Microvascular invasion (MVI) is a poorer prognostic predictor for small hepatocellular carcinoma

Abstract

BackgroundSmall hepatocellular carcinoma (SHCC) is a special type of hepatocellular carcinoma with the maximum tumor diameter ≤ 3 cm and excellent long-term outcomes. However, the prognostic factors for SHCC remain controversial. The purpose of this study is to clarify the predictive factors of SHCC.MethodsThe study population consisted of 458 patients underwent hepatectomy for single SHCC between January 2006 and December 2008. Clinical data (included age, gender, virus infection, serum alfa-fetoprotein level, cirrhosis, capsule, border), histopathologic features (included differentiation, morphology subtype, microvascular invasion, tumor infiltrative lymphocytes (TIL), inflammatory injury grade and fibrosis stage of surrounding liver), were evaluated to identify prognostic factors influencing SHCC patients’ survival and microvascular invasion.ResultsThere were 384 males (83.8%) and 74 (16.2%) females with median ages of 52 years. The median progression-free survival (PFS) and overall survival (OS) durations were 53 and 54 months, respectively. About 91.9% (n = 421) SHCC were infected by Hepatitis B. One hundred forty-seven of the 446 (33.0%) patients with pre-operation serum AFP level record had serum alfa-fetoprotein (AFP) level ≥ 200 ug/ml and 178 of the 280 (63.8%) patients with post-operation serum AFP level record had AFP level ≥ 20 ug/ml. Liver cirrhosis was present in 411 cases (89.7%), while 434 (97.3%) tumors had clear border, and 250 (55.6%) tumors were encapsulated.MVI was identified in 83 patients (18.1%). In univariate analysis, a significant association between the presence of MVI and shortened PFS and OS was found (p = 0.012, 0.028, respectively). Histological differentiation had strong relationship with MVI (p = 0.009), in terms of MVI was more easily presented in patients with worse histological differentiation. In patients with MVI, worse survival was correlated with female patients, patients with G2 or G3 histological differentiation, pre-operation serum AFP level ≥ 200 ug/ml or post-operation serum AFP level ≥ 20 ug/ml, and TIL ≥ 50/HPF.ConclusionsMVI is an independent poorer prognostic factor for PFS and OS of single SHCC patients. Tumor histological differentiation was closely related with MVI.

Practice guidelines for the pathological diagnosis of primary liver cancer: 2015 update

“…In a systemic review that included 20 observational studies of patients undergoing liver transplantation (LT), the presence of MVI shortened their 3-year disease-free survival [RR = 3.41 (2.05-5.7)] and 3-year overall survival [RR = 2.41 (1.72-3.37)][33]. A similar correlation between MVI and poor prognosis was also observed in patients with SHCC of ≤ 3 cm[38]. Furthermore, Pawlik et al[39] found that the occurrence of MVI was positively correlated with the size of HCC, suggesting that the size and number of tumors are important predictive indices for MVI.…”

Microvascular invasion predicts a poor prognosis of solitary hepatocellular carcinoma up to 2 cm based on propensity score matching analysis

“…However, with the standardization of the sampling protocol and the refinement of MVI classification, MVI is still an essential biological behavior parameter in the pathological diagnosis of HCC . An increasing number of studies have confirmed that MVI is a key factor leading to early recurrence and a poor prognosis of HCC . Therefore, a growing number of studies are devoted to the preoperative prediction of MVI .…”

“…In addition, the presence of MVI is widely reported to be a significant prognostic factor for HCC . Even for patients with small HCCs up to 3 cm, MVI enhances the rate of tumor recurrence and dramatically shortens long‐term survival . Meanwhile, the tumor biology and condition of the underlying liver, instead of tumor size, were determined to be better indicators of the prognosis and should be given more attention .…”

Microvascular invasion has limited clinical values in hepatocellular carcinoma patients at Barcelona Clinic Liver Cancer (BCLC) stages 0 or B

“…MVI status was determined according to histological pathology. The diagnosis of MVI, when tumor cells were detected in microvessels upon microscopic observation, was made based on our established criteria described elsewhere [3]. The data of MVI status were retrospectively retrieved from pathological reports.…”

“…Microvascular invasion (MVI) is defined as the presence of tumor cells in portal veins, in large capsule vessels, or in a vascular space lined by endothelial cells [3]. MVI is an early means of cancer cell spread via the vasculature [4].…”