From the Guidelines
Cancer seeding occurs in approximately 0.1% to 0.7% of cases, particularly in patients with hepatocellular carcinoma (HCC), with risk factors including aggressive tumor biology and certain surgical techniques. The percentage of cancer seeding and its associated risk factors have been studied in various contexts, including liver biopsies and percutaneous image-guided biopsies. According to a study published in the Journal of the American College of Radiology in 2020 1, the rate of seeding in patients with HCC is estimated to be between 0.1% and 0.7%. This study highlights the importance of careful consideration and preparation for possible complications, including anaphylaxis, when performing biopsies on suspicious lesions.
Some key points to consider when evaluating the risk of cancer seeding include:
- The type of cancer being biopsied, with HCC and pancreatic cancer carrying higher risks of seeding
- The technique used for the biopsy, with coaxial approaches and smaller needle gauges potentially reducing the risk of seeding
- The number of needle passes and the amount of tissue sampled, which can impact the risk of dislodging cancer cells
- The use of techniques such as tract ablation and protective port sleeves to minimize the risk of seeding during diagnostic and therapeutic procedures
It is essential to weigh the benefits of diagnostic and therapeutic procedures against the relatively low risk of cancer seeding in most cases, as the benefits often outweigh the risks. By understanding the risk factors and taking steps to minimize them, clinicians can reduce the likelihood of cancer seeding and provide optimal care for their patients. As noted in a study published in Hepatology in 2009 1, the risk of tumor seeding can be decreased with the use of a coaxial approach, highlighting the importance of careful technique in reducing this risk.
From the Research
Cancer Seeding Percentage and Risk Factors
- The percentage of cancer seeding varies depending on the procedure and location of the tumor.
- A study on tumor seeding during colonoscopy estimated the risk to be 0.3%-0.6% 2.
- Another study on percutaneous radiofrequency ablation for hepatocellular carcinoma found a neoplastic seeding rate of 0.9% 3.
- A review of seeding following percutaneous diagnostic and therapeutic approaches for hepatocellular carcinoma reported a median risk of seeding of 2.29% for biopsy, 1.4% for percutaneous ethanol injection (PEI), and 0.61% for radiofrequency ablation (RFA) without biopsy 4.
Risk Factors for Cancer Seeding
- Previous biopsy is a significant risk factor for tumor seeding, as shown in a study on percutaneous radiofrequency ablation for hepatocellular carcinoma 3.
- Subcapsular tumor location, poorly differentiated tumors, and high alpha-fetoprotein (AFP) levels are also associated with an increased risk of tumor seeding 3.
- The use of biopsy before percutaneous ablation is discouraged, particularly when liver transplantation is a possibility at a later date 3.
- The self-seeding paradigm suggests that circulating tumor cells can move multi-directionally, seeding not only distant sites but also their tumors of origin, which may contribute to the risk of cancer seeding 5.