Researchers are calling early trials of a treatment using patients' immune cells to fight cancer "unprecedented."
In one study by an international team of scientists, the symptoms of severe leukemia disappeared for 9 out of 10 patients. In another study, the treatment had positive effects on 4 out of 5 patients with blood cancers, with more than half becoming symptom-free.
READ MORE: WHO backs new weapons in Zika fight
These patients had been projected to live two to five months before the studies.
The treatment involves taking immune cells, called T-cells, out of patients' bodies and attaching "receptor" molecules to them that specifically target cancer. Then, the cells are put back into the patients.
While presenting at an American Association for the Advancement of Science conference in Washington, D.C., the lead researcher called the treatment a "potential paradigm shift."
He admitted more work needs to be done, though. For instance, the researchers don't know how long these patients will stay symptom-free.
The two studies mentioned also had small sample sizes. In a past study, however, 94 percent of roughly 35 patients with a form of leukemia went into complete remission.
RELATED: Common foods that can cause cancer