Characteristics and risk differences of different tumor sizes on distant metastases of hepatocellular carcinoma: A retrospective cohort study in the SEER database.

INTRODUCTION

A typical feature of hepatocellular carcinoma (HCC) is growth with metastasis to distant organs, which is associated with poor survival. Whether tumor size can predict distant metastases in HCC remains unclear.

METHODS

We identified 29,170 HCC patients with or without distant metastases between 2010 and 2016 in the Surveillance, Epidemiology and End Results database. According to an optimal cutoff value of tumor size (58 mm) for predicting distant metastases using Youden's index, patients were categorized into groups of tumor size ≤30 cm, 30-58 mm, and ≥58 mm.

RESULTS

Tumor size had a significantly positive correlation with distant metastases (r = 0.245, P < 0.001). Among patients with distant metastasis, the most common metastasis site was lung (39.3%), followed by bone (30.0%), and brain (2.0%). Incidence of distant metastases in patients with tumor ≥58 mm was 5.7 times (22.8%/4.0%) that of patients with tumors ≤30 mm and 2.9 times (22.8%/7.9%) that of patients with tumors 30-58 mm. Multivariate analyses showed that compared with ≤30 mm, tumor size ≥58 mm was an independent risk predictor of overall distant metastases (OR, 5.200; 95% CI, 4.635-5.834; P<0.001), lung (OR, 6.036; 95% CI, 5.006-7.278; P<0.001); bone (OR, 3.365; 95% CI, 2.781-4.071; P<0.001); and brain metastasis (OR, 1.905; 95% CI, 1.023-3.547; P<0.05).

CONCLUSIONS

Tumor size ≥58 mm is significantly associated with HCC distant metastases. In clinical practice, patients with tumors ≥58 mm may benefit from timely identification of distant metastases.