Ways to Lessen Toxic Effects of Chemo in Older Adults

William H. Hung, MD, MPH

Older adults are more susceptible to adverse drug reactions due to changes in physiology, clearance, and reserves. Age-related changes that potentiate adverse drug reactions include alterations in absorption, distribution, metabolism, and excretion. As such, older patients often require adjustments in medications to optimize safety and use. Medication adjustment is especially important for older patients on complex medication regimens for multiple conditions, such as those undergoing cancer treatment. Three recent high-quality randomized trials evaluated the use of geriatric assessment (GA) in older adults with cancer.^[1,2,3]

Interdisciplinary GA can identify aging-related conditions associated with poor outcomes in older patients with cancer (eg, toxic effects of chemotherapy) and provide recommendations aimed at improving health outcomes. The results of these trials suggest that interdisciplinary GA can improve care outcomes and oncologists' communication for older adults with cancer, and should be considered an emerging standard of care.

Geriatric Assessment and Chemotherapy-Related Toxic Effects

A cluster randomized trial^[1] at City of Hope National Medical Center conducted between August 2015 and February 2019 enrolled 613 participants and randomly assigned them to receive a GA-guided intervention or usual standard of care in a 2-to-1 ratio. Participants were eligible for the study if they were age ≥ 65 years; had a diagnosis of solid malignant neoplasm of any stage; were starting a new chemotherapy regimen; and were fluent in English, Spanish, or Chinese.

The intervention included a GA at baseline followed by assessments focused on six common areas: sleep problems, problems with eating and feeding, incontinence, confusion, evidence of falls, and skin breakdown. An interdisciplinary team (oncologist, nurse practitioner, pharmacist, physical therapist, occupational therapist, social worker, and nutritionist) performed the assessment and developed a plan of care. Interventions were multifactorial and could include referral to specialists; recommendations for medication changes; symptom management; nutritional intervention with diet recommendations and supplementation; and interventions targeting social, spiritual, and functional well-being. Follow-up by a nurse practitioner continued until completion of chemotherapy or 6 months after starting chemotherapy, whichever was earlier.

The primary outcome was grade 3 or higher chemotherapy-related toxic effects using National Cancer Institute criteria, and secondary outcomes were advance directive completion, emergency room visits and unplanned hospitalizations, and survival up to 12 months. Results showed a 10% absolute reduction in the incidence of grade 3 or higher toxic effects (P = .02), with a number needed to treat of 10. Advance directive completion also increased by 15%, but no differences were observed for other outcomes. This study offers high-quality evidence that a GA-based intervention can reduce toxic effects of chemotherapy regimens for older adults with cancer.

Geriatric Assessment in Community Oncology Practices

A recent study by Mohile and colleagues^[2] is the first nationwide multicenter clinical trial to demonstrate the effects of GA and GA-guided management. This study was conducted in 40 oncology practices from the University of Rochester National Cancer Institute Community Oncology Research Program network. Centers were randomly assigned to intervention or usual care (362 patients treated by 68 oncologists in the intervention group and 371 patients treated by 91 oncologists in the usual-care group). Eligibility criteria were age ≥ 70 years; impairment in at least one GA domain other than polypharmacy; incurable advanced solid tumor or lymphoma with a plan to start new cancer treatment with a high risk for toxic effects within 4 weeks; and English language fluency. Both study groups underwent a baseline GA that assessed patients' physical performance, functional status, comorbidity, cognition, nutrition, social support, polypharmacy, and psychological status. For the intervention group, a summary and management recommendations were provided to the treating oncologists.

The primary outcome was grade 3 or higher toxic effects within 3 months of starting a new regimen; secondary outcomes included treatment intensity and survival and GA outcomes within 3 months. A smaller proportion of patients in the intervention group experienced toxicity (51% compared with 71%), with an absolute risk reduction of 20%. Patients in the intervention group also had fewer falls and a greater reduction in medications used; there were no other differences in secondary outcomes. This study offers very strong and generalizable evidence that incorporating GA in the care of older adults with cancer at risk for toxicity can reduce toxicity and as well as improve other outcomes, such as falls and polypharmacy.

Geriatric Assessment and Oncologist-Patient Communication

A secondary analysis^[3] of data from Mohile and colleagues^[2] evaluated the effect of GA-guided recommendations on oncologist-patient communication regarding comorbidities. Patients (N = 541) included in this analysis were 76.6 years of age on average and had 3.2 (SD, 1.9) comorbid conditions. All patients underwent GA, but only oncologists in the intervention arm received GA-based recommendations. Clinical encounters between oncologist and patient immediately following the GA were audio-recorded and analyzed to examine communication between oncologists and participants as it relates to chronic comorbid conditions.

In the intervention arm, more discussions regarding comorbidities took place, and more participants' concerns about comorbidities were acknowledged. More important, participants in the intervention group were 2.4 times more likely to have their concerns about comorbidities addressed through referral or education compared with the usual-care group (P = .004). Moreover, 41% of oncologists in the intervention arm modified dosage or cancer treatment schedule due to concern about tolerability or comorbidities. This study demonstrates beneficial effects of GA in increasing communication and perhaps consideration of comorbidities of older adults when planning cancer treatment.