Thanks to a boom in diagnostic tests, thousands of American men are now discovering prostate tumors that would once have gone unnoticed. Cancer screening is supposed to save lives, by helping doctors destroy tumors before they invade the rest of the body. But no one is sure whether that rule applies to prostate cancer. The disease can kill, yet when left alone it usually doesn’t. And because the standard treatments have never been tested in controlled trials, no one knows how much good they do. Surgeons swear by surgery. Radiation oncologists swear by radiation. Some doctors prefer doing nothing at all unless the cancer starts to spread. And patients are caught in the middle. “Nobody has good evidence,” says Dr. John Wasson, the director of Dartmouth’s Center for the Aging. “It’s a mess.”
At the center of the mess is a puny gland that sits at the base of the bladder, forming a ring around the urethra. Though quiet and dutiful in young men, the prostate grows notoriously cranky with age. By the time they’re 65, three out of four men suffer from a noncancerous prostatic swelling that disrupts urination, and most of those who live long enough develop some cancer as well. Autopsy studies reveal cancerous prostate cells in 30 to 40 percent of men over 50 and in half of those who survive into their 80s. Yet only 3 percent of American men die of the disease. PSA tests can help spot a silent tumor, but they can’t determine its potential.
Until recently the primary tool for detecting prostate cancer was a rubber glove. By placing a gloved finger in a man’s rectum and pressing forward, a doctor can discern lumps in the gland, and a needle biopsy can determine whether they’re cancerous. Unfortunately, most of the cancers that doctors detected this way had already spread beyond the prostate. The trend toward earlier detection started in the 1970s, as technologies such as ultrasound came into wide use. But the real boom began in the late ’80s, when a company called Hybritech started marketing the blood test for PSA (prostate-specific antigen), a protein produced exclusively by prostate cells.
A high PSA reading doesn’t always signal cancer, and some tumors produce no rise in PSA. But because a cancerous prostate tends to release that protein into the blood, the test offers a good rough indicator of tumor activity. In 1986 the government approved PSA testing as a way to track patients’ responses to treatment. And shortly after the test hit the market, the manufacturer and the American Cancer Society began promoting it as a universal screening tool for men over 50. The National Cancer Institute resisted the idea, since no one had demonstrated that the practice would save lives, but doctors and patients readily embraced it.
The screening craze has had dramatic effects already. Though there’s no evidence that prostate cancer is actually on the rise, the rate of new diagnoses has increased by 85 percent since 1973 and is jumping by as much as 16 percent annually. Treatment rates have risen even more dramatically. In a study published last spring, researchers at Dartmouth Medical School tracked the rate of radical prostatectomy (complete removal of the prostate) among Medicare patients and documented an increase of nearly 600 percent from 1984 to 1990. In 1990 alone, doctors performed 16,000 operations on Medicare recipients–more than in 1984, 1985 and 1986 combined–and the trend has vet to peak. Healthcare experts calculate that if all of the nation’s 20 million or so eligible men got PSA tests, some 400,000 would become candidates for surgery and the bill would exceed $10 billion.
Doctors differ vehemently on whether these trends are all for the good. To enthusiasts the benefits of early, aggressive treatment are obvious. “The old paradigm is based on common sense,” says Dr. William CataIona, director of urological surgery at Washington University in St. Louis and a leading prostate surgeon. “We know that little cancers become big cancers. and big cancers can spread and kill you.” But skeptics maintain that common-sense impressions are no substitute for scientific evidence when so many lives and dollars are at stake. Recent studies have helped bolster that position. In the Medicare study, for example, the Dartmouth researchers found that men in Alaska were 20 times as likely as men in Rhode Island to undergo prostate surgery–but no less likely to die of the disease. The usual way to resolve such a puzzle is to conduct a single study in which some patients get a particular therapy and some don’t. Since the standard prostate-cancer treatments have never been tested that way, members of the Dartmouth team concocted a surrogate experiment.
For this study they pooled data from the medical literature and compared the benefits of aggressive treatment with those of “watchful waiting.” After adjusting for the fact that prostatectomy has traditionally left 85 percent of the recipients impotent and 27 percent at least partially incontinent, the researchers surmised that aggressive treatment could add three or four years to the life of a 65- to 69-year-old patient with a fast growing tumor. But for men over 70–who receive roughly half of all prostate-cancer treatment–the benefits were negligible and the risks high. Analysis showed that 8 percent of the surgical patients over 75 had suffered serious complications, such as heart failure, and 2 percent had died of them. The researchers noted that “if the medical community were to apply the same standards of safety and efficacy required for approval of new drugs…it is likely that neither radical prostatectomy nor radiation therapy would be approved…”
Spoken to an accomplished surgeon, those are fighting words. “Are some people getting surgery when they’re too old or too ill?” asks Dr. Patrick Walsh, director of Johns Hopkins University’s James Buchanan Brady Urological Institute. “Yes. But there are more patients out there not getting surgery when they need it.” Walsh faults the Dartmouth studies for down-playing the complications that can follow watchful waiting–which include castration and death–and for failing to consider recent improvements in surgical technique. Thanks to the nerve-sparing procedures Walsh has pioneered, many surgeons now boast far lower complication rates than past studies have shown, and less invasive treatments are now in the works. When 35,000 men are dying of prostate cancer each year, says Catalona, stopping to subject time-honored treatments to controlled clinical trials would be obscene. “This new crowd, what they say is unless you can absolutely prove that this treatment is going to save lives and be cost-effective, you shouldn’t do it.”
Actually, no one proposes shutting down the nation’s surgical suites. But critics worry that until controlled trials are conducted, most men will be stuck relying on their doctors’ wildly varied biases. According to a 1988 study, nearly 80 percent of U.S. urologists (but only 4 percent of those in Britain) would favor radical prostatectomy for a man in his 60s with a tumor confined to the gland. The same study found that 92 percent of radiation oncologists would shun surgery–and recommend radiation. Until a consensus is on the horizon, members of both specialties would do well to remind their patients that there is no definitive treatment for prostate cancer–and that their own informed choices are as valid as a doctor’s.
