Rapid Results: MSK Researchers Link Genetic Mutation to Rare Bladder Cancer

Two initiatives unique to Memorial Sloan Kettering — MSK-IMPACT™, a groundbreaking genetic test, and Cycle for Survival, a nationwide series of indoor cycling events that raises money for rare cancer research — have helped produce an important discovery about a rare, aggressive form of bladder cancer in a short time. The finding will help guide treatment decisions and shed light on how the disease develops so that researchers can design better therapies.

The disease, plasmacytoid variant carcinoma, accounts for 2 percent of muscle-invasive bladder cancer cases in the United States each year — approximately 300 people. It spreads early, recurs quickly after surgery, and is resistant to chemotherapy.

MSK researchers have now identified a mutation in a gene called CDH1 that plays a central role in triggering the runaway invasion that is the hallmark of this cancer.

 “Prior to this study, we did not understand why this form of bladder cancer was so aggressive,” says David Solit, Director of the Marie-Josée and Henry R. Kravis Center for Molecular Oncology (CMO). Dr. Solit led the research, which was recently published in Nature Genetics. “This discovery is a major step toward improving the treatment of patients with this rare cancer.”

Fast Research Results

This finding was largely made possible by two innovative MSK programs. The first, MSK-IMPACT^™, is a genetic test now used routinely to analyze tumors in MSK patients with advanced cancers. MSK-IMPACT helps clinicians understand what makes individual tumors grow and spread and is used by oncologists to match patients with appropriate standard therapies or investigational clinical trials. The diagnostic test, now entering its third year, recently reached a milestone when it sequenced its 10,000th patient tumor.

The second initiative is Cycle for Survival, a philanthropic program that raises money for rare-cancer research through indoor cycling events held in multiple cities each year in February and March. Since 2007, Cycle for Survival has raised more than $100 million to support research projects focused on identifying treatments for rare cancers, which make up almost 50 percent of all cancers.

Dr. Solit is an enthusiastic supporter of and participant in Cycle for Survival. He says this discovery represents a striking example of how quickly fund-raising for rare cancers can produce significant advances. The research took only a few years from its start to the publication of the findings.

“This study highlights what is so special about Cycle for Survival,” he explains. “It supports the kind of research that is very rarely funded by the National Institutes of Health because it concerns a very rare tumor type. Unfortunately, the patients who have this disease do very poorly, and new treatments are desperately needed.”

The Telltale Mutation

For the study, the researchers performed genetic sequencing on plasmacytoid variant bladder tumors and found that most had a mutation in CDH1. Many of the tumors analyzed in the study had been sequenced by MSK-IMPACT as part of the patients’ clinical care. The test looks for abnormalities in more than 400 of the most important cancer-related genes.

Dr. Solit emphasizes the importance of MSK-IMPACT’s contribution to the research.

“Tumor sequencing is rapidly changing the way cancers are diagnosed and patients are treated,” Dr. Solit says. “Now that we’ve identified this critical disease-causing mutation, we can correctly classify the disease earlier in the patient’s treatment course and potentially direct such patients to investigational approaches. If a patient has the CDH1 mutation, we know there will be a very high risk of the cancer returning after surgery, so that’s a strong argument for adding additional therapy around the time of surgery.”

Cause for Optimism

One potential treatment that could benefit this patient group is a new immunotherapy drug called atezolizumab that is showing great promise against bladder cancer. A recent report in the journal Lancet describes encouraging results from a clinical trial led by MSK medical oncologist Jonathan Rosenberg.

The same type of drug has already proven effective against several other cancers, including melanoma and lung and kidney cancers. If approved, this would be the first new therapeutic advance for metastatic bladder cancer in more than 25 years.

“This new form of immunotherapy is something that we would want to try early in patients with plasmacytoid variant bladder cancers,” Dr. Solit says. “In addition, our genetic research has revealed other co-occurring mutations that possibly could be targeted with new or existing drugs. Going forward, we hope Cycle for Survival funding for similar projects investigating other rare cancers will allow us to replicate this approach.”