Seeding risk following percutaneous approach to hepatocellular carcinoma

Tumour biopsy is usually considered mandatory for patient management by oncologists. Currently percutaneous ablation is used therapeutically for cirrhotic patients with small hepatocellular carcinoma (HCC), not suitable for resection or waiting for liver transplantation. However malignant seeding is a recognized complication of both diagnostic and therapeutic procedures in patients with HCC. Although percutaneous therapy whether with or without biopsy of a suspected HCC nodule may minimize the risk of seeding, this has not been confirmed.

To evaluate the risk of seeding, defined as new neoplastic disease occurring outside the liver capsule, either in the subcutaneous tissue or peritoneal cavity following needle biopsy and/or local ablation therapy (LAT).

A literature search resulted in 179 events in 99 articles between January 1983 and February 2007: 66 seedings followed liver biopsy, 26 percutaneous ethanol injection (PEI), 1 microwave, 22 radiofrequency ablation (RFA), and 64 after combined biopsy and percutaneous treatment (5 microwave; 33 PEI; 26 RFA).

In 41 papers specifying the total number of patients biopsied and/or treated, the median risk of seeding was 2.29% (range 0-11%) for biopsy group; 1.4% (1.15-1.85%) for PEI when used with biopsy and 0.61% (0-5.56%) for RFA without biopsy, 0.95% (0-12.5%) for RFA with biopsy and 0.72% (0-10%) for liver nodules (including non-HCC nodules) biopsied and ablated.

Risk of seeding with HCC is substantial and appears greater with using diagnostic biopsy alone compared to therapeutic percutaneous procedures. This risk is particularly relevant for patients being considered for liver transplantation.