Nomogram Predicts Microvascular Invasion Risk in HBV-Related HCC

Key preoperative factors associated with the risk of microvascular invasion in patients with hepatitis B virus-associated hepatocellular carcinoma have been identified

medwireNews: A nomogram comprising seven preoperative variables can predict the risk of microvascular invasion after liver resection in patients with early-stage hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC), say researchers from China.

“Using the model, the risk for an individual patient to harbor [microvascular invasion] can be determined, which can lead to a rational therapeutic choice”, they write in JAMA Surgery.

Among 1004 patients with HBV-related HCC within the Milan criteria for liver transplantation who underwent resection between 2004 and 2011 at a Chinese institution, approximately a third had histopathologically identified microvascular invasion.

In the training cohort comprising 707 patients, the 5-year recurrence rates were 78.5% and 58.4% in patients with and without microvascular invasion, respectively, a significant difference. And the corresponding 5-year overall survival rates were 46.9% and 70.9%, which also differed significantly.

On multivariate analysis, seven preoperative factors were significantly associated with microvascular invasion – namely, large tumour diameter, multiple tumours, incomplete tumour capsule, presence of typical dynamic pattern on magnetic resonance imaging, serum α-fetoprotein levels higher than 20 ng/mL, platelet count lower than 100 x 103/μL and HBV DNA levels higher than 104 IU/mL.

The team incorporated these variables into a nomogram that estimated the risk of microvascular invasion with a concordance index of 0.81 in the training cohort and 0.80 in a validation cohort of 297 patients.

With a cutoff of 200, where values higher than the threshold indicated high risk, the nomogram predicted the risk of microvascular invasion with a sensitivity of 73.5%, a specificity of 76.6%, a positive predictive value of 57.2% and a negative predictive value of 87.2% in the training cohort. The corresponding values in the validation cohort were 61.8%, 80.8%, 57.9% and 83.2%.

Researcher Feng Shen, from the Second Military Medical University in Shanghai, and co-authors point out that the false-positive and false-negative rates for the nomogram are high.

But they add that if validated in other studies, the nomogram could have myriad uses, such as enrolling patients into trials of neoadjuvant therapies for HCC.

Writing in a linked piece, Ernesto Sparrelid and Marco del Chiaro, both from Karolinska Institute in Stockholm, Sweden, agree that “the specificity rates imply a substantial risk for both false-positive and false-negative predictions.”

Nonetheless, they believe that “the nomogram is an interesting contribution to the challenging clinical evaluation of these patients”, and await the results of studies evaluating “the validity of the nomogram in a prospective, randomized clinical trial, preferably with several expert centers in collaboration.”

References

Lei Z, Li J, Wu D, et al. Nomogram for Preoperative Estimation of Microvascular Invasion Risk in Hepatitis B Virus–Related Hepatocellular Carcinoma Within the Milan Criteria.JAMA Surg 2015; Advance online publication 18 November. doi:10.1001/jamasurg.2015.4257

Sparrelid E, Del Chiaro M. Microvascular Invasion in Hepatitis B Virus–Related Hepatocellular Carcinoma. Another Step Toward Preoperative Evaluation? JAMA Surg 2015; Advance online publication 18 November. doi:10.1001/jamasurg.2015.4267

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