Hyperprogressive disease in patients receiving immune checkpoint inhibitors.

Hyperprogressive disease (HPD) is an unexpected response pattern observed in immune checkpoint therapy and associated with poor prognosis in several cancers. Such patients can't benefit from immunotherapy and even experience a rapid disease progression. At present, many researchers have explored the HPD phenomenon, but there is no consensual definition of HPD in different studies. The incidence of HPD is about 4%-29% in various tumors. Many studies demonstrated that HPD was associated with worse prognosis, but the mechanism of HPD has not yet been fully clarified. Predictive factors in patients with HPD before treatment is one of the keys to managing patients receiving immune checkpoint inhibitors. Some factors, such as MDM2/4 amplification, EGFR mutations, and old age may be risk factors for HPD, but the results are discordant in different studies. Performing imaging evaluation and biopsy as early as possible is the main method to avoid the iatrogenic injury of immunotherapy at present.