The risk and prevalence of dementia and cancer climb with advancing age during late adulthood, increasing the likelihood that elderly patients will experience both diseases simultaneously, complicating informed consent, treatment decision making, and compliance.1-3 Yet expertise in cancer care and dementia care remain largely separate, clinically siloed in different departments.

An umbrella term for distinct progressive brain disorders that cause worsening cognitive decline, impaired judgment, and changes in personality, dementia is associated with increasingly significant memory lapses, declining communication skills and difficulty living and making decisions independently.4,5 Common types of dementia include Alzheimer disease, Lewy body dementia (seen with Alzheimer and Parkinson diseases), frontotemporal dementia, and vascular dementia.4 (Lewy bodies are accumulations of alpha-synuclein protein in the brain.)

Nearly 1 in 5 patients with cancer (19.7%) also have dementia, overall, according to a recent study in Germany.6 Although a stronger association was found with dementia among patients with lung cancer, the researchers reported significantly elevated rates of dementia among patients across all examined cancer types, including skin, gastrointestinal, breast, genitourinary, and hematologic malignancies.6 A study in New York showed that hospitalizations of patients with both dementia and cancer increased significantly between 2007 and 2017 — a trend that is expected to continue during the coming decade.7

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A Complex Comorbidity

There have been recent calls for integrated, evidence-based treatment guidelines that harmonize cancer and dementia care, and for longer or additional appointments for cancer care decision making when patients have dementia.1,2

The biologic and epidemiologic connections between dementia and cancer risk are a complex and contested terrain.8,9 Early studies suggested that patients with cancer might be less likely to suffer dementia than the elderly population in general, but more recent research suggests the opposite.6,8,9

Elderly patients with both cancer and dementia have higher mortality rates than those with only one or the other, likely in part because of a higher average number of comorbidities.5 Patients with dementia also undergo curative-intent cancer radiotherapy, chemotherapy, or surgery less frequently.1,10 Clinical decision making for patients with dementia tends to emphasize quality of life and reduced risk of adverse treatment effects, rather than cure, because dementia precludes long-term survival in most cases, and cancer treatment can involve painful and quality of life-degrading side effects.1 In one 2019 study of patients with dementia, researchers noted that radiotherapy “often represents a more optimal therapy in patients with dementia, as surgery and chemotherapy may be contraindicated.”11

Advanced cancer and advanced dementia are both associated with cachexia, a dangerous muscle wasting and weight loss condition, but the extent to which the underlying metabolic dysfunctions interact to increase risk or mortality remains unknown.12 Cancer treatment is also frequently associated with cognitive effects (“chemo-brain” and contested evidence that androgen deprivation therapy is associated with dementia).

Unique Challenges to Treatment

Dementia complicates cancer treatment. Patients with dementia may rapidly and repeatedly forget instructions, or where they are, leading to noncompliance with radiotherapy set-up positioning instructions, for example. Cancer centers and care are rarely designed specifically for these patients’ needs, which include simple layouts with reduced sensory demands. They can have difficulty understanding and navigating between the different departments and services involved in their cancer care, and independently getting from home to the cancer center and back.3

Patients with dementia benefit from comfortable seating with arm rests, a clearly identified call or help button within easy reach, personal music, familiar faces during patient setup, and reassuring, calm communication.10 They also benefit from reduced visual clutter, clear signage, hallway handrails, and distinctive differences between floors to help them orient.10

Radiation suites commonly have unfamiliar and confusing sensory environments that might confuse and even panic patients with dementia.11 Empathetic, calm, patient and gently repeated reassurance and reminders by radiotherapy team members may help patients manage confusion and anxiety.

Approaches to cancer care planning and delivery should be informed by a patient’s diagnosis, and stage, of dementia. But dementia is frequently undiagnosed, and early and moderate symptoms can be subtle.13 Overlapping symptoms and adverse effects of dementia, cancer, and cancer treatment can obscure the co-occurrence of dementia and cancer. For example, memory problems and confusion are common among elderly people undergoing care for cancer even when they do not have dementia.

Dementia is sometimes misdiagnosed when symptoms are really caused by another problem. Not every forgetful elder has dementia. Depression among elderly patients, for example, can lead to uncommunicativeness and cognitive problems that mimic dementia — a condition known as pseudo-dementia.14 It stands to reason that early dementia, in turn, can be mistaken for depression and go undiagnosed.

When interacting with elderly radiation oncology patients, nurses should be vigilant about 4 sets of dementia symptoms9:

  • The patient’s ability to remember details of their cancer such as their diagnosis, prognosis, and treatment decisions.
  • Language difficulties, including confusion over words or simple sentences.
  • Difficulty understanding the costs and benefits of treatment options, and managing adverse events associated with treatment.
  • Signs of unfamiliarity with people or previously visited environments such as the radiation suite.

Mild dementia or cognitive impairment can frequently be accommodated, especially when patients have invested family members or other caregivers, with frequent reorienting reminders of where the patient is, and why.

Incorporating a Dementia Diagnosis Into Cancer Care

Staging dementia can be challenging, particularly in the context of a cancer diagnosis, and oncology clinicians are frequently not trained in diagnosing or staging dementia. Therefore, cancer teams should include dementia specialists early in elderly patients’ treatment journey when dementia is suspected.14

Family member or other informal caregiver descriptions of the patient’s symptoms can be used to help stage dementia.15

Dementia is typically classified as mild (or early), moderate, or severe (or late) stage disease. Approaches to staging vary and different staging or scale tools are used depending on which form of dementia is suspected or diagnosed, but generally, the clinical diagnosis of dementias center on patients’ sustained focus, remembering how to do things, recall of recent and long-ago events, language comprehension, social cognition (for example, recognizing facial expressions), and executive function. (Executive function is related to prioritizing and planning, and sustained attention to a given task.)

Oncology clinicians should be familiar with 2 common dementia staging systems, known as the GDS and the FAST scales.

The Global Deterioration Scale for Assessment of Primary Degenerative Dementia (GDS), quantifies symptoms to classify dementia into 7 stages of cognitive degeneration, ranging from normal function and no memory loss (stage 1) through inability to speak or communicate, loss of motor skills, and requiring help with walking and most activities (stage 7, very severe cognitive decline, or late dementia).16 Stages 1 through 3 do not carry a dementia diagnosis at all.

  • Stage 1 Normal function, no memory loss
  • Stage 2 Trouble remembering names and with misplacing objects
  • Stage 3 Increased forgetfulness, difficulty finding words, more frequently becomes lost and confused
  • Stage 4 (Moderate cognitive decline) Difficulty concentrating and completing tasks, social withdrawal or isolation, cannot travel alone to new places or manage finances
  • Stage 5 (Moderately severe decline; “early” dementia) Cannot remember own address or phone number, date, or where they are; needs assistance with activities of daily living
  • Stage 6 (Severe cognitive decline, “middle” dementia) Forgets loved ones’ names, recent events, major past events, has incontinence and difficulty speaking; difficulty counting from 10 down to 1. Patients sometimes evidence delusions and frequently are anxious
  • Stage 7 (Very severe, “late” dementia) Patient is unable to communicate verbally or walk on their own

The Functional Assessment Staging Test (FAST) is another commonly used 7-stage classification system specific to staging Alzheimer’s disease.17 FAST stages range from normal adults without functional declines (stage 1) to severe Alzheimer’s disease (stage 7, involving mumbling, unintelligible words, lost ability to walk or sit up, to smile, or hold one’s head up).


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This article originally appeared on Oncology Nurse Advisor