Egyptian biochemists say a pair of proteins could potentially detect bladder cancer earlier and help doctors monitor the effectiveness of treatments. As with all cancer, early detection and the right choice of treatment are key to survival for diabetics and others with bladder cancer.
Researchers from the Faculty of Pharmaceutical Sciences and Pharmaceutical Technologies at Future University in Cairo tested the sensitivity and specificity of angiogenin and clusterin, proteins associated with important cellular processes. Clusterin is linked to apoptosis, the natural death of cells that often malfunctions in cancer cases. Angiogenin is an amino acid protein that stimulates the formation of new blood vessels (angiogenesis) needed to form and grow bladder tumors.
Currently, bladder cancer is usually detected by a combination of an imaging procedure called cystoscopy, which involves putting a camera into the bladder, and cytology to look for cancer cells in urine.
But researcher Marwa Shabayek and colleagues say testing for angiogenin and clusterin in the urine, along with standard cytology, has the potential to dramatically improve bladder cancer diagnosis and treatment. “Combined use of the cytology with the studied biomarkers can improve the sensitivity for detecting bladder cancer, and may be very useful in monitoring the effectiveness of antiangiogenic and apoptotic therapies in bladder cancer,” writes Shabayek in Pathology and Oncology Research.
The team reached that conclusion after studying 50 patients with malignant bladder cancer, 20 with a non-malignant type of bladder cancer, and 20 healthy subjects. The team found an overall sensitivity ( number of correct positive results) for bladder cancer of 66% for angiogenin and 70% for clusterin. Both biomarkers were even more accurate in their specificity, the ability to correctly indicate which patients did nothave bladder cancer.
When the two markers were combined with urine cytology, they were able to correctly identify bladder cancer 88% of the time, which indicates better sensitivity than cytology alone or in combination with either marker separately. The study suggests that more information can be gained from urine testing in bladder cancer cases than doctors are currently gathering.
An estimated 74,000 Americans were diagnosed with bladder cancer in 2013, many of them diabetics. Several studies have indicated that the risk of bladder cancer in diabetics is increased by the drug Actos, a blood glucose regulator. Concern over the possible link between Actos use and bladder cancer has prompted several countries to ban the drug.
Shabayek, MI et al, “Diagnostic evaluation of urinary angiogenin (ANG) and clusterin (CLU) as biomarkers for bladder cancer”, April 3, 2014, Pathology and Oncology Research, Epub ahead of print