The biopsy debate

Many people with suspected cancer undergo biopsies to diagnose their condition; however, there are growing concerns that biopsies carry their own risks and may even seed cancer cells into surrounding tissue.

A biopsy is the removal of a sample of tissue from the body for examination under a microscope to assist diagnosis. The type of biopsy will depend on the area of the body under examination and the nature of the problem. Tissue samples may be removed surgically either under general or local anaesthetic, or a needle may be used to extract cells or tissue as in the case of prostate or liver biopsies.

Most health professionals argue that small biopsies are very safe with only a small risk of bleeding or infection. However, larger open biopsies, like the removal of breast lump, can be riskier because patients need to be given general anaesthetics, with all the risks that go with them.

But do biopsies seed cancer cells? Central to this debate is the safety of needle biopsies. In this procedure, a hollow needle is inserted into a suspected tumour in order to retrieve samples for microscopic examination. The technique has many advantages: needle biopsies are nearly painless and bloodless procedures, and much less expensive and time-consuming than surgical biopsies.

The worry is that cancer cells are pulled along the track formed by the needle or worse, spill directly into the lymphatic system or bloodstream. This is more likely when the doctor needs to puncture the tumour a number of separate times in order to obtain adequate tissue for diagnostic purposes.

In June 2004 a report from the John Wayne Cancer institute in California concluded that a needle biopsy may increase the spread of the disease by 50 percent compared to patients who receive the more traditional biopsies (or lumpectomies) – when a lump or suspicious area is removed surgically.

For now, the majority of medics believe that there is not enough evidence to show that biopsies cause cancer spread and the advantages gained by fast and efficient diagnosis significantly outweighs any risk.

NICE guidelines recommend that patients should have all the available information given to them before they undergo a biopsy and that, crucially, a patient makes up his own mind about whether or not to go ahead with the procedure,