Hyperprogression after Immunotherapy: Nivolumab. Analysis of Imaging Findings Associated with Hyperprogression and Tumor Growth Kinetics

Introduction The increased use of new checkpoint inhibitors in cancer therapy has led to the discovery of new unconventional responses, like pseudoprogression and hyperprogression disease (HPD). The study documents imaging findings of HPD and analyzes the growth kinetics in advanced metastatic cancers patients treated with immunotherapy. Methods We retrospectively reviewed patients treated with anti-PD-1 (anti-progressive disease-1) antibody therapy (nivolumab) between January 2017 and December 2017 at our institute. The patients who exhibited early and rapid progression rates after initiation of immunotherapy were further analyzed for tumor growth kinetics (TGKs) and imaging findings. All prebaseline, baseline, and post nivolumab imaging were retrospectively reviewed to assess the TGKs, time to treatment failure (TTF), and rate of progression according to Response Evaluation Criteria in Solid Tumors (RECIST) 1.1. Results Four patients with HPD had peculiar imaging appearance of unilateral circumferential nodular pleural thickening along with conglomerate pleural masses and effusions. Both primary and secondary sites progressed along with the appearance of new lesions in all these patients. The mean progression-free survival (PFS) was 32 days using Kaplan Meier analysis. Conclusion The unique and recurring imaging pattern of disease progression in patients with HPD as reported in our case series in addition to TGK ratio, and TTF may prove to be of additional help in early identification of this unique and ghastly outcome.