Prostatic Intraepithelial Neoplasia (PIN)*
Prostatic Intraepithelial Neoplasia (PIN) is when there are changes in how the prostate gland cells look under the microscope, but the abnormal cells do not look like they are growing into other parts of the prostate (like cancer cells would). Based on how abnormal the patterns of cells look, they are classified as:
- Low-grade PIN – the patterns of the prostate cells appear almost normal
- High-grade PIN – the patterns of cells look more abnormal
PIN begins to appear in the prostates of some men as early as their 20s. Almost half of all men have PIN by the time they reach 50. High-grade PIN is considered a pre-cancer of the prostate because it may turn into prostate cancer over time. Low-grade PIN in general should not be on a biopsy report, as it has no significance.
Frequently Asked Questions
If I have high-grade PIN, does that mean it will turn into prostate cancer? No. In most cases high-grade PIN will not turn into cancer over the next several years. Still, the risk of getting cancer later is higher if high-grade PIN is found in ore than one biopsy core.
What does it mean if the report says that only one of my biopsy samples (cores) shows high-grade PIN, but it does not mention carcinoma (cancer)? It means there is no cancer in the biopsy sample. In most cases, even a repeat biopsy will not show cancer.
Do I need a repeat prostate biopsy over the next year or several years after a diagnosis of high-grade PIN? In most cases, the chance of finding cancer is low, so a repeat biopsy done soon after the diagnosis of high-grade PIN is not useful. However, some patients do have a higher risk, such as men with multiple cores showing high-grade PIN. Discuss if and when you have a repeat biopsy with your urologist.
* Information for Prostatic Intraepithelial Neoplasia (PIN) provided by the American Cancer Society. For more details visit the ACS site here.