A large, population-based, retrospective study demonstrated that the odds of detecting high- to intermediate-risk prostate cancer for men with stage T1cN0M0 are much higher for men over the age of 75 and African-American men.

The findings represent the first indication that a significant number of elderly men and African Americans may have an aggressive form of prostate cancer diagnosed because of PSA testing.

T1cN0M0 stage prostate cancer can only be detected through PSA testing, as the tumor causes no symptoms, cannot be felt during a physical exam and is not seen during imaging.

While this provides insight into when PSA testing may be warranted and why, more research is needed to verify that early detection and intervention is beneficial for those patients. 

If we stop PSA screening altogether, we have no other way to detect this form of prostate cancer sufficiently early to have the best chance of helping this group of high-risk patients,” said lead author Hong Zhang, MD, PhD, Associate Professor of Radiation Oncology at the University of Rochester. “The findings of this study will help physicians and certain patients make more informed decisions on whether or not they want to proceed with PSA testing, although more research (and longer follow-up) is needed to determine the effect of early detection and intervention on outcome in these high-risk patients.” 

There is convincing evidence that a substantial proportion of men who have asymptomatic, PSAdetected prostate cancer will remain asymptomatic throughout their life and have good outcomes even without treatment. Given the harms associated with “over treatment,” the U.S. Preventative Services Task Force (USPSTF) recommended against PSA screening for men in the general U.S. population. While at any given time, the percentage of all men who have either intermediate- or high-risk prostate cancer diagnosed exclusively because of PSA is small (about 1 in 8000 men), for those patients, early diagnosis and treatment might be life-saving, particularly if they have a life expectancy of more than 10 years.

Among the 70,345 U.S. men with T1cN0M0 prostate cancer evaluated in the study, 47.6 percent, 35.9 percent, and 16.5 percent had low-, intermediate-, and high-risk disease, respectively. Men older than 75 years accounted for 40 percent of all patients with high-risk disease. Patients aged 75 and older had a 4.4-fold higher probability of developing intermediate-risk disease and 9.4- fold higher probability of developing high-risk disease compared with patients younger than 50.

In addition, African Americans of all ages had a 1.8-fold higher likelihood of developing highrisk disease compared with white men. 

The present study identifies two subpopulations of patients – men older than 75 years and African Americans – in which the potential benefit of PSA screening may need further investigation.

Since the release of the USPSTF recommendations, there has been a decline in PSA screening for all age groups. ASCO issued guidance in 2012 recommending that physicians discuss the benefits and risks of PSA screening with their asymptomatic male patients who have a life expectancy of more than 10 years. ASCO recommended against screening for men expected to live less than 10 years because the harms appear to outweigh potential benefits. Physicians should therefore assess life expectancy before offering PSA screening to their elderly patients. ASCO’s decision aid for patients explains available data and important considerations about PSA testing in lay language.

The average 10-year survival rates are 91 percent for low-risk, 84 percent for intermediate-risk and 80 percent for high-risk disease.

The risk levels are defined based on clinical stage, PSA level and Gleason score. Patients have different treatment options depending on the aggressiveness of their cancer.

For example, while active surveillance is appropriate for low-risk disease, intermediate- and high-risk patients are typically offered radiation, surgery, and/or androgen deprivation therapy.

Source: ASCO