Background:

Pulmonary metastasis (PM) following curative hepatectomy for hepatocellular carcinoma (HCC) is indicative of a poor prognosis. This study aimed to develop a nomogram to identify patients at high risks of PM.

Methods:

A primary cohort of patients who underwent curative hepatectomy for HCC at the Eastern Hepatobiliary Surgery Hospital from 2002 to 2010 was prospectively studied. A nomogram predicting PM was constructed based on independent risk factors of PM. The predictive performance was evaluated by the concordance index (c-index), calibration curve and decision curve analysis (DCA). During the study period, a validation cohort was included at the First Affiliated Hospital of Fujian Medical University.

Results:

Postoperative PMs were detected in 106 out of 620 and 45 out of 218 patients, respectively, in two cohorts. Factors included in the nomogram were microvascular invasion, serum alpha-fetoprotein, tumour size, tumour number, encapsulation and intratumoral CD34 staining. The nomogram had a c-index of 0.75 and 0.82 for the two cohorts for predicting PM, respectively. The calibration curves fitted well. In the two cohorts, the DCA demonstrated positive net benefits by the nomogram, within the threshold probabilities of PM> 10%.

Conclusion:

The nomogram was accurate in predicting PM following curative hepatectomy for HCC.

Main

Hepatocellular carcinoma (HCC) is the fifth common malignancy and a major cause of cancer-related mortality (Ferlay et al, 2010). Partial hepatectomy and transplantation still remain the major curative therapeutic options available to patients with HCC. However, following partial hepatectomy there is a significant chance of recurrence (Poon et al, 2000). Although intrahepatic recurrence is most common after operation, extrahepatic metastases (EHMs) still account for 14.0–25.5% of all recurrences. Pulmonary metastases (PMs) represent nearly 50% of all EHM (Hong et al, 2003; Yang et al, 2007; Li et al, 2012).