Research suggests 'chemo brain' may involve neurophysiological change

April 19, 2013 by Shaun Mason

(Medical Xpress)—For many years, breast cancer patients have reported experiencing difficulties with memory, concentration and other cognitive functions following cancer treatment. Whether this mental "fogginess" is psychosomatic or reflects underlying changes in brain function has been a bone of contention among scientists and physicians.

Now, a new study led by Dr. Patricia Ganz, director of cancer prevention and control research at UCLA's Jonsson Comprehensive Cancer Center, demonstrates a significant correlation between poorer performance on neuropsychological tests and in post-treatment, early-stage patients—particularly those who have undergone combined chemotherapy and radiation.

"The study is one of the first to show that such patient-reported —often referred to as 'chemo brain' in those who have had chemotherapy—can be associated with neuropsychological test performance," said Ganz, who is also a professor of health policy and management at UCLA's Fielding School of Public Health and a professor of medicine at the David Geffen School of Medicine at UCLA.

The study was published April 18 in the online edition of the Journal of the National Cancer Institute and will appear in an upcoming print edition of the journal.

Ganz and her colleagues looked at 189 breast cancer patients, who enrolled in the study about one month after completing their initial breast cancer treatments and before beginning endocrine hormone-replacement therapy (70 percent planned to undergo hormone therapy). Two-thirds of the women had had breast-conserving surgery, more than half had received chemotherapy, and three-quarters had undergone . The average age of study participants was 52.

Because cognitive complaints following cancer treatment have often been associated with anxiety and depressive symptoms, limiting confidence that "chemo brain" and similar difficulties reflect a cancer treatment toxicity, the researchers excluded women with serious depressive symptoms. They also took careful account of the cancer treatments used and whether or not menopause and hormonal changes could be influencing the cognitive complaints. A sample of age-matched healthy women who did not have breast cancer was used as a control group.

The researchers provided a self-reporting questionnaire to the women and found that those with breast cancer reported, on the whole, more severe complaints than normal; 23.3 percent of these patients had higher complaints about their memory, and 19 percent reported higher complaints about higher-level cognition (problem-solving, reasoning, etc.). Significantly, those breast who reported more severe memory and higher-level cognition problems were more likely to have undergone both chemotherapy and radiation.

While earlier studies had not identified a consistent association between cognitive complaints and neuropsychological testing abnormalities, the UCLA research team found that even when patients reported subtle changes in their memory and thinking, neuropsychological testing showed detectable differences.

In particular, they discovered that poorer performance on the neuropsychological test was associated both with higher levels of cognitive complaints and with combined radiation-and-chemotherapy treatment, as well as with symptoms related to depression.

"In the past, many researchers said that we can't rely on patients' self-reported complaints or that they are just depressed, because previous studies could not find this association between neuropsychological testing and cognitive complaints," Ganz said. "In this study, we were able to look at specific components of the cognitive complaints and found they were associated with relevant neuropsychological function test abnormalities."

The findings are part of an ongoing study that seeks to examine the extent to which hormone therapy contributes to memory and thinking problems in breast cancer survivors, and this pre-hormone therapy assessment was able to separate the effects of initial treatments on these problems. Earlier post-treatment studies of were difficult to interpret, as they included women already taking hormone therapy.

"As we provide additional reports on the follow-up testing in these women, we will track their recovery from treatment, as well as determine whether hormone therapy contributes to worsening complaints over time," Ganz said.

Explore further: Breast cancer survivors struggle with cognitive problems several years after treatment

More information: jnci.oxfordjournals.org/conten … djt112.full.pdf+html

Related Stories

Breast cancer survivors struggle with cognitive problems several years after treatment

December 12, 2011
A new analysis has found that breast cancer survivors may experience problems with certain mental abilities several years after treatment, regardless of whether they were treated with chemotherapy plus radiation or radiation ...

First study on long-term cognitive effects of breast cancer CMF chemotherapy finds subtle impairment

February 27, 2012
Dutch investigators have reported that women who received CMF chemotherapy (a combination regimen including the drugs cyclophosphamide, methotrexate, and 5-fluorouracil) for breast cancer between 1976 and 1995 scored worse ...

Stress contributes to cognitive declines in women with breast cancer, researcher says

April 11, 2012
Women undergoing treatment for breast cancer can experience cognitive declines, such as decreased verbal fluency or loss of memory and attention. Often experienced by patients undergoing chemotherapy, the declines have become ...

Researchers find cancer therapies affect cognitive functioning among breast cancer survivors

April 20, 2012
Researchers at Moffitt Cancer Center and colleagues at the University of South Florida and University of Kentucky have found that breast cancer survivors who have had chemotherapy, radiation or both do not perform as well ...

Recommended for you

New therapeutic approach for difficult-to-treat subtype of ovarian cancer identified

July 24, 2017
A potential new therapeutic strategy for a difficult-to-treat form of ovarian cancer has been discovered by Wistar scientists. The findings were published online in Nature Cell Biology.

Anti-cancer chemotherapeutic agent inhibits glioblastoma growth and radiation resistance

July 24, 2017
Glioblastoma is a primary brain tumor with dismal survival rates, even after treatment with surgery, chemotherapy and radiation. A small subpopulation of tumor cells—glioma stem cells—is responsible for glioblastoma's ...

Immune cells the missing ingredient in new bladder cancer treatment

July 24, 2017
New research offers a possible explanation for why a new type of cancer treatment hasn't been working as expected against bladder cancer.

Shooting the achilles heel of nervous system cancers

July 20, 2017
Virtually all cancer treatments used today also damage normal cells, causing the toxic side effects associated with cancer treatment. A cooperative research team led by researchers at Dartmouth's Norris Cotton Cancer Center ...

Molecular changes with age in normal breast tissue are linked to cancer-related changes

July 20, 2017
Several known factors are associated with a higher risk of breast cancer including increasing age, being overweight after menopause, alcohol intake, and family history. However, the underlying biologic mechanisms through ...

Immune-cell numbers predict response to combination immunotherapy in melanoma

July 20, 2017
Whether a melanoma patient will better respond to a single immunotherapy drug or two in combination depends on the abundance of certain white blood cells within their tumors, according to a new study conducted by UC San Francisco ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.