PSA Testing Can Reduce Unnecessary Prostate Biopsies

Photo: Blood Collection

Separate study suggests combining
blood test with PSA can aid
cancer diagnosis;

Doctor Martin G. Sanda and his colleagues suggest that instead of using “one-size-fits-all” levels of Prostate-Specific Antigen (PSA) to determine who should have a biopsy, considering other factors such as prostate size can substantially improve the ability of PSA testing to identify aggressive prostate cancers for which treatment is warranted, while avoiding detection of indolent cancers that are better undiagnosed because they do not require treatment.

A second study led by Sanda suggests the presence or absence of genes commonly found in the urine of men, when combined with a PSA test, can also be used to determine whether a biopsy is necessary.

The new suggested approaches come as the United States Preventive Services Task Force expert panel concluded that current PSA-based prostate cancer screening saves few or no lives, but causes harm through treatment or further invasive testing such as biopsies. That is because prostate cancers can vary in aggressiveness and more men die of other causes aside from that cancer – and because the PSA test alone cannot determine how dangerous any particular cancer may be.

“The US Preventative Services Task Force threw the baby out with the bathwater by their blanket recommendation against prostate cancer screening,” says Sanda, noting that PSA screening can instead be refined to more selectively identify only aggressive cancer for which treatment is indicated by adjusting PSA results for other considerations such as family history, obesity, and prostate size.

Results from the multi-centre study that suggest that PSAD levels of less than 0.1 – in contrast to the unadjusted level of between 2.5 and 4 – can be a better benchmark of a potential cancer. The density, determined by a digital rectal exam, enables physicians to take into account other factors like benign prostatic hyperplasia, an enlargement of the gland that affects all men as they age.

Combining the PSAD with the digital exam, a look at the patient’s family history and a body mass index of 25 of less – the calculation used to define obesity – would avoid biopsy in approximately one-quarter of biopsy-eligible men, the researchers found.

“Urological practice, patient outcome and cost-effectiveness of health care would each benefit from new targeted strategies, such as nomograms (a predictive tool) that improve prediction of aggressive cancers, to enable selective identification of candidate for prostate biopsy that would improve the yield of clinically significant, histologically aggressive cancers warranting subsequent definitive treatment,” researchers say.; Source: Beth Israel Deaconess Medical Centre