iRECIST accurately detects pseudo-progression in lung cancer
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CHICAGO — The iRECIST guideline more accurately identified radiologic pseudo-progression than RECIST1.1 criteria among patients receiving anti-PD-1 treatment for non-small cell lung cancer, according to results presented at the International Association for the Study of Lung Cancer Multidisciplinary Symposium in Thoracic Oncology.
Sharyn I. Katz, MD, assistant professor of radiology at Hospital of the University of Pennsylvania, and colleagues reviewed electronic medical records of 228 adults with NSCLC consecutively treated with either nivolumab (Opdivo, Bristol-Myers Squibb; 80%) or pembrolizumab (Keytruda, Merck; 20%) between 2013 and 2016.
“There were 166 evaluable patients and 80% of all the patients with NSCLC were treated with nivolumab,” Katz said during her presentation.
Researchers assessed clinical response to anti-PD-1 therapy with CT imaging. If an image was clinically suspected of radiologic tumor pseudo-progression at first reimaging, researchers retrospectively radiologically analyzed the image to determine if subsequent imaging resulted in subsequent radiologic response or progression.
Researchers compared pseudo-progression and true-progression responses via RECIST1.1 and iRECIST.
Of 15 patients initially suspected of radiologic pseudo-progression, researchers confirmed 2% (n = 4) had nonprogression due to the radiologic response at subsequent reimaging. The other 11 cases were deemed true progression.
iRECIST better characterized radiologic pseudo-progression as nonprogression than RECIST 1.1 in all four cases. None of the four cases were deemed progression on iRECIST, whereas three cases were labeled progression on RECIST1.1.
“Both the unidimensional immune-related response criteria and the iRECIST result in delays in assessment at radiologic pseudo-progression due to requirement of confirmatory CT,” Katz said. “Unidimensional immune-related response criteria and iRECIST require validation in clinical trials.” – by Melinda Stevens
Reference:
Katz S, et al. Abstract OA02.01. Presented at International Association for the Study of Lung Cancer Multidisciplinary Symposium in Thoracic Oncology; Sept. 14-16, 2017; Chicago.
Disclosure: Katz reports no relevant financial disclosures.