ECOG Performance Status (ECOG PS)

The Eastern Cooperative Oncology Group (ECOG) Performance Status scale is the most widely used tool for assessing a cancer patient's functional reserve and capacity to tolerate cancer-directed therapy. It stratifies patients from 0 (fully active) through 4 (completely disabled) to 5 (death) on the basis of ambulatory status, self-care ability, and waking-hours activity. ECOG PS directly informs clinical trial eligibility (most trials require PS 0–1 or PS 0–2), chemotherapy dosing decisions, palliative care referral thresholds, and prognostic modeling. The scale was first published by Oken et al. in 1982 and is used interchangeably with the Zubrod scale.

Performance Status — ECOG PS Criteria

• 0: Fully Active — Fully active; able to carry on all pre-disease activities without restriction. Eligible for all standard regimens and most clinical trials. Full chemotherapy doses are generally appropriate. No dose attenuation required for PS alone.
• 1: Restricted in Strenuous Activity — Restricted in physically strenuous activity but ambulatory and able to carry out work of a light or sedentary nature (e.g., light housework, office work). Eligible for most clinical trials. Standard chemotherapy regimens are generally well tolerated. Prophylactic G-CSF should be considered for myelosuppressive regimens. Monitor for cumulative fatigue and dose-limiting toxicity more closely than in PS 0 patients.
• 2: Ambulatory, Unable to Work — Ambulatory and capable of all self-care but unable to carry out any work activities. Up and about more than 50% of waking hours. Eligibility for clinical trials is variable — many trials exclude PS 2. Standard-intensity doublet chemotherapy carries higher toxicity risk; single-agent or dose-attenuated regimens are often preferred. Geriatric oncology assessment is recommended. Begin early palliative care integration.
• 3: Limited Self-Care — Capable of only limited self-care; confined to bed or chair more than 50% of waking hours. Cytotoxic chemotherapy generally confers more harm than benefit. Consider best supportive care, targeted therapy if actionable driver exists, or immunotherapy with close monitoring. Palliative care consultation is essential. Most clinical trials exclude PS 3.
• 4: Completely Disabled — Completely disabled; cannot carry on any self-care; totally confined to bed or chair. Cancer-directed systemic therapy is very rarely appropriate. Goals-of-care discussion and hospice eligibility evaluation are indicated. Comfort-focused care is the standard of care for most patients at this level.
• 5: Death — Patient has died. Recorded as outcome for clinical trial data capture and registry purposes.