I need hardly mention that most clinical encounters with patients include the conduct of a physical examination—vital signs, heart and lung examination, palpation of the abdomen, etc. But for me, most of the time, 90% of what I care about on the physical examination is apparent when the patient enters my office/examining room and walks the 10 feet to the chair next to my desk. Is the patient using a wheelchair or walker or otherwise less than fully ambulatory? Is he/she alert and oriented? Cheerful, good spirits?
One of the most important measures in the assessment of a cancer patient is the performance status (PS). The performance status is an estimate of the patient’s well-being and ability to cope with their activities of daily living. It evaluates how a patient is able to care for him/herself—getting dressed, eating, bathing, cooking, working.
PS is a very powerful predictor of prognosis, tolerance of treatment, and survival. Multiple scales have been devised over the years in order to assign objective measures of PS to patients. Two are widely used in the U.S. One is the Karnofsky Performance scale (KPS), which rates patients on a scale of 10-100%. The other is the scale developed and used by the Eastern Cooperative Oncology Group (ECOG), which rates patients on a scale of 0 to 4. I will describe the latter since it is the one I use, is simpler, and is, I believe, significantly more widely used.
Basically, a rating of 0 indicates that the patient is fully active and able to carry on all of his/her activities of daily living without any significant restrictions. On the other hand, a rating of 1 means that the patient is ambulatory but symptomatic and able to carry out most of his/her daily activities. Thus, a patient with rectal bleeding or some abdominal pain controlled by analgesics or an occasional cough would fall into this category.
When you get to a rating of 2, you are starting to experience significant impairment of ambulation or work activities. At a level of 2 you are still able to ambulate or be out of bed or work more than 50% of the time, but there is more than simple symptomatology as in those who have a PS of 1. For those with a PS of 3, the impairment has increased to restrict the patient to bed or a chair more than 50% of the time and they have only limited self-care. A performance status of 4 restricts a patient to bed or a chair full-time or virtually 100% of the time and they are effectively totally disabled.
The significance of the performance status is highlighted by the fact that it is almost always an eligibility criterion for clinical trials. In order to be eligible for a trial a cancer patient must have a PS of 0 or 1. A score of 2 or worse would interfere with the patient’s likelihood of benefiting from the therapy and therefore such patients are avoided in trials.
More generally, it is also true that a PS or 2 or 3 is associated with a dramatically reduced likelihood of benefiting from chemotherapy treatment and concomitant increased risk of toxicity and adverse effects. Innumerable studies have shown that after drugs are proven effective in clinical trials, their efficacy is dramatically reduced in post-marketing studies, largely reflecting the use of the drugs in patients who would never have been allowed near a study, but especially because of ignoring PS. Oncologists may ignore the PS level in prescribing chemotherapy because of family or patient desperation, a reluctance to disappoint families, or perhaps because of cupidity. Nonetheless, a study I collaborated on with Ho0lly Prigerson of Cornell published in JAMA Oncology in 2016 looked at 661 patients with advanced cancer at six centers. We found that patients with a poor performance status did not benefit from chemotherapy and in fact had worse quality of life as a consequence of treatment.
Today I saw in clinic a longstanding patient, a 64-year-old man with colon cancer who has received several chemotherapy regimens and has recently progressed. As I spoke to him, I was considering prescribing a new recently approved drug for his disease. He almost never complains but today he said that he was feeling weaker and less energetic than usual. I asked what had changed. He told me that he lives in a six-floor walk-up in the Bronx and for the last few weeks he has had to pause on the fifth floor to catch his breath. I prescribed the new drug.
Alfred I. Neugut, MD, PhD, is a medical oncologist and cancer epidemiologist at Columbia University Irving Medical Center/New York Presbyterian and Mailman School of Public Health in New York. Email: [email protected].
This article is for educational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment, and does not constitute medical or other professional advice. Always seek the advice of your qualified health provider with any questions you may have regarding a medical condition or treatment.
