PHILADELPHIA (April 5, 2016) — The typical test used to gauge how well treatment works for patients with localized prostate cancer may not be as useful as many researchers thought, according to researchers from Fox Chase Cancer Center.
In a study recently published in the American Journal of Clinical Oncology, which is published by Wolters Kluwer, the researchers analyzed data from 12 randomized controlled trials of external beam radiation treatment for 6,884 patients with non-metastatic prostate cancer. These randomized controlled trials have been conducted around the world, from the 1980s until the 2010s. In addition to looking at outcomes with the prostate-specific antigen (PSA) test (the typical test used to gauge how well the treatments worked), they examined long-term outcomes, such as metastasis, death from prostate cancer, and death from any cause.
Researchers found little correlation between PSA outcomes and patient survival, leading researchers to question how useful the PSA test is.
“Currently, many clinical trials for prostate cancer patients are using PSA (the main marker we check after treatment) as a proxy for how long patients will survive. We found that our reliance on the PSA test, is not as useful as many researchers thought. Thus, our findings have broad implications for the design of future clinical trials and the interpretation of current and previous studies,” said lead study investigator Nicholas G. Zaorsky, MD, resident physician in radiation oncology at Fox Chase.
Moving forward, researchers may need to find a better detection method than the PSA test to determine how patients are progressing and a better method for determining which patients may be at risk for metastasis.