, according to a study published in .
The study found trials that failed to show improved quality of life often reported their quality of life outcomes more favorably. Non–immunotherapy-targeted drugs were found to lead to worse quality of life outcomes more often than did cytotoxic agents. And, while there is an association between quality of life benefit and overall survival, no such association was found with progression-free survival.
“In this study, we evaluated the outcomes of cancer drug trials with regard to patients’ quality of life and found that only a quarter of phase 3 cancer drug trials in the advanced-disease setting demonstrated improved quality of life,” wrote authors who were led by Bishal Gyawali, MD, PhD, of the Cancer Research Institute, Queen’s University, Kingston, Ont.
“Improved quality of life outcomes were associated with improved overall survival but not with improved progression-free survival. Importantly, almost half of the cancer drugs drug trials that showed improved progression-free survival showed no improved overall survival or quality of life (i.e., PFS-only benefit). Some reports included conclusions regarding quality of life (QOL) findings that were not directly supported by the trial data, particularly for inferior or non–statistically significant QOL outcomes, thereby framing the findings in a favorable light or downplaying detrimental effects of the study intervention on QOL. Furthermore, contrary to common perception, inferior QOL outcomes were more common with targeted drugs than cytotoxic drugs. Taken together, these findings have important policy implications,” the authors wrote.
These findings are based on the results of a cohort study of 45 phase 3 research clinical trials of 24,806 patients. Only a small percentage of patients showed QOL benefits. The study found that industry-funded clinical trial reports often framed QOL findings more favorably than was warranted by the data.
The study found improved QOL with experimental agents in 11 of 45 randomized controlled trials (24.4%). Studies that reported improved QOL were more likely to also show improved overall survival as compared with trials in which quality of life was not improved (7 of 11 [64%] versus 10 of 34 [29%] trials). For improved progression-free survival, however, there was no positive association (6 of 11 [55%] trials versus 17 of 34 [50%] trials without improved QOL). Among six trials reporting worsening QOL, three (50%) were trials of targeted drugs. Among 11 trials reporting improved QOL, 6 (55%) were trials of immunotherapy drugs. Among the 34 trials in which QOL was not improved compared with controls, the findings were framed favorably (versus neutrally or negatively) in the abstract or conclusions in 16 (47%), an observation that was statistically significantly associated with industry funding (chi-squared = 6.35; P = .01).
“It is important to clearly understand and communicate the effects of cancer drugs”
To fulfill the obligation to inform patients about proposed treatments, the authors wrote that it is important to clearly understand and communicate the effects of cancer drugs on patient quality of life alongside their effects on overall survival and intermediate end points such as progression-free survival. “Patients with advanced cancer expect treatment to help them live longer or have better lives,” the authors wrote. In that respect, in clinical trials of cancer medicines, overall survival and quality of life are the most important measures. Toxicity profiles and disease progression delays do not reliably predict quality of life, and studies have shown poor correlations between quality of life, overall survival, and progression-free survival. This raises the question of validity of progression-free survival as a surrogate endpoint. “Progression-free survival is meaningless without overall survival or quality of life gains,” Dr. Gyawali said in an interview.
Writing in , Dr. Gyawali stated that, because progression free survival “does not directly measure how a patient feels or functions, or how long a patient lives, progression-free survival was not intended to inform clinical practice or establish whether a new therapy provides clinically meaningful benefits for patients. However, over the past 2 decades, it has become the most common primary endpoint in oncology clinical trials. We are deeply worried about how the term survival in this phrase can influence clinical practice and patient choices. We propose replacing the phrase progression-free survival with a less ambiguous term: progression-free interval.”
In JAMA Oncology, Dr. Gyawali aimed to elucidate relationships between QOL, overall survival, and progression-free survival, and to assess, as well, how QOL results are framed, especially in industry-sponsored research. When drug trials they analyzed showed no change in QOL but reported that QOL did not worsen or QOL was maintained rather than stating that QOL did not improve, or if there was downplaying of worse QOL outcomes, the study had favorable interpretation, Dr. Gyawali and associates wrote. The expectation of patients receiving cancer drugs would be improved QOL rather than “not worse” QOL, Dr. Gyawali said.
Regarding the finding that QOL outcomes were described as favorable in 47% of trials with unimproved QOL outcomes, Dr. Gyawali said, “the bias in reporting should be corrected by the reviewers and editors of journals. Also, quality of life reporting should be made mandatory. Without unbiased quality of life information, informed decision making on whether or not to use a certain drug is impossible. Patients and physicians need to know that information. Regulators can demand that this should be mandatory in all trials in noncurative settings.”
He remarked further on the worsening QOL in some targeted drug trials, “People tout chemo-free regimens as automatically having better quality of life, but that doesn’t seem to be the case. Targeted drugs can have a severe impact on quality of life, probably due to prolonged duration of side effects. Quality of life should be measured and reported for all drugs.”
Dr. Gyawali and associates noted the limitation in that several studies with negative QOL results are not published at all or are published after a considerable delay, so the present observations may understate the issues that have been raised.
Dr. Gyawali declared that he received no funding and disclosed no conflicts of interest for this study.