When a PSA level is abnormal or a clinical examination of the prostate is not reassuring, a prostate MRI may be performed. If this MRI reveals a target area , the question of a prostate biopsy then becomes very clear.
For many men, this is a worrying test. Is it really necessary? What exactly are they looking for? How is it actually performed? And above all, should they expect a painful test?
The prostate biopsy has a simple but fundamental objective: to determine if there is prostate cancer , and if so, to assess its aggressiveness in order to choose the most appropriate treatment.
Why a prostate biopsy is sometimes necessary
The biopsy is not performed randomly. It usually takes place after a stage of suspicion.
The most frequent scenario is as follows:
- abnormal PSA
- Abnormal clinical examination
- MRI of the prostate showing a suspicious lesion, called a target area
In this situation, MRI provides guidance, but it is not sufficient on its own to make a definitive diagnosis. Only a biopsy allows for the removal of prostate tissue for microscopic analysis.
In other words, the biopsy serves to answer the essential question: is there cancer, yes or no?
What the biopsy is really looking for
It is often thought that a biopsy is only used to detect the presence of cancer. This is true, but it is only part of its purpose.
Analyzing the samples helps answer two main questions:
- Is there such a thing as prostate cancer?
- If so, what is its level of local aggressiveness?
This second question is crucial, because not all prostate cancers are the same. Some are slow-growing and can be managed with monitoring. Others, on the contrary, require more active treatment.
How is a prostate biopsy performed today?
The current technique relies on an increasingly precise approach. The biopsy is performed under ultrasound guidance , with a fusion of MRI- ultrasound images .
In practice, the MRI images are transferred to the ultrasound. This allows for a three-dimensional visualization of the prostate and precise localization of the target area identified on the MRI.
The objective is clear: to take samples exactly from the suspect area , rather than taking samples blindly.
This precision improves the diagnostic quality of the examination and allows for better characterization of any potential lesion.
Which path does the needle take?
Today, prostate biopsies are performed via the perineal route , that is, through the skin located in front of the anus.
This development is important. The transrectal route, long used, is now much less common because it posed a greater risk of infection.
The perineal route has therefore become the reference in this safety logic.
Local anesthesia or short general anesthesia
Depending on the circumstances, the examination may be carried out:
- under local anesthesia
- or under short general anesthesia
The choice depends on the organization, the habits of the medical team, and the context of each patient.
When wondering if a biopsy is painful, it's important to understand that the procedure is carefully managed to minimize discomfort. The use of local or short-acting general anesthesia serves this purpose.
What happens to the samples after the biopsy?
Once the samples have been taken, they are analyzed by an anatomopathologist , that is to say a doctor specializing in the study of tissues under a microscope.
It is this analysis that allows the final diagnosis to be established.
Two situations can then arise.
1. There is no cancer
If no cancer is found, this is obviously reassuring news. In this case, no further cancer treatment is undertaken, but appropriate monitoring continues.
2. A cancer is identified
If biopsies reveal cancer, the analysis does not stop at this simple observation. It will allow for its specific identification and evaluation.
Several elements are then studied.
What biopsies can reveal in the case of cancer
The number of positive biopsies
First question: how many samples contain cancer?
This point is important because it provides information on the local extent of the damage.
The location of the cancer in the prostate
We also want to know:
- if only biopsies of the target area are positive
- or if cancer is also found elsewhere in the prostate
- if the cancer affects only one lobe
- or both lobes
This information helps to better understand the distribution of cancer within the prostate gland.
The aggressiveness of tumor cells
The other major piece of information provided by the biopsy is the degree of aggressiveness of the cancer. This is where the Gleason score comes in, sometimes written in different ways but corresponding to the same concept.
The principle is simple:
- The lower the Gleason score, the less aggressive the cancer.
- The higher it is, the more aggressive the cancer is.
Understanding the Gleason score
The Gleason score is often written as an addition, for example 3 + 3 , 3 + 4 or 4 + 4 .
Why an addition? Because it is the sum of two grades :
- the most frequent grade in the tumor
- the most aggressive grade found
Each grade ranges from 3 to 5 :
- 3 corresponds to the least aggressive profile
- 5 corresponds to the most aggressive profile
The total amount therefore ranges from:
- 3 + 3 = 6
- up to 5 + 5 = 10
This score is a central element of the biopsy report, as it directly contributes to the risk assessment.
The ISUP score: the classification often used today
In many centers, the Gleason score is now supplemented or replaced in routine practice by the ISUP score , which corresponds to an international classification.
The principle is to group cancers into five categories of increasing risk:
- ISUP 1 corresponds to Gleason 3 + 3
- then the classification progresses up to ISUP 5
This presentation is often simpler to read and use to guide therapeutic decisions.
Why these results are so important for what comes next
A biopsy is not just used to label a diagnosis. It allows us to determine the local aggressiveness of the cancer and to develop a coherent strategy.
To do this, the results of the biopsies are cross-referenced with other data:
- the PSA
- the results of the prostate MRI
- possibly other additional tests if necessary
All of this information allows for a precise assessment of prostate cancer and the selection of the right treatment option.
It is this comprehensive approach that helps to avoid two pitfalls:
- over-treating a low-grade cancer
- subcontracting a more advanced cancer
Key takeaways
If you are offered a prostate biopsy after an abnormal PSA level, an abnormal digital rectal exam, or an MRI showing a target area, it is not a routine test done out of excessive caution. It is a key test to obtain a reliable answer.
- It helps determine if cancer is present.
- It precisely targets the suspicious area thanks to MRI-ultrasound fusion.
- Today, it is performed via the perineal route , in order to reduce the risk of infection.
- It can be performed under local anesthesia or short general anesthesia
- It specifies the local extent and aggressiveness of the cancer
- It provides essential elements such as the Gleason score or the ISUP score
In practice, biopsy is often the decisive step that allows us to move from a simple suspicion to a clear, personalized medical decision adapted to the reality of your situation.