Comparing Recommendations by Urologists and Radiation Oncologists for Treatment of Clinically Localized Prostate Cancer

abstract & commentary

Synopsis: The survey revealed that for clinically localized disease, the majority of both groups of specialists would recommend for patients the therapy that they themselves deliver.

Source: Fowler FJ Jr., et al. JAMA 2000;283:3217-3222.

According to fowler and colleagues, about 180,400 men will be diagnosed as having prostate cancer in the United States this year, most with clinically localized disease who will mainly choose one of three therapies: radical prostatectomy, external beam radiotherapy, or brachytherapy. A 1988 survey of urologists and radiation oncologists revealed that when asked what they would personally do if diagnosed as having clinically localized prostate cancer, 79% of U.S. urologists chose radical prostatectomy while 92% of radiation oncologists chose external beam radiotherapy. The purpose of this study was to again survey the two specialties to determine whether the current era of prostate-specific antigen (PSA) testing has led to an alteration in such polarity of views as well as gain further insight beyond simply preference for treatment.

When asked if primary care practitioners (PCPs) should include PSA testing as part of the routine physical examination, close to 100% of both specialists believed that screening was appropriate for patients between the ages of 50-70 years of age. Interestingly, beyond age 70 years, 43% of oncologists continued to recommend the screening test, compared to only 16% of urologists. When asked to compare radical prostatectomy and external beam radiotherapy for patients with more than 10 years life expectancy, 93% of urologists thought that radical prostatectomy was better compared to 72% of radiation oncologists’ perception that the two therapies were equivalent. Interestingly, even when asked about tumors with low Gleason scores (3 or 4 and PSA no higher than 5 ng/mL), only 10-20% of either specialty favored watchful waiting, which dropped to near zero for higher grade tumors. The two groups were essentially identical in predicting the likelihood of aggressive therapy causing either sexual dysfunction or impotence.

The survey again revealed that for clinically localized disease, the majority of both groups of specialists would recommend the therapy for patients that they themselves deliver. A majority of radiation oncologists stated that they believed that radical prostatectomy is overused and about half thought that radiation and brachytherapy are underused. In contrast, 51% of urologists thought that radical prostectomy was used at about the correct rate and 37% thought that external beam radiation was overused. There was no uniformity of opinion by either specialty regarding the appropriate use of brachytherapy. As Gleason scores and PSA levels increase, both groups started to consider androgen deprivation as primary therapy, and urologists began to recommend radiation more often than surgery.

Comment by michael k. rees, md, mph

In an accompanying editorial, Wilt reminds us that—to date—there is no conclusive evidence that screening and treatment of prostate cancer improve either survival or quality of life and that the only randomized, controlled trial (RCT) comparing surgery with watchful waiting demonstrated no difference in survival up to 23 years.1 He notes that physicians in Sweden and the United Kingdom are much less aggressive in their approach to both screening and therapy intended to be curative; nevertheless, mortality rates for prostate cancer de-creased in Sweden from 1993 to 1996 and U.K. mortality rates are similar to those in the United States. While the rate at which prostate cancer is diagnosed in the United States has increased about 80 per 100,000 since the early 1990s, prostate cancer death rates have only decreased by four per 100,000 and remain greater than in the 1970s-80s. Wilt argues that this small decline began too early after widespread PSA testing and early intervention to be due to these factors.

According to Wilt, though well intended, selective interpretation of uncontrolled reports leads to advocating a particular option by a specialist or country and dismissal of other options and, in many instances, the results of well conducted RCTs disprove therapeutic recommendations that were based upon observational studies. He argues that dissemination of unsubstantiated theories as proven medical care increases practices likely to be harmful. "For example, because most prostate cancers do not cause mortality or serious morbidity, early intervention is not necessary in the vast majority of men. However, while watchful waiting appears to provide comparable survival, and avoids the harmful side effects that can occur with surgery or radiation therapy, it is rarely recommended in the United States."

Perhaps no area of decision making so perplexes and frustrates the PCP as does therapy of prostate cancer. In a time when we take pride in basing therapeutic decisions on the results of well conducted randomized, double-blinded, controlled trials, for this disease we remain largely dependent on expert opinion. However, when it comes to choosing therapy for a clinically localized tumor, urologists and radiation oncologists each strongly favor the form of therapy that they deliver—both of which are associated with a high rate of severe morbidity. They express no uniformity of opinion on the appropriateness of brachytherapy and are almost uniformly against the option of watchful waiting, unless the tumor is extremely low grade and life expectancy is less than 10 years.

I agree with Wilt that there is an urgent necessity for entering our patients with prostate cancer into RCTs. "Accrual in RCTs is likely to increase by enhancing public awareness of the importance and benefits of clinical trials as the treatment of choice for cancer and by making participation socially, medically, and financially acceptable and preferred as the best current choice for patients and physicians." Currently, there are at least three trials that may be available to our patients, the Prostate Cancer Intervention Versus Observation Trial (PIVOT), the Prostate, Lung, Colorectal and Ovarian Screening Trail, and a trial comparing brachytherapy with surgery. For information on the availability of RCTs, see http://clinicaltrials.gov or http://cancernet. nci.nih.gov/pdg.html.

Finally, in a humorous personal view, Tannock observes that, to date, our major accomplishment has been to eradicate asymptomatic prostate cancer.2 "Unfortunately, in medicine some discoveries may lead to more harm than good. It remains to be seen whether there will be net benefit following the discovery of PSA. In the meantime, a large population of men who, 15 years ago, would have remained happily unaware of any problem, now have impaired quality of life because they are consumed by anxiety about their PSA. Such is progress."

References

1. Wilt TJ. JAMA 2000;283:3258-3260.

2. Tannock IF. Lancet Oncology 2000;17-18.