"You take a patient's own cells, you attack their own cancer with their own cells and you attack a unique mutation that's present in their cancer and none others", explained Dr. Steven Rosenberg of the National Cancer Institute.
Olufunmilayo Olopade, director of the Comprehensive Cancer Risk and Prevention Clinic at University of Chicago, said the study helps move forward the push for precision medicine - a philosophy of treating patients with the right medicine for their exact problems at a defined time.
"This is another significant step towards personalised breast cancer treatment and we hope these practice-changing findings will now help refine our use of chemotherapy on the NHS", she said. This therapy has allegedly been an essential treatment for many women as it lowers the risk of cancer recurrence, newtumors from appearing, and even death from the disease.
In a separate analysis, hormonal therapy alone did seem very effective in deterring the spread of cancer for women with an Oncotype score of 10 or below.
Chemotherapy did provide some benefit to women in the study who scored between 16 and 25, and were younger than 50 and premenopausal.
"Those are the cancers that have likely already metastasized and a small amount could be hiding in a woman's lung, liver or bones", said Brawley.
The usual treatment for such patients is surgery to remove the tumour, followed by several years of hormone-blocking medications, such as tamoxifen. This has the potential to spare thousands of women from the bad side effects of chemotherapy, including nausea, hair loss, and heart and nerve damage.
The trial results are the latest piece of the puzzle on how to treat early-stage breast cancer. It was the women in the intermediate stages of 11-25 who oncologists often had differing views when prescribing standards of care.
Chemo and hormone therapy didn't work but this one-time treatment with more personalized immunotherapy did work for Perkins.
In an attempt to settle this question, investigators designed a clinical trial that assessed the long-term outcomes in women receiving radiation to their IM-MS lymph nodes compared to a control group that did not. Rates for freedom from disease recurrence at a distant site were also similar, at 94.5% and 95% for the endocrine therapy and chemoendocrine therapy groups, respectively, as were rates for freedom from disease at a distant or local-regional site (92.2% and 92.9%, respectively) and for overall survival (93.9% vs 93.8%.).
Hormone-receptor-positive, axillary node-negative disease accounts for approximately half of all cases of breast cancer in the USA, and the National Institutes of Health has previously recommended adjuvant chemotherapy for most patients, the authors write. She's still cancer-free two years later. "It's exactly the sort of study that we need to make decisions about these genomic tests". That means more than 85,000 women a year can safely forgo chemotherapy.
But there is a note of caution in interpreting the study's findings.
He told the BBC: "We think this is a remarkable result".
Women aged 50 or younger were the notable exception.
Those women should carefully discuss their options with their oncologist, said Brawley, because they would likely be candidates for the more aggressive, dual therapies. This gives the genes a point score from zero to 100 based on how active they are.