Human epidermal growth factor receptor 2 (HER2) is a very important biomarker in breast cancer therapy, and a new study has revealed that it may also be a very important target for treatment in some patients with bladder cancer. Researchers at the Mayo Clinic have found an application for HER2 in the treatment of micropapillary urothelial carcinoma (MPUC); the presence of HER2 amplification may be associated with particularly aggressive tumors.
“Potentially, it is very promising,” said study investigator John Cheville, MD, a pathologist at the Mayo Clinic in Rochester, MN, in an interview with ChemotherapyAdvisor.com. “HER2 amplification has been found before, but we were surprised that it was associated with a more aggressive clinical course.”
Dr. Cheville said that trastuzumab, which has been shown to be effective in HER2-positive breast cancers, may result in effective therapy against some bladder cancers; therefore, screening for HER2 amplification may be appropriate for patients with MPUC. He and his research team found that HER2 amplification is more frequent in MPUC than in typical urothelial carcinoma.1 The investigators also discovered that patients with MPUC who have HER2 amplification had worse cancer-specific survival than those who did not have HER2 amplification.
Dr. Cheville explained that, although HER2 amplification occurs in approximately 20% to 30% of breast cancer cases, it is uncertain what percentage of bladder cancers may have HER2 amplification and would subsequently benefit from HER2-targeted therapy. Men are almost four times more likely to be diagnosed with bladder cancer, and according to The American Cancer Society, 72,570 new cases of bladder cancer were estimated for 2013 (~54,610 in men and ~17,960 in women).2
Old Medicine Finding New Use
Because there is a great need for new chemotherapy combinations for bladder cancer, one new approach involves taking an “old” drug off the shelf and adding it to the treatment armamentarium. Emetine dihydrochloride (Ipecac syrup), once stocked in medicine cabinets in case of accidental poisoning, is now showing promise for treating bladder cancer. According to researchers at Loyola University Medical Center, although emetine dihydrochloride is no longer recommended to induce vomiting because of its potential for harm,3 it can inhibit the proliferation of bladder cancer cell lines.4 Their study, recently published in the Journal of Urology, showed that emetine dihydrochloride alone and in combination with cisplatin, primarily induced tumor cell growth arrest but not apoptosis, thus making normal urothelial cells relatively resistant to the treatment.