In some patients with cancer who have failed immune checkpoint blockade treatment, the addition of radiotherapy may bring about conversion to response.
This effect has been studied in various cancers, most famously in melanoma, in which a case study detailed treatment of a patient who was irradiated due to a mass compressing the spine after failing immunotherapy. After radiation, not only did the irradiated lesion respond, but so did lesions that were distant from the irradiated field, suggesting an abscopal effect.
Despite previous studies in other cancers, this effect is only currently being studied in breast cancer. Silvia Formenti, MD, associate director, Meyer Cancer Institute, Weill Cornell Medical College, New York, NY, and fellow researchers are doing just that.
“That is an interesting concept because something that has failed before now you add radiotherapy, and you can rescue and make the patient respond. I wish more often, before taking a patient off immunotherapy we could give a chance to irradiating one lesion, and see whether now you can rescue them and we can go to response,” said Dr. Formenti.
Dr. Formenti reports the following disclosures:
Grant/research support from: Bristol Myers Squibb, Varian, Janssen, Regeneron, Eisai, Merck
Honorario from: Briston Myers Squibb, Varian, Elekta, Janssen, Regeneron, GlaxoSmithKline, Eisai, Dynavax, Astra Zeneca, Merck