Merkel cell carcinoma is a rare but highly aggressive form of skin cancer known for its rapid growth and tendency to metastasize. Despite the promise of immune checkpoint blockade therapy, which can boost the body's immune response against cancer cells, nearly half of patients do not respond to this treatment. A new study published today in Cancer Discovery is providing insights into why some Merkel cell carcinoma patients respond to this type of immunotherapy while others do not.
In collaboration with scientists at Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Moffitt Cancer Center researchers conducted the largest and most comprehensive study to date on Merkel cell carcinoma. They analyzed samples from 116 patients using advanced multimodal techniques -; bulk and single cell RNA sequencing, spatial transcriptomics and multiplexed immunofluorescence -; to gain insights into the immune response and tumor characteristics.
Their findings reveal that specific immune cells, particularly tissue resident CD8 T cells and γδ T cells, play a crucial role in the body's response to immune checkpoint blockade therapy. The research team, co-led by Kenneth Tsai, M.D.
, Ph.D., vice chair of Pathology Research at Moffitt, and Jaehyuk Choi, M.
D., Ph.D.
, at Northwestern University, discovered that those who respond to immune checkpoint blockade therapy have higher levels of preexisting tissue-resident CD8 T cells or Vδ1 γδ T cells within their tumors. These cells .