"We can spare thousands and thousands of women from getting toxic treatment that really wouldn't benefit them", said Dr Ingrid A Mayer, from Vanderbilt University Medical Center, an author of the study.
"It feels miraculous, and I am beyond amazed that I have now been free of cancer for two years", Ms Perkins said.
It found that Merck pharmaceutical's drug Keytruda (pembrolizumab) - which famously helped former U.S. president Jimmy Carter stave off advanced melanoma that had spread to his brain - helped lung cancer patients live 4 to 8 months longer than chemo.
"It means we can better use the treatments... so that we can achieve our ultimate goal", Dr. David Cescon of Toronto's Princess Margaret Cancer Centre told CTV News. Endocrine therapy, such as tamoxifen, is more important with this disease than chemotherapy, said Otis Brawley, chief medical and scientific officer for the American Cancer Society.
According to the study, more than 20,000 women in the United Kingdom are diagnosed with hormone-receptor positive, HER2-negative, node-negative breast cancer annually.
So the biggest unanswered questions involved women in the intermediate-risk category: Did chemo reduce their chance of recurrence?
The Oncotype DX genetic test has been available on the NHS since 2013, but the National Institute for Health and Care Excellence (Nice) is now updating its guidance on whether it should be recommended for use.
Dr. Rosenberg added, "This is highly experimental and we're just learning how to do this, but potentially it is applicable to any cancer". "So we have two yes-no answers for each gene".
A leading oncologist said the findings will lead to a "fundamental change" in how the disease is treated. Her cancer did not respond to any treatments, including chemotherapy and hormone therapy, until this one- time treatment with more personalized immunotherapy.
Tetris Effect drops psychedelic PS4 trailer from space
Fan-favorite modes like Marathon, Sprint, and Ultra, with more all-new modes and other features to be revealed before launch. The game will come this fall for PS4 with a PlayStation VR mode included, and it will be playable at E3.
But it has many torturing side-effects including vomiting, hair loss, fatigue, anemia, nerve pain and, in rare cases, heart failure and leukaemia. She also had new drugs to overcome a cancer's ability to shield itself from the immune system.
"If confirmed in a larger study, it promises to further extend the reach of this T-cell therapy to a broader spectrum of cancers", he said.
Six in 10 women had a recurrence score of between 11 and 25, and were randomly assigned to have either hormone therapy or a combination or hormone therapy and chemotherapy.
Patients with a recurrence score of up to 10 out of 100 have been shown not to benefit from chemotherapy and only hormone treatment is required. "Women don't have to suffer more than there is necessary to be better".
Nine-year survival rates were 93.9% without chemotherapy and 93.8% with chemotherapy, the study found.
The new study of almost 7,000 women found that use of the already available Oncotype DX gene test could pinpoint those women who needed chemotherapy, and those who did not. Apparently, those who are receiving the said treatment under current medical standards don't actually need it. Most women who fit this criteria need only surgery and hormone therapy, he said.
But there is a note of caution in interpreting the study's findings. The results showed that the chemo made no significant difference at all in which women died from their cancer (about 6 percent for both groups) and which didn't go into remission (about 16 percent for both groups).
"We've had the results for the Oncotype for a number of years". Some women 50 or younger, however, did see benefits from chemo.