Key to High Cure Rate Is Early Diagnosis
by William J. Catalona, M.D.
"We should be able to cure 90% of prostate cancer with early detection and appropriate treatment recommendations."
The key to good results in treating localized prostate cancer is to make the diagnosis as early as possible.
Now, at least 80% of prostate cancers can be detected while they are still contained within the prostate, and 90% of prostate cancers can be cured if early diagnosis and effective treatments are used appropriately.
The PSA test is now the most accurate early detection test for prostate cancer.
When we initially published the results of our PSA study, which now includes 35,000 men, we set the normal level for PSA at 4, and that has been pretty much accepted around the world as the standard.
It has been generally believed that if a mans PSA is less than 4, it's normal, and if it's above 4, then that's worrisome that he may have prostate cancer. However, within a few years of starting the study, it became apparent to me that a lot of men whose PSA was higher than 2.5 were on the way up, and 50% of these men had a PSA that was higher than 4 within a few years.
In 1995, we lowered the PSA cutoff level to 2.5 in our study, and we found that about 22% of men who had a PSA between 2.5 and 4 had prostate cancer detected on biopsy.
Although I am in the minority using this lower cut off in the US, things are changing. A study performed at the MD Anderson Hospital also found that about 24% of patients with a PSA of 2.5 to 4 had prostate cancer. Large screening studies in Europe and in Quebec use a cutoff of 3.
The important difference is that using the 4 cutoff detects about 70% of the prostate cancers while they are still organ-confined; whereas, using the 2.5 cutoff detects 80 or 85% of cancers while they are localized to the prostate.
Using the lower PSA cutoffs requires more patients to undergo biopsies, but the cancer will be detected earlier and most of the cancers will be contained within the prostate.
Also, it has become apparent that biopsies can miss a lot of prostate cancers. If only six tissue cores are taken from the prostate, then at least 25% of the detectable prostate cancers are missed.
We have some men who have had up to ten biopsy sessions because their PSA either remained elevated or kept getting higher despite repeated negative biopsy results.
On the first biopsy session, nearly 30% were found to have cancer but even out to the sixth biopsy session, we still detected cancer in about 7% of the patients. Of the cancers detected in our screening study, only 75% were detected on the first biopsy. We didn't get near 100% detection until five biopsy sessions.
The bottom line is that if a man has an elevated or rising PSA and has had a negative biopsy, there can be no certainty that he doesn't have prostate cancer. The solution to this problem is for doctors initially to take more biopsy cores.
Recently, we have learned how to anesthetize the prostate with local anesthesia just as the mouth would be anesthetized for dental work. With a local block of the prostate, biopsies can be obtained with a lot less discomfort.
Now, the tendency is for doctors to obtain more biopsy cores initially to diagnose the cancer earlier and avoid multiple biopsy sessions.
If we can identify 80% of prostate cancers while they are still contained within the prostate and cure some of those that have spread just barely outside the prostate, then we should be able to cure 90% of prostate cancer with early detection and appropriate treatment recommendations.