Audience responses
After the debate, the audience was polled on what effect they thought chemotherapy was having in lower-risk HR+, HER2- breast cancer patients. About two-thirds responded that it was all or mostly due to ovarian function suppression.
However, the next question split the audience. They were presented with a clinical scenario: a 43-year-old woman with a mammographically detected 1.4-cm, intermediate grade, HR+, HER2- breast cancer who also had metastatic disease in one of three sentinel lymph nodes and whose recurrence score was 13.
When asked about the treatment plan they would choose for this patient, the audience was split over whether to opt for chemoendocrine therapy or endocrine therapy alone.
A similar clinical question was posited recently on Twitter, when Angela Toss, MD, PhD, from the University of Modena and Reggio Emilia, Italy, asked respondents which they would chose from among three options.
From the 815 votes that were cast, 46% chose Oncotype DX testing to determine the likely benefit of chemotherapy, 48% chose chemotherapy, and 6% picked ovarian function suppression and an aromatase inhibitor.
In response, Paolo Tarantino, MD, from the Dana-Farber Cancer Institute, commented: “If you had any doubt of which is the most controversial topic in breast oncology, doubt no more. 815 votes, no consensus.”
Approached for comment, Eric Winer, MD, director of the Yale Cancer Center, New Haven, Conn., said that the data from RxPONDER “in many ways was helpful, but ... it created about as many questions as it answered, if not more.”
Because the results showed a benefit from chemotherapy for premenopausal women but not for postmenopausal women with breast cancer, Dr. Winer told this news organization that one of the outstanding questions is “whether premenopausal women are fundamentally different from postmenopausal women ... and my answer to that is that is very unlikely.”
Dr. Winer added that the “real tragedy” of this trial was that it did not include women with more than three positive nodes, particularly those who have a low recurrence score, he said.
Clinicians are therefore left either “extrapolating” data from those with fewer nodes or “marching down a path that we’ve taken for years of just giving those people chemotherapy routinely,” even though there may be no benefit, Dr. Winer commented.
Another expert who was approached for comment had a different take on the data. Matteo Lambertini, MD, IRCCS Ospedale Policlinico San Martino, Genoa, Italy, agreed with Loibl’s argument that chemotherapy has a cytotoxic effect in premenopausal women with HR+, HER2- breast cancer in addition to its effect on ovarian function suppression.
He did not agree, however, that there is a question mark over what to do for patients with more than three positive lymph nodes.
Dr. Lambertini said in an interview that he thinks “too much” trust is placed in genomic testing and that there is a “risk of forgetting about all the other factors that we normally use to make our treatment choices.”
A patient with five positive nodes will benefit from chemotherapy, “even if she had a very low recurrence score,” he said, “because there is a very high clinical risk of disease recurrence,” and chemotherapy “is of benefit” in these situations, he asserted.
Dr. Lambertini said that the RxPONDER results – and also studies such as TAILORx, which demonstrated the ability of Oncotype DX to identify which patients with early breast cancer could skip chemotherapy – show that “chemotherapy has a role to play” and that most patients should receive it.
He suggested, however, that “probably the benefit of chemotherapy is smaller” in real life than was seen in these trials, because in the trials, they did not use optimal adjuvant endocrine therapy.