Delayed adjuvant hormonal therapy and its impact on mortality in women with breast cancer

Adjuvant hormonal therapy (HT) is important for the management of hormone-sensitive breast cancer. However, the timeliness for adjuvant HT and the consequences of delayed initiation of treatment have not been analyzed. The purpose of this study was to characterize delays to HT and assess the impact on clinical outcomes. The study cohort consisted of female patients with invasive ductal and/or lobular, hormone receptor-positive breast cancer diagnosed between 2010 and 2015. Initiation of HT >6 months (180 days) after surgery was defined as delayed. Patients receiving chemotherapy were excluded from the study cohort. Multivariable logistic regression modeling was performed to establish associations between delayed HT and demographic, facility, and clinical factors. Survival analysis was performed using the Kaplan-Meier estimation and Cox proportional hazards regression to evaluate overall survival. Of 179 590 women assessed in the National Cancer Database, 3.2% had a delay in the initiation of adjuvant HT. Positive demographic-related risk factors were younger age, ethnic minority groups, and multiple comorbidities. Clinical factors significantly associated with delayed initiation of adjuvant HT were high-grade tumor, larger tumor size, greater lymph node involvement, having an unplanned readmission within 30 days of surgery, and positive final surgical margins. Adjusted survival analysis showed a survival disadvantage of delayed initiation of HT. Risk factors for delayed initiation of HT specific to demographic and clinical characteristics were identified. Delayed initiation of HT was associated with a survival detriment.