Judy Perkins is free of advanced drug-resistant breast cancer two-and-a-half years after cells were used to target her deadly tumours. The study confirmed that using a 21-gene analyzation to assess cancer recurrence risk can successfully indicate whether or not a woman needs to undergo invasive and unnecessary chemotherapy treatment.
"The impact is tremendous", said the study leader, Dr. Joseph Sparano of Montefiore Medical Center in NY.
A test that measures gene activity can help tailor treatment for some women with early stage breast cancer, according to a clinical trial. "[The findings] are both important and significant, and also practice-changing", says, Dr. José Baselga, a medical oncologist and physician in chief at Memorial Sloan Kettering Cancer Center in NY, who was not involved with this research. Previous studies had made clear that women with low scores could skip chemotherapy and those with high scores should get it.
Doctors were unsure, however, whether women in the medium-risk range were benefiting from chemotherapy or just experiencing the side effects.
Previous research has shown that women with a low Oncotype Dx recurrence score (less than 10) are likely to respond to hormone therapy alone, whereas those with a score above 26 benefit from having a combination of chemotherapy and hormone therapy. "It was all gone", she said. But many women also are urged to have chemo to help kill any stray cancer cells. Or was it sufficient for them to be treated only with endocrine therapy, which blocks the cancer-spurring properties of hormones? Doctors know that most don't need it, but evidence is thin on who can forgo it.
The challenge so far in cancer immunotherapy is it tends to work spectacularly for some patients, but the majority do not benefit.
While the technique is still in its early days, scientists have welcomed its potential as a future treatment for cancers that have resisted all other forms of therapy.
These come from small, early stage studies through to large randomised clinical trials.
All of the women in the study, called the Trial Assigning Individualized Options for Treatment (Rx), or TAILORx, had their breast tumors analyzed with a molecular test.
Otis Brawley, chief medical and scientific officer of the American Cancer Society, called the trial a good example of "precision medicine" and said it would save many women from unneeded chemotherapy. They could potentially encourage patients to incorrectly avoid or stop treatment-with potentially tragic consequences. Similarly, women with high risk scores - above 25 - should receive chemotherapy in addition to hormone therapy.
This resulted in a "highly personalised" anti-cancer therapy that yielded "complete tumour regression", the researchers wrote.
In a paper published in December, Kurian and Katz reported that chemotherapy use was plunging among patients with early-stage breast cancer.
In past studies. doctors looked back at the data for patients in this third group and determined that they would benefit from chemotherapy.
"One of the challenges that we've had in breast cancer is we thought once size fit all, and everyone was getting too much treatment", Olopade said. There is still a long way to go, he said, but it's an approach that isn't specific to a certain cancer type, meaning it could evolve into an effective therapy for many forms of the disease, he said.