Breast Cancer: Enter Personalized Medicine

What is personalized medicine?

In the last 5-10 years, a lot of public interest and media attention has been focused on the phrase “Personalized Medicine”. The idea behind personalized medicine is a simple one. Every individual is unique. Every cancer is unique. Individuals response to treatments is different. The idea behind personalized medicine is therefore how to customize the treatment approach based on how an individual may respond.

Personalized Medicine: A requirement for Breast Cancer

Looking at this through the lens of early-stage breast cancer: it is already a well-known fact that not every patient will benefit from chemotherapy. In fact, many patients can safely forego chemotherapy, which not only shows no clinical benefit, but the patient can also avoid many of the risks of chemo (not to mention the additional cost). The idea is to identify the group of women who will benefit from chemotherapy and the group who won’t.

Historically, a doctor would decide based on clinical factors such as tumor size and nodal status.

Tumor size: the larger the tumor, the more likely the patient would be placed on chemotherapy.

Nodal Status: the more nodes which show cancer, the more likely the patient would be placed on chemotherapy.

Drawbacks of the One-Size-Fits-All Approach

However, this approach is far from perfect. Patients who have a small tumor and/or very few node(s) affected with cancer may still require chemotherapy. Vice-versa, patients with a large tumor size and many nodes affected may not. Breast cancer recurrence testing helps identify exactly which patients will require chemotherapy and which patients can avoid it.

Breast Cancer Recurrence Testing for Chemotherapy

To assist with decision making, breast cancer recurrence testing includes clinicopathological factors (tumor size and nodal status) while going far beyond. Breast cancer recurrence tests such as EndoPredict by Myriad Genetics also test for the gene expression. The gene expression data is then parsed through an algorithm which reveals the exact benefit of chemotherapy. For example, an EndoPredict test will be able to accurately report a patient’s absolute benefit of chemotherapy for 10 years is 1.9%. This patient can safely avoid chemotherapy. All patients based on their score are classified into either low risk (typically can avoid chemo) or high risk (typically require chemo).

Is it Accurate?

Absolutely. EndoPredict has undergone clinical validation on thousands of patients. EndoPredict is also recommended by most leading international guidelines including NCCN, ASCO, NICE, and many more.

What Percentage of Patients can avoid chemotherapy with EndoPredict?

In general, for small tumor size patients approximately 2 out of 3 patients can avoid chemo. For larger tumors which have may have nodes positive approximately 1 out of every 3 patients can chemo.

Is breast cancer recurrence testing available in India?

EndoPredict has been available in India since 2015 and has been used by hundreds of Indian women to guide their treatment. The following data has also been published and presented in international conferences on EndoPredict cases completed in India.