Cancer-Related Cognitive Impairment in Patients With a History of Breast Cancer

Clinical reports of cognitive difficulties in patients with breast cancer began to appear in the literature in the 1990s, coincident with the increasing use of postoperative adjuvant chemotherapy.1 Symptoms were more frequently reported in women who received very high-dose chemotherapy, raising concerns that cognitive impairment might become a dose-limiting treatment toxicity.However, this has not occurred, in that over the past 2 decades there has been a deescalation of both the intensity and generalized use of adjuvant chemotherapy in patients with breast cancer.Because of the initial association of cognitive symptoms with chemotherapy treatment, early research focused on what was referred to as chemobrain or chemofog, finding preliminary evidence of measurable neurocognitive effects among patients with breast cancer who were exposed to chemotherapy.Subsequent studies have documented cognitive changes before any cancer-directed therapies, as well as in association with other common breast cancer treatments (eg, radiation, endocrine therapy).The evolving body of research on this subject led to a renaming of the condition as cancer-related cognitive impairment (CRCI).Although they are most commonly reported in close proximity to initial breast cancer treatments, for some patients, symptoms of CRCI can persist for years after treatment completion. 2 Importantly, although breast cancer has been the most studied tumor type with CRCI, there is a growing literature on this condition in persons with other types of cancer, including lymphoma, head and neck cancers, and brain tumors, and patients who have received stem cell transplants.