A Look at Immunotherapy’s Potential for Head and Neck Cancer Treatment

by Susan Bernstein •

Combination therapy may work due to the “abscopal effect,” where a patient experiences regression of metastatic cancer distant from the site of local radiation, possibly a systemic response, said Dr. Sunwoo. He shared a case of a female patient with melanoma who had a growing paraspinal mass and high levels of pain. She started ipilimumab therapy, but her cancer slowly progressed. Once she started a combination therapy of radiation and ipilimumab, her cancer responded, and she progressed to stable disease.

This led to a new trial at Stanford of ipilimumab and radiation in Stage IV melanoma. So far there have been three complete and three partial responders, and five stable patients, he said. Mass cytometry revealed potentially predictive markers for positive response: Responders had higher central-memory T cells that express IL-2. Research in this area may point the way to more effective treatment of patients with aggressive head and neck cancers, the panel concluded.

Susan Bernstein is a freelance medical writer based in Georgia.

Take-Home Points

  • The programmed-death ligand (PD-1/PD-L1) pathway is an essential factor in immunotherapy. The immune system recognizes a tumor cell as foreign and sends lymphocytes to infiltrate it and mount a cytotoxic reaction. Tumor cells respond by producing PD-1 to bind to the receptor on the T cells and turn them off.
  • Anti-PD-L1 is a negative co-stimulator, said Dr. Koh. PD-L1 expression is in response to IFN-γ expressed by T cells. This is an example of adaptive resistance.
  • Radiation can make the tumor more sensitive to PD-L1 therapy, leading to enhanced tumor control and improved survival.