Targeted CBT May Be Best for Treating Cognitive Problems in Cancer Survivors

Thanks to advances in cancer therapy, cancer survivors are leading longer, fuller lives. As the population of cancer survivors has grown, however, it has become increasingly clear that some will experience long-term cognitive effects of cancer therapy—a condition commonly known as “chemobrain.”

“Most patients will report cognitive issues during the chemotherapy process, but as these are potent agents, feeling weak, confused, or disoriented is not surprising,” said Tim Ahles, Ph.D., a behavioral psychologist at Memorial Sloan-Kettering Cancer Center who has dedicated himself to understanding the cancer-cognition connection. Ahles noted that evidence also indicates hormonal therapies and radiation for cancer may also compromise cognition.

“If these problems were limited to the short term, it might not be a big issue,” he continued. “However, cancer survivors are still showing signs of cognitive impairment years after their last treatment.”

Although older patients with cancer might be expected to show some degree of age-related cognitive decline (such as loss of episodic memory), Ahles noted that chemotherapy-induced problems most often affect attention, working memory, and processing speed. In addition, these deficits typically do not get progressively worse as would be expected with an age-related disorder.

A recent study from St. Jude Children’s Research Hospital also found higher exposure to a chemotherapy drug was associated with long-term executive dysfunction in survivors of pediatric cancer (Psychiatric News, July 1).

Ahles thinks that chemotherapy agents may compromise the brain’s ability to distinguish relevant information from irrelevant information, which might explain why cancer survivors experience symptoms that resemble attention-deficit/hyperactivity disorder (ADHD). Because most chemotherapy drugs cannot cross the blood-brain barrier, however, the exact mechanism by which they exert their effects is unknown (with brain tumors being an exception).

Treating cognitive issues with cancer patients and survivors can be challenging. While many cancer patients and survivors experiencing chemotherapy-induced cognitive problems are given stimulants such as methylphenidate or modafinil, it remains unclear whether this is the best approach for all patients, who may be in a weakened state due to ongoing chemotherapy. Cognitive therapies can also be used to treat chemotherapy-induced cognitive dysfunction, but this approach also presents challenges.

As Robert Ferguson, Ph.D., an assistant professor of medicine at the University of Pittsburgh Cancer Institute Biobehavioral Oncology Program told Psychiatric News, an important component of cognitive-behavioral therapy (CBT) is to educate patients about their disorder, so they can be more aware of their behaviors and actively work to change them.

“But we don’t really have that luxury when discussing cancer-related cognition problems, because our understanding of what these chemotherapies are doing is still quite limited,” he said.

He noted that while many cancer survivors are older adults, the distinct manifestation of chemotherapy-induced problems means that applying existing CBT programs for dementia may not be appropriate. At the same time, ADHD-tailored cognitive therapies, which often require intensive training to get patients to improve their attention and working memory skills, may not be a good fit either.

Such cognitive training is time consuming, Ferguson said, “and cancer survivors have already given up a lot of their time. They want to get back to their regular lives as quickly as possible.”

To assist cancer survivors with cognitive dysfunction, Ferguson and colleagues at the University of Maine (where he was prior to joining Pittsburgh) have been working on a CBT therapy known as Memory and Attention Adaptation Training (MAAT).

MAAT, which was designed to be administered over the course of just one month, focuses on teaching patients compensatory skills to manage cognitive issues; such strategies include encouraging patients to make schedules or softly talk through tasks as they are being performed.

A few years back Ferguson carried out a small clinical study in 40 breast cancer survivors and found that MAAT did provide modest benefits for some elements of cognitive function, as well as anxiety related to their cognitive problems. In a more recent study, Ferguson found cancer survivors also reported cognitive improvements following MAAT by videoconference. (Patients could participate in the program at home, which Ferguson noted was another important consideration for cancer survivors.)

While Ferguson noted that more research is needed to determine the long-term effects of MAAT on larger populations of cancer survivors, he said he believes MAAT may serve as a simple way to offer them a strategy for coping with cognitive challenges. ■