JERUSALEM, Dec. 29 (Xinhua) -- An international team of researchers has discovered a new method to fight cancers that no longer respond to treatment, using the very mutations that make tumors drug-resistant, Israel's Weizmann Institute of Science said in a statement on Monday.

One of the biggest challenges in cancer care is when a therapy stops working. In many metastatic cancers, drugs that initially work lose their effect over time as cancer cells mutate and continue to grow.

The new study, published in Cancer Discovery, introduced a computational tool called SpotNeoMet, which identifies therapy-resistance mutations common to many patients.

These mutations produce tiny protein fragments called neo-antigens, which appear only on cancer cells. These shared neo-antigens may provide the basis for new immunotherapy approaches that prompt the immune system to selectively target cancer cells.

The researchers tested their approach on metastatic prostate cancer, a disease where most patients eventually become resistant to standard treatments. They identified three neo-antigens that showed promising results in lab experiments and in mouse models.

The researchers said the approach differs from highly personalized therapies because it targets resistance mutations shared by many patients, allowing the same treatment to be applied more broadly to people with treatment-resistant cancers. ■