Cancer survivors, take note. The mental fog and forgetfulness of "chemo brain" are no figment of your imagination.
A new UCLA study shows that chemotherapy causes changes to the brain's metabolism and blood flow that can linger at least 10 years after treatment. Reported Oct. 5 in the online edition of the journal Breast Cancer Research and Treatment, the findings may help to explain the disrupted thought processes and confusion that plague many chemotherapy patients.
"People with 'chemo brain' often can't focus, remember things or multitask the way they did before chemotherapy," explained Dr. Daniel Silverman, head of neuronuclear imaging and associate professor of molecular and medical pharmacology at the David Geffen School of Medicine at UCLA. "Our study demonstrates for the first time that patients suffering from these cognitive symptoms have specific alterations in brain metabolism."
Silverman and his colleagues used positron emission tomography (PET) to scan the brains of 21 women who had undergone surgery to remove breast tumors five to 10 years earlier. Sixteen of them had been treated with chemotherapy regimens near the time of their surgeries to reduce the risk of cancer recurrence.
The team compared PET images evaluating the chemotherapy patients' brain function to PET scans from five breast-cancer patients who underwent surgery only, and 13 control subjects who did not have breast cancer or chemotherapy.
As the women performed a series of short-term memory exercises, the UCLA team measured blood flow to their brains. The researchers also ran a scan of the patients' resting brain metabolism after the women finished the exercises.
"The PET scans show a link between chemo-brain symptoms and lower metabolism in a key region of the frontal cortex," explained Silverman, a member of UCLA's Jonsson Comprehensive Cancer Center. "We found that the lower the patient's resting brain metabolism rate was, the more difficulty she had performing the memory test."
The scans revealed that blood flow to the frontal cortex and cerebellum spiked as the chemotherapy patients performed the memory tests, indicating a rapid jump in these brain regions' activity level.
"The same area of the frontal lobe that showed lower resting metabolism displayed a substantial leap in activity when the patients were performing the memory exercise," said Silverman. "In effect, these women's brains were working harder than the control subjects' to recall the same information."
Finally, the researchers discovered that women who underwent hormonal therapy in addition to chemotherapy displayed changes to their basal ganglia, a part of the brain that works to bridge thought and action. On average, these women showed an 8 percent drop in resting metabolism in this brain region.
"Chemotherapy used to be prescribed primarily to treat metastatic disease," observed Silverman. "Now it's common for doctors to administer chemotherapy to patients near the time of surgery to prevent metastasis. As many of these patients become long-term survivors, doctors are recognizing lasting side-effects of chemotherapy, and, in particular, the kind of chemo-brain symptoms we are studying."
"Our findings suggest that PET scans could be used to monitor the effects of chemotherapy on brain metabolism," he added. "The approach could be easily added to current whole-body PET or PET/CT scans already being used to monitor patients for tumor response to therapy."
Although chemo brain is an acknowledged phenomenon, doctors don't know what mechanisms cause it. More studies are needed to uncover how the damage occurs and whether modification of chemotherapy drugs could prevent it.
The National Cancer Institute recently awarded a five-year grant to oncologist Dr. Patricia Ganz, who is organizing a long-term study on chemo brain of a larger group of breast-cancer survivors with Silverman and their colleagues at UCLA.
More than 211,000 new cases of breast cancer are diagnosed a year, making it the most common cancer in women. Experts estimate that at least 25 percent of chemotherapy patients are affected by chemo brain, and a recent study by the University of Minnesota reported an 82 percent rate.
Elaine Schmidt | EurekAlert!
A sudden drop in outdoor temperature increases the risk of respiratory infections
11.01.2017 | University of Gothenburg
Urbanization to convert 300,000 km2 of prime croplands
27.12.2016 | Mercator Research Institute on Global Commons and Climate Change (MCC) gGmbH
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
18.01.2017 | Power and Electrical Engineering
18.01.2017 | Materials Sciences
18.01.2017 | Life Sciences