New studies suggest better Prostate cancer screening methods

This year at the 110th Annual Scientific Meeting of the American Urological Association (AUA), four new studies will be presented which examine different approaches to what researchers believe are smarter methods to screen for prostate cancer. 

Prostate cancer key statistics:

• Prostate cancer is the second most common cancer in American men, other than skin cancer. 

• Prostate cancer is the second leading cause of cancer deaths in men. 

• About 1 in 7 men will be diagnosed with prostate cancer in their lifetime. 

• The average age of diagnosis is 66. 

• Prostate cancer is very rare in men younger than 40, but the risk of developing prostate cancer significantly increases after age 50. About 6 in 10 cases of prostate cancer are found in men over the age of 65.

• It is estimated that in 2015, there will be about 220,800 new cases of prostate cancer diagnosed. 

• African American men are 70 percent more likely to be diagnosed with prostate cancer.

• Having a father or brother with prostate cancer more than doubles a man’s risk of developing the disease. The risk is much higher for men with multiple relatives with a history of the disease. 

• Obesity and metabolic syndrome can increase risk by 57 percent; they can also mean increased prostate cancer tumor volume and recovery risks.

• For now, the PSA test is the best way to establish a prostate health baseline; men should have a baseline PSA test starting at age 40.

• Robotic prostate surgery remains a leading treatment option, with highly successful recovery and quality of life results when performed by an experienced surgeon.

Controversy remains surrounding the use of the PSA test to screen for prostate cancer. This is due to the belief that the PSA test may lead to over-diagnosis and over-treatment in men with low-grade, less aggressive forms of the disease. The four new studies examine other ways to screen for prostate cancer using various methods which researchers believe are a better and smarter form of screening. 

According to a press release published by the American Urological Association, the new studies suggest four new approaches which include identifying the optimal prostate cancer screening frequency for men based on PSA levels and associated risk factors; applying genetic markers to PSA levels in order to provide a more accurate picture of a man's risk for prostate cancer and help avoid unnecessary biopsies; utilizing the Prostate Health Index to discern aggressive prostate cancer from slow-growing prostate cancer; and evaluating the genetic profile of prostate cancer to better identify high-risk patients, or those who may benefit most from prostate cancer screening.

The first study, Long-term Risk of Prostate Cancer is Directly Related to Baseline PSA, from the University of Texas Health Science Center at San Antonio, San Antonio, TX, suggests that men with low baseline PSA levels should not be annually screened for prostate cancer. Instead, they should be screened once every ten years. The researchers say this method could significantly reduce the cost of screening and the detection of low-grade prostate cancers that potentially have no health consequences. The study analyzed 2,923 men who did not have a history of prostate cancer. They were studied over a course of 7.4 years in order to determine whether baseline PSA could predict intermediate-term risk of prostate cancer.

The results showed that among the 2,923 men, 302 were diagnosed with prostate cancer during follow up. Men with baseline PSA (0.1-0.9 ng/mL) had a reduced risk of between 2 and 5 percent of being diagnosed with prostate cancer after tenyears and 90 percent of the cancers were low-risk. Men with higher PSA levels (2.3-9.9 ng/mL) had a 10 to 36 percent risk of cancer detection, and a 36 percent risk of cancer after 10 years.

The second study, Genetic Correction of PSA Can Reduce the Number of Men Diagnosed With Potentially Insignificant Prostate Cancer: Results From a Surgical and Active Surveillance Cohort, from Northwestern University Medical Center in Chicago, IL, suggest that a man's genetic risk for prostate cancer may reduce the number of biopsies and diagnoses of low-grade, low-risk prostate cancer. The researchers used genotypes of four genetic variants associated with serum PSA levels to study how genetic correction of PSA in men with known low-risk prostate cancer resulted in PSA results below biopsy thresholds. 

The results showed that among the surgical cohort, genetic correction of serum PSA was linked to a significantly reduced percentage of men meeting biopsy thresholds of greater than or equal to 2.5 ng/ml and greater than or equal to 4.0 ng/ml.Within the active surveillance cohort, similar analyses showed genetic correction of the four PSA genetic variants mayreduce the number of biopsies and prostate cancer diagnosis by 39 and 40 percent. Researchers said that by correcting for the effects of the PSA levels variants, ‘it may be possible to create a personalized PSA cutoff to more accurately identify individuals for whom biopsy is recommended.’

The third study was from Emory University School of Medicine, University of Michigan Medical School, Weill Cornell Medical College, and Johns Hopkins University School of Medicine, called Multicenter Evaluation of the Prostate Health Index (PHI) for Detection of Aggressive Prostate Cancer in Biopsy-Naïve. Researchers demonstrated how the Prostate Health Index (PHI) was more specific than total PSA or percent free PSA and could be used to decreaseunnecessary prostate biopsies. The study applied the PHI, which combines three known biomarkers (total PSA, percent free PSA and proPSA), to identify aggressive prostate cancer from slow-growing or no cancer in men who had not previously had biopsies. 

The results showed that PHI identifies aggressive prostate cancer with a better specificity compared to total PSA or percent free PSA and therefore, could be a useful tool in reducing the number of unnecessary, repeat prostate biopsies. It also showed that using the PHI, up to 41 percent of unnecessary prostate biopsies could be avoided.

The PHI test is currently available in many states throughout the country. The test is produced by Innovative Diagnostics Laboratory. It is better than the current PSA test because it uses three different prostate specific markers, which makes the test three times more specific for prostate cancer. This test gives doctors a more accurate picture in regards to what an elevated PSA level indicates as well as the probability of finding cancer on a prostate biopsy. 

The last study from the University of Texas Health Science Center, Wake Forest School of Medicine, University of California at San Diego, and Fudan University was The Prostate Genetic Score (PGS) Stratifies Baseline Risk of Prostate Cancer and Improves PSA Performance in the PLCO Trial. This study evaluated the genetic risk for prostate cancer in order to improve PSA screening methods for patients who are considered high-risk. Researchers collecteddata from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial and aggregated genomic data from 2,244 patients with either no cancer, non-aggressive or aggressive prostate cancer. The results showed that using the prostate genetic risk score could potentially help to better determine a person’s risk for prostate cancer as well as patients who may benefit from screening.