Cognitive Complaints in Survivors of Breast Cancer After Chemotherapy Compared With Age-Matched Controls: An Analysis From a Nationwide, Multicenter, Prospective Longitudinal Study

Abstract

Purpose Cancer-related cognitive impairment is an important problem for patients with breast cancer, yet its trajectory is not fully understood. Some previous cancer-related cognitive impairment research is limited by heterogeneous populations, small samples, lack of prechemotherapy and longitudinal assessments, use of normative data, and lack of generalizability. We addressed these limitations in a large prospective, longitudinal, nationwide study. Patients and Methods Patients with breast cancer from community oncology clinics and age-matched noncancer controls completed the Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog) at prechemotherapy and postchemotherapy and at a 6-month follow-up as an a priori exploratory aim. Longitudinal models compared FACT-Cog scores between patients and controls at the three assessments and adjusted for age, education, race, menopausal status, and baseline reading ability, anxiety, and depressive symptoms. A minimal clinically important difference cutoff determined percentages of impairment over time. Results Of patients, 581 patients with breast cancer (mean age, 53 years; 48% anthracycline-based regimens) and 364 controls (mean age, 53 years) were assessed. Patients reported significantly greater cognitive difficulties on the FACT-Cog total score and four subscales from prechemotherapy to postchemotherapy compared with controls as well as from prechemotherapy to 6-month follow-up (all P < .001). Increased baseline anxiety, depression, and decreased cognitive reserve were significantly associated with lower FACT-Cog total scores. Treatment regimen, hormone, or radiation therapy was not significantly associated with FACT-Cog total scores in patients from postchemotherapy to 6-month follow-up. Patients were more likely to report a clinically significant decline in self-reported cognitive function than were controls from prechemotherapy to postchemotherapy (45.2% v 10.4%) and from prechemotherapy to 6-month follow-up (36.5% v 13.6%). Conclusion Patients with breast cancer who were treated in community oncology clinics report substantially more cognitive difficulties up to 6 months after treatment with chemotherapy than do age-matched noncancer controls.

Fig 1.

CONSORT diagram.

Fig 2.

Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog) total scores in patients with breast cancer and controls prechemotherapy, postchemotherapy, and 6 months after chemotherapy. Smaller values imply greater cognitive deficit. Patients reported significant decline, that is, greater perceived difficulty, in FACT-Cog score after chemotherapy and 6 months after chemotherapy. Assessment 1 is prechemotherapy (0 months), assessment 2 is postchemotherapy (4.8 months), and assessment 3 is 6 months after assessment 2 (11.5 months). Controls are assessed at the same time intervals as patients. Scores represent mean and 95% CIs, not adjusted for multiplicity.

Fig 3.

Prevalence of overall perceived cognitive difficulties via Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog) total score from (A) prechemotherapy to postchemotherapy and (B) prechemotherapy to 6-month follow-up. Better is defined as an increase of ≥ 13.8 points in FACT-Cog, and Worse is defined as a decrease of ≥ 13.8 points.