From the book
“The Best Options for Diagnosing & Treating Prostate Cancer
by James Lewis, Jr. Ph.D. Survivor and Author

A man is never cured of PCa. However in this artical  cure can be defined as being diseased free for 10 years. 

The PSA nadir test is the single most important test made after any treatment for prostate cancer. It is far more important than pretreatment PSA, Gleason score, or stage. The PSA nadir test determines whether or not a man will be cured of prostate cancer.

The PSA nadir is the lowest PSA reading achieved after any treatment for prostate cancer. This includes any radiation technique (e.g., seed implantation, conformal beam radiation, proton beam radiation, prosRcision), radical prostatectomy and cryosurgery. Every man treated for prostate cancer should know his PSA nadir.

Only men have a prostate gland, and PSA is produced only by prostate cells, both normal and cancerous, but not by any other cell. In contrast, women do not have a prostate gland. If you performed a PSA test on a woman, you would not find any.

Also, prostate cancer cells produce PSA no matter where they are located. Prostate cancer cells inside the prostate, those that have penetrated the capsule, and those that have metastasized to bone, all manufacture PSA equally well.

To illustrate how the PSA nadir works, let's imagine that a man has been diagnosed with stage T1c prostate cancer, has undergone a radical prostatectomy, and has been cured. When the surgery was performed, the prostate gland (all normal prostate cells) was removed, and since the man was cured. all prostate cancer cells would have been removed also. Thus, there would be no prostate cells left in this man. Therefore there would be no prostate cells to make PSA. His PSA would have quickly fallen to an undetectable level after surgery. Since the PSA nadir is the lowest PSA reached we would say this man has achieved an undetectable PSA nadir and that he has been potentially cured of prostate cancer by radical prostatectomy. Note the word potentially.

The actual PSA number that means an undetectable PSA is found in cure-rate calculations after radical prostatectomy in research papers published in medical journals. Dr. Patrick Walsh uses a PSA nadir 0.2 ng/ml or lower to indicate an undetectable PSA when he reports cure rates.

But what happens when a PSA nadir of 0.2 ng/ml or lower is not achieved after radical prostatectomy? If the PSA is still detectable, then prostate cancer cells were left behind. Detectable PSA (above 0.2 ng/ml) after surgery guarantees that a patient is not cured.

As you can see, if a PSA of 0.2 ng/ml or lower is achieved after surgery, the patient has been potentially cured. But if the PSA is more than 0.2 the man still has prostate cancer.

Achieving 0.2 ng/ml or lower after surgery, however does not guarantee a cure. It is only the first step toward cure. There is a second step: the PSA nadir of 0.2 ng/ml must be achieved and must stay at 0.2--or lower--forever. From a practical standpoint, it should stay at that level for at least 10 years after surgery.

Suppose a man has achieved a PSA level of 0.2 ng/ml (or lower) after a radical prostatectomy. Now, let's assume that a tiny amount of microscopic cancer cells were left behind. Although these cells produce PSA, there are not enough of them to manufacture a detectable amount immediately after surgery. However, as time passes, these cells will multiply. and eventually there will be enough of them to produce enough PSA to cause the PSA level to rise above 0.2 ng/ml.

 The rate at which prostate cancer grows varies considerably. Some cancer cells multiply rapidly, and more than 0.2 ng/ml of PSA can be found only a few months after surgery. Other cancer cells multiply slowly and require several years to produce a detectable PSA. Almost all cancer cells left behind after surgery will produce a detectable amount of PSA within 10 years of treatment, although a few of Dr. Walsh's patients have had a recurrence after more than 10 years.

Using the PSA nadir test, the cure rates for radical prostatectomy can be calculated. Cure of prostate cancer is defined as the percent of treated men who achieved and maintained a PSA nadir of 0.2 ng/ml  or lower 10 years after surgery. The radical-prostatectomy medical study most commonly quoted is from Johns Hopkins University, with surgery performed by Dr. Patrick Walsh. Dr. Walsh's 10-year cure rate is 68 percent. This means that of every 100 men who had a radical prostatectomy, 68 achieved and maintained an undetectable PSA nadir of 0.2 ng/ml or less for 10 years after surgery. This also means that 32 out of 100 either never achieved PSA nadir 0.2 ng/ml or achieved this level for less than 10 years.

PSA Nadir After Radiotherapy of Prostate Cancer

In contrast to surgery, the prostate gland is still present after radiotherapy of prostate cancer. Therefore, you might think that use of the PSA nadir test would be different after radiation. That is not true.

For men to be cured with radiotherapy, an undetectable PSA nadir (0.2ng/ml) or lower) must be achieved and maintained after treatment. If a PSA nadir of 0.2 ng/ml is not achieved, or if it is not maintained, men will not be cured of prostate cancer by radiotherapy except under rare circumstances. This principle applies to any form of radiation-- prostRcision, seed implant alone, conformal beam radiation, proton beam radiation, and so on.

The only difference between radiotherapy and radical prostatectomy is the time it takes after treatment to achieve a PSA level of 0.2 ng/ml. When a radical prostatectomy is performed, both normal prostate cells and hopefully all cancer cells are removed immediately. The PSA should reach an undetectable nadir within 6 weeks of surgery.

However, after radiotherapy, it takes time for normal prostate cells and cancer cells to die and disintegrate. Death of these cells is indicated by falling PSA level after treatment. The median time to achieve 0.2 ng/ml after radiotherapy is 27 months. the death rate of normal prostate cells and cancerous prostate cells varies considerably, but the cure rate is unrelated to how fast these cells die.

The finding that a PSA nadir of 0.2 ng/ml or lower is required after radiotherapy of prostate cancer is based on measuring the PSA nadir that was achieved and maintained by men cured of prostate cancer by radiation. Dr. Citz's group was the first group to find the relationship between PSA nadir and cure with radiation. Almost all research on PSA nadir radiotherapy for prostate cancer has been performed by doctors at Radiotherapy Clinics of Georgia in men treated with prostRcision. They have had four peer-reviewed research papers published on this subject, the first in 1995. Additionally, they have presented their findings at all major peer-reviewed medical meetings: the American Urological Association (AUA) American Society of Clinical Oncology (ASCO), American Radium Society (ARS) and American Brachytherapy Society (ABS). Their last peer-reviewed research paper was published in the Journal of Urology in April 1999.

In their initial research in 1995 , Dr. Critz's group showed that the PSA nadir goal for cure of prostate cancer by radiotherapy was 0.5 ng/ml. However, they noted that most men's PSA fell to much lower levels. Dr. Critz's group reanalyzed all their data in preparation for the May 1999 meeting of the American Urological Association (AUA) in Dallas, Texas, where their findings were presented. Dr. Critz conclusively showed that to be cured of prostate cancer by irradiation, with few exceptions, a man must achieve and maintain a PSA nadir of 0.2 ng/ml or lower. He showed that of all men cured with prostRcision using the new, high-dose ultrasound-guided implant method, 97 percent achieved and maintained a PSA nadir of 0.2 ng/ml or lower. Only 3 percent of cured men had a PSA nadir of 0.3 to 1.0 ng/ml. None with a PSA nadir above 1.0 ng/ml were cured. Dr. Critz concluded that cure-rate calculations for radiotherapy of prostate cancer should be done using a PSA nadir of 0.2 ng/ml. He also noted that most men who achieved 0.2 ng/ml or less actually achieved 0.1 ng/ml or less. However, measuring 0.1 ng/ml requires a special PSA test.

Urologists use a PSA nadir of 0.2 ng/ml to determine cure after radical prostatectomy. Therefore, the definition of cure of radiotherapy of prostate cancer is identical to that after surgery: men must achieve and maintain an undetectable PSA nadir, meaning 0.2 ng/ml or less, for 10 or more years after treatment. These findings should apply to any radiotherapy method. 

The identical PSA nadir goal for both prostRcision and radical prostatectomy indicates that all prostate cells. both normal and cancerous, are destroyed by prostRcision just as effectively as having them surgically removed by a radical prostatectomy. In other words, if you give enough radiation to cure prostate cancer, all, or virtually all, normal prostate cells are also destroyed. The dose of radiation needed to cure prostate cancer is more than what normal prostate cells can tolerate. Remember with prostRcision, the dose of radiation inside the prostate is intensified by giving conformal beam radiation after the iodine seed implant since both normal and cancer cells are irradiated simultaneously. 

If you think about it, a "prostatectomy" is performed by prostRcision, just as is done with surgery, except that the muscles that control urination and the sex nerves are not removed with prostRcision. The word prostRcision is derived from this concept, since prostRcision means "excision of the prostate with radiation."

These findings may also explain why the cure rate for prostRcision is so high. If you leave normal prostate cells behind after radiation, what is to prevent them from making more prostate cancer? However, if you destroy all normal and cancerous prostate cells, you will prevent a man from getting any new cancer.

These findings from the Radiotherapy Clinics of Georgia--that patients need to achieve and maintain a PSA nadir of 0.2 ng/ml after radiotherapy--have not been popular with doctors in the United States who treat prostate cancer by other radiotherapy methods. These doctors believe that an undetectable PSA nadir is too strict for radiotherapy. They are afraid that calculating cure rates with an undetectable PSA nadir will lower their cure-rate claims.

These other doctors believe that you can destroy 100 percent of all prostate cancer cells, but that normal prostate cells, which are located next to cancer cells inside the prostate, will not be bothered very much by radiation and will keep on making normal amounts of PSA. this is not logical. No research paper has ever been published to back up the belief that normal cells remain after destroying all cancer cells with radiation. It is much more reasonable to believe that if you give enough radiation to destroy prostate cancer cells, you also destroy all, or virtually all, normal cells. All peer-reviewed research papers show this.