Detection and Treatment of Prostate Cancer

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Prostate cancer and treatment results

 

More information about prostate problems available here.

View information on Cryosurgery.

Dr. Herb Riemenschneider at the 9/27/01

Riverside Urology Prostate Cancer Support Group

One of the most significant developments in the management of prostate cancer is the fact that men have taken their concerns about this disease and made them public. Women did this regarding breast cancer about 10 years earlier. Once men made their concerns public, funding for research began to flow from both the government and the private sector. This research has resulted in significant improvement in the management of prostate cancer, the most common malignancy in men.

Between 1976 and 1994 the incidence of prostate cancer doubled and the mortality increased by 20%. The of incidence of this disease occurrence increases with age, for example 45/100,000 in the age group of 50-60; and 1,000/100,000 men in age group 65 and over.

This disease is often thought to be one which strikes only the older population, in fact 20% of the victims are under 65 and a startling number are only in their 40’s.

The anatomic location of the prostate is critically close to many of the pelvic organs, for example, urine passes from the bladder, to outside of the body, through the prostatic urethra. The colon is very close to the prostate; the nerve and vessels that allow penile erection to occur are closely applied to the surface of the gland. The prostate is nestled behind the pubic bone and surrounded by large blood vessels.

The prostate can be easily examined by putting a finger in the rectum and by doing so, the consistency is assessed.

Not all prostate cancers can be easily detected by digital exam, some occur in places that are not easily felt.

Prostatic Specific Antigen (PSA) is a glycoprotein that is produced by prostatic tissue; when the prostate is diseased; PSA is produced in a higher amount per gram of prostate tissue. PSA is prostate specific, but not cancer specific.

PSA can be elevated by the size of a benign prostate, from causes such as inflammation (known as prostatitis) and trauma to the prostate, for example from the seat of a bicycle when riding. Malignant tissues within the prostate can also cause a significant PSA elevation.

PSA is used in many models to determine the health of the prostate, some of these are known as PSA density, the amount produced per gram of tissue, PSA velocity which refers to the rate of increase of PSA over a given period of time such as three or six months.

Age specific PSA is related to a man’s time in life, it tends to be lower early and higher later simply because the prostate gets bigger as men age. Fractionated PSA is an indicator that may allow a differentiation of malignant tissue from benign prostatic enlargement.

 

 

 

 

Screening For Prostate Cancer

The FDA approved the use of PSA screening for prostate cancer. It is clearly demonstrated that screening for this disease, when readily available at no cost, clearly influences the detection of prostate cancer and ultimately its treatment in such a way that

the frequency of this disease causing severe illness or death over time will decrease.

An examples of this type of testing can be seen in a study done in Austria and one done in Minnesota.

Once there is a significant suspicion based on either physical examination or PSA elevation ultrasound of prostate, with guided needle biopsy, can clearly be utilized to detect malignant tissue.

Grading of prostate cancer is done by what is known as the Gleason Grading System. A low-grade cancer is a Gleason I, and a high grade is a Gleason 5. The low-grade cancer looks almost like normal tissue; high-grade cancer is hard to identify, as originating in the prostate.

Staging of prostate cancer refers to the volume of the tumor present, at the time the diagnosis is made.

This is important because volume of tumor frequently correlates with grade of malignancy and can be used to predict the aggressiveness of the biologic behavior of the tumor. Prostate Intraephthial Neoplasia, known as PIN, occurs close to an area where prostate malignancy may exist. When this is found on biopsy there is substantial risk that cancer is present and repeat biopsies there is substantial risk the cancer is present and repeat biopsies are indicated. (J Urol, vol.158, pp 12-22, July 1997)

Treatment Alternatives

Radical prostatectomy is the surgical procedure for totally removing the prostate. The prostate is enseathed by large vessels, is close to the rectum, and also has nerves, arteries and veins that pass very close to the prostate on their way to supply the urethral sphincter and the penile erection mechanism. The goal of radical prostatectomy is to totally remove the prostate and seminal vesicles thereby removing tumor which is contained within, while controlling bleeding and preserving sphincter function and the neurovascular bundle thereby preserving the ability of the patient to have an erection of the penis. The experienced urologic surgeon achieves these goals the vast majority of the time. When radical prostatectomy is preformed on patients who have disease confined to the prostate, durability of cure of prostate cancer is very high.

Radiation Therapy

A.External Beam

Radiation therapy can be administered by external beam source; it has been utilized in treatment of prostate cancer since the late 1950’s. The literature though, shows that there is evidence of failure, in other words, recurrence of cancer as judged by a rising PSA. When recurrence happens it usually occurs within the first three years, the rate of recurrence maybe as high as twenty to thirty percent.

B. Brachytherapy

Brachytherapy is the technique of putting radioactive seeds into the prostate, this done through the perineum, or bottom, and is guided by ultrasound imagining.

The radioisotopes, utilized most frequently are Iodine 125 ( a half-life of 60 days) or Palladium 103 (half-life of approximately 18 days). Iodine 125 is usually used for low-grade cancer and Palladium 103 is used for a high-grade cancer.

Brachytherapy is currently quite popular and is utilized in many patients. The literature suggests that this form of therapy may be on a par with radical prostatectomy, in terms of success and duration of cure. Peer-reviewed literature demonstrates that that rate of reoccurrence of prostate cancer is rising. The scientific literature, in this situation is contradictory, and time will be required to resolve this controversy.

Cryosurgical Ablation of the Prostate

For Treatment of Prostate Cancer

Cryosurgical ablation of the prostate for treatment of prostate cancer is currently undergoing a renaissance. Cryosurgery destroys targeted tissue with extremely cold temperatures. This maybe thought of as a technique of targeted frostbite to tissues that harbor prostate malignancy. Cryosurgical ablation of the prostate was applied in the 1960’s and again later in the 1980’s and continued through the 1990’s. This procedure emerged as the result of advances in transrectal ultrasound and the development of the technology to deliver supercold temperature to the prostate, by introducing cryo probes through the perineum into the prostate gland.

The technique as preformed in the 80’s and early 90’s required further refinement of the delivery technology. One of the major breakthroughs was being able to develop thermocouples that allowed accurate temperature monitoring, during the freeze. Another significant development, was a warming device for the urethra, that was approved for this application by the FDA. This prevented urethral destruction during the cryoablative freeze of prostate. Currently cryosurgical technology involves smaller more efficient and directable probes, sophisticated real-time ultrasound monitoring of the prostate freeze and development and delivery of extremely cold temperatures using argon gas through the new small cryo probes.

Literature that supports the application of cryosurgical ablation of the prostate for malignant conditions of the gland is summarized in article by Whyte, J Urol, Vol 162, pp 1386-1387, 1999. This paper demonstrated that the series published by John Long, has five year pooled analysis of 988 patients, 82% of whom had a negative biopsy rate. Bahn and Lee describe a series of 445 patients with a minimum of five year follow up and a negative biopsy rate of 79%. Chin from Alhambra, California describes a series of 117 patients 82% had negative biopsies and again this was after a five year follow up.

Comparative data demonstrates that cryosurgical ablation techniques for prostate cancer are comparable or exceed the benefit of radiation, in the ability to eliminate disease

Cryoablation of the prostate can be utilized as salvage therapy; this means that if there is a recurrence after radiation therapy or radical prostatectomy or the initial cryosurgical ablation procedure, a second treatment can be administered to the locally involved area and is often successful in eliminating this disease.

Cryosurgical ablation of the prostate is an effective minimally invasive treatment to eliminate prostate cancer when the disease is confined to the gland. In the hands of the experience urologic cryosurgeon the complication rate is very low.

 

Summary

We have reviewed the methods of diagnosis of prostate cancer strategies for determining the aggressiveness and the extent of disease. We have reviewed the methods to treat this disease for cure. In the year 2001, with the availability of PSA not only as a tumor marker but as a screening tool it is possible to establish a very early diagnosis of prostate cancer and as result have the opportunity to treat these patients for cure. Further, it is clear that two events have occurred, since 1993 (1) PSA has lead to earlier diagnosis of prostate cancer and because of this (2) the number of deaths per thousand is declining. It is also true that the number of deaths per hundred thousand men is declining.

Finally it is Riemenschneider’s recommendation that men, over the age of 40, should have a serum PSA and rectal examination, on an annual basis.