Genetic Test Aims to Prevent Over-Treatment, Lower Care Costs in Bladder Cancer

A new test that identifies which bladder cancer tumors will become invasive could help reduce health care costs and over-treatment in patients, according to a study recently published in the journal Clinical Cancer Research.

While the disease is less common in women, the American Cancer Society notes that bladder cancer is the fourth most common cancer in men. Most cases involve non-invasive polyp-like lesions or tumors in the bladder that can be removed via a routine procedure. Other times, however, the cancer spreads to the surrounding muscle and becomes a bigger problem.

Not knowing if a cancer will become invasive is one of the biggest problems with bladder cancer, according to Todd Waldman, M.D., Ph.D., professor of oncology at Georgetown Lombardi Comprehensive Cancer Center. In an interview with CURE, Waldman explained, “They have these tumors that are taken out all the time, and most of the time this is fine. But some of the time, it comes back as a much worse tumor which will eventually kill you.”

To avoid these negative outcomes, doctors tend to take an overly cautious — and expensive – approach to post-surgery monitoring that involves frequent invasive cystoscopies. Additionally, patients with high-risk, non-muscle-invasive cases are also sometimes given Bacillus Calmette-Guérin (BCG) therapy, although it is not always clear who should receive this treatment.

After his previous research identified the STAG2 gene as key to the development of potentially deadly bladder tumors, Waldman, along with a team of researchers from the US and Denmark, set out to create a test that checks for STAG2, which will, in theory, identify which tumors will eventually recur and turn deadly.

The resulting diagnostic test is easy to use and, as Waldman’s study shows, 1.9 times more accurate at predicting the tumors that are likely to progress and 2.4 times more accurate in identifying the STAG2 gene.

Using the knowledge gleaned from this test, doctors will be able to adjust treatment plans accordingly and avoid costly, invasive over-treatment. “It gives people [clinicians] extra information so they can decide how frequently to look in a patient’s bladder to see if it’s come back, and whether the patient needs that kind of therapy to keep it from coming back,” said Waldman.

As for whether the science behind this test could translate to tests for other types of cancer, Waldman says it is possible, as the STAG2 gene is important to several other cancer types, including some types of leukemias and Ewing sarcoma, although further study would be needed.

“Yes, we developed this test for bladder cancer, but in principle it could be applied to other tumor types as well, we just don’t know if it’s as predictive of those other tumor types,” said Waldman.

Moving forward, Waldman explained the next steps involve further study to bring the test to more patients. “If it [the test] proves itself in a separate study to also be useful, then there’s a better chance that it will be integrated into routine clinical practice,” he said.