Prognostic impact of intrahepatic lymphatic and microvascular involvement in cases of colorectal liver metastases

The purpose of this study was to evaluate the effect of intrahepatic microvascular and lymphatic infiltration on survival in cases of colorectal liver metastases. Prospectively collected data of 331 patients were analyzed for microvascular invasion (V), lymphatic infiltration (L), and resection margins (R) with respect to overall and disease-free survival. One-, 3-, and 5-year overall survival rates for R0 resected patients were 89%, 64%, and 39%, respectively. The corresponding survival rates for R1 resected patients were 83%, 42%, and 24% (p < 0.001). The sole presence of microvascular invasion (V1) or lymphatic infiltration (L1) was not associated with a diminished overall survival (p > 0.05). However, patients with a combination of L1V1 had a significantly worse overall survival of 68%, 20%, and 0% when compared to L0V0 patients. This difference was not influenced by the status of the resection margin. No other parameter investigated was found to be of predictive value. The presence of combined lymphatic and vascular invasion (L1V1) constitutes a predictor of poor overall and disease-free survival. This subgroup of patients might benefit from adjuvant strategies such as chemotherapeutic treatment.