Personalized medicine for breast cancer patients through multigene test

Personalized medicine is showing increasing popularity in the field of oncology. It can be defined as medical care that it is based on the biological characteristics of individual patients.  By using genomics and proteomics, individuals can be classified into subpopulations based on their susceptibility to a particular disease or response to a specific treatment.  They may then be given preventive or therapeutic interventions that will be most effective given their particular characteristics.

In oncology, personalized medicine has the potential to be especially influential in patient treatment because of the complexity and heterogeneity of each form of cancer.Previous studies have proved that cancer patients can survive longer under treatments based on their individual genetic profiles.

Breast cancer patients are also likely to benefit from this form treatment with the help of multigene test. The test called Oncotype DX®, made by Genomic Health Inc, basically analysis 21 genes in a tumor sample and gives information about how active the tumor is and whether there are chances for its recurrence. Based on these results doctors can determine if chemotherapy could benefit the patient or can opt for the best treatment approach that could be most suitable for the patient under consideration. A test score in the range of 0 to 100 determine the chances of cancer recurrence .Women with a low test score have less probability of cancer recurrence and hence might not require chemotherapy. Over 120,000 breast cancer patients have made use of the multigene test ever since its introduction in 2004.Its target is a specific type of breast cancer called estrogen receptor-positive breast cancer which over 100,000 patients are diagnosed with each year. The test costs nearly $3,910.

The study led by Dr. Shelly Lo, Loyola University Health System Medical oncologist is published in the Journal of Clinical Oncology.It included 89 breast cancer patients who received the multigene test. They were treated by 17 medical oncologists at Loyola, University of Michigan, University of California at Davis and Edward Hospital in Naperville, Il.Doctors changed treatment decisions for 28 patients. In 20 of these cases, they changed their decision from hormone therapy plus chemotherapy to hormone therapy alone. Twenty-four patients changed their treatment decisions, including nine who dropped chemotherapy. Doctors said the test increased their confidence in their treatment recommendations in 76 percent of cases. And in 97 percent of cases, doctors said they would order the test again. After receiving test results, patients reported they were significantly less conflicted about their decision and felt significantly less anxiety about their situation.

“This test of patients’ own breast cancer provides us with greater certainty of who derives benefit from chemotherapy and who can safely avoid it,” said senior author Dr. Kathy Albain, professor in the Department of Medicine, Division of Hematology/Oncology, Stritch School of Medicine.