Too frequently, cancer clinical trial endpoints—and therefore oncologists’ discussions with patients about treatment options—reflect assumptions about the goals of therapy, rather than what patients themselves value and prioritize, according to researchers such as Jason N. Doctor, PhD, director of health informatics at the Leonard D. Schaffer Center for Health Policy and Economics, and associate professor in the School of Pharmacy, University of Southern California in Los Angeles, California.
Treatments associated with longer median progression-free survival (PFS), or overall survival (OS), for example, are often assumed to be the best choices for a patient. Researchers may set a survival landmark endpoint, like 12-month PFS rate, with research or regulatory considerations in mind, rather than with a goal of informing the patients on whom the drug will be used.
“This is problematic because patients may have goals or aspirations that require patient-centered landmarks,” Dr Doctor told Cancer Therapy Advisor. “A patient may want to live long enough to see her daughter graduate college. If the researcher sets the survival landmark, then these personal goals are ignored and may be missed.”
Average or median survival-time endpoints assume that each year of life “has the same value no matter when it is received,” he explained. “For example, average survival assigns the same value to a treatment that offers a 25% chance of living 4 years as it does to a treatment that offers a 100% chance of living 1 year.”
But these alternatives might well represent very different probable outcomes from a patient’s perspective.
“We might favor a safe bet that offers limited but certain survival, or we might favor a risky therapy that offers the chance of a hopeful outcome,” Dr Doctor explained. “In contrast, mean survival summarizes the expected outcome or expected consequence of our choices. These 2 things are different.”
Oncologists should convey the evidence base to patients—including which endpoints were employed in key clinical trials—and think about those endpoints’ implications in light of each patient’s goals and values, Dr Doctor said.
“One useful clinical strategy would be to discuss a patient’s survival goals or aspirations within the context of what we know about PFS landmarks for different therapies,” said Dr Doctor. “Patients may have things they want to accomplish while tumor progression is halted. They may also realize they have to devote greater time and attention to therapy when the tumor starts progressing again.”
“I’d like to see a more patient-centered approach, 1 that considers patients’ desires,” Dr Doctor said. “Their reasons for survival are what matters. Right now we assume a year of survival is a year of survival, no matter when a patient gets it.”