A 50-year old woman who suffered from colon cancer that had spread to her lungs is now free from cancer following a clinical trial using her own white blood cells.

Her remarkable recovery was recently published in the New England Journal of Medicine. Before treatment, the patient had 7 tumors in her lungs. 40 days following treatment, all 7 of her lung metastases had shrunk. At a 9-month follow up, one of the tumors appeared to have started to develop resistance to the treatment, although it was successfully removed by surgery. The patient has since remained cancer free. No adverse side effects were reported.

Her cancer cells contained a mutation in a gene called KRAS, which is very common in cancers such as colorectal and pancreatic cancers. Cancers with this mutation generally have a poor prognosis, and previous attempts by scientists to target this mutation had been unsuccessful. This study marks the first successful attempt to target this KRAS mutation in a cancer.

Essentially, the immunotherapy treatment works by extracting the white blood cells that swarm around the patient’s tumors (these white blood cells are also known as Tumor Infiltrating Lymphocytes (TILs), multiplying them in the lab, and then returning them to the patient.

The patient’s TILs included some cells that could recognise the KRAS mutation present on the tumor. This meant that the TILs could very specifically identify and lock into her cancer cells, like a guided missile. Once bound, the TILs can kill the cancer cells*.

This clinical trial is led by Dr Steven Rosenberg, Chief of Surgery at the National Cancer Institute, Maryland, who has pioneered the use of TILs in immunotherapy.

The study is currently still recruiting participants. Here is a link to the trial if you would like to find out more (including eligibility criteria, etc).

Although one experiment on one patient doesn’t guarantee that the treatment will be effective in others, it’s a promising start that may lead to a better treatment for thousands of other patients.

*If you’re interested in learning a bit more about how TILs actually kill cancer cells, I’ve written a very short follow-up explanation here.