Level III Services: Preventive services that clinicians and care systems could provide to patients, but only after careful consideration of the costs and benefits. Providing these services is left to the judgment of individual care systems, clinicians and their patients.
|The USPSTF recommendations are fully endorsed by the ICSI Preventive Services work group.
||Grade of Recommendation and Level of Certainty as Evaluated by USPSTF|
||Grade of Recommendation:
Level of Certainty:
The primary goal of prostate cancer screening is to reduce deaths due to prostate cancer and, thus, increase length of life. An additional important outcome would be a reduction in the development of symptomatic metastatic disease. Reduction in prostate cancer mortality was the primary outcome used in available randomized, controlled trials of prostate cancer screening. Although one screening trial reported on the presence of metastatic disease at the time of prostate cancer diagnosis, no study reported on the effect of screening on the development of subsequent metastatic disease, making it difficult to assess the effect of lead-time bias on the reported rates.
Men with screen-detected cancer can potentially fall into one of three categories: those whose cancer will result in death despite early diagnosis and treatment, those who will have good outcomes in the absence of screening, and those for whom early diagnosis and treatment improves survival. Only randomized trials of screening allow an accurate estimate of the number of men who fall into the latter category. There is convincing evidence that the number of men who avoid dying of prostate cancer because of screening after 10 to 14 years is, at best, very small. Two major trials of PSA screening were considered by the USPSTF: the U.S. PLCO (Prostate, Lung, Colorectal, and Ovarian) Cancer Screening Trial and the ERSPC (European Randomized Study of Screening for Prostate Cancer). The U.S. trial did not demonstrate any prostate cancer mortality reduction. The European trial found a reduction in prostate cancer deaths of approximately one death per 1,000 men screened in a subgroup of men ages 55 to 69 years. This result was heavily influenced by the results of two countries; five of the seven countries reporting results did not find a statistically significant reduction. All-cause mortality in the European trial was nearly identical in the screened and non-screened groups.
There is adequate evidence that the benefit of PSA screening and early treatment ranges from 0 to 1 prostate cancer deaths avoided per 1,000 men screened.
Adequate evidence shows that nearly 90% of men with PSA-detected prostate cancer in the United States have early treatment with surgery, radiation or androgen-deprivation therapy. Adequate evidence shows that up to 5 in 1,000 men will die within one month of prostate cancer surgery and between 10 and 70 men will have serious complications but survive. Radiotherapy and surgery result in long-term adverse effects, including urinary incontinence and erectile dysfunction in at least 200 to 300 of 1,000 men treated with these therapies. Radiotherapy is also associated with bowel dysfunction.
Some clinicians have used androgen-deprivation therapy as primary therapy for early-stage prostate cancer, particularly in older men, although this is not a U.S. Food and Drug Administration (FDA)-approved indication, and it has not been shown to improve survival in localized prostate cancer. Adequate evidence shows that androgen-deprivation therapy for localized prostate cancer is associated with erectile dysfunction (in approximately 400 of 1,000 men treated), as well as gynecomastia and hot flashes.
There is convincing evidence that PSA-based screening leads to substantial over-diagnosis of prostate tumors. The amount of over-diagnosis of prostate cancer is of important concern because a man with cancer that would remain asymptomatic for the remainder of his life cannot benefit from screening or treatment. There is a high propensity for physicians and patients to elect to treat most cases of screen-detected cancer, given our current inability to distinguish tumors that will remain indolent from those destined to be lethal. Thus, many men are being subjected to the harms of treatment of prostate cancer that will never become symptomatic. Even for men whose screen-detected cancer would otherwise have been later identified without screening, most experience the same outcome and are, therefore, subjected to the harms of treatment for a much longer period of time. There is convincing evidence that PSA-based screening for prostate cancer results in considerable overtreatment and its associated harms.
The USPSTF considered the magnitude of these treatment-associated harms to be at least moderate.
Although the precise, long-term effect of PSA screening on prostate cancer-specific mortality remains uncertain, existing studies adequately demonstrate that the reduction in prostate cancer mortality after 10 to 14 years is, at most, very small, even for men in what seems to be the optimal age range of ages 55 to 69 years. There is no apparent reduction in all-cause mortality. In contrast, the harms associated with the diagnosis and treatment of screen-detected cancer are common, occur early, often persist, and include a small but real risk for premature death. Many more men in a screened population will experience the harms of screening and treatment of screen-detected disease than will experience the benefit. The inevitability of over-diagnosis and overtreatment of prostate cancer as a result of screening means that many men will experience the adverse effects of diagnosis and treatment of a disease that would have remained asymptomatic throughout their lives. Assessing the balance of benefits and harms requires weighing a moderate to high probability of early and persistent harm from treatment against the very low probability of preventing a death from prostate cancer in the long term. The USPSTF concludes that there is moderate certainty that the benefits of PSA-based screening for prostate cancer do not outweigh the harms.”
|Implementation Tools and Strategies:
Screening for Prostate Cancer