Applied Evidence

Screening for prostate cancer: Who and how often?

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References

Harms of screening

The chances of undergoing a biopsy based on an abnormal screening PSA are estimated at 15% to 40% depending on the patient’s age (FIGURE 2).3 There are adverse effects associated with transrectal biopsy of the prostate. In 2 large population-basedstudies of screening, the most frequent complications were hematuria and hematospermia (LOE: 1b, 2b) (TABLE 3), with more serious consequences such as sepsis and hospitalization occurring in fewer than 1% of patients. A study of 100 screened men with an abnormal PSA who underwent prostate biopsy found that although 69% felt moderate to severe pain with the biopsy, 80% would be willing to undergo a repeat biopsy (LOE: 1b).49

Treatment options. If the biopsy result is positive, the most common treatment options for localized cancer—which represents over 80% of all prostate cancers diagnosed6—include radical prostatectomy, external beam radiation therapy, brachytherapy (internal radiation therapy) or expectant management (watchful waiting). Population-based studies have reported outcomes for these treatment options (TABLE 2). Outcomes derived from hospital-based series of other prostate cancer treatments, such as cryotherapy and 3-dimensional radiation, are available, but the estimates often reflect the experience of only a few hospitals and are not representative of other facilities. Androgen ablation is the standard treatment for metastatic prostate cancer.

Untoward effects of treatment. Approximately 60% of radical prostatectomy patients report some incontinence 12 months or more after surgery (LOE: 2b),50,51 and about 30% of patients need to wear pads for urine leakage (LOE: 2b).50-53 Men undergoing radiation therapy have less urinary incontinence, but about 30% complain of diarrhea and loose stools (LOE: 2b).51,52 Both therapies are associated with a high percentage of erectile dysfunction: approximately 60% of radiation therapy patients and 75% of surgery patients report their erections are not firm enough for intercourse (LOE: 2b).51,52

Expectant management (following the cancer with regular PSA and ultrasound testing) is sometimes difficult to “sell” to patients whose fear of cancer dictates that the only logical response is to “cut it out.”44 A recent randomized trial indicated that radical prostatectomy lowers prostate cancer mortality, local progression, distant metastasis, and overall survival as compared with watchful waiting over a median of 8.2 years of follow-up (LOE: 1b).54 However, these results may have little relevance to prostate cancer screening since only 5% of the cancers were screen-detected and 76% were palpable.

FIGURE 2
Yield of screening 1000 men for prostate cancer

TABLE 3
Percentage of patients with specific complication of transrectal prostate biopsy

CONDITIONTYROL STUDY63EUROPEAN RANDOMIZED STUDY OF SCREENING 64
Gross hematuria >1 day12.5%22.6%
Hematospermia29.8%50.4%
Significant pain4.0%7.5%
Rectal bleeding0.6%1.3%
Nausea0.8%0.3%
Fever >38.5°C0.8%3.5%
Epididymitis0.7%0.07%
Sepsis0.3%Not available
HospitalizationNot available0.5%
Tyrol study63: LOE: 2b, N=6024 biopsies; ERSS study64: LOE: 1b, N=5802 biopsies.

Recommendations from expert groups

Different expert groups have conflicting recommendations. Both the American Urological Association and the American Cancer Society recommend annual PSA screening starting at age 50 for most men; younger if risk factors are present. Groups that are evidence based tend to recommend a shared decision making process with patients. The AAFP and American College of Physicians advise physicians to counsel men on the known risks and uncertain benefits of screening for prostate cancer. The US Preventive Services Task Force 2002 update concluded that evidence is insufficient to recommend for or against routine screening for prostate cancer using PSA or DRE. The National Cancer Institute cites a lack of evidence to determine a net benefit for PSA or DRE screening.

When will we know more?

Only 1 randomized controlled trial of prostate cancer screening has been completed55: 46,193 men were randomized to either PSA and DRE or no screening from 1989 to 1996. The study had methodological problems; for instance, only 23% of the group randomized to screening was screened. The investigators in the trial have interpreted its results as demonstrating a decrease in prostate cancer deaths in the screened group compared with the unscreened group (15 vs 48.7 per 100,000 man-years).55 Others have criticized the statistical analysis and calculated the results using an “intent to screen” analysis, finding no difference in prostate cancer deaths between the 2 groups.3,56

Two randomized controlled trials of screening are ongoing: the National Cancer Institute’s Prostate, Lung, Colon, Ovarian (PLCO) Screening Trial57 and the European Randomized Study of Screening for Prostate Cancer.58 Both were started in the mid-1990s and will not have results available for a few more years. Also underway is a randomized trial of intervention (radical prostatectomy) versus expectant management, called the Prostate Cancer Intervention Versus Observation Trial (PIVOT).59

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