Paradoxical progression.

Did you know there is a subset of non-small cell lung cancer (NSCLC) that finds immune checkpoint inhibition to be its fertilizer of choice? "Hyperprogressive disease” is the term coined in the literature for this phenomenon of increased tumor growth upon administration of ICI, but a clear consensus definition is still lacking. This French retrospective study of 406 patients receiving ICI for NSCLC aims to remedy that. Among 5 proposed definitions for hyperprogressive disease, the winning one—so deemed by proving most correlated with survival and most distinguishable from plain ole progressive disease—was a change in tumor growth rate pre- and post-ICI. To be exact, monthly tumor volume increase during ICI therapy must be 50% higher than the monthly increase before treatment. Shockingly, this was the case in 14% of the patients examined. TBL: ICI is an amazing advancement in the treatment of NSCLC, but, for cases where it isn't helping, it may be harming more than we realize. | Kas, JAMA Oncol 2020