There are two performance scales: the Eastern Cooperative Oncology Group (ECOG)/WHO system and the Karnofsky Performance Status (KPS) scale. Each ranks your functioning and ability to care for yourself.
Performance status is often mentioned in the setting of clinical trials, where researchers use them as a way to ensure results are reproducible in people with similar health conditions. But it is essential in the overall care and management of anyone living with cancer because it can help quantify a treatment’s effect on your quality of life.
This article explains ECOG performance status and KPS performance status, as well as how to interpret scores.
What Performance Status Reveals
ECOG performance status or KPS determine how well you are doing with your activities of daily living, or ADLs. This says a lot about the current state of your disease and what treatments may be viable options for you.
A healthcare provider may reference performance status:
To see if/how your cancer is progressing To estimate prognosis To determine if you are in reasonable health to tolerate treatments such as chemotherapy, surgery, or radiation therapy To evaluate your response to treatment As selection criteria for clinical trials To help understand if you require special assistance so that appropriate referrals can be made to improve quality of life
This is why your oncologist or a clinical trial investigator asks all of those questions about your daily life.
Performance Status Scales
Two primary performance scales are used to measure performance status for those living with cancer: the Eastern Cooperative Oncology Group (ECOG)/WHO system, and the KPS.
ECOG performance status ranks performance status on a scale of 0 to 5. KPS uses a scale of 0 to 100. Note that these scales differ in whether a lower number or a higher number means better performance status. With the ECOG/WHO performance status, the ideal score zero, whereas with the KPS the ideal number is 100.
ECOG/WHO Performance Status
0: Fully active, no restrictions on activities. A performance status of 0 means no restrictions in the sense that someone is able to do everything they were able to do prior to their diagnosis. 1: Unable to do strenuous activities, but able to carry out light housework and sedentary activities. This status basically means you can’t do heavy work but can do anything else. 2: Able to walk and manage self-care, but unable to work. Out of bed more than 50% of waking hours. In this category, people are usually unable to carry on any work activities, including light office work. 3: Confined to bed or a chair more than 50% of waking hours. Capable of limited self-care. 4: Completely disabled. Totally confined to a bed or chair. Unable to do any self-care. 5: Death
Karnofsky Performance Status
100: Normal, no symptoms or evidence of disease90: Minor symptoms, but able to carry on normal activities80: Some symptoms, normal activity requires effort70: Unable to carry on normal activities, but able to care for self60: Able to care for most needs, some occasional assistance with self-care50: Needs considerable assistance with self-care, frequent medical care40: Disabled; needs special care and assistance30: Severely disabled; possibly hospitalized20: Very ill; significant supportive care is needed10: Actively dying0: Death
How Performance Status Impacts Treatment
Many of the treatments for cancer, whether surgery, chemotherapy, radiation therapy, targeted therapies, clinical trials, or stem cell transplants, can be challenging enough for those who are very healthy at the time of diagnosis.
Therefore, ECOG performance status and KPS can help people with cancer and their healthcare providers weigh the potential benefits and risks of different options.
This is even more important now that there are many more treatment choices than in the past. For example, people with lung cancer who have a poor performance status are more likely to experience adverse effects and have a poorer overall survival if they receive standard chemotherapy.
In contrast, targeted therapies, when appropriate, are much better tolerated by those who have a poor performance status.
Performance Status and Quality of Life Issues
When talking about cancer treatment, quality of life issues can sometimes be pushed to the back burner. By routinely measuring quality of life with ECOG performance status and KPS, and noting changes, oncologists can be more aware of problems that are reducing quality of life and recommend appropriate resources.
This may include options such as physical therapy, occupational therapy, and cancer rehabilitation (such as the STAR program), equipment ranging from oxygen to a walker or wheelchair, as well as the need for in-home health services or a referral for transitional or hospice care.
Predicting Prognosis
Many people with cancer and their families ask about prognosis. While it may seem morbid to ask about life expectancy, having an idea of prognosis (while knowing that healthcare providers including oncologists do not have a crystal ball and that everyone is different) allows people to consider advance care planning and end of life issues, and can also help people have a better idea when hospice may be an appropriate choice.
Both the KPS and ECOG scales appear to be equally effective in predicting survival, with studies showing that survival drops roughly by half with each adverse change in performance status. (For example, a person with an ECOG performance of 3 would be expected to survive only half as long as someone with an ECOG performance of 2.)
Use in Clinical Trials
Many clinical trials require patients to have a good performance status before trying an experimental treatment.
Many people get frustrated by this. Why is it so necessary? Doesn’t it exclude people who could benefit from an investigative treatment?
There are a few reasons researchers use the criteria of performance status to determine eligibility for entering a clinical trial.
One is so that their results are “reproducible.” In other words, if another researcher were to do a similar trial, it’s important to start with people in the same general health condition.
Another reason, however, is important for you personally. By recording performance status, healthcare providers are able to monitor the new treatments to see if they have a negative effect on performance status.
For example, if people responded to a drug but started with a performance status of 0, which dropped to 2, healthcare providers would then need to consider whether or not the side effects of the treatment justified the positive results they found in treating the cancer.
