Time to Surgery and the Impact of Delay in the Non-Neoadjuvant Setting on Triple-Negative Breast Cancers and Other Phenotypes.

BACKGROUND: Characterization of breast cancer phenotypes has improved our ability to predict breast cancer behavior. Triple-negative (TN) breast cancers have higher and earlier rates of distant events. It has been suggested that this behavior necessitates treating TNs faster than others, including use of neoadjuvant chemotherapy (NACT) if time to surgery is not rapid.
METHODS: A review of women diagnosed with non-inflammatory, invasive breast cancer was conducted using the National Cancer Database for patients not having NACT, diagnosed between 2010 and 2014. Changes in overall survival due to delay were measured by phenotype.
RESULTS: Overall, 351,087 patients met the inclusion criteria, including 36,505 (10.4%) TNs, 77.9% hormone receptor-positive (HR+) and 11.7% human epidermal growth factor receptor 2 (HER2)-enriched (HER2+). Phenotype, among other factors, was predictive of treatment delays. Adjusted median days from diagnosis to surgery and chemotherapy were 29.9, 31.6 and 31.5 (p< 0.001), and 72.7, 78.0 and 74.4 (p< 0.001) for TNs, HR+ and HER2+ cancers, respectively. After diagnosis, OS declined for all patients per month of preoperative delay (hazard ratio 1.104; p< 0.001). In models separating or combining surgery and chemotherapy, this survival decline did not vary by breast cancer phenotype (p > 0.3).
CONCLUSIONS: Delays cause small but measurable effects overall, but the effect on survival does not differ among breast cancer phenotypes. Our data suggest that urgency between diagnosis and surgery or chemotherapy is similar for breast cancers of different subtypes. Although NACT is sometimes advocated solely to avoid treatment delays, this study does not suggest a greater surgical urgency for TNs compared with other breast cancer phenotypes.