Key points from article :
People with untreatable cancers have had their immune system redesigned to attack their own tumours.
In an experimental study on 16 patients, treatment was developed for targeting specific weak spots.
To boost levels of cancer-spotting T-cells, and it is tailored to each patient as each tumour is unique.
Researchers scoured patient's blood for T-cells that already had receptors which could sniff out their cancer.
Harvested other T-cells that could not find the cancer and redesigned them using gene-editing technology Crispr.
Modified cancer-searching T-cells were then put back into the patient.
Disease continued to get worse in 11 patients, but stabilised in the other five.
It is too early to fully assess the therapy's effectiveness and it is expensive and time-consuming.
"This is a leap forward in developing a personalised treatment for cancer," said Antoni Ribas, co-researcher.
It was a "powerful early demonstration of what might be possible with newer techniques", - Waseem Qasim,
Study published in the journal Nature.
