Breast cancer patients likely to benefit under a new precision medicine approach

Hyderabad: The results from ‘Trial Assigning Individualized Options for Treatment’ also called TAILORx study, the largest ever breast cancer treatment trial, that were published in the New England Journal of Medicine recently revealed some interesting insights.

Breakthrough finding by the TAILORx study demonstrated that the Oncotype DX Breast Recurrence Score® Test definitively identifies the 70 percent of women with early-stage breast cancer who receive no benefit from chemotherapy, and the 30 percent of women for whom chemotherapy benefit can be life-saving.

Study was supported by the United States National Cancer Institute (NCI), part of the National Institutes of Health, and designed and led by the ECOG-ACRIN Cancer Research Group.

Dr Vijay Anand Reddy, Senior Consultant – Clinical Oncology and Radiotherapy at Apollo Health City, Hyderabad, commented, “I strongly agree with the findings of the study as I believe more in hormonal therapy, which- in most cases- is sufficient. Chemotherapy has more toxicity and minimal benefits. This finding will definitely aid in reducing the unnecessarily administered chemotherapy which is a relief to both the doctors and the patients.”

Breast cancer is the most common cancer in women in India and accounts for 27 percent of all cancers in women. At an incidence rate of 25.8 per 100,000 it is lower than in some developed countries, but the mortality rate (12.7 per 100,000) is comparable to that in western countries. Data on incidence rates of breast cancer from six major cancer registries of India show that the annual percentage increase in the incidence of breast cancer has been in the 0.46 to 2.56% range.

The majority of breast cancer patients diagnosed worldwide have hormone-positive, HER2-negative, node-negative cancer. The TAILORx study definitively established that chemotherapy may be spared in about 70 percent of these patients, including all women older than 50 with Breast Recurrence Score® results of 0 to 25 and all women age 50 or younger with Breast Recurrence Score results of 0 to 15.

Importantly, 30 percent of early-stage breast cancer patients will derive benefit from chemotherapy, including women of any age with Breast Recurrence Score results of 26 to 100, and in women younger than 50, where a modest (2 percent) benefit from chemotherapy was observed with Breast Recurrence Score results of 16 to 20, which gradually grew as scores increased up to and above 25. This important finding reveals a new level of precision of chemotherapy benefit for younger patients that only the Oncotype DX® test can provide.

“The TAILORx findings can spare thousands of women from getting toxic chemotherapy treatment that really wouldn’t benefit them. By identifying the right patients who can benefit from chemotherapy, and sparing chemotherapy and its toxic side effects in those who will not benefit from its treatment, the personalized treatment approach is a breakthrough advancement in the medical fraternity. As the sole commercial representative in India for Genomic Health, we hope to bring changes in the standard of care in India,” said Mr Prasad Vaidya, CEO, Medilinks Inc.

The trial enrolled 10,273 women with breast cancer from 6 countries across the globe. It used the Oncotype DX Breast Recurrence Score® test that assesses the expression of 21 genes associated with breast cancer recurrence to assign women with early-stage, HR- positive, HER2-negative, axillary lymph node–negative breast cancer to the most appropriate and effective post-operative treatment.

TAILORx participants with Breast Recurrence Score results from 0 to 10 were treated with endocrine therapy alone based on the prior results from the NSABP B-20 study, which showed no opportunity for chemotherapy benefit. TAILORx participants with Breast Recurrence Score results from 26 to 100 were treated with chemotherapy plus endocrine therapy based on the prior results from the NSABP B-20 study, which showed an absolute benefit of chemotherapy greater than 20 percent.

To more precisely define the effect of chemotherapy for women considered to be at intermediate risk for recurrence, 6,711 women with Oncotype DX Breast Recurrence Score results of 11 to 25, the primary study group in TAILORx, were randomized to receive endocrine therapy with or without chemotherapy. These randomized patients comprised two-thirds of all patients enrolled in TAILORx and were followed by the investigators for approximately nine years on average.

“This is a brilliantly executed study with a well-represented sample of patients. The only drawback of Oncotype DX Breast Recurrence Score® Test mentioned in the study is that it is an expensive test- costing around Rs.2.75 lakh- which makes it less affordable in India. The Oncotype Dx test helps in identifying high risk patients who will benefit with chemotherapy. Results of the TAILORx study showed that 70% of most common type of breast cancer did not benefit with chemotherapy. Only hormonal therapy, with fewer side effects is enough to cure more than 90% of these patients. The test makes clear distinction which will help inavoiding chemotherapy and side effects to a large number of patients,” said Dr P S Dattatreya, Sr. Consultant Medical Oncologist, Omega Hospitals, Hyderabad.

Dr Suresh Advani, a renowned oncologist and Padma Bhushan recipient, concluded, “Today, personalized medicine has allowed us to avoid chemotherapy for certain group of patients. We can select the people who don’t need chemo and administer it to only those who need it.”