Presence of comorbidities is associated with fewer patient-physician discussions regarding clinical trials, with fewer offers made and less patient participation, according to a report published in JAMA Oncology. Updating eligibility criteria would increase access to new treatments in trials.
Clinical trial participation faces many barriers to enrollment, one of which is eligibility criteria. Although other factors are greater, criteria regarding comorbidities are potentially easier to alter. “Some amount of selection bias in trials related to comorbidities is inevitable to maintain patient safety, but modernizing trial eligibility criteria could expand access to trials and speed their conduct,” the researchers reported.
In an effort to make study populations more similar to real-world patient populations and increase participation in clinical trials, stakeholders in the American Society of Clinical Oncology (ASCO), Friends of Cancer Research, and the US Food and Drug Administration (FDA) sought to determine if common criteria could be safely modified and what effect would the modifications have on clinical trial participation.
For the study, the researchers embedded a national survey within a treatment-decision tool accessible on several cancer-oriented websites. Participants had breast, lung, colorectal, or prostate cancer. Primary outcomes, measured via yes vs no responses, were patient discussion of a clinical trial with the physician; if discussed, whether trial participation was offered; and if offered, trial participation. Logistic regression analysis and simulations were used to analyze data collected from 5499 patients who were involved in treatment decisions within the past 3 months.
Of the 5499 patients, 62.6% (3420) were women, 37.8% (2079) were men, mean [SD] age was 56.63 [10.5] years, and 65.6% (3610) had 1 or more of 18 comorbidities. The most common comorbidity was hypertension (1924 patients [35%]).
Compared with those who reported no comorbidities, the presence of 1 or more comorbidities was associated with fewer trial discussions (44.1% vs 37.2%), fewer trial offers (21.7% vs 15.7%), and fewer patients participating in trials (11.3% vs 7.8%). Furthermore, an additional 6317 clinical trial registrations would have been generated in 2018 if the ASCO-recommended comorbidity restrictions were removed.
Study limitations included survey participants were less likely to be older or African American, the approach required self-reported data on disease conditions, and inability to examine outcome differences for patients with less common comorbidities. Furthermore, the researchers could not cross-validate the survey results with clinical records and information on comorbidity severity was lacking.
Despite the study limitations, the researchers conclude that changes to eligibility criteria to include older patients and those with well-managed comorbidities could be safely achieved. However, they state that most changes are more likely to be modifications to rather than elimination of criteria.
Unger JM, Hershman DL, Fleury ME, Vaidya R. Association of patient comorbid conditions with cancer clinical trial participation [published online January 10, 2019]. JAMA Oncol. doi: 10.1001/jamaoncol.2018.5953