Detection of prostate cancer by sialic acid level in patients with non-diagnostic levels of prostate-specific antigen

Introduction

Ideally, there will be reproducible markers easily and non-invasively available to test for malignancy, or alternative procedures when there is no accurate marker available. For prostate cancer, one of the most common cancers in men, levels of prostate-specific antigen (PSA) lack specificity and sensitivity for the determination of malignancy when they fall within a range of values termed the ‘grey zone’.

Objective

To examine the predictive value of sialic acid in prostate neoplasms.

Study design

In our study of diagnostic accuracy we recruited 70 men complaining of urinary symptoms who presented in the urology department as outpatients or inpatients. All patients were checked with biopsy and pathology in order to relate benign and malignant lesions of the prostate to levels of sialic acid, a member of a family of acetylated products of neuraminic acid, which has so far proved to be a very sensitive and accurate marker of malignancy.

Results

The sialic acid level was found to be elevated in patients with prostate cancer (mean 75.06 ± 10.4 mg/dl) and reduced in patients with benign prostate hyperplasia (mean 57.086 ± 8.7 mg/dl) (p < 0.01); it had a sensitivity of 86% and specificity of 84% in diagnosing malignancy.

Conclusion

Sialic acid can be used as an adjunct in predicting prostate malignancy when PSA values fall in the grey zone.