Electric nose could be used to detect prostate cancer by smell

Technology can discriminate between prostate cancer and benign prostatic hyperplasia in urine samples.

Prostate cancer is the second most common cancer in males and is also a leading cause of cancer death. Current methods of diagnosis include a digital rectal examination and testing for prostate-specific antigen (PSA), both of which have limitations. Alternative diagnosis can be done through an ultrasound-guided biopsy, but this is costly, can be uncomfortable for the patient and does not always detect cancer.

Now, a team of scientists from Finland have recently reported a novel, noninvasive technique that can detect prostate cancer using an electric nose. The proof-of-principle study successfully discriminated between prostate cancer and benign prostatic hyperplasia by “sniffing” urine headspace, that is, the space directly above the urine sample.

Lead investigator Niku K.J. Oksala, from Tampere University Hospital (Tampere, Finland) commented, “Electric noses have been studies in various medical applications, including early detection of cancer, especially from exhaled air. 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.”

The electric nose used (ChemPro^® 100-eNose [Environics Inc., Mikkeli, Finland]) consists of a cluster of nonspecific sensors, and when the device is exposed to the sample it produces a profile. In the present study, the nose was tested on 50 patients who had been diagnosed with prostate cancer confirmed by biopsy, and 15 patients with benign prostatic hyperplasia. Results revealed that the nose achieved a sensitivity of 78%, specificity of 67% and AUC of 42.0.

“The performance with the electric nose matches that of PSA results in previous literature and the results are achieved rapidly and in a completely noninvasive manner,” explained Oksala. “PSA is known to correlate positively with prostate volume, which is a potential source of diagnostic error when comparing prostate cancer with benign disease…further studies are now warranted to enhance current technology and to identify the molecules behind the distinct odors.”

Sources: Roine A, Veskimäe E, Tuokko A et al. Detection of prostate cancer by an electric nose: a proof of principle study. J Urol DOI:10.1016/j.juro.2014.01.113 (2014) (Epub ahead of print); Electric nose sniffs out prostate cancer using urine samples.