SAN ANTONIO—When it comes to systemic therapies, sometimes “less is more,” and it is time to look for more ways to de-escalate systemic treatments for breast cancer, Hope S. Rugo, MD, of the University of California San Francisco, told attendees of an education session on strategies for minimizing interventions at the 2015 San Antonio Breast Cancer Symposium.1
The cumulative benefits of incremental improvements in treatment have led to better outcomes for women with early-stage breast cancers. But “typically, when we talk about incremental improvements, we talk about adding treatments,” said Dr. Rugo. “But subtyping can identify not those who need more treatment, but those who will do well with less.”
“Do all patients need all therapies,” she asked. There was a time when many thought the answer to that question was “yes,” she explained: many thought that it was best to “try everything” in hopes of securing a benefit for the patient.
“Additional therapy adds toxicity, expense, and often time,” she said. “One size does not fit all.”
Clinical oncology is making progress in doing less by applying less chemotherapy for low-risk patients and using neoadjuvant treatment as a model for predicting who needs less.
Recent studies like CALGB 40101 have shown that longer treatment time is not necessarily better when it comes to chemotherapy; patients with low risk cancer sometimes enjoy comparable survival rates after fewer cycles of chemotherapy.
The neoadjuvant setting can be a good opportunity to reduce the intensity of therapy. “Pathological complete response [pCR] correlates with disease-free survival,” Dr Rugo noted. “Improved pCR with the addition of agents is the mechanism for accelerated regulatory approval. Lack of benefit in subsets might allow better differentiation of those who need more vs less treatment.”
Similarly, identifying who is at greatest risk of late recurrence helps differentiate those who could be spared longer-duration hormone therapy. Expression analysis makes it possible to identify a group of women with very low risk, node-negative, HR-positive breast cancer with a very low (1%) risk of distant recurrence at 5 years with endocrine therapy alone,” she said. “There’s no impact for age, tumor size, or grade.” There are several ongoing trials to evaluate intermediate-risk and lymph node-positive disease, she said, including TAILORx, RxPONDER, OPTIMA, and MINDACT.
RELATED: Tamoxifen, Anastrozole Chemoprevention Reduces Invasive Breast Cancer Risk
Improving our understanding of biologic tumor subtypes will open the door to other strategies to reduce treatments and minimize side-effects, she predicted. Pharmacogenetics will provide important insight about how best to balance risk versus benefit, as well.
- Rugo HS. Less is more: de-escalating systemic therapy for breast cancer. Oral presentation at: San Antonio Breast Cancer Symposium 2015; December 8, 2015; San Antonio, TX.