New Zealand has one of the highest rates of breast cancer in the world, with one in 10 women suffering from the disease, accounting for nearly half of all cancer cases in women, according to the latest global cancer epidemiology statistics. About 2.1 million women worldwide develop breast cancer each year, and 600,000 die of the disease despite good treatments.
In all breast cancer patients, there are more than 75% of patients are oestrogen-dependent patients, endocrine therapy is currently the most effective treatment for this type of breast cancer, but a large proportion of patients will have disease recurrence, and in endocrine therapy, the body of the tumor will often develop drug resistance.
In a new study, researchers have developed a new breast cancer test that can help patients and clinicians make better treatment decisions by helping them predict their response to endocrine therapy and their risk of disease recurrence.
Breast cancer is not a single disease, which is a kind of complex diseases, each tumor response to therapy is not the same, estrogen receptor-positive breast cancer is a kind of breast cancer subtypes, and as such the body often present in patients with estrogen receptors, it is showed that the cancer cells can like normal breast cells, receiving signals from estrogen and promote the growth of cancer cells; Currently, clinicians rely on the number of estrogen receptors in tumors as biomarkers to predict patients' response to endocrine therapy, but unfortunately, the accuracy of this test is not satisfactory, because estrogen-dependent tumors produce drug resistance.

The response of patients to endocrine therapy is only 30%-40%, up to 40%-50% of patients will not benefit from endocrine therapy, and the disease will recur. There is no known way to predict breast cancer resistance to endocrine therapy drugs. Accurately predicting response to therapy for cancer patients correctly and timely treatment is critical, no reaction of the patients and can't benefit from endocrine therapy, at the same time it also may experience adverse effects associated with therapy, ineffective treatment will not delay response for other treatment time, this could give patients caused loss of life.

If as early as possible the correct treatment, breast cancer can be cured, and now researchers have discovered a new way to improve the effectiveness of the patients received endocrine therapy, if they can predict which patients will not react to therapy, the researchers can choose other treatments, such as more toxic chemotherapy drugs, etc., it may be can improve the inventory rate and quality of life of cancer patients.

In the end, the researchers say more research is needed before they can be used in human clinical trials.