Prostate biopsy results: PIN and ASAP

PIN and ASAP are changes in the cells in the prostate, which can only be seen under a microscope. PIN stands for prostatic intraepithelial neoplasia. ASAP stands for atypical small acinar proliferation.

If you've been diagnosed with PIN, it's probably high grade PIN. There is also low grade PIN, but there's no evidence that this can cause problems in a man's lifetime. You can check with your doctor if you're not sure. When we say PIN, we mean high grade PIN.

PIN is not the same as prostate cancer

What is PIN?

PIN is not prostate cancer.

PIN stands for prostatic intraepithelial neoplasia. It's the name for certain kinds of changes to cells in the prostate. These changes can only be seen under a microscope.

We don't know what causes PIN, but we do know that the chance of finding it increases as you get older.  

Although PIN is not prostate cancer, many men with prostate cancer do have some PIN as well. Not all men with PIN get prostate cancer.

What is ASAP?

ASAP stands for atypical small acinar proliferation. It means there are unusual cells in your prostate but it's not clear what they are or if they are cancerous.  

ASAP can be a group of cells that could be cancer cells but that are still too small to see clearly under the microscope. This means they can't be diagnosed as cancer cells. Or ASAP might be other unusual cell changes that won't become cancer.  Because it's uncertain, you will usually need to have more tests if you have ASAP.

It's possible to have both ASAP and PIN in your prostate.

Am I more likely to get prostate cancer if I have PIN or ASAP?

You may be more likely to develop prostate cancer if you have PIN or ASAP.

If you've been diagnosed with PIN or ASAP and are worried about prostate cancer, speak to your doctor or nurse.

Read more about your risk of getting prostate cancer. Or you could speak to one of our Specialist Nurses.

What are the symptoms of PIN and ASAP?

PIN and ASAP don't cause any symptoms on their own. But they're usually diagnosed when a man has tests or treatment for another prostate problem, which often does have symptoms. For example, if you have an enlarged prostate as well as PIN, you might have problems urinating (peeing) that are caused by the enlarged prostate, not the PIN.

If you do have any symptoms such as problems urinating, speak to your doctor. They can do more tests to find out what's causing them, and suggests treatments that may help.

How are PIN and ASAP found?

PIN and ASAP can only be found by looking at prostate tissue under a microscope. This might happen if:

How common are PIN and ASAP?

We don’t know how many men in the UK have PIN or ASAP. But for men who have had their prostate tissue looked at under a microscope (after a biopsy, for example):

  • up to one in 20 men (five per cent) have PIN, and
  • around one in 50 men (two per cent) have ASAP.

Black men are more likely to get PIN than White men of the same age. Some research also suggests Black men may get a larger amount of PIN at an earlier age than White men. But the reasons for this are unclear. There hasn’t been any research to look at how likely it is for Asian or Mixed-race men to get PIN or ASAP.

We do know that Black men are more likely to get prostate cancer than other men of the same age in the UK. In fact, one in four Black men will be diagnosed with prostate cancer. But we still don’t know the reasons why. Read more in our leaflet, What do you know about your prostate? Information for Black men.

Will I need treatment for PIN and ASAP?

You won't need any treatment for PIN or ASAP, but you might need regular check-ups to check for any changes that might suggest that cancer is growing.

You may have:

You might also have an MRI scan to check there's no cancer in parts of the prostate that weren't looked at in your biopsy.

The tests you have will depend on your own situation. Talk to your doctor or nurse if you have any questions . You can also speak to our Specialist Nurses.

If you are diagnosed with cancer, it is more likely to be an early stage because you'll have had these regular check-ups. This means it can be carefully monitored or treated if necessary.

If you do get prostate cancer, you won't continue to have regular check-ups for PIN or ASAP.

Questions to ask your doctor or nurse

  • Have I got high grade PIN or ASAP?
  • How much high grade PIN or ASAP do I have?
  • Do I need further tests to find out more?
  • What is my risk of getting prostate cancer?
  • Can I do anything to reduce my risk of prostate cancer?
  • How often will I need to have check-ups?
  • What will my check-ups involve?
  • Will I need to have another biopsy?
  • Will I need any other tests?


Updated June 2016 | Due for review May 2019

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