Elsevier

Journal of Thoracic Oncology

Volume 7, Issue 11, November 2012, Pages 1728-1734
Journal of Thoracic Oncology

Original Article
Optimization of Response Classification Criteria for Patients with Malignant Pleural Mesothelioma

https://doi.org/10.1097/JTO.0b013e318269fe21Get rights and content
Under an Elsevier user license
open archive

Introduction

Response-assessment metrics play an important role in clinical trials and routine patient management. For patients with malignant pleural mesothelioma (MPM), the standard for response assessment is image-based measurements of tumor thickness made according to the modified RECIST (Response Evaluation Criteria in Solid Tumors) protocol. To classify tumor response, changes in tumor thickness are compared with the standard RECIST −30% and +20% cutoffs for partial response (PR) and progressive disease (PD), respectively, which are not specific to MPM. The purpose of this work is to optimize the correlation between tumor response and patient survival by assessing the validity of existing response criteria in MPM and proposing alternative criteria.

Methods

Computed tomography measurements of tumor thickness were acquired at baseline and throughout treatment for 78 patients undergoing standard-of-care chemotherapy. Overall survival was correlated with best response and first follow-up response using Harrell's C statistic. The response criteria for PD and PR were each varied in 1% increments to obtain optimized classification criteria. The performance was cross-validated using a leave-one-out approach.

Results

Median survival was 14.9 months. The performance of the standard RECIST criteria in correlating response with survival was C=0.778, whereas the optimized performance of C=0.855 was obtained with criteria of −64% for PR and +50% for PD. After cross-validation, this performance was slightly reduced to C=0.829.

Conclusions

Optimized tumor-response classification criteria were obtained for patients with MPM. These criteria improve the correlation between image-based response and patient survival.

Key Words

Malignant pleural mesothelioma
Therapy response assessment
Chest computed tomography

Cited by (0)

Disclosure: Dr. Armato receives royalties and licensing fees through the University of Chicago related to computer-aided diagnosis. Dr. Nowak is a remunerated speaker for Eli Lilly and has received travel funding from Eli Lilly.

Supported, in part, by The University of Chicago Comprehensive Cancer Center, the Raine Medical Research Foundation, United States Public Health Service grant number R01CA102085, the Simmons Mesothelioma Foundation, the Kazan Law Firm's Charitable Foundation, the National Health and Medical Research Council, Australia, and the Cancer Council Western Australia.