of the 21 patients, it was necessary to reconsider planned surgical procedure which was determined prior to colorectal surgery. Hepatic disease-free survival was significantly different between patients undergoing delayed and simultaneous hepatectomy. Multivariate analysis showed that the delayed hepatectomy was a significant independent prognostic factor in hepatic disease-free survival. Conclusion Tumor progression was recognized and occult metastases were detected after the interval reevaluation. Delayed hepatectomy may be a useful approach to reduce rapid remnant liver recurrence in synchronous CRLM.