Prostatic Intraepithelial Neoplasia (PIN)

PIN is not the same as prostate cancer but it can be in the prostate gland alongside cancer cells. Some research suggests that finding PIN may mean that there is a higher chance of finding prostate cancer cells in the future.

However, we need more research before we can say for sure what the exact relationship is between finding PIN and developing prostate cancer.

High-grade PIN
You may hear your diagnosis of PIN called high-grade PIN. This is because there is another type of PIN, called low-grade PIN. However, you will not usually be told if you have low-grade PIN and it is not thought that low-grade PIN is related to prostate cancer.

PIN can only be found by looking at the prostate tissue under the microscope. This can happen:

• If you have tests for prostate cancer. If your doctor is concerned that you might have prostate cancer, you may have a test called a biopsy. This involves removing small pieces of tissue from the prostate to look at more closely under a microscope. The doctor studying the prostate cells (the pathologist) will look for signs of prostate cancer as well as other changes, such as PIN.
• After treatment for an enlarged prostate. If you have symptoms caused by an enlarged prostate, you may have surgery to remove the parts of the prostate that have overgrown. The prostate tissue that is removed may then be checked under the microscope for signs of any changes to the cells.

No, PIN is not the same as ASAP. ASAP stands for atypical small acinar proliferation. It is the term used when your prostate tissue shows signs of prostate cancer, but there is not enough evidence to say for certain whether you have prostate cancer or not. It is found in the same way as PIN, by looking at prostate tissue under the microscope

If you are told you have ASAP, you may need to have a biopsy so that the pathologist can take another look at the cells in your prostate.

It is possible to have areas of both ASAP and PIN in your prostate.

Some research suggests that PIN is found in around one out of 25 men (four per cent) who have their prostate tissue looked at under a microscope. However, it is difficult to say how common PIN is in the general population because not all men will have their prostate tissue studied in this way.

You do not need treatment for PIN. However, because some research suggests that PIN may increase your risk of developing prostate cancer in the future, you might see a specialist at the hospital for regular follow-up tests. For example, you may have routine PSA blood tests or, in some cases, biopsies.

There are no guidelines in the UK for how often men with PIN should have follow up tests. You can discuss the possible options with your doctor.

Some studies have looked at whether certain drugs can reverse or stop the development of PIN in the prostate. We need more evidence from large studies to show that these treatments work before they become available to men with PIN.

There is still a lot we do not know about PIN, especially about the relationship between finding PIN and developing prostate cancer.

If you are diagnosed with PIN, you may feel frustrated by this lack of knowledge. You may also feel anxious about developing prostate cancer.

You may find it helpful to talk to your doctor or specialist nurse about how you are feeling, or you can call our confidential Helpline.

You can read about other sources of support on our online fact sheet.