The high incidence of occult carcinoma in total hepatectomy specimens of patients treated for unresectable colorectal liver metastases with liver transplant

Abstract

Objective: 

To describe the rate of missed carcinoma deposits in total hepatectomy specimens from patients treated with liver transplant (LT) for colorectal liver metastases (CRLM).

Background: 

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.

Methods: 

Retrospective review of 14 patients who underwent LT for CRLM, at two centers. Radiographic and pathologic correlation of the number of tumors and their viability before and after LT was performed.

Results: 

The median (IQR) 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 five patients (35.7%); six (42.9%) underwent surgical resection and five (35.7%) received locoregional therapy. The indication for LT was unresectability in eight patients (57.1%) and liver failure secondary to oncologic treatment in the remaining six (42.9%). Before LT, seven patients (50%) demonstrated FDG-avid tumors and seven (50%) had a complete radiographic response. Histopathologically, 11 patients (78.6%) had 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 prior to LT. Furthermore, four (57.1%) of the seven patients who demonstrated complete radiographic response harbored viable carcinoma on explant pathology.

Conclusions: 

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 option to prevent indolent disease progression from disappearing CRLM.