SAN ANTONIO – The longer the delay in initiating adjuvant chemotherapy, the worse the survival in patients with triple-negative breast cancer (TNBC), findings from a review of nearly 700 cases suggest.
Delays of more than 30 days between surgery and initiation of chemotherapy were associated with lower disease-free survival (DFS), distant recurrence–free survival (DRFS), and overall survival (OS), Zaida Morante, MD, reported at the San Antonio Breast Cancer Symposium.
In 687 women with clinical stage I, II, or III TNBC who were diagnosed at the Instituto Nacional de Enfermedades Neoplasicas in Lima, Peru, during 2000-2014 and followed for a median of 8.5 years, time to chemotherapy was less than 30 days in 189 patients (27.5%), 31-60 days in 329 patients (47.9%), 61-90 days in 115 patients (16.7%), and more than 91 days in 54 patients (7.9%), said Dr. Morante, a medical oncologist at the institute.
Overall survival at 10 years was 82% in those who received chemotherapy within 30 days of surgery, compared with 67.4%, 67.1%, and 65.1% in those treated at 31-60, 61-90, and more than 91 days after surgery, respectively, she said.
“The difference was consistent across the different periods of the evaluation,” she said during a press briefing at the symposium. “Additionally, the benefit of receiving chemotherapy within 30 days exists and is statistically significant for [nodal status] N0 and N1 (hazard ratios, 1.701 and 2.498).”
In those with N2 and N3 nodal status, there was a numerical difference, but it didn’t reach statistical significance.
DFS was also significantly worse if treated later than 30 days after surgery; those treated within 30 days had 10-year DFS of 81.4%, compared with 68.8%, 70.8%, and 68.1% in the other groups, respectively. The difference was even more pronounced for 10-year DRFS, which was 80.2%, 64.9%, 67.5%, and 58.6% in the groups, respectively.
Multivariate analyses confirmed that time to adjuvant chemotherapy was an independent prognostic factor for survival, she said, noting that compared with patients treated within 30 days of surgery, those treated at 31-60 days had 1.9-fold increased risk of death, and those treated at 61-90 days had a 2.4-fold increased risk of death.
“The difference in 10-year overall survival rates between receiving chemotherapy within 30 days after surgery and after 30 days was more than 10%,” she said. “These results represent a feasible opportunity for improving outcomes in triple-negative breast cancer patients.”
Although only 28% of patients in this review received adjuvant chemotherapy within 30 days, most patients in the United States “will fall within the 30 days and under” category, said press briefing moderator, professor and director of the Harold C. Simmons Comprehensive Cancer Center at UT Southwestern Medical Center in Dallas.
However, the findings might suggest a greater role for neoadjuvant chemotherapy in these patients.
“Because this is systemic therapy ... it’s treating the systemic disease. I wonder if this is arguing ... that we need to have an impetus to deliver the systemic therapy as soon as we can – early, even before the operation,” he said.
Indeed, while timing isn’t everything, Dr. Morante’s findings and others presented at the meeting “highlight the possibility that perhaps it is more important than we previously suspected,” discussant, said at the meeting, adding that the findings raise questions about current paradigms for management of breast cancer.
“We now have substantial data suggesting that the timing of adjuvant chemotherapy matters in triple-negative breast cancer, and that 30 days may be optimal,” said Dr. Sparano, professor at the Albert Einstein College of Medicine, New York.
“This doesn’t mean that patients who may not be ready for the chemotherapy because of complications related to the surgery should be forced into a situation where they are at higher risk from receiving the chemotherapy, but nevertheless, the results are important,” he said.
Dr. Morante and Dr. Arteaga each reported having no relevant conflicts of interest to declare. Dr. Sparano has received consulting fees from Roche, Eli Lilly, Novartis, Celldex, AstraZeneca, Pfizer, and Adgero. He also has ownership interests with MetaStat.
SOURCE: Morante Z et al. SABCS 2018, .