| Part I. A Wide Resection Margin Improves Long-term Prognoses of Liver Resection for HBV-related Hepatocellular Carcinoma with Microvascular InvasionOBJECTIVE: The association between wide/narrow resection margin and long-term survival outcomes after liver resection for hepatocellular carcinoma(HCC) is still controversial. Microvascular invasion(MVI), as a well-recognized risk factor of surgical prognosis, can be present well beyond tumor capsules. If there is evidence to show a wide margin resection can produce survival benefits for patients with MVI, this will provide the basis to recommend a wide surgical margin using preoperative MVI prediction. We aim to evaluate the short- and long-term prognoses after liver resection with a wide or a narrow resection margin for hepatitis B virus(HBV)-related HCC with or without MVI.PATIENTS AND METHODS: The data on 3263 consecutive patients with a solitary HBV-related HCC who underwent R0 resection at the Eastern Hepatobiliary Surgery Hospital between 2000 and 2013 were analyzed. Tumor recurrence and overall survival(OS) were estimated and compared using the Kaplan-Meier method and the log-rank test, respectively. The Cox regression analysis was used for uni- and multivariable survival analyses.RESULTS: MVI was histologically present in 1213(37.2%) patients. A wide margin resection(≥ 1 cm, n=648) produced significantly better prognoses than a narrow margin resection(<1cm, n=565) in patients with MVI(5-year recurrence and OS rates: 75.5% vs. 83.8%; 44.0% vs. 28.5%, both p < 0.001), but not in patients with no MVI(p = 0.359, 0.431). A narrow margin resection was an independent risk factor of recurrence and OS in the MVI group(hazard ratio [HR]: 1.32 and 1.42). The early recurrence rate was also only decreased by a wide margin resection in the MVI group(59.7% vs. 68.7%, p = 0.001). In 945 cirrhotic patients with MVI, a wide or a narrow margin resection yielded significant differences in complication rates(36.0% vs. 26.5%, p = 0.002), but not in mortality rates(1.5% vs. 2.3%, p = 0.367). A narrow margin was also an independent risk factor of recurrence and OS in these patients(HR: 1.26 and 1.51). CONCLUSIONS AND RELEVANCE: A wide margin resection increased long-term prognoses in HBV-related HCC patients with MVI, and in the subgroup of patients with cirrhosis.Part II. Nomogram for preoperative estimation of MVI in hepatitis B virus-related hepatocellular carcinoma within the Milan criteriaOBJECTIVE: The presence of microvascular invasion(MVI) decreases surgical outcomes of hepatocellular carcinoma(HCC). An accurate preoperative prediction of MVI presence can help surgeons to better choose surgical procedures, but it is still difficult to achieve. We aim to develop a nomogram to predict MVI presence before liver resection for hepatitis B virus(HBV)-related HCC within Milan criteria.PATIENTS AND METHODS: The data of 1004 consecutive patients who underwent liver resection for HBV-related HCC within Milan criteria at the Eastern Hepatobiliary Surgery Hospital between 2004 and 2011 were prospectively collected. Of these, patients who were operated in an earlier period formed the training cohort(707 patients) for nomogram development, and those who were operated thereafter formed the validation cohort(297 patients) to confirm the model’s performance. Overall survival(OS) and time to recurrence(TTR) after liver resection were measured. Multivariate logistic regression was used to identify the independent MVI predictors which were incorporated into the nomogram.RESULTS: Histopathological MVI was identified in 211 and 89 patients in the two cohorts, respectively. In the training cohort, the 5-year recurrence and OS rates were 78.5%, 58.4% respectively in patients with MVI, and 46.9%, 70.9% respectively in patients without MVI(both P <.001). The preoperative predictors of MVI were large tumor diameter, multiple nodules, incomplete capsule, alpha fetoprotein >20μg/L, platelet count <100×109/L, viral load >104 IU/m L, and typical dynamic pattern of tumors on contrast-enhanced MRI. The nomogram incorporated these seven predictors achieved good concordance indexes of 0.81(95% confidence interval: 0.78 to 0.85) and 0.80(0.75 to 0.86) in predicting MVI in the two cohorts, and had well fitted calibration curves. The positive and negative predictive values of the nomogram were calculated. Patients who had a nomogram score of <190 or ≥190 were predicted to have low or high risks of MVI presence. Wide resection margin can significantly improve the prognosis for the patients with high-risk of MVI according to the nomogram(5-year survival rate: wide margin group, 62.4% vs. narrow margin group, 47.9%, p = 0.013; the 5-year recurrence rate: wide margin group, 61.1% vs. narrow margin group, 77.5%, p = 0.008), but for patients with low risk of MVI, there was no significant difference in tumor recurrence(p = 0.172) and overall survival(p = 0.504) between wide and narrow margin groups.CONCLUSIONS AND RELEVANCE: The nomogram achieved an optimal preoperative prediction of MVI in HBV-related HCC within Milan criteria. Using the model, the risk for an individual patient to harbor MVI can be determined which can lead to a rational therapeutic choice.Part III. Indentification of driver genes related to MVI in Hepatocellular carcinoma by whole exome sequencingObjective: In order to further explore the molecular mechanism of MVI in the early stage(solitary, and tumor diameter ≤3cm) of hepatocellular carcinoma(HCC), to find out the mutation genes highly related to the formation of MVI. We used the whole exon sequencing techniques to search for multiple SNVs including point mutations and insertions deletions in early HCC with or without MVI, respectively. It would help to explore the molecular mechanisms of the development of MVI in HCC at the cellular level and ultimately to provide foundation for prediction of MVI in cell-free DNA in blood.Methods: We have collected 16 paired whole exome sequencing data of early HCC. Then the related SNV were screened and annotated. Using multiple bioinformatics data analysis methods, the significant SNVs correlated with early HCC were found and compared betweet the MVI positive and negative groups. The driver genes associated with MVI were determined by the Mut Sig CV method. Finally, the functional pathway about the driver genes were analysed to examine their molecular mechanism for the MVI development.Results: In the study, 16 cases with clinical information of early HCC patients and all the SNVs were collected. We identified 133 driver genes in MVI positive group, and 34 driver genes in MVI negative group by the algorithm of Mut Sig CV, respectively. The driver genes including FBN3, LAMC3, TNR, COL6A3, VCAN, NID2, KIK7, GP6 et.al. Enrichment pathway analysis showed that the driver genes significantly associated with extra-cellular matrix(ECM) pathway in the MVI positive patients.Conclusion: The ECM pathway may contribute to the formation of MVI, which indicated the tumor microenvironment may play a more important role in promoting tumor cell metastasis. These findings may help to further elucidation of the molecular mechanism of MVI. The detection of these mutations in peripheral blood may increase prediction accuracy of MVI in the furture. |
PDF Full Text Request