The extraordinary response of a woman against thyroid cancer is providing researchers with new insights on how best to fight against cancer.

The thyroid cancer case involving 56-year-old Grace Silva can possibly show scientists on how to use certain drugs to win against cancer.

Silva's thyroid cancer completely vanished for 18 months after receiving treatment in the form of the anti-cancer drug everolimus. However, after 18 months, the thyroid tumor was able to develop a resistance to the drug, returning with the cancer as it begins to spread through her body.

The cancer initially spread through Silva's lungs despite chemotherapy, radiation and surgery. However, with the drastic response to everolimus, Silva has been able to survive far longer than the few months that anaplastic thyroid cancer usually takes before it becomes fatal.

The researchers working on the case discovered two previously unknown mutations in the genes of Silva's cancer. The first mutation made the woman's cancer very sensitive to everolimus, while the second mutation allowed the cancer to develop resistance to the drug.

The mutations were identified to have occurred in a gene named TSC2.

A newly developed drug of the same type is ready to undergo clinical trial tests for patients that have similar TSC2 mutations. The tests will involve patients with different kinds of cancer.

With Silva still alive after four years from when she was first diagnosed with thyroid cancer, she will be receiving the experimental cure.

The study on Silva's case was published in the New England Journal of Medicine.

The team of scientists working on the study from the Dana-Farber Cancer Institute said that the results show that determining the DNA of the cancer of each patient before being treated and then again after the cancer begins to exhibit signs of resistance to the drug could help cancer treatment methods.

"This is personalized, precision medicine at its best," said Jochen Lorch, the senior author of the study and a specialist for thyroid cancer at Dana-Farber's Head and Neck Treatment Center.

"The study of patients with extraordinary responses can yield critically important insights," said Nikhil Wagle, the first author for the study and an oncologist at Dana-Farber.

According to Wagle, studies such as the one they carried out for the thyroid cancer case of Silva can help scientists create new methods for matching drugs to patients, determine the effective usage for "failed" treatments, and develop new strategies for the battle against cancer.