Today’s treatment strategies for prostate cancer
June 26, 2001 | 12:00am
(This article was written as part of the observance of Prostate Cancer Awareness Month of the Philippine Cancer Society.)
Each year, the impact of prostate cancer in men rivals that of breast cancer in women. Men have one in six lifetime risk of prostate cancer compared with one in eight lifetime risk for breast cancer in women. Indeed, prostate cancer kills more Filipino men than any other malignancy except lung cancer.
But here’s good news. Today, about 90 percent of all prostate cancers are diagnosed early (while malignant cells are still confined, or localized, to the prostate gland), and prostate cancer deaths have been dropping steadily for the past decade. Many experts think that increased screening with a blood test for prostate specific antigen (PSA) may account for the trend, but it will take years to confirm the association. Meanwhile, there is discussion about which treatments are most effective for men diagnosed with this disease. Here are some recommendations, based on the best available research, for what men should do until definitive answers are available.
An enzyme produced by prostate cells to break down coagulated semen, PSA is often elevated in men with prostate cancer. The PSA test is a simple laboratory blood analysis that can detect PSA elevations. However, PSA may rise owing to other factors, including benign prostate hyperplasia (BPH, the non-malignant enlargement of the prostate) or prostatitis (an inflamed prostate sometimes caused by infection). Thus, an elevated finding (over 4 ng/ml) is not diagnostic. Rather, it indicates the need for further evaluation. In addition, certain medications affect blood PSA levels. For example, finasteride (a medication marketed as Proscar for BPH and as Propecia for baldness), can reduce PSA values by up to 50 percent.
Studies show that regular PSA screening, combined with digital rectal examination (DRE), can help identify prostate cancer five years sooner than had been possible with DRE alone (the only screening method available prior to 1987 when PSA testing was introduced for clinical use). Preliminary research, as well as clinical experience, strongly suggests that the early diagnosis made possible by the joint use of these two measures, followed by prompt treatment, saves lives. One recent population study published in the medical journal Urology, documented a 22 percent decline in prostate cancer mortality.
Additional gains may occur as PSA testing becomes more widely practical. As yet, there are no official recommendations about whether PSA testing is advisable or when to begin. Definitive results may come from a trial of 75,000 men that has been examining the question since 1994. Results are expected in about 10 years. However, the potential benefits of early diagnosis are so great, and PSA screening is so simple, that many experts urge all healthy men to consider annual testing starting at age 50. Men at higher risk for prostate cancer (such as those with a family history of the disease) should talk to their doctors about starting sooner – perhaps as early as age 40.
The current procedure for radical prostatectomy is a special nerve-sparing technique, introduced in the early 1980s, wherein certain nerves that travel just outside the prostate, are preserved. Grouped together in two bundles, these nerves trigger erections. The more nerve cells that remain intact, the lower the risk of post-surgical erectile dysfunction (ED, the inability to maintain an erection adequate for sexual intercourse).
A confidential survey recently published in Urology of patients who had nerve-sparing radical prostatectomy assessed post-surgical complications in a group of 64 men who had no erectile problems before the procedure. Both nerve bundles were preserved in 89 percent of the participants. The researchers found that after 18 months, 86 percent of the participants in all age groups, 90 percent of those in their 50s, and 75 percent of those in their 60s, could have intercourse; 84 percent said that ED was not bothersome.
These findings are among the best ever reported for radical prostatectomy. The improvement can be partially attributed to the increasing number of early tumors diagnosed through screening because the smaller the tumor, the easier it is to preserve both nerve bundles. The availability of the ED medication sildenafil (Viagra) also played a role. Viagra minimizes or eliminates ED in 80 percent of men who experience erectile problems after nerve-sparing surgery.
Especially important, urinary problems – the other potential complication of prostate removal because of the potential for damaging the urinary sphincter – were minimal. A year after surgery, 93 percent of the men reported that they did not need a pad or adult diaper for urinary leakage; 98 percent said they were bothered by urinary problems only slightly or not at all. Most important, the long-term survival rate associated with the nerve-sparing surgery is excellent – at least 95 percent after 10 years.
Because much of the surrounding tissue (including the rectum, bladder and large intestine) can be avoided, higher doses of radiation are possible and side effects (such as rectal bleeding, persistent diarrhea, urinary frequency and incontinence) are minimal. The five-year disease-free survival rate, as reported in one study, is 80 percent in men with PSA of less than 20 ng/ml before treatment; in men younger than age 65, 79 percent are potent at three years and 59 percent are potent after five years.
Brachytherapy, also called interstitial radiation therapy or "seed" therapy, is an interval form of radiation. It involves the surgical implantation of dozens of tiny radioactive pellets directly into the prostate. Radiation from the pellets, or "seeds," exposes malignant cells to a highly concentrated continuous dose of radiation around the dock for several months. Most of the radioactivity is absorbed directly into the prostate, sparing the rectum and the bladder. Implantation can often be performed on an outpatient basis and typically takes about an hour. Normal activities can resume within one to three days with little or no pain. Short-term side effects, such as urinary frequency and voiding difficulty, are common, and impotence rate can be as high as 20 percent, to 40 percent after two years.
Based on information currently available, Dr. Walsh recommends radical prostatectomy for otherwise healthy men who are diagnosed with localized prostate cancer before age 60. Radical prostatectomy may also be appropriate after age 60, depending on the man’s general health and the tumor characteristics.
3D CRT may be a more appropriate choice after age 70, for men with more advanced disease and for men who prefer not to undergo surgery. In some cases, it may be advisable to combine 3D CRT with brachytherapy – especially for tumors that have aggressive characteristics, for tumors that involve more than half of one lobe of the prostate, or when the PSA is greater than 10 ng/ml. Many experts do not recommend brachytherapy alone for men with a life expectancy of more than 10 years.
Watchful waiting is an option for men who do not wish aggressive treatment. However, it is generally best reserved for patients with a life expectancy of less than 10 years (and even then, only when examination of the tumor cells indicates that it is likely to progress at a slow rate) or for those with a coexisting medical problem such as severe, unstable heart or respiratory disease that might comprise recovery after treatment. Whatever your choice, it is clear though, that today’s treatment strategies have already added not only years to life but also life to years, for men with prostate cancer.
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