Delays in adjuvant chemotherapy treatment among patients with breast cancer are more likely in African American and Hispanic populations: a national cohort study 2004-2006

Abstract

Purpose: Previous studies have indicated poorer survival among women receiving adjuvant chemotherapy > 90 days after surgery compared with women receiving adjuvant chemotherapy within 90 days of surgery.

Patients and methods: Women diagnosed between 2004 and 2006 with invasive breast cancer (stages I to III) and treated with surgery and adjuvant chemotherapy were selected from the National Cancer Database (n = 107,587). We evaluated factors associated with prolonged time to start adjuvant chemotherapy (≥ 60 and ≥ 90 days after surgical resection) using multivariable log binomial models to estimate risk ratios (RRs) and 95% CIs.

Results: The average time to adjuvant chemotherapy was 41.46 days (± 24.46 days). Overall, 85.2% and 95.8% of women received adjuvant chemotherapy within 60 and 90 days of surgery, respectively. African American and Hispanic patients had higher risk of 60-day delay (RR, 1.36; 95% CI, 1.30 to 1.41 and RR, 1.31; 95% CI, 1.23 to 1.39, respectively) and 90-day delay (RR, 1.56; 95% CI, 1.44 to 1.69 and RR, 1.41; 95% CI, 1.26 to 1.59, respectively) compared with white patients. Insurance type, stage, comorbidity, and facility type were also associated with adjuvant chemotherapy delay.

Conclusion: The majority of women in our study received adjuvant chemotherapy within the time frame (90 days) for which there is no evidence of poorer outcome. However, the rate of delay varied by patient and by clinical and facility factors. Future studies on the role of structural, physician, clinical, and patient factors in adjuvant chemotherapy delay in populations of women with higher rates of delay and potential interventions are needed.