Giving Prostate Cancer the Cold Shoulder
Robert Donnell, MDMedical College of Wisconsin Urologist
Many treatment options are available to patients with prostate cancer. Choosing one is a highly personal decision. Patients and physicians consider factors such as age, lifestyle and disease status when designing a treatment plan. Robert Donnell, MD, describes cryosurgery, a minimally invasive surgical option.
Q. What is cryosurgery?Cryosurgery, or cryoablation, is a process that uses extremely cold temperatures to treat and destroy cancer cells in the body. We use a specialized needle that looks very much like a small knitting needle, and under ultrasound guidance, we place that needle through the skin and into the tumor. We then circulate a gas, in this case argon, through the needle, which drops the temperature to approximately –140 to –150 degrees centigrade. We may need to use four to eight needles in order to generate an ice ball that is specific to the size of the prostate we’re treating. But there are no incisions, no real cuts. There are only small needle holes.
Q. For what types of cancer is cryosurgery appropriate?It is most commonly used for prostate and kidney cancers. Other specialties also use cryosurgery for liver cancer, cancers that have spread to the bone and tumors that are causing trouble or pain. Cryoablation is being used to treat lung cancers that are blocking the airways, heart arrthymias that have not responded to other therapies, in select eye tumors and for some pre-malignant breast tumors.
Q. When is cryosurgery appropriate for prostate cancer treatment? There are two broad categories of patients we treat with cryoablation. When prostate cancer does not respond to radiation (either radioactive seed implants or external beam radiation) or when prostate cancer recurs after a period of time, cryoablation is the only therapy that can potentially cure a man of this cancer without the high complication rate associated with radical surgery after radiation. If the recurrent cancer appears to be confined to the prostate gland and the patient has a life expectancy of at least eight years, therapies designed to cure the patient provide real benefit to patients compared with those treatments designed to slow/alter the growth of the cancer. Cryosurgery is an excellent option for such patients.
Some men who have not received prior treatment for their prostate cancer are also good candidates for cryoablation. These men often desire a faster recovery compared with radical surgery. Finally, there are men in whom cryoablation is the only option. Often these men have a history of surgery, other medical problems, or radiation for prior rectal cancers that prevent them from considering radical surgery or additional radiation.
Q. What are the benefits of cryosurgery?Recovery is typically faster. Another potential advantage is that cryoablation may have a lower risk of urinary incontinence and rectal side effects.
Cryoablation does have a higher rate of erectile dysfunction. But, for the man who already has decreased erectile function, which many of these men have, there is a definite benefit to cryoablation. Cryoablation is also a procedure that can be repeated, if necessary.
There is one more exciting possibility. Cryoablation offers the potential to treat only the area of the prostate where the tumor is located. Focused treatment is already being researched in breast cancer — similar to prostate cancer in that both are hormonally based malignancies. For some years, researchers have studied limiting treatment to the breast tumor only, hoping to find an option that improves quality of life (shorter treatment times, fewer side effects), while continuing to preserve life expectancy. Similar options are being explored for prostate cancer patients. Preliminary research data show that individuals in whom we treat only the tumor portion of the prostate gland may experience the same benefits desired for breast cancer patients. In addition, men who participate in treatment limited to the tumor may have improved preservation of sexual function. It’s important to note that the relative merit of focused treatment remains unproven — there are still many questions research must answer. This is especially true in prostate cancer, a disease which often has a long natural history. As a result, years of data are needed in order to prove that a new technique is equal to or better than conventional treatment.
Q. What are the short-term and long-term outcomes?In the short term, there’s a faster recovery compared with surgery and a delivery time that is faster than radiation. There is also less risk.
The cancer control rates are best measured in long-term analysis. And right now, an analysis shows the success rate of cryoablation is somewhere between that of surgery and external beam radiation therapy.
Q. How is recovery time versus other treatment options?When you look at radiation, the side effects can be progressive with time. In other words, the greater the interval between radiation and the present, the more likely a patient is to have side effects. Like most surgical procedures, cryoablation’s side effects — if there are side effects — occur soon after the procedure is done and get better with time. The majority of individuals who receive cryoablation are back to 80 percent of their activity levels three to four weeks later. And they would be expected to continue to improve for the rest of the residual over a short period of time. Cryoablation provides a little faster healing than regular prostate surgery.
Source: Every Day, Interview with Robert Donnell, MD
Date: Aug - Dec 2006