Prostate Biopsy
Advantages and Limitations of Prostate Biopsy
There is no currently available blood test, imaging test or other test which can establish the diagnosis of prostate cancer. In very rare cases, the weight of evidence from clinical evaluation may make a biopsy redundant - but in such cases advanced, incurable disease is always present. In men with potentially curable disease, a biopsy is always necessary. Information on the process of a prostate biopsy can be found.
A prostate biopsy is a sample of from the prostate. The sample is evaluated by a specially trained physician (Pathologist) with a microscope, sometimes using special techniques to define the different structures in the sample. The pathologist reports their findings based on the tissue that was taken and evaluated. Note that only a very small part of the prostate is taken, but with ultrasound guidance the goal is to take representative samples from the prostate gland. The entire tissue in the prostate cannot be completely evaluated with currently available tests. With today's technology, evaluating the entire gland with 100% certainty would require removing the entire gland - an unattractive prospect for any man.
Therefore, the 'pathology report' which results from the process of a prostate biopsy specifically comments only on the samples taken from the prostate. It is reasonable to extend these findings to the rest of the prostate because the samples which are obtained by ultrasound guided biopsy are representative of what is happening in the entire gland. As a result, the one caveat of a prostate biopsy is that it cannot exclude the presence of prostate cancer with 100% certainty.
An analogy would be trying to discover if oil was present if drilling for oil were the only way to do this. If you were looking for oil in a defined area of land, you would probably space your test drills evenly through the area. If you struck oil, you would know that oil was there/ However, if you didn't find oil, you couldn't be 100% sure that the reason you didn't find oil was because (1) there isn't any oil or (2) there was oil and you just didn't hit it. By analogy, we will sometimes increase the number of samples taken or repeat a biopsy if we think there remains a high chance that a cancer is present but was not detected.
Prostate Biopsy: Frequently Asked Questions
+ Does a biopsy spread cancer?
No. There is no risk that a prostate biopsy will seed cancer along the biopsy site or cause it to spread through the body. Some types of non-prostate cancer can be seeded with a biopsy, but multiple studies have demonstrated that prostate cancer does not behave like that.
+ How accurate is prostate prostate biopsy?
See the discussion above. If cancer is found in the sample, then the prostate definitely contains cancer. If no cancer is found in the sample, then the prostate is unlikely to contain cancer. Sometimes the results of a biopsy are indeterminant and additional testing is required.
+ Are there any 'non-invasive' alternatives to prostate biopsy to diagnose cancer
No. Obtaining a sample of prostate tissue, either by biopsy or transurethral resection, is the only definitive way to diagnose prostate cancer. There are rare circumstances where a presumptive diagnosis of prostate cancer is made based on clinical evaluation and where the risks of a biopsy are not justified given the clinical picture.