by Dr. C. H. Weaver M.D. 12/2018
Patients with triple-negative breast cancer who delayed starting adjuvant chemotherapy for more than 30 days after surgery are at higher risk for cancer recurrence compared with those who started the treatment in the first 30 days after surgery, according to a study presented at the 2018 San Antonio Breast Cancer Symposium.
The optimal time to initiate chemotherapy following surgery is not clearly specified and most guidelines suggest four to six weeks. In order to gather insight the study authors analyzed real-world data to determine whether delaying the start of chemotherapy following surgery for TNBC impacts patient outcomes.
The authors found that delaying adjuvant chemotherapy for more than 30 days after surgery had a more than 90 percent increased risk for disease recurrence and death compared with those who started the treatment in the first 30 days after surgery.
The study authors analyzed data obtained from the medical records of 687 patients with stage 1–3 triple-negative breast cancer who had undergone surgery and went on to receive adjuvant chemotherapy. Overall 189 patients chemotherapy at or before 30 days, 329 started it from 31 to 60 days, 115 started it from 61 to 90 days, and 54 started it more than 90 days after surgery.
As the time to starting adjuvant chemotherapy increased, the number of individuals who survived without evidence of cancer at 10 years decreased. Compared with patients who started adjuvant chemotherapy in the first 30 days after surgery, risk for disease recurrence was increased by 92 percent for those who delayed starting the treatment for 31 to 60 days after surgery, by 138 percent for those who delayed starting the treatment for 61 to 90 days after surgery, and by 147 percent for those who delayed starting the treatment for more than 90 days after surgery. The risk of death compared with patients who started adjuvant chemotherapy in the first 30 days after surgery also increased by 94 percent, 145 percent, and 179 percent for the three groups, respectively.
Although the analyses was retrospective in nature and these differences may be explained by other factors the study suggests that starting adjuvant chemotherapy as soon as possible after surgery is prudent and unnecessary delays should be avoided.