Most of us think that ASAP stands for “as soon as possible” … and of course for most of us it does. But if you are a prostate cancer specialist, it stands for something very different — atypical small acinar proliferation.
ASAP and its “cousin” — prostatic intraepithelial neoplasia or PIN — are two critical findings that are not actually prostate cancer but which seem to be highly predictive of the likelihood of current or future prostate cancer.
In other words, before patients get prostate cancer, many of them may have either PIN or ASAP or both. In this section of The “New” Prostate Cancer InfoLink, we will try to explain what ASAP is, and perhaps more importantly what you and your doctor should consider doing about it. PIN is dealt with on another page.
What is ASAP — and How Is It Recognized?
ASAP actually signals an experienced pathologist’s inability to render an absolute diagnosis of prostate cancer in a prostate biopsy specimen.
Sometimes, after the pathologist has looked very carefully at the specimens under the microscope (probably several times), he or she is quite sure that there are no actual prostate cancer cells, but can see up to a couple of dozen worrisome “acini.” Acini are the tiny sacs that produce the fluids for ejaculation, and most prostate cancers start in the acini. A group of 18-24 acini is no larger than the head of a pin, so if a group of them look a little odd the pathologist’s concern is not to go overboard and diagnose prostate cancer based on insufficient evidence.
We aren’t going to get into a detailed discussion of the pathologic diagnosis of ASAP. Anyone who is interested in that can read the article by Bostwick and Meiers that is available on line. And although ASAP is the recommended term for this diagnosis that is widely used around the world, a variety of other terms or synonyms that include the word “atypical” are also used to describe this diagnosis.
For the patient and his doctor what a diagnosis of ASAP means is that the biopsy specimen in question has features that are neither clearly malignant (“We can’t tell you it’s cancer”) nor clearly benign (“And we can’t tell you it’s NOT cancer either”) and that very careful follow-up of the patient is going to be important.
Bostwick and Meiers define three questions that a good pathologist needs to answer before choosing between a diagnosis of ASAP or cancer in a small group of acini when there is no other clear sign of cancer:
- Would you be absolutely confident of this biopsy diagnosis if it were followed by a radical prostatectomy with negative findings?
- Would another pathologist of similar experience agree with a diagnosis of cancer?
- Can you confidently support the diagnosis of cancer based solely on this biopsy result?
In their opinions, if the answer to any of these questions is “No,” then the more conservative diagnosis of ASAP is the correct diagnosis.
About 2 percent of contemporary prostate needle biopsy specimens contain collections of small acini that are suspicious for cancer but that fall below the diagnostic threshold and are reported as ASAP, implying suspicion of cancer but not diagnostic of malignancy. Prostate cancer has been identified in specimens from subsequent biopsies in up to 60 percent of cases of ASAP, indicating that this finding is a significant predictor of cancer.
What You and Your Doctor Need to Do About ASAP
ASAP is a problem.
Just like high-grade PIN, ASAP is highly predictive for cancer if a repeat biopsy is carried out. In at least 40 percent of such cases, ASAP appears to represent “undersampled” cancer (which means that not enough biopsy cores may have been taken on the initial biopsy). We know that even when ASAP is diagnosed in the first set of biopsy cores, but only benign tissue or high-grade PIN is found in the cores from a second biopsy, some men may still have cancer that was not detected.
The current recommendation by the best prostate cancer pathologists is that the presence of ASAP (with or without PIN) in a biopsy specimen is a significant predictor for concurrent or subsequent cancer compared to patients lacking these lesions. A repeat biopsy is always indicated for these patients.
At this time there is no known treatment for ASAP.