An increasing number of women survive breast cancer. Of the 11.4 million cancer survivors in the United States alone, female breast cancer survivors represent the largest population at 23%, or 2.6 million women [1
]. Although breast cancer is the second leading cause of cancer death in women, mortality rates have declined steadily since about 1990 [2
]. However, survival may come at a cost for some, as biomedical researchers have begun to acknowledge that cancer treatment itself (surgery, radiation, chemotherapy) can result in long-term physiological damage, which in turn can vastly impact quality of life. One post-treatment side effect that has received growing medical attention is popularly referred to as “chemobrain.” This condition encompasses a range of symptoms such as memory loss, inability to concentrate, difficulty in thinking, and other subtle, cognitive changes. Although the severity of cognitive difficulty varies among patients, the slightest deterioration in cognitive function can be devastating for the patient’s quality of life [3
]. It is currently unknown exactly how many breast cancer survivors suffer from this condition, and anecdotal evidence suggests that the phenomenon may even affect a broad array of cancer survivors beyond those who experienced breast cancer. Although some current biomedical cancer studies do seek to understand the nature and etiology of chemobrain, there is a dearth of information about its psychosocial ramifications—how do individuals suffering from this condition experience the symptoms? How does it impact their lives and functioning? To what extent is their daily experience compromised?
A growing body of research examines cognitive dysfunction in breast cancer patients who have undergone standard-dose chemotherapy. A study by Wieneke and Dienst [4
] analyzed 28 participants who were treated for early-stage breast cancer with either CMF chemotherapy, CAF chemotherapy, or a combination of the two. A series of neuropsychological tests were performed in order to determine any affect on cognitive functioning. Their results indicated that 75% of the participants suffered from cognitive impairment on one or more neuropsychological tests. A study conducted by Schagen et al. [5
] of thirty-nine breast cancer patients treated with adjuvant (CMF) chemotherapy showed that 28% had deficits in the areas of concentration and memory versus 12% of the thirty-four patients in the control group who did not receive adjuvant chemotherapy. Van Dam et al. [6
] correlated the level of cognitive impairment with the dosage of adjuvant chemotherapy. Their results showed that 32% of patients who had undergone high-dose chemotherapy were affected adversely with respect to cognitive functioning while only 17% of the patients who were given a standard dose of chemotherapy were adversely affected, demonstrating a dose response rate. Brezden et al. [7
] surveyed 3 groups of women: group A consisted of breast cancer patients undergoing adjuvant chemotherapy, group B consisted of women who had finished chemotherapy treatment on average of 2 years ago, and group C consisted of healthy controls. Women in both groups A and B suffered more cognitive dysfunction than those in group C; furthermore, group A proved to have greater cognitive deficits than group B. Ahles et al. [8
] reviewed the cases of breast cancer or lymphoma survivors who had been diagnosed and treated with chemotherapy in the previous 10 years. The study indicated that cognitive deficits were still present even a decade after treatment and that patients treated with adjuvant chemotherapy were much more likely to perform poorly on neuropsychological tests than patients who had undergone local therapy only. A later study by Castellon et al. [9
] further confirmed these previous findings, again reaffirming that chemotherapy negatively impacts neurocognitive functioning.
Since 2004, the number of studies investigating post-treatment cognitive impairment has significantly increased. In 2005, Shilling et al. [10
] published the preliminary results of their longitudinal study of patients who had received chemotherapy and compared their cognitive function to that of healthy controls. Of the chemotherapy patients, 34% showed a decline in cognitive function versus 18.6% of the control group. In 2006, Bender et al. [11
] found that women who received chemotherapy exhibited deteriorations in working memory compared to the control group. Another 2006 study [12
] evaluated subjects’ cognitive function before chemotherapy and 6 months after completing chemotherapy; 25% of the subjects exhibited cognitive decline from the baseline cognitive test. According to a 2006 article by Raffa et al.[13
], chemobrain’s existence has been “well established,” even if a direct causal relationship has not been indisputably proven. Thus, many in the medical community have generally accepted the existence of post-treatment cognitive impairment, although the mechanism of the phenomenon is still unknown. Since 2007, numerous studies have sought to uncover this mechanism, and the exponential growth in research investigating chemobrain will undoubtedly continue in the coming years [14
It should be noted, however, that although numerous studies have shown cognitive dysfunction in patients who have undergone chemotherapy, many of these studies did not assess the baseline cognitive function of patients before they underwent chemotherapy. In fact, a 2004 study that did assess baseline function found that 35% of women demonstrated cognitive impairment before the initiation of chemotherapy for their breast cancer, underscoring the importance of establishing pre-chemotherapy baseline cognitive functioning to accurately assess whether or not chemotherapy is indeed responsible for their cognitive decline [19
]. Additionally, some studies researching chemobrain have concluded that there was no statistically significant difference in domains such as attention, cognition, or language between breast cancer patients who received chemotherapy and those who did not [20
]. Another study looked into the relationship between self-reported and objective cognitive dysfunction in breast cancer patients treated with adjuvant therapy. It found that self-reported memory and concentration problems were actually associated with psychological distress, rather than true cognitive decline as assessed by objective cognitive testing [22
]. Data from more recent studies suggest that chemobrain may be more complex in its etiology, caused not solely by chemotherapy treatment but potentially also precipitated by the “impact of surgery and anesthesia, hormonal therapy, menopause, anxiety, depression, fatigue, supportive care medications, genetic predisposition, comorbid medical conditions, or possibly paraneoplastic phenomenon” [23
]. Cited as problematic in this body of research is the lack of standard measures of cognitive impairment and small sample sizes. Certainly, overall, while there is no definitive understanding of chemobrain, there is consensus that there is yet a need for large, multi-center studies to further explore this phenomenon.
Although the controversy over chemobrain persists, survivors continue to report post-chemotherapy cognitive changes, and a significant body of research validates the existence of cognitive impairment experienced by breast cancer survivors subsequent to chemotherapy. A 2005 meta-analysis of chemobrain literature concluded that cognitive impairment was indeed a reality for many breast cancer survivors who underwent chemotherapy [24
]. Indeed, the health care community has already begun an examination of chemobrain’s effects on patients’ lives. A 2005 article by Matsuda et al. [25
] recognized that the “principle negative effect” of this mild cognitive impairment was “deterioration of quality of life.” Citing a 2001 article by Bender et al. [26
], Matsuda et al. noted that the most devastating effects are “for patients who hold professional and social positions.” Despite the observation that cognitive impairment can have devastating effects on the personal and professional lives of women, there has been little discussion about the psychosocial ramifications of this condition. Both national and international media have become increasingly alerted to the quality of life problems that women with cognitive impairment experience [27
], and commercial products have been manufactured to help patients with chemobrain [29
]. However, despite the media attention on the subject, only a small number of medical journals have detailed the direct effects of cognitive impairment on the lives of breast cancer patients [22
]. There is, therefore, a paucity of literature focusing solely on the psychosocial effects of chemobrain, and our paper is one of the few in-depth descriptions of the psychosocial ramifications of chemobrain in the words of cancer survivors. Such literature needs to be available not only for breast cancer survivors, who may seek reassurance and often voice a longing for validation of their cognitive symptoms, but also for nurses and physicians, who need to better understand the sorts of changes their patients may be undergoing during and after chemotherapy so that they can be informed and compassionate providers for their patients.