3.4 Performance Status, Frailty & Geriatric Assessment
Key Takeaways
- ECOG performance status runs from 0 (fully active) to 5 (deceased); the pivotal distinction between ECOG 2 and ECOG 3 is whether the patient is up and about, or confined to bed or chair, for more than 50% of waking hours.
- Most cytotoxic combination regimens and most clinical trials require ECOG 0 to 1 or a Karnofsky score of at least 70, and ECOG 3 to 4 patients generally derive toxicity without survival benefit from aggressive cytotoxic therapy.
- Performance status is prognostic but insensitive to frailty, so an older adult with ECOG 1 can still be at high risk for severe toxicity.
- The CARG and CRASH scores predict grade 3 to 5 chemotherapy toxicity in older adults more accurately than ECOG or Karnofsky status and should inform dose and regimen selection.
- ASCO recommends geriatric assessment for patients aged 65 and older receiving systemic therapy, covering function, comorbidity, cognition, nutrition, psychological state, social support, and polypharmacy.
3.4 Performance Status, Frailty & Geriatric Assessment
Blueprint focus: ONCC Domain I.B.2 — Patient assessment, including performance status scales. Functional assessment is the gatekeeper for every treatment decision in this guide: it determines trial eligibility, regimen intensity, dose, and whether disease-directed therapy is appropriate at all.
Why Function Predicts Outcome
Performance status is one of the strongest independent prognostic variables in oncology, often outweighing stage in patients with advanced disease. It measures physiologic reserve — the capacity to absorb the insult of cytotoxic therapy and recover. A patient who cannot climb a flight of stairs is unlikely to recover from grade 4 neutropenia without a life-threatening infection.
Performance status also carries ethical weight. Offering aggressive chemotherapy to a patient with ECOG 4 disease creates the appearance of choice while delivering toxicity without benefit. Recognizing that boundary and converting the conversation to goals of care is core APRN practice.
The Two Standard Scales
| ECOG | Definition | Approximate Karnofsky |
|---|---|---|
| 0 | Fully active, able to carry on all pre-disease activity without restriction | 100 to 90 |
| 1 | Restricted in physically strenuous activity but ambulatory and able to do light or sedentary work | 80 to 70 |
| 2 | Ambulatory and capable of all self-care, unable to carry out any work activities, up and about more than 50% of waking hours | 60 to 50 |
| 3 | Capable of only limited self-care, confined to bed or chair more than 50% of waking hours | 40 to 30 |
| 4 | Completely disabled, no self-care, totally confined to bed or chair | 20 to 10 |
| 5 | Deceased | 0 |
The ECOG 2 versus 3 boundary is the most heavily tested item on the scale. Both patients have significant impairment. The discriminator is the proportion of waking hours spent up and about versus confined, and whether self-care is complete (2) or only partial (3).
Karnofsky uses 10-point increments from 100 down to 0 and is more granular, which makes it common in transplant eligibility and palliative research. Note the direction: a higher Karnofsky score means better function, the reverse of ECOG.
The Palliative Performance Scale (PPS) extends Karnofsky by adding ambulation, activity and evidence of disease, self-care, intake, and level of consciousness. It is widely used to support hospice prognostication, where a PPS at or below 50% to 40% with declining intake supports a limited prognosis.
How Performance Status Drives Treatment Decisions
- Clinical trials almost always require ECOG 0 to 1, occasionally ECOG 2 for supportive-care or single-agent studies.
- Intensive combination cytotoxic regimens generally require ECOG 0 to 1 or Karnofsky at least 70 to 80.
- Single-agent or attenuated regimens and most targeted oral agents may be reasonable at ECOG 2.
- ECOG 3 to 4 patients typically receive best supportive care with palliative intent; immune checkpoint inhibitors are not an exception, since response rates fall sharply and immune-related toxicity is poorly tolerated in this group.
- Allogeneic transplant additionally requires a comorbidity index assessment such as the HCT-CI, because performance status alone underestimates organ-specific risk.
The Limits of Performance Status in Older Adults
Performance status was designed decades ago in trial populations that were younger and healthier than the patients now treated. It is insensitive to frailty: an older adult can look like ECOG 1 in clinic and still have impaired instrumental activities of daily living, undiagnosed cognitive impairment, poor nutrition, falls, and eight interacting medications. That patient's real risk of grade 3 to 5 toxicity is much higher than the ECOG score suggests.
ASCO recommends geriatric assessment for patients aged 65 and older who are being considered for systemic therapy.
Domains of the comprehensive geriatric assessment
| Domain | Instruments commonly used | What an abnormal result changes |
|---|---|---|
| Functional status | ADLs, IADLs, Timed Up and Go, number of falls in 6 months | Home support, physical therapy, dose attenuation |
| Comorbidity | Charlson index, CIRS-G | Drug selection, organ-function-based dosing |
| Cognition | Mini-Cog, MoCA, Blessed Orientation-Memory-Concentration | Capacity to consent, adherence support, caregiver involvement |
| Nutrition | Unintentional weight loss, body mass index, Mini Nutritional Assessment | Dietitian referral, mucositis and cachexia risk |
| Psychological | Geriatric Depression Scale, distress thermometer | Psycho-oncology referral, treatment of depression before therapy |
| Social support | Living situation, caregiver availability, transport | Feasibility of outpatient regimens and oral agents |
| Polypharmacy | Full medication reconciliation, Beers criteria | Deprescribing, anticipation of drug–drug interactions |
Validated Toxicity Prediction Tools
Two calculators outperform performance status for predicting chemotherapy toxicity in older adults, and both are fair game on the exam.
- CARG (Cancer and Aging Research Group) score — combines age, tumor type, planned chemotherapy dose and number of drugs, hemoglobin, creatinine clearance, hearing, falls, need for help with medications, ability to walk a block, and social activity. It stratifies risk of grade 3 to 5 toxicity into low, intermediate, and high.
- CRASH (Chemotherapy Risk Assessment Scale for High-Age Patients) score — produces separate estimates for hematologic and non-hematologic toxicity, using diastolic blood pressure, instrumental ADLs, lactate dehydrogenase, cognition, nutrition, and the regimen's own toxicity profile.
A high CARG score does not mandate withholding treatment. It should drive a concrete plan: attenuated starting dose, a less toxic regimen, primary growth factor prophylaxis, closer monitoring intervals, home support, and an explicit re-evaluation point.
Documenting the Assessment
Record the numeric score, the scale used, and the observation that justifies it — "ECOG 2: ambulatory, independent in all self-care, stopped working, rests approximately 4 hours during the day." A bare number without narrative is not defensible when it is later used to justify or withhold therapy. Reassess at every cycle, because a decline of one ECOG level during treatment is a stronger signal to change course than any single laboratory value.
A 71-year-old woman with metastatic pancreatic cancer spends most of the day in a recliner, gets up only for meals and the bathroom, and needs help bathing and dressing. She is awake and oriented. Which performance status best describes her?
An 80-year-old man with newly diagnosed diffuse large B-cell lymphoma has an ECOG performance status of 1. He takes 9 medications, has fallen twice in the past 6 months, needs help managing his pill box, and has lost 6 kg unintentionally. What is the most appropriate next step before selecting a regimen?
How do the ECOG and Karnofsky performance status scales relate to one another?