Screening Guidelines: Prostate Cancer

Prostate cancer is the most commonly diagnosed invasive cancer and the second leading cause of cancer deaths among American men. More than 192,000 men were diagnosed with prostate cancer in 2009, and about 27,300 died of the disease. Men in the United States have about a 16 percent chance of eventually being diagnosed with prostate cancer and about a 3 percent chance of eventually dying of it. Those who undergo regular prostate-specific antigen (PSA) testing have a higher likelihood of undergoing prostate biopsy and being diagnosed with prostate cancer compared with men who do not undergo PSA testing.

Prostate Cancer Screening Tests

Several medical organizations, such as the American Cancer Society, issued prostate cancer early detection guidelines, which include two tests to screen men for prostate cancer. In the first, known as a digital rectal examination (DRE), a doctor inserts a gloved finger into the rectum to feel for lumps in the prostate. In the second, a blood test detects the amount of a protein called prostate-specific antigen (PSA) circulating in a man's blood. PSA is a good indicator of activity (such as cell division) in the gland. While an abnormal DRE and an elevated PSA level (greater than or equal to 4.0 ng/ml) may be indicators of prostate cancer, neither test alone or in combination can provide a definitive diagnosis of prostate cancer — for this, a biopsy of the prostate is required. For example, men who have a common, noncancerous condition called benign prostatic hyperplasia (BPH) may also have elevated PSA levels.

Other medical organizations note that reliable studies have yet to show that early detection and treatment result in fewer deaths from prostate cancer. However, most experts agree that the introduction of early detection programs such as DRE and the PSA test have played a significant role over the past ten years in the increased number of prostate cancer patients being diagnosed at early stages. And a number of studies have shown that prostate cancers detected through screening are more often confined to the prostate gland, and thus more easily treated, than those detected by a DRE alone. Additionally, the recent decline in deaths from prostate cancer in the US may have been caused, in part, by the increase in early detection.

Our Prostate Cancer Screening Guidelines

Memorial Sloan-Kettering's guidelines for prostate cancer screening are based on the following principles:

1. Many men with prostate cancer do not need to be treated: A diagnosis of prostate cancer is information used to help make decisions, not an indication for immediate treatment.
2. Compliance with screening will increase if men are told whether they are at high, intermediate, or low risk and are informed accordingly about their need for subsequent screening.
3. There is a balance between the harms and benefits of screening: The ratio between benefits and harms will be maximized if screening focuses on men at highest risk of life-threatening prostate cancer.

Our doctors recommend the following screening guidelines:

1. All men should receive a PSA test at age 45. For these men with a:
   1. PSA greater than or equal to 3 ng / mL: Consider biopsy
   2. PSA greater than 1 but less than 3 ng / mL: Return for PSA every two years
   3. PSA from 0.65 to 1 ng / mL: Return for PSA at age 50
   4. PSA less than 0.65 ng / mL: Return for PSA at age 55
2. For men aged 45 to 59 with a:
   1. PSA greater than or equal to 3 ng / mL: Consider biopsy
   2. PSA greater than 1 but less than 3 ng / mL: Return for PSA every two years
   3. PSA from 0.65 to 1 ng / mL: Return for PSA in five years, or age 60 if age > 55
   4. PSA less than 0.65 ng / mL: Return for PSA at age 60
3. For men aged 60 to 70 with a:
   1. PSA greater than or equal to 3 ng / mL: Consider biopsy
   2. PSA greater than 1 but less than 3 ng / mL: Return for PSA every two years
   3. PSA less than or equal to 1 ng / mL: No further screening
4. For men aged 71 or older:
   1. No further screening

Explanatory notes

Patients should be informed of their risk. A 50 year-old man with a PSA of 2 ng / mL has a much higher risk of a subsequent life-threatening prostate cancer than a man of similar age who has a PSA of 0.4 ng / mL. The current approach, to inform both men that “PSA results were negative” and that they should return for regular testing, leads to imperfect compliance. Instead, the man with the PSA of 2 ng / mL should be informed that, although he may not need an immediate biopsy, he is in a high-risk category, and he should have his PSA checked regularly so that, were he to develop prostate cancer, it would be diagnosed early. The man with the low PSA, on the other hand, can be reassured that he is at low risk and does not need further PSA testing for many years (e.g., a repeat PSA testing at age 55 or 60).

Guidelines should be individualized. The guidelines should be modified to deal with individual patients. A patient with a strong family history of prostate cancer might reasonably be considered for a PSA test at age 40. Conversely, a man recently diagnosed with a life-threatening heart condition might be advised against subsequent PSA screening. Similarly, intensity of screening can be individualized within risk groups. As an example, the recommendation is for screening every two years for men with a PSA of 1 to 3 ng / mL. A physician may choose to recommend a four-year interval for an older man with a PSA close to 1 ng / mL, or an interval of less than two years for a younger man with a PSA close to 3 ng / mL.

Background

The intense controversy surrounding early detection of prostate cancer has prompted many medical organizations to develop prostate cancer early detection guidelines. The American Urological Association (AUA) has recently updated their prostate cancer screening recommendation originally published in 2000. The new policy states: “There are two notable differences in the current policy. First, the age for obtaining a baseline PSA has been lowered to 40 years. Secondly, the current policy no longer recommends a single, threshold value of PSA which should prompt prostate biopsy. Rather, the AUA recommends that the decision to recommend prostate biopsy should be based primarily on PSA and digital rectal examination (DRE) results, but should take into account multiple factors including free and total PSA, patient age, PSA velocity, PSA density, family history, ethnicity, prior biopsy history, and other health conditions. In addition, although recently published trials show different results with regard to the impact of prostate cancer screening on mortality, both suggest that prostate cancer screening leads to over-detection and overtreatment of some patients. Therefore, the AUA strongly supports that men be informed of the risks and benefits of prostate cancer screening before biopsy and the option of active surveillance in lieu of immediate treatment for certain men newly diagnosed with prostate cancer.”

Opponents of systematic early detection programs for prostate cancer note that prospective, randomized trials do not show an unequivocal benefit for early detection and definitive therapy. For this reason, the US Preventive Services Task Force and the American College of Physicians do not support routine PSA examinations as a screening procedure for prostate cancer.

Most experts believe, however, that the introduction of early detection programs such as DRE and the serum PSA test has played a critical role in the increase in the diagnosis of early-stage prostate cancers seen over the past decade. Currently, 80 to 90 percent of prostate cancers are clinically organ confined at diagnosis. Multiple studies have unequivocally shown that prostate cancer cases detected through screening are more often confined to the prostate than those detected solely by an abnormal DRE. In addition, the recent decline in prostate cancer mortality within the United States may be attributable, in part, to prostate cancer early detection. Population-based prostate cancer screening studies in Tyrol, Austria, for example, show a marked decline in prostate cancer mortality with screening compared to the general population of Austria.

Perhaps the most compelling evidence that selected patients with prostate cancer benefit from active treatment compared to watchful waiting (defined as no treatment until symptoms from prostate cancer develop) comes from a Scandinavian Trial, which randomized 695 men with clinically localized prostate cancer to either radical prostatectomy or watchful waiting with systemic treatment deferred until the development of symptomatic progression. The primary end point of this study was death from prostate cancer. During a median follow-up of 8.2 years, 50 of 348 of those assigned to watchful waiting died from prostate cancer, compared to 30 of 347 of those assigned to radical prostatectomy. The men assigned to surgery had a lower relative risk of distant metastases than did the men assigned to watchful waiting. For men who were managed conservatively, the cumulative probability of developing metastatic disease ten years after diagnosis was 25 percent and the cancer-specific mortality rate was 15 percent. Most importantly, there was an absolute and statistically significant increase in overall survival at ten years for patients in the surgery arm. This study firmly documents the overall benefit of radical prostatectomy in patients with clinically localized prostate cancer diagnosed in the absence of systematic screening of the population. The relevance of this study to cancers detected by screening, which may be much earlier in their natural history, is uncertain.

Prostate Cancer Screening Guidelines: Summary

There is unequivocal evidence that screening with PSA detects prostate cancer at an early stage when the cancer is usually curable with surgery or radiation therapy. The Memorial Sloan-Kettering Cancer Center Prostate Cancer Disease Management Team recommends that men interested in the early detection of prostate cancer be informed of the risks and be advised to consider screening according to the following guidelines:

Candidates for screening should be made aware that, while the evidence is suggestive, definitive proof of an overall benefit for screening is not yet available and that there is the possibility of harm from screening in increased anxiety, complications from biopsy (a small risk of bleeding and/or infection), and the diagnosis of prostate cancer that may not have caused illness or death if left undetected. At the same time, the risk of not screening should be noted, including the possibility of developing an advanced, incurable prostate cancer that may result in premature death.