SABCS 2018: When to Initiate Adjuvant Chemotherapy in Triple-Negative Breast Cancer
Posted: Thursday, December 6, 2018
For patients with triple-negative breast cancer, delaying the initiation of adjuvant chemotherapy more than 30 days after surgery was associated with a higher risk for disease recurrence and death than initiating adjuvant chemotherapy within the first 30 days after surgery. These retrospective study findings were presented at the 2018 San Antonio Breast Symposium (SABCS; Abstract GS2-05).
“Our data show that it must be a priority for patients with triple-negative breast cancer to begin adjuvant chemotherapy within 30 days of completing surgery,” stated Zaida Morante, MD, of the Instituto Nacional de Enfermedades Neoplásicas, Lima, Peru, in an SABCS press release. “After this period of time, the benefit of chemotherapy is significantly diminished.”
The investigators focused on data from the medical records of 687 patients with triple-negative breast cancer who received adjuvant chemotherapy at their institution between 2000 and 2014. Patients were grouped according to the time to chemotherapy (the number of days between surgery and the first dose of chemotherapy). The median time to chemotherapy was 41 days. A total of 27.5% received chemotherapy at or before 30 days, 47.9% received it between 31 and 60 days, 16.7% received it between 61 and 90 days, and 7.9% received it beyond 90 days. The median follow-up was 101 months.
As the time to starting adjuvant chemotherapy increased, the 10-year disease-free survival rate decreased: 81%, 69%, 71%, and 68% among those who received chemotherapy at up to 30 days, 31 to 60 days, 61 to 90 days, and 91 days and beyond, respectively (P = .005). So too did the 10-year overall survival rate: 82%, 67%, 67%, 65% among those who received chemotherapy at up to 30 days, 31 to 60 days, 61 to 90 days, and 91 days and beyond, respectively (P = .003).
In a multivariate analysis, the investigators found that the time to chemotherapy was an independent prognostic factor for both recurrence-free and overall survival. Those who delayed adjuvant therapy beyond 31 days after surgery had worse survival than did those who initiated treatment within 30 days after surgery.