This innovative cancer treatment could cause... a new cancer

A pioneering treatment that raises questions: could CAR T-cell therapy, designed to fight certain cancers, itself cause a new cancer? A recent study brings this issue to light.


CAR T-cell therapy, which genetically modifies patients' immune cells to target specific cancers, represents significant hope. Approved since 2017, this treatment now raises concerns about its risks, despite its successes.

Cases of secondary cancer have been observed after chemotherapy and radiotherapy. However, only about twenty cases of T-cell cancer following CAR T-cell therapy have been recorded in the United States, making these incidents extremely rare.

A new study from The New England Journal of Medicine reports the case of a 71-year-old patient who developed intestinal cancer after CAR T-cell therapy for multiple myeloma. The cancerous cells originated from the modified CAR T cells, raising questions about the genetic modification process.

Scientists do not know whether the modification of the T cells caused this cancer or if the cells were already precancerous. In-depth research shows genetic alterations in the modified cells, but no direct cause has been identified.

To minimize these risks, it is crucial to analyze the DNA of CAR T cells before infusion and to turn to more precise methods like CRISPR-Cas9. Cases of secondary cancers remain rare, but increased vigilance is necessary to optimize the safety of this promising therapy.