Cancer patients experience a number of adverse symptoms, including cognitive impairment, fatigue, pain, sleep disturbance, and others, often in combination. Fortunately detailed symptom assessment is becoming increasingly recognized as a part of routine patient care by physicians, allied health care providers, and accrediting agencies. Cancer treatment may be considered successful only if these symptoms are managed, but successful management is hampered by insufficient knowledge of mechanisms. Interest in the mechanisms, patterns of symptoms, and interventions is growing as the survivorship community grows and must deal with these adverse effects of cancer and cancer treatment.

Cognitive dysfunction occurs in most cancer patients who are receiving active therapy and is frequently a symptom that heralds the diagnosis. In addition, cognitive dysfunction persists in a substantial number of patients long after treatment is discontinued. This type of cognitive dysfunction is popularly termed “chemobrain” or “chemo fog.” However, cognitive symptoms secondary to cancer and cancer treatment are part of a differential diagnosis of exclusion because a number of factors may be causal, and the specific intervention is based on the etiology of the cognitive dysfunction (Table 20.1).

In an effort to gather information directly from cancer survivors about their experience of “chemobrain” during and following treatment, an online survey conducted by the Hurricane Voices Breast Cancer Foundation specifically queried the impact of neurocognitive symptoms on a survivor’s ability to work. Nearly two-thirds of the 471 survey respondents (most of whom were survivors of breast cancer) reported that cognitive changes had an adverse impact on their work functioning or relationships at work, and 10 respondents reported leaving jobs or being terminated. Nearly 300 of the 471 respondents felt that their cognitive symptoms warranted discussion with a medical professional; however, their concerns were met with mixed reactions. Fifty-five percent of respondents felt that their oncologist was understanding, but 42% felt that their oncologist’s response was dismissive or indifferent. Only 10% were offered assistance; 6% of respondents had neuropsychological testing and less than 8% were referred for an intervention for their cognitive symptoms. The authors concluded that “Despite the pervasive impact on patients’ lives, cognitive changes are not adequately acknowledged and addressed by healthcare providers” (Hurricane Voices Breast Cancer Foundation 2007). Oncologic professionals’ lack of familiarity with research demonstrating that brain function is affected by treatment was cited as a potential factor responsible for the current state of affairs. However, assessment of cognitive function in cancer survivors is becoming more routine. For many patients, addressing cognitive problems that existed before the start of treatment is important, and the underlying cause can be proactively addressed. In addition, cognitive testing is increasingly becoming an endpoint in clinical trials. In this way, the effect of new agents or treatments on brain function can be evaluated.