A pattern of genetic defects in tumours could indicate whether ovarian cancer patients will respond to common chemotherapy drugs before treatment starts, reveals a Cancer Research UK study published in the Proceedings of the National Academy of Sciences today (Monday).
The researchers studied patterns of gene expression that indicate high levels of abnormal chromosomes or chromosomal instability (CIN) in cancer.
They showed that a subset of these genes are needed by CIN cancer cells to survive - and that these cells have higher levels of these genes, making them more resistant to a drug called paclitaxel.
They then investigated whether CIN can help doctors identify which patients are most likely to respond to the chemotherapy drugs paclitaxel or carboplatin in a prospective clinical trial of ovarian cancer patients.
Patients with high levels of the CIN gene pattern were more resistant to paclitaxel.
Crucially, patients with high levels of CIN responded well to carboplatin - another commonly used ovarian cancer drug.
In contrast, tumours with low levels of CIN were resistant to carboplatin but responded to paclitaxel.
The researchers believe clinical tests for CIN - which can be identified by dye-stained cells under a microscope - may be available within five years, saving patients from ineffective chemotherapy and leading to personalised treatment.
Senior author Dr Julian Downward, based at Cancer Research UK's London Research Institute, said: "Our work suggests that resistance to paclitaxel is driven by distinct irregularities in the cancer cell that lead to abnormal cancer cell division. These changes may also render cancers more sensitive to carboplatin treatment."
Each year in the UK over 6,600 cases of ovarian cancer are diagnosed, and around 4,500 women die from the disease.