Cedars-Sinai investigators have identified a subtype of cancer cells that could help predict how bladder cancers respond to certain therapies, it was announced Wednesday.
The findings likely will guide physicians toward the most effective treatment for patients with that cancer type and potentially pave the way to discover new drug therapies, according to Cedars-Sinai.
Of the roughly 83,000 cases of bladder cancer diagnosed in the United States each year, about 25% are muscle-invasive, meaning the cancer has spread to muscles in the bladder wall and is more likely to spread farther to lymph nodes and other organs. While the five-year average survival rate for cancer confined to the bladder is about 69%, that figure drops to 37% or below if the cancer spreads.
In recent years, the gold-standard treatment for muscle-invasive bladder cancers has been neoadjuvant chemotherapy, which helps shrink the tumors prior to surgical removal of the bladder. Immune checkpoint therapy — using the patient’s own immune cells to battle tumors — has emerged as another therapeutic option for patients whose cancer has spread beyond the bladder or those who can’t tolerate chemotherapy or major surgery.
“Neoadjuvant chemotherapy and immune checkpoint therapy have revolutionized bladder cancer management,” said Dr. Dan Theodorescu, director of Cedars-Sinai Cancer and co-senior author of the study, which was published online by Nature Communications. “However, determining which patients would benefit most from each type of therapy remains a major challenge.”
With other types of cancer, particularly breast cancer, classifying whole tumors according to their genetic fingerprints has helped physicians choose targeted treatments that improve outcomes, Theodorescu explained. But this type of stratification has been less satisfactory for bladder cancer.
“When you do genetic profiling of a whole tumor, you’re looking at all the proteins that are expressed,” Theodorescu said. “That tissue includes cancer cells, immune cells, cells from the connective tissue and the lining of blood vessels, and others. My hypothesis was that if we looked at the expression of individual cells within the bladder tumor, we could develop more effective tools to guide treatment and perhaps even find novel targets for future therapies.”