Less well established forms of treatment for early stage (localized) prostate cancer
Posted Sep 17 2008 1:50pm
Note: The information provided below is basic information only. The content of this section will be upgraded in the near future to offer a more detailed commentary on less well established forms of treatment for early stage (localized) disease.
Cryotherapy (also known as cryosurgery or cryoablation) is an old technique which was reborn as a result of advances in technical capability. Rather than removing the prostate (as in conventional surgery) or using radiation therapy, cryotherapy is a method of freezing the prostate and other appropriate nearby tissues to extremely low temperatures. This was done historically using liquid nitrogen and liquid argon, but is now carried out using argon gas technology. This technique is designed to kill all the prostate cancer tissue without having to take the risks involved in carrying out invasive surgery.
While cryotherapy is an interesting and important addition to the options which physicians can offer patients with prostate cancer, many still be consider it to be an investigational technique at this time. Even physicians who have carried out several hundred cryosurgical procedures for prostate cancer will still say that they are unsure of the precise future role for this form of therapy.
If you decide that cryotherapy is an option which you wish to consider, you should certainly seek out a physician who has considerable experience with this technique. You should ask that physician very specific questions about whether cryosurgery is appropriate for you. Most importantly, you should ask whether that physician believes that cryosurgery can be used to cure your cancer or whether it would be given primarily to reduce the amount of cancer in your body.
It would be most appropriate if you could find a physician who was interested in talking to you about cryotherapy within a carefully controlled trial comparing the effectiveness and safety of this technique to the effectiveness and safety of other, traditional first-line curative treatments (i.e., surgery and radiation therapy).
The known side effects of cryotherapy can include impotence (in about 80 percent of patients), scarring of the urethra and urinary dysfunction (which are relatively unusual), and irritation of the bladder, the urethra, the rectal wall, and the genitalia. This last group of side effects can include pain on urination, a burning sensation during urination, frequent and unexpected urination, blood in the urine (hematuria), and swelling of the penis or the scrotum.
High-Intensity Focused Ultrasound (HIFU)
HIFU is a newer therapeutic option than cryotherapy. It has not yet been approved as a treatment regimen for prostate cancer in the USA, but it has been approved in Europe and is available in other countries too (including Canada, Mexico and the Dominican Republic). A detailed report on the clinical use of HIFU to date is available on another page.
The basic principle behind HIFU is that by focusing a beam of ultrasound waves through the wall of the rectum into the prostate, one can heat the prostate tissues to such high levels that they are effectively “cooked.” This kills the prostate tissues and (in theory) the prostate cancer too. According to one physician who has been carrying out HIFU for several years now, “The control and precision of HIFU allow the accomplished surgeon to accurately target the tissue to be destroyed without injuring adjacent tissue. HIFU destroys tissue by heat, rather than by cavitation or mechanical shearing forces.”
There are basically two types of HIFU equipment available (in various countries), and “second generation” equipment started to become available in the past few years. The operating principles behind each set of equipment are slightly different, and therefore the results obtained by one group of physicians using one type of equipment are not necessarily comparable to the results obtained by a different set of physicians using different equipment!
Only very recently have the first relatively long-term results started to be published. These results are based on the use of “prototypes” and “first generation” equipment and are based on experience treating patients during the earliest stages of the use of this equipment (i.e., during the physicians’ “learning curve”). As a consequence, it is almost inevitable that the results to date are not as good as one might expect if one went today to an experienced HIFU specialist who had access to “second generation” equipment.
The bottom line is that there is still a great deal to be learned about the real potential of HIFU, and it will probably be another 10 years before we can make definitive decisions about the value of this technique in the management of localized prostate cancer compared to surgery and radiation.
What is absolutely certain is that if this is a treatment technique that you want to consider, you would be wise to go to a center that had already treated as manty patinets as possible and that had access to the latest equipment.
Known side effects of HIFU include the short-term retention of urine (because of sloughing of prostate tissue and tissue swelling), a risk for anal fistula and incontinence (both of which seem to be relatively small), and a significant risk for impotence.
A major clinical trial of HIFU as a first-line treatment for localized prostate cancer is currently recruiting patients at several centers in the USA using second-generation equipment. Any patient who is interested in this technique might wish to consider participating in such clinical trials. However, this trial compares HIFU to cryotherapy and only patients with a Gleason score of 6 or less are eligible. (This is a little odd since many such patients — and particularly those of 70 years and older — may not actually need treatment at all, and could potentially be managed with watchful waiting or active surveillance!)