Prostatic intraepithelial neoplasia (PIN)
Though defined as a noncancerous lesion on the outside of the prostate, PIN is often a precursor to the development of cancer. Two types of the condition are possible, low-grade and high-grade. Though low-grade PIN is usually not associated with prostate cancer, high-grade PIN is increasingly being linked to the eventual development of prostate cancer. Because high-grade PIN isn’t a disease and has no symptoms, it is up to your doctor to discover the lesion through various early-detection methods for prostate cancer.
According to the Prostate Cancer Research Institute, nearly 16 percent of all males who have prostate biopsies will show signs of PIN. Certain people are more at risk of having PIN than others. As men age, the odds of PIN existing gradually increase. Besides age, other demographic variables like race are often factors. African Americans may be at a higher risk of having PIN than Caucasians, and the reasons for this are relatively unknown.
Atypical small acinar proliferation (ASAP)
Often confused with PIN, ASAP is another precancerous lesion of the prostate. This classification can include any number of different lesions, including adenosis, atypical adenomatous hyperplasia, intraductal hyperplasia and acinar atypical hyperplasia. Men discovered to have a form of ASAP may be twice as likely to develop prostate cancer as men who don’t have any precancerous lesions.
If either high-grade PIN or ASAP is discovered by your doctor or pathologist, the tissue removed for the biopsy should be carefully examined for any signs of cancer. Even if prostate cancer is not diagnosed, if PIN or ASAP is indicated, it's typically recommended that subsequent diagnostic tests be regularly administered to test for cancer. It has not yet been proven that PIN or ASAP are signs of prostate cancer, and as a result, sometimes nothing is done to treat PIN or ASAP. In other cases, medicinal regimens may be used to eliminate the cells.