‘Factories’ that fight tumours from within discovered

Lurking deep inside some tumours are “factories” full of immune cells that help the body fight a rearguard action against cancer and are key to helping some patients recover, new research has shown.

In recent years, doctors have turned to a new treatment for cancer, immunotherapy, which works by leveraging the body’s immune system to fight tumours.

The technique has largely focused on white blood cells called T-cells, which are “trained” to recognise and attack cancer cells.

But the innovative treatment only works well for around 20% of patients, and researchers have been trying to understand why some people respond better than others.

Three papers published yesterday in the journal Nature point the way, identifying a key formation inside some tumours: tertiary lymphoid structures (TLS).

These structures function like “factories or schools” for immune cells that help the body fight cancer, Wolf H Fridman, a professor emeritus of immunology at the Cordeliers Research Centre of the Paris Descartes University medical school, said.

He helped lead one of the studies.

“The cells need to be educated in schools, which are the tertiary lymphoid structures, where they effectively learn to recognise and attack cancer cells,” Fridman said.

Key to the findings is that Tcells are far from the only immune cells capable of taking the fight to cancer, with researchers finding the TLS were full of B-cells, a kind of immune cell that produces antibodies.

“We have been T-cell addicts for 15 years in cancer,” Fridman said with a laugh.

“We analysed these sarcomas to see what groups they had and what’s striking is that these B-cells appeared.”

Beth Helmink, a fellow in surgical oncology at the University of Texas’s MD Anderson Cancer Centre who worked on a second study, said the research changed perceptions of the role of B-cells in immunotherapy.

“Through these studies, we find that B-cells are not just innocent bystanders, but are themselves contributing in a meaningful way to the anti-tumour immune response,” she said.

The discovery is something of a surprise, as an abundance of B-cells in cancer patients has sometimes been seen as a marker for poor prognosis.

But the studies found that patients with high levels of Bcells inside TLS in their tumours were more likely to respond well to immunotherapy.