Why Screen for Prostate Cancer?
Screening finds earlier stage cancers, allows for simpler treatments with fewer side effects, and saves lives. For example, in 1985, prior to PSA screening, the prostate cancer five-year survival rate was 69% compared to 99% in 2006. It’s unclear whether this dramatic survival increase is entirely due to PSA screening. Other factors, such as improved therapy have also contributed.
Why Is There A Controversy about Screening?
Prostate cancer can be very slow growing. If a man already has a short life expectancy, the cancer may never affect him. Therefore, the side effects of treatment may be worse than the disease. In addition, two studies evaluating the usefulness of PSA screening failed to show a benefit, perhaps because too many men in the comparative group who were supposed to forgo PSA screening ended up getting PSA testing outside the study. In a third study from Europe, in which the unscreened comparative group had a much lower exposure to outside PSA testing, the study showed an improvement in ten-year survival.
Is Immediate Biopsy Appropriate?
As medicine is presently being practiced in the United States, an elevated PSA almost always leads to an immediate 12-core, random needle biopsy. Over a million men get biopsied every year. Unfortunately, few people realize that low-grade prostate cancer is so common in the general population that a biopsy will be positive 20% of the time, even in men with normal PSA! The majority of cancers found on random biopsy are small and do not require treatment. However, consider the emotional devastation of a cancer diagnosis. Men can be literally frightened to death. Studies have shown that there is a sharp increase in suicides and heart attacks after a cancer diagnosis.
Stop PSA Screening Altogether?
Due to concerns about over-diagnosis and serious side effects from unnecessary treatments, the U.S. Preventative Services Task Force has come out recommending against routine PSA testing. Unfortunately, the Task Force is missing the point. PSA is not the main concern. The problem is the prevailing medical policy in which doctors routinely refer men with high PSA for immediate random biopsy leading to over diagnosis of low grade cancers.
Role of New Imaging Technology?
Rather than doing an immediate biopsy, doctors should consider prostate imaging with multiparametric MRI or Color Doppler Ultrasound. In experienced hands with state-of-the-art equipment, high-grade cancer can be ruled out with 95 to 98% accuracy. And when imaging detects a high-grade lesion, a targeted biopsy directed specifically at the area of abnormality can be performed. If the scans show that no high-grade disease is present, the patient can forgo biopsy and simply monitor the situation with further PSA testing and if necessary, consider additional imaging in six to twelve months.
The Frequency of PSA Testing is Affected by Various Factors:
Annual PSA testing and a digital rectal examination are the foundation of screening. Men with increased risk due to family history or because of African-American race should consider starting at age 40. Otherwise, men can begin PSA screening at age 50. It is reasonable however, for all men to get a baseline PSA between 40 and 50 years old, and then decide about further testing based on that initial reading.
· Begin PSA testing age 40-45 if a relative had prostate cancer before the age of 60.
· Begin PSA testing age 45-50 if you have a father, brother, or uncle who had prostate cancer at any age or if you are an African American.
· Yearly PSA for men age 50-75 if your PSA 1-2ng/ml then every 2 years is okay.
After age 75 general health factors are the most important consideration. When overall health status is good it’s reasonable to continue screening past age 75.
If the PSA is higher than 2.5ng/ml or if there is an abnormality detected on digital rectal examination, further evaluation with imaging is needed.