Management of Colorectal Cancer in Older Adults

The Eastern Cooperative Oncology Group performance status (ECOG PS) and Karnofsky Performance Status (KPS) are crude measures of functional status.¹² Generally, elderly patients with good ECOG PS or KPS scores are considered fit enough to receive standard therapy similar to their younger counterparts. Evaluation of functional status using these performance scores is often suboptimal, resulting in patients with a normal or adequate performance status score who may still experience poor outcomes, including decreased survival and inability to tolerate treatment. A study that explored parameters among older patients that predict for increased risk of chemotherapy-related toxicities found that physician-rated KPS score did not accurately predict the risk for adverse events.¹³ Therefore, a CGA represents a better way to evaluate functional status and other domains.

Functional status can also be evaluated by self-reported tools such as activities of daily living, which refer to basic self-care, and instrumental activities of daily living (IADLs), which are essential for independent living in the community.^14,15 Mobility, gait, and balance can also be measured using the “Timed Get Up and Go” test and gait speed. Klepin et al found that faster gait speed was associated with overall survival (OS) in patients with metastatic cancer.¹⁶

Cognitive function is an important component of the geriatric assessment in older patients with cancer, as dementia is a prognostic factor for survival in the overall geriatric population. In a retrospective review, patients with dementia were less likely to have a biopsy-proven diagnosis and were twice as likely to have their CRC diagnosed postmortem.¹⁷ In addition, establishing that the patient has intact cognitive function prior to initiating treatment is essential to ensure that the patient can comply with treatment and understands when to report adverse effects. Nutritional status is an important portion of the geriatric assessment because malnutrition is associated with increased mortality and decreased tolerance for chemotherapy.^18–20 Evaluating the patient’s psychosocial support is crucial as well because older patients are at greater risk of social isolation and depression.²¹ While the incidence of depression is lower in older adults with cancer than in younger adults with cancer, clinically significant depression is still noted in 3% to 25% of elderly cancer patients.²² Other critical components of the CGA are review of the patient’s comorbidities and medications to avoid complications of polypharmacy.

Both the Cancer and Aging Research Group (CARG) and Chemotherapy Risk Assessment Scale for High-Age Patients (CRASH) toxicity tools are valuable tools, as they predict chemotherapy tolerance in elderly patients.^13,23 These tools can help guide discussions between oncologists and patients as well as the formulation of an appropriate treatment plan.²⁴ Although toxicity tools can help to determine which patients are at risk for severe toxicity secondary to treatment, these tools do not replace the CGA. A prospective cohort study that evaluated the impact of CGA on tolerance to chemotherapy in older patients with cancer compared patients aged ≥ 70 years at the start of their treatment with chemotherapy (± radiation therapy) using geriatrician-delivered CGA versus standard care given by oncology.⁸ Patients who received geriatrician-guided CGA interventions tolerated chemotherapy better and completed treatments as planned (odds ratio 4.14 [95% confidence interval {CI} 1.50 to 11.42], P = 0.006) with fewer treatment modifications.

Unfortunately, the CGA is time-consuming to administer and difficult to incorporate into a busy oncology practice. Therefore, other screening models are used to identify patients who may benefit from a full CGA. The International Society of Geriatric Oncology performed a systematic review of screening tools used to identify older cancer patients in need of geriatric assessment and found that the 3 most studied screening tools are the G8, the Vulnerable Elders Survey-13 (VES-13), and the Flemish version of the Triage Risk Screening Tool.²⁵ Another study found that the G8 was more sensitive than the VES-13 (76.5% versus 68.7%, P = 0.0046), whereas the VES-13 was more specific than the G8 (74.3% versus 64.4%, P < 0.0001).²⁶ In addition to providing guidance to initiate a full geriatric assessment, these screening tools may assist in decision making for older cancer patients, especially those with advanced disease.