Prostate Cancer: To Test or Not to Test?

05/10/2010 05:12 am ET | Updated Nov 17, 2011

To test or not to test? That is the question every man needs to confront with his doctor.

The updated 2010 American Cancer Society Guideline for the Early Detection of Prostate Cancer is long and complicated. It addresses the issues surrounding the performance of the prostate-specific antigen (PSA) screening test, discourages routine or mass screening and encourages a discussion with your doctor.

If you're a man who has a history of prostate cancer occurring in multiple family members before age 65, or is otherwise predisposed to having the disease, the decision to test is a no-brainer. For everyone else, it's a little trickier. The bottom line is this: For a man without symptoms suggestive of prostate cancer and who has at least an additional 10-year life expectancy, a screening test should only take place after a frank discussion between the man and his doctor about the risks, benefits and consequences of the test.

Part of the reason it is difficult to decide for those that do not have existing risk factors is the lack of a really good screening test for prostate cancer that is both sensitive and specific. Sensitivity refers to the test's ability to detect a cancer when it is still potentially curable. The PSA test is only fair for this, as patients with prostate cancer often, but not always, have an elevated level of PSA in their blood. Specificity refers to the absence of false positives, meaning that the test remains normal with non-cancerous conditions. Unfortunately, the PSA test is not entirely specific, as patients whose prostate is enlarged from a benign condition or who have an infection or inflammation in their prostate will also have an elevated level. When one screens a low-risk patient with a PSA test, there is a good likelihood that an elevated level is due to a benign condition rather than cancer.

One could argue that since the PSA test is readily available and inexpensive and can detect some potentially curable cancers, why not have everyone tested? The issue is that prostate cancer tends to be very slow growing in most patients, and autopsy studies have shown that microscopic prostate cancer is present in many men who die of unrelated conditions and who were never aware that they had prostate cancer. Unlike screening for breast cancer, colon cancer and cervical cancer, there's no definitive scientific study that shows PSA testing results in lower mortality rates for prostate cancer. The medical community had hoped that two studies published about a year ago would settle the question. However, there were mixed results. The American study of 76,693 men found no survival benefit from the screening. In contrast, a European study, looking at 162,243 men, found a 20 percent reduction in deaths from prostate cancer in the screened group. That study found that it was necessary to screen 1,400 men and treat 48 cancer cases to save one life.

This means there will be a lot of biopsies done on men who have a benign condition, not a malignant one - a case where the testing and treatment may do more harm than good. An even less reliable screening method, the digital rectal examination, was brushed off in the guidelines, for similar reasons - there was no proof that it saves lives.

So, men have to decide. Is it better to know they may have prostate cancer, and potentially undergo a host of examinations and treatment that could result in such side effects as incontinence and erectile dysfunction, or risk leaving cancer undetected? The risk of testing early and often is that men may be treated for cancers that would not have caused them ill effects. Nevertheless, if you are that one man out of 48 with prostate cancer whose life is saved by early screening, the benefit to you certainly outweighed the risk. However, we have no way of predicting who will be the man whose life is saved by aggressive therapy, and, therefore, all 48 will have to be treated or undergo careful follow-up.

The ACS has wisely based its guidelines on the best scientific information available at this time, and also encourages men to weigh their personal risk with their physicians. Men at average risk should begin these discussions with their doctors at age 50. Men at higher risk, including African American men and those with a father or brother diagnosed with prostate cancer before age 65, should start at 45. Men with multiple family members diagnosed before 65 should consider testing starting at age 40.

Further, the new guidelines recommend that anyone who already has a life expectancy of less than 10 more years shouldn't bother with the test. This is because in most cases, prostate cancer grows so slowly, it's highly likely that someone in this population would die from another disease and not from the prostate cancer. Additionally, a more aggressive form of prostate cancer will present itself through other symptoms.

Prostate cancer screening has been controversial for a long time - and these guidelines are likely not the definitive last word on PSA testing. There is already some discussion in the medical community that the study findings released last year were a bit premature, and the value of PSA testing may show an increase after more time passes. There are two points most can agree on, however: First, we need a better screening test for prostate cancer, ideally one that can distinguish between those tumors that are not killers and those that are. That way we can concentrate our therapy on the latter and give reassurance (and periodic follow-up) to those with the former. Second, as medicine continues along the trend of becoming more individualized, and information becomes more widely available to the public, guidelines such as this, which emphasize shared decision making between patient and doctor, will likely become more common - and that is a good thing.