A woman with late-stage breast cancer that had spread throughout her body is now completely clear of the disease, thanks to a treatment that used her own immune cells to destroy the cancer.

The doctors who treated the woman say while their approach is still experimental, they believe it could be adapted to treat other kinds of cancer as well.

“…Because this new approach to immunotherapy is dependent on mutations, not on cancer type, it is, in a sense, a blueprint we can use for the treatment of many types of cancer,” said Dr. Steven Rosenberg, the chief of the surgery branch at the National Cancer Institute’s Center for Cancer Research.

The team reports the case of a Florida woman named Judy Perkins, who was diagnosed in 2003 with breast cancer when she was still in her 30s. The disease returned 10 years later, creating tumours throughout her liver and chest.

Perkins underwent several rounds of chemotherapy but the cancer kept spreading and doctors gave her just months to live.

She agreed to take part in a clinical trial with the National Cancer Institute to try a new treatment involving immunotherapy. This growing area of medicine involves using the body’s own immune system to destroy cancer cells and has shown great promise in treating advanced melanoma.

The research team took a sample of Perkins’ tumours and sequenced her cancer’s DNA, as well as the DNA of her normal tissue, to see which mutations were unique to her cancer. 

The found 62 mutations, including four they knew could be targeted with T-cells called TILs, or tumour-infiltrating lymphocytes, which are white blood cells that attack invaders.

The team then grew large numbers of the TILs in the lab – 90 billion of them – and prepared to inject them back into Perkins bloodstream. But first, she had to undergo grueling medications to suppress her immune system and tamp down her other white blood cells. That then allowed the doctors to inject the lab-grown TILs to mount an attack against the cancer.

Perkins tells the BBC she began to feel better almost immediately, and could even feel the tumours shrinking in her chest after just one week.

The treatment is not only expensive but physically demanding and several other patients in the clinical trial died during treatment, including several who succumbed to side effects.

But almost two years later, all of Perkins’ cancer cells have disappeared and doctors say she is in remission. The now-52-year-old has returned to backpacking and sea kayaking, and even recently went on a five-week kayaking trip around the tip of Florida.

“This is an illustrative case report that highlights, once again, the power of immunotherapy,” said Tom Misteli, the director of the CCR at NCI.

“If confirmed in a larger study, it promises to further extend the reach of this T-cell therapy to a broader spectrum of cancers.”   

The team is now using the same approach to try to treat patients with advanced liver cancer and colorectal. Their full findings are published in Nature Medicine.