Melanoma Immunotherapy Most Effective in Older Patients

A well-aged tumor microenvironment, of the sort found in older cancer patients, may be more susceptible to checkpoint blockade, a form of cancer immunotherapy. This finding, reported by scientists based at the Wistar Institute, suggests that “aging” the tumor microenvironment—by depleting it of immune suppressive T cells—could improve immunotherapy response rates for younger cancer patients.

With each decade of life, the Wistar team discovered, the likelihood of progression of melanoma after treatment with anti-programmed cell death protein 1 (anti-PD1) immunotherapy decreased by 13%. This relationship between patient age and therapeutic response came as a surprise. Prior research by the Wistar team had shown that the tumor microenvironment in older patients promoted melanoma metastasis and resistance to targeted therapy with a BRAF inhibitor.

The new observation, however, seemed solid. It was based on an analysis of a multinational, multi-institutional cohort of almost 500 melanoma patients treated with pembrolizumab, ...