Genes May Predict Drug Response to Popular Breast Cancer Drug, New Study Finds

Genetic markers can predict a breast cancer patient’s response to the chemotherapy drug paclitaxel (Taxol), according to a study published in the journal Lancet Oncology.

The study found that measuring the activity of six specific genes could determine whether a breast cancer tumor would be susceptible to paclitaxel, a chemotherapy drug prescribed to shrink tumors in roughly 15 percent of breast cancer patients before surgery.

 “A great challenge in cancer medicine is determining which patients will benefit from particular drugs and it is hoped this research is a step towards more rapid developments in personalized medicine,” said Charles Swanton, head of the study conducted at Cancer Research UK’s London Research Institute.

If study findings are supported through future clinical trials, up to half of patients currently prescribed paclitaxel may not receive any benefit, while still experiencing serious side effects associated with its use including nerve pain, hair loss and a compromised immune system.

Similar studies have discovered genetic signatures for other cancer treatments. For example, patients with bowel cancer who have a gene mutation called KRAS, do not benefit from treatment with the chemotherapy drug cetuximab (Erbitux).

The study evaluated 829 genes, which were inactivated one by one in breast cancer cells to determine if they would be more receptive to paclitaxel treatment.

Further research must be completed before the study’s findings can be confirmed and used in a clinical setting, which may take up to three years, said Swanton. Additional studies will be necessary to determine alternative treatments for cancer patients who are not genetically susceptible to paclitaxel treatment.

Additional information about drugs and drug side effects may be found on DrugWatch.com.