Needle track seeding following biopsy of liver lesions in the diagnosis of hepatocellular cancer: a systematic review and meta-analysis

Background: Needle biopsy of a suspicious liver lesion could guide management in the setting of equivocal imaging and serology, although it is not recommended generally because there is the possibility of tumour dissemination outside the liver. The incidence of needle track seeding following biopsy of a suspicious liver lesion is ill-defined, however. Methods: A systematic review and meta-analysis of observational studies published before March 2007 was performed. Studies that reported on needle tract seeding following biopsy of suspicious liver lesions were identified. Lesions suspected of being hepatocelleular cancer ( HCC) were considered. Data on the type of needle biopsy, diagnosis, incidence of needle track seeding duration to seeding, follow-up and impact on outcome were tabulated. Results: Eight studies identified by systematic review on biopsy of HCC were included in a meta-analysis. The pooled estimate of a patient with seeding per 100 patients with HCC was 0.027 ( 95% confidence interval ( CI) 0.018 to 0.040). There was no difference whether a fixed or random effects model was used. Q was 4.802 with 7 degrees of freedom, p=0.684; thus the observed heterogeneity was compatible with variation by chance alone. The pooled estimate of a patient with seeding per 100 patients per year was 0.009 ( 95% CI 0.006 to 0.013), p=0.686. Conclusions: In this systematic review we have shown that the incidence of needle tract tumour seeding following biopsy of a HCC is 2.7% overall, or 0.9% per year.