New system accurately and reliably captures patient experience with cancer drug side effects

In cancer clinical trials, symptom side effects patients experience, like nausea, are typically reported by doctors, and not directly by patients. Previous research has shown that doctors under-report these symptoms.

Ethan Basch, MD, MSc, director of the UNC Lineberger Cancer Outcomes Research Program and associate professor of medicine and public health at the University of North Carolina School of Medicine, has led studies and national initiatives to enable patients to directly report their own symptoms during cancer drug development. In an article published in JAMA Oncology, a study led by Basch and colleagues for the National Cancer Institute shows that a system they developed accurately and reliably captures the patient experience with cancer drug side effects.

"This is a landmark study because patient-reported information has not been used for measuring side effects in cancer research," said Basch, the paper's senior author. "This study shows that these patient-reported measures perform well, and are ready for implementation in cancer research."

The study tested the reliability and validity of a group of measures previously developed by Basch and colleagues for the National Cancer Institute to test patient-reported adverse events. Basch as well as other authors were contracted to develop the measures, which are called the Patient Reported Outcomes version of the Common Terminology Criteria for Adverse Events, or PRO-CTCAE.

The researchers tested 124 of the measures that had been developed for the NCI to question patients about 78 potential adverse events. The study involved nearly 1,000 patients who were undergoing outpatient chemotherapy, radiation therapy or both at one of nine U.S. cancer centers or oncology practices.

"In order to establish the validity of the 124 questions in the survey we developed using the NCI measures, we conducted statistical analyses to compare the new measurement tools to other metrics, such as to clinician reports of patient function and to data on the underlying characteristics of the patients' cancer and their treatments," Basch said.

The study found that the PRO-CTCAE measures performed extremely well, demonstrating validity and reliability across items.

Basch said that the study is important as it validates measures developed to obtain reports of adverse events directly from patients. He noted a study by researchers in Europe published earlier this year in the Journal of Clinical Oncology found that doctors under-report side effects by as much as half in cancer trials. (Di Maio, et al. 2015)

"Patient reporting improves the quality of information that we have about how patients feel and function, and it provides a fuller picture of the impact of treatments on people's lives," Basch said. "This is important because in risk-benefit balancing for drugs, we need to have comprehensive and valid information about risk."