Women with breast cancer treated in community oncology clinics reported substantial cognitive difficulties for as long as 6 months after chemotherapy treatments, according to a large prospective, longitudinal, nationwide study published in the Journal of Oncology.
These issues, also referred to as “chemo-brain,” can affect memory, attention and pressing information.
Michelle C. Janelsins
“Our study, from one of the largest nationwide studies to date, shows that cancer-related cognitive problems are a substantial and pervasive issue for many women with breast cancer,” Michelle C. Janelsins, PhD, assistant professor of surgery at James P. Wilmot Cancer Institute at University of Richmond Medical Center, said in a press release.
Patients with breast cancer who have had surgery, chemotherapy, radiation, hormone therapy or immunotherapy are subject to cancer-related cognitive impairment. Previous research, however, has been limited by heterogenous populations, small sample sizes and lack of prechemotherapy and longitudinal assessments.
Janelsins, who also serves as the director of Wilmot’s Psychoneuroimmunology Laboratory, and colleagues hypothesized that self-reported cognitive impairment assessed via Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog) would be more prevalent in women with breast cancer than a noncancer control group. Further, they hypothesized that patients who received anthracyclines — thought to be cardiotoxic and neurotoxic — would have more cognitive complaints than those who received nonanthracycline regimens.
Researchers evaluated data from 581 women with breast cancer (mean age, 53 years) who received chemotherapy at community oncology clinics and age-matched them with 364 controls (mean age, 53 years). Forty-eight percent of the women with breast cancer received anthracycline-based regimens.
Researchers assessed patients prior to and after chemotherapy receipt, and then again at
a 6-month follow-up. They used longitudinal models to compare FACT-Cog scores at the three assessments, adjusting for age; education; race; menopausal status; and baseline reading ability, anxiety and depressive symptoms.
Women with breast cancer reported 45% more cognitive impairment than those without cancer. Over a period of nearly 1 year — from diagnosis and prechemotherapy to follow-up at 6 months — 36.5% of women with breast cancer reported a decline in cognitive function compared with 13.6% of those without cancer (P < .001).
The greatest incidence of cognitive impairment occurred from prechemotherapy to postchemotherapy, when 45.2% of patients with breast cancer reported a decline compared with 10.4% of controls. The difference in impairment between women with breast cancer and controls was less prominent from postchemotherapy to 6-month follow-up (18.4% vs. 11.5%).
In a separate model for patients with breast cancer only, no statistically significant differences in mean FACT-Cog scores were observed between treatment regimens, radiation therapy or hormonal therapy. There were also no significant differences in cognitive impairment in women given anthracycline agents compared with nonanthracyclines, although anthracyclines were more inflammatory and neurotoxic.
Researchers noted it is not known what effect breast cancer has on cognitive impairments or whether other symptoms, such as fatigue, may contribute to baseline function. They also reported that black and younger women are more likely to develop cognitive impairments and that further studies are necessary to discern contributing factors.
Janelsins and colleagues noted they are currently observing a small subset of patients in the cohort through 2 years posttreatment.
“More research is needed to address moderating and mediating effects of anxiety, depression and other factors, particularly depression, as our measure was limited,” Janelsins and colleagues wrote. “Studies that more fully evaluate cognitive impairment in older and younger patients with breast cancer are warranted, as well as investigation of minority populations.”
In an accompanying editorial, Kathleen Van Dyk, PhD, psychiatrist at the Resnick Neuropsychiatric Hospital at UCLA, and Patricia A. Ganz, MD, medical oncologist and faculty member at UCLA School of Medicine, applauded the inclusion of self-reported cognitive complaints the study because it adds another layer of information to objective neuropsychological assessment.
“Self-reported cognitive difficulty has several important advantages in both research and clinical settings, often providing the first clinical indications of a problem,” Van Dyk and Ganz wrote. “Self-report taps a patient’s self-knowledge of their previous ability, which is valuable when determining changes from a prior level of functioning, whereas neuropsychological testing usually approximates premorbid functioning by using test-based norms.
“Furthermore, cognitive changes associated with cancer and its treatments are usually subtle, and standard definitions of impairment on neuropsychological assessments may not formally identify these mild but nonetheless functionally disruptive changes,” they added. “... Of importance, self-report also requires substantially fewer resources than does formal neuropsychological assessment and is generally more accessible.”
Van Dyk and Ganz noted that a Sisters Study Survivorship Survey showed that only 37% of respondents with cognitive problems reported having discussed them with a clinician.
“This suggests that cognitive problems are not being regularly evaluated in follow-up clinical visits, missing important opportunities to intervene and improve quality of life for those survivors who suffer from enduring cognitive changes,” they wrote. “For many survivors of breast cancer, cognitive dysfunction is not a transient problem that only co-occurs with chemotherapy treatment, but can be a lasting difficulty well into survivorship.” – by Chuck Gormley
Disclosure: The NIH and the NCI funded the study. Janelsins, Ganz and Van Dyk report no relevant financial disclosures. Please see the study for a full list of all other researchers’ relevant financial disclosures.