Prostate Cancer

Prostate Cancer - DiaPat®-PC test

A positive PSA test (>4 ng/ml) often results in a prostate biopsy. Inflammations, bleeding or tumour spreading are frequent negative side effects of this procedure.
The DiaPat®-PC test enables identification of patients not harbouring prostate cancer with high probability that therefore should not undergo prostate biopsy. Analysing the urine proteome, DiaPat®-PC test is a non-invasive, riskless and highly reliable diagnostic method.
PSA is of limited value in the discrimination of benign and malignant prostate conditions and results in 70% false positive test results. DiaPat®-PC test detects those patients having a positive test result, i.e. tumour is indicated when in fact no cancer is present and consequently can help to reduce the number of biopsy interventions and the related risks.

 

Advantages of the DiaPat®-PC test

• Painless (non-invasive urine sample)
• Riskless sampling
• Reliable (improved accuracy compared to PSA)

 

Risk factors:

• Advanced age (>50)
• Family history of cancer
• Unbalanced diet or excess weight
• Smoking
• Frequent exposure to cancer-causing chemicals (e.g. solvents, oil, petrol)

Since the advent of prostate specific antigen (PSA) screening, a significant number of men have had a PSA performed and this led to a considerable increase in the number of diagnosed cases. The inaccuracy of PSA screenings leads to estimated 800,000 unnecessary prostate biopsies per year in the United States.

In clinical trials, the DiaPat®-PC test showed high accuracy in detection of prostate cancer with sensitivity of 90-86% and specificity of 61-59% in patients with PSA between 2 and 20 ng/ml, hence a negative predictive value of 91-93%. This represents a major advancement over serum PSA and determination of free PSA, with a positive predictive value of 25-30%. The non-invasive DiaPat®-PC test is a highly valuable complement of prostate cancer diagnostics for patients with suspicious PSA and/or digital-rectal examination.

DiaPat - PC
Urine sample Accurate tumour detection in 9 out of 10 cases1
PSA - Test	Biopsy
Bloodsample	Tissue samples are collected using 6- 12 hollow needles
≈ 70% of positive test results are false positive ((tumour is indicated when in fact no cancer is present)2	In ≈ 30% of patients with cancer needles miss the tumour (false negative biopsy)3

1 Dan Theodorescu et al., 2008, PROTEOMICS Clinical Applications
2 Schroeder et al., 2009, NEJM
3 Anastasiadis et al., 2006, Eur. Urol.

Compared to invasive diagnostic methods the advantages of the DiaPat®-PC test are obvious:

The DiaPat®-PC test does not affect everyday life, because it does not require any pre-treatment or aftercare (e.g. taking antibiotics) as invasive biopsy methods. The collection of a simple urine sample represents a convenient and time-efficient method for both patients and physicians.

In case of a negative DiaPat®-PC test result, its high negative predictive value of >90% allows watchful waiting and the DiaPat®-test can be repeated at any time for control purposes. A positive test result provides a clearer indication for a biopsy than PSA testing alone.

References:

Schiffer E.
Biomarkers for prostate cancer.
World J Urol 2007; 25: 557-562

Theodorescu D, Schiffer E, Bauer HW et al.
Discovery and validation of urinary biomarkers for prostate cancer.
Proteomics Clin Appl 2008; 2: 556-570

Marshall S.
Comments on the article "Biomarkers for prostate cancer" by Eric Schiffer.
World J Urol 2009; 27: 577-578

 

Prevalence

The worldwide incidence of prostate cancer (PCa) ranks third among cancers in men. The occurrence of prostate cancer strongly depends on age. Prostate cancer develops most frequently in men over the age of 50. The mean age of onset is 72 years. Worldwide, several hundred thousand men die each year from prostate cancer. It is essential to detect prostate cancer at early stages, before cancer will spread to other organs, forming secondary tumours. At early stages, it is possible to cure prostate cancer in 80-90% of cases with only minimal or short-term treatment side effects. Following figures stress the importance of early diagnosis (www.urotoday.com):

 

	Incidence	Prevalence	Mortality
Germany	44,383	162,895	12,158
North America	257,943	1,114,247	36,447
Europe (exept D)	180,844	580,475	70,908