Leeds DNA find could help personalise skin cancer treatment

Scientists found that DNA repair genes in cancer tumours help determine the success or failure of chemotherapy.

Higher levels of activity from the genes, which mend damaged strands of DNA, were associated with a poorer response to treatment.

Knowing who is most affected by the genes could help doctors tailor individual treatments at an early stage, thereby increasing patients' chances of survival. DNA repair systems are beneficial in healthy cells, but the new research shows how they can interfere with cancer therapy.

Many anti-cancer drugs work by damaging the DNA of tumour cells. But too-efficient DNA repair genes can override this effect, allowing the cancer cells to survive and spread. The study involved 472 patients with malignant melanoma, the most serious form of skin cancer.

Scientists examined 502 cancer-related genes. They found that higher levels of protein produced by certain DNA repair genes in melanoma tumours were associated with resistance to chemotherapy treatment.

It is the first time that genes involved in DNA repair were identified as potential markers for a patient's response to therapy. The findings were reported in the journal Clinical Cancer Research.

Lead researcher Professor Julia Newton-Bishop, from the Cancer Research UK Centre at the University of Leeds, said: "Our study found that the increased expression of DNA repair genes in melanomas predict poorer outcome overall and provide preliminary evidence that those patients whose tumours have lower levels of the genes may respond better to standard chemotherapy for melanoma."

Sara Hiom, director of health information at the Cancer Research UK charity, said: "Chemotherapy can be an unpleasant experience for some patients. This study shows that a genetic marker could help doctors assess whether a melanoma tumour will be resistant to chemotherapy and ensure that a patient receives a treatment that will be the most effective for them."