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!
New study: How does Europe become a leading player for software and IT services?
03.04.2017 | Fraunhofer-Institut für System- und Innovationsforschung (ISI)
Reusable carbon nanotubes could be the water filter of the future, says RIT study
30.03.2017 | Rochester Institute of Technology
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Life Sciences
28.04.2017 | Life Sciences
28.04.2017 | Life Sciences