Patients whose small acoustic neuroma tumors are being watched but not treated with surgery or radiation will be offered a new treatment option at the UC Brain Tumor Center: aspirin.
Ravi Samy, MD, FACS, an ear, nose and throat surgeon and Director of the Adult Cochlear Implant Program at the UC Neuroscience Institute, now plans to offer aspirin to patients who are undergoing observation for small, asymptomatic acoustic neuromas. The change is the result of a study published in the February issue of the journal Otology and Neurotology by researchers from Harvard University, the Massachusetts Institute of Technology and affiliated hospitals. The researchers demonstrated that aspirin intake may correlate with a halt in the growth of acoustic neuromas.
An acoustic neuroma, also known as a vestibular schwannoma, is a tumor that grows from the sheath covering the vestibulocochlear nerve, which is responsible for relaying hearing and balance signals from the inner ear to the brain. The tumor typically causes hearing loss, dizziness and ringing in the ear (tinnitus). About 3,000 new cases are diagnosed in the United States each year, making acoustic neuroma the fourth most common brain tumor.
Although benign, an acoustic neuroma can cause damage to other nerves and the brain if it grows too large.
Dr. Samy says that although the Harvard-MIT study was small, its findings are impressive and intriguing, suggesting that “for the first time we may be able to offer an inexpensive, anti-inflammatory medication that could potentially reduce the growth rate of acoustic neuroma and delay the need for surgery or radiation therapy.”
The majority of patients who undergo surgery or radiation eventually lose their hearing in the affected ear.
The aspirin therapy could be especially valuable for patients with “incidental acoustic neuromas” that are discovered during an MRI scan but do not yet cause symptoms. These patients could be prescribed aspirin and told to return for a follow-up MRI at a later date, Dr. Samy says.
Coincidentally, the average age of diagnosis for people who develop an acoustic neuroma is between 40 and 50, approximately the same age as adults who are prescribed aspirin to reduce their risk of heart attack and stroke.
The aspirin study was a retrospective analysis of 689 people. It compared the growth rates of acoustic neuromas in patients who said they had taken aspirin to the growth rates of tumors in patients who said they had not taken aspirin.
The next step for researchers, Dr. Samy says, is a prospective, multi-center study with patients randomly assigned to receive a specific dose of aspirin or a placebo. That type of study would help confirm the retrospective study’s results while helping researchers arrive at an optimal dose.
“At this point, we don’t know what the ideal dose would be,” Dr. Samy says. “But I have started telling my patients that aspirin therapy is an option. I don’t want them to think it is guaranteed to work, but I tell them it might be worth a try.”
Risks associated with taking aspirin include stomach ulcers and a greater tendency to bleed. A patient who takes aspirin and requires surgery will have to discontinue taking aspirin ahead of time to avoid an elevated risk of bleeding during surgery.
Dr. Samy, who also sees patients at Cincinnati Children’s Hospital Medical Center, would like to see the therapy tested in children with neurofibromatosis 2 (NF2), a genetic disorder in which tumors form on the nerves of the brain and spine. Children with NF2 often develop acoustic neuromas in both ears (bilateral), putting them at high risk for deafness.
Treatment options for these children, Dr. Samy says, are limited to intravenous Avastin therapy, which is expensive and offers only short-term benefits. “We need to study aspirin’s potential to inhibit vestibular schwannoma across all age groups,” he says.
— Cindy Starr