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FDA approves first home-use tumor marker
Of the many cancer tests currently on the market, the BTA stat test for recurrent bladder cancer has achieved a unique position as the first tumor marker test to receive FDA approval for home use. Manufactured by Bion Diagnostic Sciences Inc. (Redmond, WA) and available by prescription, the BTA stat test allows recovering patients to monitor their risk for cancer recurrence. Bladder cancer is one of the most common cancers in both men and women. After initial treatment, there is a 75% chance of recurrence, which necessitates regular testing and lifelong management.
Similar in format to the common home pregnancy test, the BTA stat test is a lateral flow immunoassay that takes only a few minutes to detect tumor antigens from a few drops of urine. The solid-phase monoclonal antibody reacts with human complement factor H–related protein (hCFHrp), which is excreted in urine by bladder cancer cells. The familiar appearance of a colored line in the membrane window indicates a positive result.
According to Bion's regulatory affairs manager, Alicia Moffat, "The test is intended as an adjunct to cystoscopy, an invasive procedure traditionally used to monitor patients with a history of bladder cancer." Based on the outcome of the BTA stat test, physicians can opt to use either a rigid or flexible cystoscope. The rigid cystoscope can remove tumors during the examination, but requires the patient to undergo general anesthesia. If warranted by negative results from the BTA stat test, the exploratory, flexible cystoscope can be used instead. "Using the flexible cystoscope requires only a local anesthetic, which is obviously more desirable for both the patient and physician," adds Moffat.
Current protocols for patient management recommend using the BTA stat test every three months in the first year after initial treatment and every six months thereafter.—Gary Woo
