Eastern Cooperative Oncology Group Performance Status

Summary / Explanation

Introduction

Advanced care planning for patients with cancer is an interdisciplinary field with many confounding variables. Clinical assessment of the patient's performance status (PS) is imperative to making a decision on a treatment regimen.[1] Often, healthcare providers, especially in the field of hematology and oncology, will use different tools to calculate the estimated PS of a patient prior to starting potentially toxic systemic anticancer regimens. One commonly used score to calculate the PS is called the Eastern Cooperative Oncology Group Performance Status (ECOG PS), which was introduced by Zubrod and colleagues in 1960.[2] 

Eastern Cooperative Oncology Group Performance Status Scale

ECOG PS uses a 0 to 5 point system, giving six performance categories to stratify and assess patients.[2][3] The six performance categories are based on their ability to carry out daily activities and self-care and are:

• 0 - Fully active, able to carry out all activities without restriction
• 1 - Restricted in physically strenuous activity but able to perform light work or sedentary tasks
• 2 - Ambulatory and capable of self-care, but unable to work; up and about more than 50% of waking hours
• 3 - Capable of limited self-care, confined to bed or chair for more than 50% of waking hours
• 4 - Completely disabled, unable to perform any self-care; bedridden and completely confined
• 5 - Deceased

Clinical Significance and Limitations

Clinicians assign a single score that best describes the patient's current functional status, with higher scores indicating greater impairment. This scale assists in treatment decision-making, prognostic assessments, and eligibility for clinical trials, providing a standardized framework for evaluating patients' abilities to tolerate and benefit from cancer therapies.[4]

Individuals with higher ECOG PS scores, indicating greater functional impairment, often have diminished physiological reserves and may be less able to withstand the side effects and toxicities associated with aggressive therapies.[5] Therefore, clinicians must carefully weigh the potential benefits of treatment against the risks of exacerbating existing comorbidities or compromising quality of life. A patient's ECOG PS serves as a crucial guide for treatment decision-making, influencing the selection of therapy regimens that prioritize symptom palliation and supportive care over aggressive interventions. By aligning treatment approaches with patients' functional capacities and treatment goals, healthcare providers can minimize treatment-related morbidity and mortality, optimize patient outcomes, and enhance the overall quality of cancer care.[6]

ECOG PS is particularly useful for quick assessments and communication among healthcare providers. However, some critics argue that its categorical nature may lack the granularity needed for nuanced patient evaluations. It is a one-dimensional functional rating predominantly evaluated by physicians, making it subjective and susceptible to bias.[7]

Another similar scale, the Karnofsky Performance Status (KPS) assesses performance on a percentage scale from 0 to 100, offering a more granular evaluation of functional capacity, with higher scores indicating better performance.[2] KPS scale offers a more continuous assessment, allowing for finer distinctions in functional status, which can be advantageous in certain contexts, such as tracking changes in performance over time or assessing subtle differences in patient functioning. However, the KPS scale may be more time-consuming to administer and may require additional training for accurate interpretation.

Clinicians may choose to use one scale over the other based on their familiarity, clinical workflow, and the specific needs of their patient population. Both scales have been found to underrepresent the degree of functional impairment in older adults with cancer.[8]

Conclusion

In summary, ECOG PS is a vital tool in oncology for evaluating a patient's functional capacity and general well-being. Its clinical significance lies in its ability to provide a standardized measure of a patient's performance status, aiding clinicians in making informed decisions regarding treatment strategies and prognostic assessments. This not only assists in determining the appropriate intensity of therapy but also allows for the identification of patients who may benefit from supportive care interventions to optimize their quality of life during cancer treatment.

Moreover, ECOG PS also serves as a crucial parameter for clinical trial eligibility and stratification.[9] By systematically categorizing patients based on their functional status, ECOG-PS ensures a degree of homogeneity within study cohorts, facilitating the comparison of treatment outcomes across groups with similar baseline characteristics. In recent times, there has been increasing advocacy for the incorporation of patients with diminished performance status (such as ECOG PS 2) into clinical trials, unless there exists a scientific or clinical justification for their exclusion based on established safety criteria.[9][10][11]

Overall, the significance of ECOG PS extends beyond individual patient care to encompass its role in guiding treatment decisions, prognostic assessments, and the advancement of oncologic research.