The criteria for measuring treatment response in malignant pleural mesothelioma is being revised—again. Researchers are hopeful that the new criteria will improve the quality and value of mesothelioma clinical trials and move researchers closer to a cure.
Researchers at the University of Chicago and the National Centre for Asbestos Related Diseases in Australia are proposing new modifications to the “modified RECIST” criteria by which researchers currently assess the response of mesothelioma tumors.
In order for mesothelioma clinical trials to be truly valuable—and have any chance of leading to a cure—researchers must be “on the same page” in how they assess the size of mesothelioma tumors and their response to treatment.
Because malignant mesothelioma is so rare, there are fewer studies focused specifically on this cancer and those studies tend to be smaller than trials involving other types of cancer. Standardization is especially critical for accurate results.
History of RECIST and Mesothelioma
The Response Evaluation Criteria in Solid Tumors (RECIST) is a set of rules designed to help cancer doctors and researchers determine if a tumor has responded, stayed the same (stabilized), or worsened (progressed) on a given treatment.
Originally published in 2000 by an international collaboration of cancer researchers in the US, Europe, and Canada, RECIST was modified in 2004 by mesothelioma experts who found the original criteria too restrictive for evaluating pleural mesothelioma. They called their new criteria “modified RECIST”.
While pleural mesothelioma is a type of solid tumor, the location of mesothelioma tumors on internal membranes and their irregular shape make them difficult to measure in the same way other types of solid tumors are measured.
The original RECIST criteria was revised as “RECIST 1.1” in 2009, but mesothelioma researchers have continued to use the 2004 “modified RECIST” as the standard for assessment of mesothelioma tumor response.
A New Way to Measure Mesothelioma Tumor Response
In a new article published in the Journal of Thoracic Oncology, Samuel Armato III of the University of Chicago and Anna Nowak of the University of Western Australia propose “modified RECIST 1.1 for mesothelioma” which they say is a “much-needed update”.
The proposed new guidelines incorporate recommendations from RECIST 1.1 and include new mesothelioma-specific approaches to issues such as
- what constitutes “minimally measurable disease”
- what is an acceptable measurement location
- how to assess pleural disease that can’t be measured
- how to handle the evaluation of lymph nodes
- accommodations for bilateral pleural disease (most mesothelioma tumors occur on one side of the chest)
The researchers say they formulated the new guidelines based on mesothelioma research done since the development of “modified RECIST” and that they align that set of standards with RECIST 1.1 for the first time.
“Adoption of the modified RECIST 1.1 guidelines for mesothelioma is recommended to harmonize the application of tumor measurement and response assessment across the next generation of clinical trials in this disease,” concludes the article summary.
Mesothelioma clinical trials are often the best treatment option for patients who have failed to respond to standard cancer treatment or whose cancer has come back after treatment.
Armato, SG and Nowak, AK, “Revised Modified RECIST Criteria for Assessment of Response in Malignant Pleural Mesothelioma (Version 1.1)”, May 9, 2018, Journal of Thoracic Oncology, Epub ahead of print, https://www.researchgate.net/publication/325053234