Immune-related tumour response assessment criteria: a comprehensive review

Abstract

Growing emphasis on precision medicine in oncology has led to increasing use of targeted therapies that encompass a spectrum of drug classes including angiogenesis inhibitors, immune modulators, signal transduction inhibitors, DNA damage modulators, hormonal agents etc. Immune therapeutic drugs constitute a unique group among the novel therapeutic agents that are transforming cancer treatment, and their use is rising. The imaging manifestations in patients on immune therapies appear to be distinct from those typically seen with conventional cytotoxic therapies. Patients on immune therapies may demonstrate a delayed response, transient tumour enlargement followed by shrinkage, stable size, or initial appearance of new lesions followed by stability or response. These newer patterns of response to treatment have rendered conventional criteria such as World Health Organization and response evaluation criteria in solid tumours suboptimal in monitoring changes in tumour burden. As a consequence, newer imaging response criteria such as immune-related response evaluation criteria in solid tumours and immune-related response criteria are being implemented in many trials to effectively monitor patients on immune therapies. In this review, we discuss the traditional and new imaging response criteria for evaluation of solid tumours, review the outcomes of various articles which compared traditional criteria with the new immune-related criteria and discuss pseudo-progression and immune-related adverse events.

Phase Ib/II study of safety and efficacy of low‐dose decitabine‐primed chemoimmunotherapy in patients with drug‐resistant relapsed/refractory alimentary tract cancer

“…Cancer immunotherapy exhibited specific patterns of response in some cases with transient increase in tumor burden followed by long‐lasting PR or SD, termed pseudo‐progression 49. Conventional response criteria, RECIST v1.1, evaluated clinical response by reduction in tumor burden without any new lesions and might not be adequate in assessing response of immunotherapy, because it might underestimate the therapeutic benefit 49, 50. Accordingly, immune‐related response criteria, namely irRECIST and iRECIST, were proposed to standardize response assessment of cancer immunotherapy 50.…”

“…Accordingly, immune‐related response criteria, namely irRECIST and iRECIST, were proposed to standardize response assessment of cancer immunotherapy 50. These new criteria have potentially demonstrated some advantages over RECIST v1.1; however, robust validation is needed 49. Regardless, RECIST remained a highly validated and reproducible tool in assessment of treatment response 49.…”

“…These new criteria have potentially demonstrated some advantages over RECIST v1.1; however, robust validation is needed 49. Regardless, RECIST remained a highly validated and reproducible tool in assessment of treatment response 49. After all, continuation of treatment might be performed beyond the conventional definition of “progression” by RECIST v1.1 and be confirmed per the irRECIST and iRECIST in the future clinical trial.…”

EPSILoN: A Prognostic Score for Immunotherapy in Advanced Non-Small-Cell Lung Cancer: A Validation Cohort

“…Recently, combinations of ICIs with platinum-doublet chemotherapy (Keynote-189 and Keynote-407) and bevacizumab (IMpower150), as well as the association of nivolumab with Anti-Cytotoxic T-Lymphocyte Antigen 4 (anti-CTLA-4) agent ipilimumab (CheckMate 227), have shown survival benefit compared to standard chemotherapy, emerging as new treatment options for first-line setting in aNSCLC [7]. The introduction of these novel treatments in the clinical practice has generated several challenges, including the evidence of novel patterns of response and the management of new adverse events [8][9][10]. Despite the survival benefit obtained with ICIs, only a proportion of patients respond to immunotherapy and/or experience a durable clinical benefit [11].…”

Novel cancer therapies for advanced cutaneous melanoma: The added value of radiomics in the decision making process–A systematic review

“…In the precision medicine era, novel therapies generate radiologic patterns different from conventional ones. For example, treatment response after immunotherapy can be associated with pseudo-progression or flair phenomena, 45 meaning that the enlargement of old lesions and the appearance of new lesions soon after treatment may not reflect real disease progression. 26 In addition, activation of the immune system to fight cancer may lead to unwanted autoimmune-mediated toxic effects that may generate atypical patterns could be mistaken for progression disease or misdiagnosed delaying appropriate clinical management.…”