Prognostic utility of tumor thickness at the tumor-normal interface in chemotherapy-treated hepatic colorectal metastasis.

In a recent report, tumor thickness at the tumor-normal interface (TNI) was confirmed as a prognosticator for patients with hepatic metastases from colorectal carcinoma after adjuvant chemotherapy. We retrospectively reviewed the hepatectomy specimens with metastasis from colonic adenocarcinoma in a single tertiary hospital. Only 23 patients could be included in this study. Following the recommendations by Maru et al., two independent pathologists, blinded to the outcome of the patients, measured the tumor thickness at the TNI in hematoxylin-eosin stained representative slides of the hepatectomy specimens. The outcome was estimated as the time elapsed between hepatectomy and death due to disease (disease-specific survival; DSS). Two patients showed a complete pathological response, 16 cases a major response, and 5 cases a minor pathological response. The mean thickness at the TNI was 0.73mm (0.01-2.5). The ROC analysis defined a cut-off point of 1.34mm best discriminated between patients with a good and a poor prognosis. The mean thickness at the TNI for patients dying of disease was 1.99 (1.06 for survivors). A comparison of the survival curves confirmed that thickness at the TNI was a significant predictor of disease-free survival (p=0.025). This study demonstrates the value of tumor thickness and TNI in predicting disease-free survival. These results are consistent with previous studies demonstrating that thickness of TNI is an important prognostic variable following hepatic resection of colon metastases. Prospective studies are necessary to confirm these retrospective results. Pathology reporting of this parameter, together with the pathological response and margin, may help clinicians to make decisions regarding further therapy.