The High Incidence of Occult Carcinoma in Total Hepatectomy Specimens of Patients Treated for Unresectable Colorectal Liver Metastases With Liver Transplant.

Abstract

To describe the rate of occult carcinoma deposits in total hepatectomy specimens from patients treated with liver transplant (LT) for colorectal liver metastases (CRLM). Previous studies have shown that patients with CRLM treated with systemic therapy demonstrate a high rate of complete radiographic response or may have disappearing liver metastases. However, this does not necessarily translate into a complete pathologic response, and residual invasive cancer may be found in up to 80% of the disappearing tumors after resection. Retrospective review of 14 patients who underwent LT for CRLM, at 2 centers. Radiographic and pathologic correlation of the number of tumors and their viability before and after LT was performed. The median (interquartile range) number of tumors at diagnosis was 11 (4-23). The median number of chemotherapy cycles was 24 (16-37). Hepatic artery infusion was used in 5 patients (35.7%); 6 (42.9%) underwent surgical resection, and 5 (35.7%) received locoregional therapy. The indication for LT was unresectability in 8 patients (57.1%) and liver failure secondary to oncologic treatment in the remaining 6 (42.9%). Before LT, 7 patients (50%) demonstrated fluorodeoxyglucose-avid tumors and 7 (50%) had a complete radiographic response. Histopathologically, 11 patients (78.6%) had a viable tumor. Nine (64.2%) of the 14 patients were found to have undiagnosed metastases on explant pathology, with at least 22 unaccounted viable tumors before LT. Furthermore, 4 (57.1%) of the 7 patients who demonstrated complete radiographic response harbored viable carcinoma on explant pathology. A complete radiographic response does not reliably predict a complete pathologic response. In patients with unresectable CRLM, total hepatectomy and LT represent a promising treatment options to prevent indolent disease progression from disappearing CRLM.