An electronic nose can sniff out prostate cancer - the second most common cancer in males - using urine samples, a new study has found.
Researchers in Finland have demonstrated that the eNose can successfully discriminate between prostate cancer and benign prostatic hyperplasia (BPH) by "sniffing" urine headspace (the space directly above the urine sample).
Prostate cancer is one of the leading causes of cancer death. The heterogeneity of prostate cancer makes it difficult to diagnose and predict tumour progression.
Both of the current cornerstones of diagnosis, ie digital rectal examination (DRE) and prostate specific antigen (PSA) have limitations, while ultrasound guided biopsies are costly, uncomfortable for the patient, and have a risk of infection.
Additionally, significant numbers of diagnosed prostate cancers are of low grade and will not cause symptoms or disease-specific mortality.
The eNose used in the new study is a device that consists of a cluster of nonspecific sensors. When the device is exposed to the sample, it produces a profile or a "smell print", researchers said.
"eNoses have been studied in various medical applications, including early detection of cancer, especially from exhaled air," said lead investigator Niku KJ Oksala, of the Department of Surgery, School of Medicine, University of Tampere and Department of Vascular Surgery, Tampere University Hospital, Finland.
"However, exhaled air is a problematic sample material since it requires good cooperation and technique from the patient and immediate analysis, while urine is simple to attain and store, and is therefore more feasible in clinical practice.
"Preliminary data suggested that detection of urologic malignancies from urine headspace was possible. Our own preliminary results on prostate cancer cells encouraged us to launch this prospective clinical study," Oksala said.
The eNose developed by Environics Inc, Mikkeli, Finland was tested on 50 patients who had been diagnosed with prostate cancer confirmed by biopsy, and 15 patients with BPH.
Both groups were scheduled for surgery. The patients provided urine samples before surgery and those with benign disease also provided samples three months after surgery to be used as a pooled control sample population.
Patients with prostate cancer underwent robotic assisted laparoscopic radical prostatectomy, while the benign disease group underwent transurethral resection of prostate.
Results with the eNose confirmed that using urine headspace, the eNose is able to discriminate prostate cancer from BPH. The eNose achieved a sensitivity of 78 per cent and specificity of 67 per cent.
The study was