When Dr. E. Donnall Thomas first pioneered bone marrow transplantation in the 1960s and 1970s, his goal was to treat patients with advanced leukemia — at the time, a nearly universal death sentence. Today, thousands of patients with blood cancers around the world are cured every year thanks to modern forms of transplantation, and the procedure is also used for dozens of other diseases besides leukemia, with many more in the research pipeline.
Most importantly for the future of cancer therapies, it was Thomas and his colleagues' work developing bone marrow transplantation at the newly founded Fred Hutchinson Cancer Research Center that revealed the potential for the human immune system to eliminate cancer.
Although the researchers originally aimed to cure leukemia by eradicating patients' malignant white blood cells with high doses of chemotherapy and radiation, and then replacing them with healthy donor cells, they found something unexpected — when a cancer patient received a transplant from an identical twin, their disease often roared back within mere months of the transplant.
But patients who received cells slightly different from their own — from donors such as siblings who were not genetically identical matches or even unrelated individuals — had much lower relapse rates. For these patients, the researchers found that the unrelated donated immune cells were better able to recognize their cancer as "foreign" and attack it.
That observation launched decades of intense exploration by research teams at the Hutch and around the world into the immune system's tumor-fighting potential. Ultimately, it laid the groundwork for the now-burgeoning field of immunotherapy, which uses a variety of techniques to harness or enhance the power of immune cells or molecules to precisely target malignant cells, sparing healthy cells the toxic side effects associated with traditional cancer treatments.
Immunotherapies represent just one of the families of treatments that continue to ripple out of transplantation, extending the reach of this landmark approach and its cousins to more and more patients. Researchers (many of whom trained under Thomas early in their careers) have built upon the foundation of transplantation new houses of treatment and cures for other diseases also once thought incurable. Thanks to one man's dedication and stubborn pursuit of a technique many believed unachievable, scientists are now working to reverse disease-causing genetic mutations, offer curative transplants to every blood cancer patient in need and cure most cancers with a single infusion of disease-fighting immune cells or molecules.