New Research Suggests Chemo Brain Can Last for Months—or Longer

Women who undergo chemotherapy may still show signs of cognitive difficulties six months after treatment, according to one recent study.

In the study, published in the Journal of Clinical Oncology, researchers looked at self-reported questionnaires from nearly 600 patients who had been treated for breast cancer at different facilities across the country. They compared this group to 364 people who didn’t have breast cancer. They found that many of the women who had been treated for breast cancer experienced long bouts of what’s known as “chemo brain,” which causes memory or thinking problems in patients who have undergone chemotherapy treatment for cancer. “Chemo brain” can last for several months, making it difficult for people to focus and perform routine tasks that require memory and concentration.

Many forms of chemotherapies affect the brain on a temporary basis, but sometimes there are residual side effects of these treatments. With chemotherapy, there’s not a good way to predict how a standardized amount of medication will impact one person compared to another and there’s often not a cause-and-effect relationship between treatment and cognitive ability that’s entirely predictable.

In the study, patients who underwent cancer treatment and those who had never had breast cancer experiences different declines in thinking ability. About a third of study participants who had undergone treatment experienced a decline in their scores on thinking tests, while only 15 percent of the control group showed signs of mental fogginess. In the study, which is one of the largest studies to examine chemotherapy-related cognitive challenges, participants told researchers they had difficulty remembering the names of familiar people, forgot where they were going and made mistakes when they wrote down numbers. Forty-five percent of study participants said their thinking abilities had significantly declined, while only 10 percent of the non-breast cancer group said the same. Thirty-six percent of breast cancer survivors in the study said they still experienced cognitive challenges six months after treatment, while only 13 percent of the control group did so. These issues were present whether someone had undergone chemotherapy alone, radiation treatment after chemotherapy or hormone therapy.

The one silver lining is that thinking ability improved over time in many study participants. Still, it’s worrisome that some people experienced these challenges for months after treatment. The study found that black women, young women and those who had greater anxiety and depression were more likely to experience cognitive decline, though it’s unclear why these groups were more susceptible to the effects of “chemo brain” than others. However, it’s also possible that comorbidities (simultaneous health conditions), such as depression and the energy loss or stress associated with going through cancer treatment, may have an impact on the brain’s ability to process and remember information.

Fortunately, there are several ways we can help patients improve their cognitive skills after treatment and partly or wholly reverse the effects of “chemo brain.” At Orlando Health, we often refer patients to a neuro-oncologist after treatment. Patients go through psychological testing that helps us determine whether the problem is functional, anatomic, or metabolic so we then can prescribe the right treatment approach to help them avoid or better negotiate memory lapses, issues with concentration and other cognitive challenges.

We often tell patients that it’s best to do things that keep the mind active, like puzzles, Sudoku and lots of reading. The worst thing you can do is constantly watch TV and be sedentary. The study’s authors said previous research also has shown that exercise may be beneficial. Previous research the study’s co-author Michelle Janelsin conducted showed that gentle yoga improved thinking ability in some patients.

What this study tells us is that the effects of chemotherapy and other cancer treatment on the brain may be more pronounced and long lasting than we think. We already carefully monitor patients after treatment, but it’s even more critical to refer them to the right resources and intervene early to help them stave off future cognitive declines. Dealing with cancer is one battle, but the side effects of treatment also can be daunting, so we must work with patients to identify symptoms of cognitive decline after treatment and take steps to help them return to the quality of life — and thinking ability — they had before their diagnosis.