Researchers from Hong Kong Baptist University (HKBU) and the Faculty of Medicine at The Chinese University of Hong Kong (CU Medicine) have jointly developed the Spermine Risk Score which, coupled with the use of a urine test, provides a non-invasive and more reliable method for the diagnosis of prostate cancer.
In a study conducted by the researchers, about 37% of the patients, who were ultimately found to have no prostate cancer, can avoid undergoing a prostate biopsy procedure. The findings have just been published in the scientific journal Prostate Cancer and Prostatic Diseases.
In search of a more reliable and non-invasive method for prostate cancer diagnosis, Professor Gary Wong Ka-leung, Professor and Head of the Department of Chemistry at HKBU, and Professor Ng Chi-fai and Dr Peter Chiu Ka-fung, Professor and Associate Professor respectively of the Division of Urology in the Department of Surgery at CU Medicine, have collaborated since 2014 to identify a new biomarker to supplement the PSA test. They found that prostate cancer patients in general have lower levels of spermine, a biogenic molecule in their urine, which offers a clue for the diagnosis of prostate cancer.
To investigate the diagnostic performance of spermine, the research team recruited 905 patients between 2015 and 2019 to participate in a study. All of them had elevated PSA levels and/or abnormal DRE, with a prostate biopsy scheduled.
Among the 905 patients, 600 of them who had PSA levels ranging from 4 to 20 ng/mL were included in the analysis. Their urine samples were collected before they underwent a biopsy procedure. The biopsy results showed that out of the 600 patients, 185 (30.8%) were diagnosed with prostate cancer.
At the same time, the urine samples of these 600 patients were also analysed. The results found that about 49% of the patients with spermine levels in the lowest quartile had prostate cancer, which was nearly triple the number of patients in the highest quartile (17%). The research team then used the urine spermine level figures and three other clinical parameters, namely DRE, PSA level and prostate volume, to develop the Spermine Risk Score, with the objective of offering a more accurate estimation of patients’ prostate cancer risk.
The higher the Spermine Risk Score, the greater the patient’s risk of developing prostate cancer. Only patients with Spermine Risk Scores higher than 6.2 will be advised to undergo the biopsy procedure. Based on Spermine Risk Scores calculated with data collected from the study, about 37% of the non-cancer patients could have avoided the biopsy procedure. Moreover, the negative predictive value of the Spermine Risk Score for significant prostate cancer is 95%, which means the chance of no significant cancer is 95% if the value of the Score is negative.
Dr Chiu concluded the findings by highlighting that, “This study confirms that urine spermine and the Spermine Risk Score are effective at identifying men at higher risk of prostate cancer and the test could help reduce the number of unnecessary biopsies.”
“It is the ﬁrst prospective study to investigate the efficacy of urine spermine in prostate cancer detection. It successfully demonstrated that the Spermine Risk Score, developed based on patients’ urine spermine levels and other clinical parameters, can serve as a novel and promising approach to address the limitations of the diagnostic methods currently in use,” said Professor Wong.
“Although there are a number of blood and urine adjuncts to guide prostate biopsy decisions in patients with elevated PSA levels, urine spermine is a convenient non-invasive test that doesn’t require another blood test or attentive DRE before specimen collection. Thus it minimizes any potential complications associated with the procedures,” said Professor Ng.