Study seeks to ease ‘chemobrain’ for cancer patients
August 24, 2015 | Nancy Humphrey
Many women who receive chemotherapy for breast cancer report problems with their thinking, memory and attention after treatment.
And as the survival rates for breast cancer increase, so do these issues associated with chemotherapy.
Paul Newhouse, M.D., professor of Psychiatry and Jim Turner Professor of Cognitive Disorders, and graduate student Jennifer Vega in Vanderbilt University Medical Center’s Center for Cognitive Medicine, are conducting a new treatment research study for cognitive impairments, commonly called “chemobrain,” that may occur after chemotherapy for breast cancer.
The center is seeking female breast cancer survivors to participate in a six-week treatment study that seeks to determine whether a nicotine patch has a positive effect on cognitive symptoms which may persist for months or years following chemotherapy, and may suggest that the treatment may have changed the way the brain functions. For many women, however, the cognitive issues resolve after completing chemotherapy.
Nicotine is a naturally occurring substance found in tobacco leaves, tomatoes, potatoes, eggplant, teas, peppers and other members of the nightshade plant family. There are receptors in the brain that are specific for nicotine and these receptors and nerve cells are crucial for functions like learning and memory. The theory is that nicotine binds to those receptors, thereby protecting and activating them.
The non-addictive nicotine replacement therapy patch has been studied in a number of disorders, such as attention deficit hyperactivity disorder (ADHD) and Mild Cognitive Impairment (a precursor condition to Alzheimer’s disease) and has shown positive results.
“There is real possibility, based on preliminary research, that nicotine therapy may be helpful for those women who believe their memory and attention have been affected by chemotherapy,” Newhouse said. “We all look forward to learning the outcome of this study and hope the results are positive and helpful to this group of women.”
Forty women who are one- to five-years post chemotherapy will be enrolled in the double-blind study (neither the participant nor those conducting the study know whether the patient is getting the actual nicotine patch or a placebo). Half will receive the nicotine patch and half the placebo, and will wear the patch for six weeks, with an additional two weeks to taper down the medication.
Participants must be nonsmokers for at least the past five years and be between the ages of 35 and 80. Vega said that nicotine has been slapped with a bad reputation because of its association with smoking.
“This is nicotine by itself and not paired with other chemicals. Studies have looked at nicotine patches and there’s no evidence that they are addicting or cause cancer without the other components found in tobacco,” she said.
Participants in the trial begin with the smallest dose of nicotine patch available (7 mg), but cut in half, and work up to 21 mg.
Patients participating in studies with a nicotine patch also don’t experience the nicotine “rush” or the cravings and withdrawal symptoms associated with quitting.
Vega said that about 90 percent of women have some cognitive issues during chemotherapy, and most go back to pre-chemo level of functioning by a year. But for 30-35 percent, the cognitive issues persist.
“We’re looking for improvement during this time. If we see positive results, hopefully it will lead to a multi-center study.”
Vega said the findings will be both subjective (asking the women how they believe their cognition is functioning) and objective (measuring reaction time and conducting memory tests).
“Most of the literature is based on breast cancer survivors, and that’s why we’re focusing on that population,” Vega said. “What we don’t know is if something like this puts you more at risk for cognitive decline like Alzheimer’s years down the road.”
The study is funded through the Vanderbilt Institute for Clinical and Translational Research.