WHEN A CANCER THERAPY aims to prolong life, rather than cure the cancer, patients have to consider both the time they stand to gain and their quality of life over that period. They may have to decide between treatments that prioritize one or the other.

Increasingly, clinical trial investigators will collect health-related quality of life data while a patient receives a new medication or treatment. These data help to assess how health status influences the way a patient perceives their physical and mental well-being. A new study found that patients generally rate their quality of life as high during treatment as part of a clinical trial. But what happens afterwards?

The study, published in JAMA Network Open in March 2020, found that researchers typically neglect to measure quality of life during the remainder of a patient’s life, leaving gaps in what we know about the lifelong effects of new cancer drugs and other treatments. Lead study author Alyson Haslam, a chronic diseases epidemiologist at Oklahoma State University in Stillwater, spoke with Cancer Today about the study and the importance of understanding how a treatment impacts a patient’s well-being at different points in life.

CT: Why did you study quality of life in cancer clinical trials?
New cancer drug approvals by the Food and Drug Administration are increasingly based on so-called surrogate endpoints such as progression-free survival. A surrogate endpoint is a substitute for a direct measure—for instance, how long a patient survives. Progression-free survival tells us how long patients survive during or after receiving treatment without the cancer getting worse. It doesn’t necessarily tell us whether a new treatment helps a patient live longer. Patients care about survival time, especially if the cancer is metastatic. If there’s no real gain in survival time, the next thing patients want to know is whether the treatment provides some quality of life benefit, and for how long. We wanted to see how cancer clinical trials were accounting for this important metric.

CT: What did you find?
We looked at 149 oncology studies and found that most trials measured quality of life during treatment and shortly after. Quality of life was rarely measured for the duration of a patient’s life. Only five of the 149 studies (3.4%) measured quality of life up until a patient’s death. Studies that measured quality of life only during the treatment period and shortly after reported more positive outcomes on patient well-being than studies that measured quality of life until death. More than half of studies reported quality of life benefits for patients during and shortly after treatment. But only one of the five studies measuring quality of life until death found that treatment had a positive effect on well-being up until the end.

CT: Why does it matter when quality of life is measured?
Haslam: It’s important to assess quality of life over the entire period, because sometimes gains in quality of life during treatment can be offset by losses after. Having a better understanding of how a given treatment may impact well-being at all points can help doctors and patients have better discussions about what to expect from treatment and care.

CT: Is it difficult to measure something as subjective as quality of life?
Having a “good” quality of life can mean different things to different people. A patient’s expectations can impact their perceived well-being, and where they are in the treatment process can have an impact too. People who have been living with cancer for a long time might have different expectations for “good” quality of life than someone who was just diagnosed. We can measure a patient’s quality of life like you would measure a score on a test. But if a patient reports an 80% quality of life measure, is that a good thing or a bad thing? Perceptions vary from person to person, making it difficult to draw the cutoff between “good” and “bad.”

CT: Should patients talk to their doctors about quality of life?
Patients should have a discussion with their doctors about quality of life before starting treatment. That talk should include what to expect from treatment, both short- and long-term. It should also include a discussion about your values and what you hope to get out of treatment. This can help your physician gauge what is important to you and better tailor a treatment plan. It’s important to periodically revisit quality of life with your physician during treatment too, as your values and desires may change.

This interview has been edited and condensed for clarity.