Pseudoprogression and Immunotherapy Phenomena

Area of Science:

• Oncology
• Immunotherapy
• Clinical Trial Design

Background:

• Traditional Response Evaluation Criteria in Solid Tumours (RECIST) assess tumor shrinkage for chemotherapy response.
• Applying RECIST to immunotherapy is challenging due to phenomena like pseudoprogression.
• Pseudoprogression involves initial tumor growth preceding a delayed treatment response.

Purpose of the Study:

• To highlight the limitations of RECIST in evaluating immunotherapy response.
• To define and explain the concept of pseudoprogression in cancer immunotherapy.
• To emphasize the importance of recognizing pseudoprogression for patient management.

Main Methods:

• Review of existing literature on cancer treatment response criteria.
• Analysis of clinical observations in patients undergoing immunotherapy.
• Comparison of RECIST criteria with observed immunotherapy treatment patterns.

Main Results:

• RECIST criteria may misinterpret pseudoprogression as disease progression.
• Initial tumor growth or new lesions in immunotherapy can represent pseudoprogression, not true progression.
• Delayed tumor shrinkage or stabilization can occur after initial apparent progression.

Conclusions:

• Advanced practitioners must understand pseudoprogression to accurately assess immunotherapy efficacy.
• Recognizing pseudoprogression prevents premature discontinuation of potentially effective immunotherapy.
• Educating patients about pseudoprogression is crucial for adherence to treatment plans.