Immune response evaluation criteria in solid tumors for assessment of atypical responses after immunotherapy

Abstract

In 2017, immune response evaluation criteria in solid tumors (iRECIST) were introduced to validate radiologic and clinical interpretations and to better analyze tumor’s response to immunotherapy, considering the different time of following and response, between this new therapy compared to the standard one. However, even if the iRECIST are worldwide accepted, to date, different aspects should be better underlined and well reported, especially in clinical practice. Clinical experience has demonstrated that in a non-negligible percentage of patients, it is challenging to determine the correct category of response (stable disease, progression disease, partial or complete response), and consequently, to define which is the best management for those patients. Approaching radiological response in patients who underwent immunotherapy, a new uncommon kind of target lesions behavior was found. This phenomenon is mainly due to the different mechanisms of action of immunotherapeutic drug. Therefore, new groups of response have been described in clinical practice, defined as “atypical responses,” and categorized into three new groups: pseudoprogression, hyperprogression, and dissociated response. This review summarizes and reports these patterns, helping clinicians and radiologists get used to atypical responses, in order to identify patients that respond best to treatment.

Efficacy and Side Effects of Irinotecan Combined with Nedaplatin versus Paclitaxel Combined with Cisplatin in Neoadjuvant Chemotherapy for Locally Advanced Cervical Cancer and Tumor Marker Analysis: Based on a Retrospective Analysis

“…In recent years, the incidence of CC has been high worldwide [ 16 ]. About 600000 women are diagnosed with CC each year, with a mortality rate of 34 percent.…”

“…Using the evaluation criteria for solid tumors [ 16 ]: (Response Evaluation Criteria in Solid Tumors, RECIST) 1.1 as an evaluation criterion (complete response, CR), (partial response, PR), (stable disease, SD), and (progressive disease, PD), CR indicates that all lesions disappeared, and no new lesions were found; PR was as follows: compared with the baseline period, the sum of the relative values of the maximum diameter of the tumor decreased by ≥30%; SD was as follows: between PR and PD; PD was as follows: compared with the baseline period, the tumor diameter increased by >20% compared with the maximum and minimum, or new lesions appeared. Objective response rate (ORR) was as follows: ORR = (CR + PR)/total number of people∗100%.…”

Radiological findings in non-surgical recurrent hepatocellular carcinoma: From locoregional treatments to immunotherapy

“…The advent of all the above-mentioned strategies, alone or combined, introduced a new class of response[ 52 ]. While about 8% can show a hyperprogression, a new atypical response is included in the iRECIST criteria[ 63 ]. However, no predictive biomarkers can help clinicians to determine the risk of atypical response during immunotherapy, and only the radiological approach, both with CT and MRI, can help follow patients during the treatment.…”

Immune-related dissociated response as a specific atypical response pattern in solid tumors with immune checkpoint blockade

“…These criteria are consistent with previous suggestions made by other investigators. 6 , 22 The lesions to evaluate DR may be primary lesions or metastatic lesions located in various organs. Although CR/PR and PD can be identified for different target lesions, the overall response evaluation for an individual patient could be PR, SD, or PD, which is dependent on the extent of the change for responding and nonresponding lesions ( Figure 2 ).…”