While the detrimental effects of delaying surgery or chemotherapy on OS following a BC diagnosis is clear, more obscure are the effects of delaying the use of adjuvant hormone therapy (AHT) in patients with HR+/HER2- early BC who have not undergone chemotherapy.
To address this concern, a large, population-based, cohort retrospective study was conducted using data from the National Cancer Database (NCDB). The purpose of this study was to assess the association of time to adjuvant hormone therapy (TTH) with BC survival and to evaluate the factors associated with the use of AHT. The NCDB is a collaboration of the Commission on Cancer of the American College of Surgeons and the American Cancer Society that serves as a hospital-based clinical registry containing about 70% of newly diagnosed cancer cases in the United States.
Patients were included in this study if they had stage I to III HR+/HER2- invasive early BC, were diagnosed between 2004 and 2014, had undergone surgical procedures, and received AHT. Exclusion criteria included patients who received neoadjuvant systemic treatment, chemotherapy, or immunotherapy; those who had a prior cancer diagnosis; those with follow-up time of fewer than 8 months; and patients with missing variables of interest.
TTH was defined as the time interval from the definitive curative operation to the start of AHT. The number of days between diagnosis and hormone therapy and between the diagnosis and surgical procedure were used to calculate TTH. Patients were divided into two groups: the timely treatment group (TTH <150 days) and the delayed treatment group (TTH >150 days). Outcome OS was defined as the number of months between the date of diagnosis and the date the patient was last contacted or died.
The study population included 144,103 patients diagnosed with HR+/HER2- BC. The median TTH was 65 days with a range of 32 to 104 days. Of these patients, 93.6% were in the timely treatment group (mean age 63.8 years) with a median TTH of 59 days (range 31-97 days). The delayed-treatment group comprised 6.4% of the population (mean age 61.7 years) and had a median TTH of 186 days (range 163-231 days). Additional demographic data revealed that 99.2% of the study population was female, 8.0% were Black, 87.4% were White, 92% were estrogen receptor positive (ER+)/progesterone receptor positive (PR+), and 8.0% were either ER+/PR- or ER-/PR+.
Median OS was 36.6 months (range 25.5-49.2 months). Patients who experienced delayed treatment had a 31% increased risk of death (hazard ratio [HR] 1.31, 95% CI 1.26-1.35, P <.001). Subgroup analyses showed delayed treatment was associated with a trend of OS reduction in all subgroups, except for the uninsured, those with stage III disease, and patients with single HR+ (either ER+PR- or ER-PR+) disease.
The most common factor associated with delayed AHT was Black race (odds ratio [OR] 1.66, CI 1.55-177), followed by having nonprivate insurance coverage, living in a metropolitan area, receiving treatment at a community hospital, having a Charlson Comorbidity Index of >2, having poorer grade differentiation, having stage II or III disease or single HR+ disease, undergoing breast conservation operations, and receiving radiotherapy.
This paper serves as a wake-up call advocating that all early BC patients should start AHT as soon as possible after surgical procedures. Pharmacists can assist in assuring that unnecessary delays in care are avoided.
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