Preoperative Prediction of Microvascular Invasion with Gadoxetic Acid-Enhanced Magnetic Resonance Imaging in Patients with Single Hepatocellular Carcinoma: The Implication of Surgical Decision on the Extent of Liver Resection.

Introduction: Microvascular invasion (MVI) is one of the most important prognostic factors for hepatocellular carcinoma (HCC) recurrence, but its application in preoperative clinical decisions is limited. This study aimed to identify preoperative predictive factors for MVI in HCC and further evaluate oncologic outcomes of different types and extents of hepatectomy according to stratified risk of MVI. Methods: Patients with surgically resected single HCC (≤5 cm) who underwent preoperative gadoxetic acid-enhanced magnetic resonance imaging (MRI) were included in a single-center retrospective study. Two radiologists reviewed the images with no clinical, pathological, or prognostic information. Significant predictive factors for MVI were identified using logistic regression analysis against pathologic MVI and used to stratify patients. In the subgroup analysis, long-term outcomes of the stratified patients were analyzed using the Kaplan-Meier method with log-rank test and compared between anatomical and nonanatomical or major and minor resection. Results: A total of 408 patients, 318 men and 90 women, with a mean age of 56.7 years were included. Elevated levels of tumor markers (alpha-fetoprotein [α-FP] ≥25 ng/mL and PIVKA-II ≥40 mAU/mL) and three MRI features (tumor size ≥3 cm, non-smooth tumor margin, and arterial peritumoral enhancement) were independent predictive factors for MVI. As the MVI risk increased from low (no predictive factor) and intermediate (1-2 factors) to high-risk (3-4 factors), recurrence-free and overall survival of each group significantly decreased (p = 0.001). In the high MVI risk group, 5-year cumulative recurrence rate was significantly lower in patients who underwent major compared to minor hepatectomy (26.6 vs. 59.8%, p = 0.027). Conclusion: Tumor markers and MRI features can predict the risk of MVI and prognosis after hepatectomy. Patients with high MVI risk had the worst prognosis among the three groups, and major hepatectomy improved long-term outcomes in these high-risk patients.

Grading severity of microscopic vascular invasion was independently associated with recurrence and survival following hepatectomy for solitary hepatocellular carcinoma.

Background: Hepatectomy is the preferred treatment for solitary hepatocellular carcinoma (HCC) without macrovascular invasion and distant metastasis, but long-term survival remains unsatisfactory in certain patients. We sought to identify whether the grading severity of microscopic vascular invasion (MVI) was associated with recurrence and survival among patients with solitary HCC. Methods: Consecutive patients who underwent hepatectomy for solitary HCC were identified from a multicenter prospectively-collected database. Patients were categorized into three groups according to the MVI grading system proposed by the Liver Cancer Pathology Group of China: M0 (no MVI), M1 (1-5 sites of MVI occurring ≤1.0 cm away from the tumor), and M2 (>5 sites occurring ≤1.0 cm or any site occurring >1 cm away from the tumor). Recurrence-free survival (RFS) and overall survival (OS) were compared among the groups. Results: Among 227 patients, 97 (42.7%), 83 (36.6%), and 47 (20.7%) patients had M0, M1, and M2, respectively. Median RFS rates among patients with M0, M1, and M2 were 38.3, 35.1, 11.6 months, respectively, while OS rates were 66.8, 62.3, 30.6 months, respectively (both P<0.001). Multivariate Cox-regression analyses demonstrated that both M1 and M2 were independent risk factors for RFS (hazard ratio 1.20, 95% CI: 1.03-1.89, P=0.040; and hazard ratio 1.67, 95% CI: 1.06-2.64, P=0.027) and OS (hazard ratio 1.28, 95% CI: 1.05-2.07, P=0.035; and hazard ratio 1.97, 95% CI: 1.15-3.38, P=0.013). Conclusions: Grading severity of MVI was independently associated with RFS and OS after hepatectomy for solitary HCC. Enhanced surveillance for recurrence and potentially adjuvant therapy may be considered for patients with MVI, especially individuals with more severe MVI grading (M2).

Impact of anatomic resection on long-term survival in patients with hepatocellular carcinoma with T1-T2 disease or microscopic vascular invasion.

BACKGROUND: This study aimed to clarify potential candidates for anatomic resection (AR) among patients with pathological T1-T2 (pT1-T2) hepatocellular carcinoma (HCC) and to determine whether AR is effective for HCC with microscopic vascular invasion (MVI). METHODS: We retrospectively analyzed 288 patients with pT1a (n = 50), pT1b (n = 134) or pT2 (n = 104) HCC who underwent curative-intent resection between 1990 and 2010. Surgical outcomes were compared between patients who underwent AR (n = 189) and those who underwent nonanatomic resection (NAR; n = 99) according to pT category and MVI status. RESULTS: Patients who underwent AR were more likely to have good hepatic functional reserve and an aggressive primary tumor than those who underwent NAR. When patients were stratified according to pT category, AR had a more favorable impact on survival than NAR only in patients with pT2 HCC in univariate (5-year survival, 51.5% vs. 34.6%; p = 0.010) and multivariate analysis (hazard ratio 0.505; p = 0.014). However, AR had no impact on survival in patients with pT1a or pT1b HCC. In patients with MVI (n = 57), AR achieved better survival than NAR (5-year survival, 52.0% vs. 16.7%; p = 0.019) and was an independent prognostic factor (hazard ratio 0.335; p = 0.020). In patients without MVI (n = 231), there was no significant difference in survival between the two groups (p = 0.221). CONCLUSION: AR was identified as an independent factor in improved survival in patients with pT2 HCC or HCC with MVI.

Comparison of portal and capsular microscopic vascular invasion in the outcomes of early HCC after curative resection.

Microscopic vascular invasion (MVI) is a strong risk factor associated with tumor recurrence and poor overall survival (OS) among hepatocellular carcinoma (HCC) patients after resection. Two types of MVI are identified: portal vein and capsular vein invasion. However, little is known about the impact of different types of MVI on HCC recurrence. The present study aimed to compare HCC recurrence and OS between the portal vein and capsule vein MVI. Patients with Barcelona Clinic Liver Cancer (BCLC) stage 0 or A HCC who underwent primary resection between January 2001 and June 2016 were consecutively recruited. Factors that influenced OS and recurrence-free survival (RFS) were analyzed using Cox proportional hazards models. Of the 857 eligible patients, 327 (38.2%) had MVI, and 530 (61.8%) were without MVI. Of the 327 patients with MVI, 85 (26.0%) were with portal vein, 178 (54.4%) with capsular vein, and 64 (19.6%) with both-MVI type. Patients with both-MVI type suffered from a higher proportion of BCLC stage A (P < 0.001), capsular invasion (P = 0.002), and satellite nodules (P < 0.001). Both-MVI type is an independent risk factor for HCC recurrence (hazard ratio [HR]: 1.69; 95% CI, 1.22-2.36, P = 0.002) and mortality (HR: 2.29; 95% CI, 1.59-3.29, P < 0.001) compared with non-MVI. We further found that both-MVI type was significantly associated with a higher risk of extrahepatic recurrence (EHR) (HR: 8.74; 95% CI, 2.38-32.03, P = 0.001). Among HCC patients after curative resection, concurrent portal and capsular MVI is a risk factor for HCC recurrence, especially for EHR, in comparison with non-MVI or only portal or capsular MVI alone.

Synergistic impact of resection margin and microscopic vascular invasion for patients with HBV-related intrahepatic cholangiocarcinoma.

OBJECTIVES: The resection margin (RM) status and microscopic vascular invasion (MVI) are known prognostic factors for intrahepatic cholangiocarcinoma (ICC). An enhanced understanding of their impact on long-term prognosis is required to improve oncological outcomes. METHODS: A total of 711 consecutive patients who underwent curative liver resection for hepatitis B virus-related ICC were retrospectively analyzed. The different impact of the RM status (narrow, <1 cm, or wide, ≥1 cm) and MVI (positive, +, or negative, -) on overall survival (OS) and recurrence-free survival (RFS) were analyzed. RESULTS: The 1-, 3-, and 5-year OS rates were 67.6%, 42.5%, and 33.2% in wide RM & MVI (-), 58.0%, 36.1%, and 26.5% in narrow RM & MVI (-), 51.0%, 27.0%, and 24.3% in wide RM & MVI (+), and 39.0%, 20.4% and 14.3% in narrow RM & MVI (+) (p < 0.001). Multivariate analysis showed that RM & MVI were independent risk factors for the OS and RFS. CONCLUSION: Combined analysis of RM and MVI can better stratify the risks of postoperative death and recurrence in patients with HBV-related ICC, which may help subsequent adjuvant therapy and closer follow-up.

Microscopic portal vein invasion is a powerful predictor of prognosis in patients with hepatocellular carcinoma who have undergone liver resection.

BACKGROUND AND OBJECTIVES: A recent study proposed simple classifications of microscopic vascular invasion (MVI): microscopic portal vein invasion (MPVI) and microvessel invasion (MI). We aim to validate these classifications of MVI. METHODS: This retrospective study consecutively enrolled 514 Barcelona Clinic Liver Cancer stage 0, A, and B naïve hepatocellular carcinoma patients who underwent liver resection in our institution from 2011 to 2017. RESULTS: Among these 514 patients, 240 patients were classified as having no MVI at all (designated as no vascular invasion, NVI), 157 patients were classified as having MI only, and 117 patients were classified as having MPVI. The 5-year overall survival (OS) rate in the MI-only group was 83.3%, which was not significantly different from that of the NVI group (87.2%), p = .20. Using NVI as a reference, multivariate analysis showed that MI-only is not an independent variable associated with OS. The 5-year OS in the MPVI group was 59.2%, which was significantly lower than those for MI-only (p < .001) and NVI groups (p < .001). Using NVI as a reference, multivariate analysis showed that MPVI is an independent variable associated with OS (HR, 3.12; 95% CI, 1.80-5.40; p < .001). CONCLUSIONS: The results of this study validate the simple MVI classifications to be clinically useful.

Microvascular Venous Invasion in Hepatocellular Carcinoma: Why Do Recurrences Occur?

PURPOSE: Hepatocellular carcinoma is the most common primary cancer of the liver. It is almost always associated with cirrhosis and it is usually diagnosed in later stages of the disease. Furthermore, recurrence rate following liver transplantation ranges between 15 and 30%. The most important factor determining the recurrence is vascular invasion. METHODS: In this review, the issue of microvascular invasion causing hepatocellular carcinoma recurrence is reviewed. Macroscopic vascular invasion is almost easy to diagnose on radiologic evaluation. However, microscopic vascular invasion is almost always diagnosed with pathologic evaluation. On the other hand, microscopic vascular invasion is associated with early recurrences and reduced disease-free survival. The type of vessel that is invaded determines the nature of the spread of the tumor cells. Invasion of the hepatic venous tributaries leads to systemic metastasis whereas portal venous invasions lead to intrahepatic spread of the tumor. Microscopic vascular invasion should be diagnosed before liver transplantation or liver resection in order to deliver the appropriate therapy to the patients. RESULTS: Yet, there is no ideal marker to suggest microscopic vascular invasion before any intervention. Markers such as alpha-fetoprotein, des carboxy prothrombin, or gamma-glutamyl transferase have been found to be correlated with microscopic vascular invasion. These parameters are not very efficient to be used in routine clinical practice. CONCLUSION: Therefore, further research is needed to define ideal marker associated with microscopic vascular invasion.

The Frequency and Prognostic Impact of Pathological Microscopic Vascular Invasion According to Tumor Size in Non-Small Cell Lung Cancer.

BACKGROUND: Microscopic vascular invasion (MVI) in patients with non-small cell lung cancer (NSCLC) has been reported to be a strong predictor of poor outcomes but it has not been a descriptor of the TNM classification. The purposes of this study were to determine whether the presence of MVI is related to a predictor of poor outcomes and to explore the degree of MVI according to tumor size. METHODS: A total of 1,884 patients with stage pT1-4N0-2 NSCLC who underwent complete resection comprised the study sample. Overall survival (OS) and recurrence-free proportion were estimated using the Kaplan-Meier method. The Cox proportional hazards model was used to assess independent predictors of poor outcomes. RESULTS: Of 1,884 patients, 1,097 (58.2%) had MVI. Multivariate analysis showed MVI was a significant independent predictor of unfavorable OS (hazard ratio, 1.666; P < .001) and recurrence (hazard ratio, 2.268; P < .001). The frequency of MVI varied according to tumor size, and in each cohort of tumor sizes ≤ 2 cm, > 2 to 3 cm, and > 3 to 5 cm, there were significant differences in survival outcome by MVI status. The proportions of patients with a 5-year recurrence-free period with tumor sizes ≤ 2 cm, > 2 to 3 cm, and > 3 to 5 cm between MVI (+) and MVI (-) were 93.0% and 72.5% (P < .001), 90.8% and 63.3% (P < .001), and 86.4% and 59.9% (P < .001), respectively. CONCLUSIONS: This study demonstrated that MVI was a strong predictor of poor outcomes and that the effect is more prominent in patients with tumor sizes ≤ 5 cm. Further analysis of survival and MVI should be collected for future revision of the TNM system.

Circulating Tumor DNA Analysis for Liver Cancers and Its Usefulness as a Liquid Biopsy.

BACKGROUND & AIMS: Circulating tumor DNA (ctDNA) carrying tumor-specific sequence alterations has been found in the cell-free fraction of blood. Liver cancer tumor specimens are difficult to obtain, and noninvasive methods are required to assess cancer progression and characterize underlying genomic features. METHODS: We analyzed 46 patients with hepatocellular carcinoma who underwent hepatectomy or liver transplantation and for whom whole-genome sequencing data was available. We designed personalized assays targeting somatic rearrangements of each tumor to quantify serum ctDNA. Exome sequencing was performed using cell-free DNA paired primary tumor tissue DNA from a patient with recurrent liver cancer after transcatheter arterial chemoembolization (TACE). RESULTS: We successfully detected ctDNA from 100 µL of serum samples in 7 of the 46 patients before surgery, increasing with disease progression. The cumulative incidence of recurrence and extrahepatic metastasis in the ctDNA-positive group were statistically significantly worse than in the ctDNA-negative group (P = .0102 and .0386, respectively). Multivariate analysis identified ctDNA (OR 6.10; 95% CI, 1.11-33.33, P = .038) as an independent predictor of microscopic vascular invasion of the portal vein (VP). We identified 45 nonsynonymous somatic mutations in cell-free DNA after TACE and 71 nonsynonymous somatic mutations in primary tumor tissue by exome sequencing. We identified 25 common mutations in both samples, and 83% of mutations identified in the primary tumor could be detected in the cell-free DNA. CONCLUSIONS: The presence of ctDNA reflects tumor progression, and detection of ctDNA can predict VP and recurrence, especially extrahepatic metastasis within 2 years. Our study demonstrated the usefulness of ctDNA detection and sequencing analysis of cell-free DNA for personalized treatment of liver cancer.

Prognostic value of microvascular invasion in predicting survival in renal cell carcinoma.

OBJECTIVE: To assess microvascular tumor invasion and other clinical and histological parameters as potential prognostic factors in surgically treated renal cell carcinoma. MATERIALS AND METHODS: Surgical specimens from 238 consecutive patients who underwent radical or partial surgery between 1990 and 2006 were retrospectively evaluated. The series included clinically localized or metastatic renal cell carcinoma (pT1-4; N0-1; M0-1). Disease-free and cancer-specific survival assessments were the end points with median follow-up of 75 months (range 1-189 months). Variables studied included: age, sex, tumor size, TNM 2010 classification, Fuhrman grade, histological subtype and microvascular tumor invasion. RESULTS: Microvascular tumor invasion was observed in 79 patients (33,2%) and was significantly associated with age (P=.010), tumor size (P=.000), Fuhrman grade (P=.000), pT stage 2010 (P=.000),N stage 2010 (P=.000) and M stage 2010 (P=.000). Multivariate analyses determined that sex, Fuhrman grade, pT stage 2010 and histological subtipe were independent prognostic factors of disease-free survival, while sex, Fuhrman grade, pT stage 2010, M stage 2010, histological subtype and microvascular invasion were prognostic factors for cancer-specific survival. CONCLUSIONS: Our study shows that microvascular tumor invasion is an independent prognostic factor for cancer-specific survival in surgically treated patients with renal cell carcinoma.