1. A real-world retrospective study of the use of Ki-67 testing and treatment patterns in patients with HR+, HER2− early breast cancer in the United States
- Author
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Jacqueline Brown, Savannah Scardo, Michael Method, Dan Schlauch, Amanda Misch, Shaita Picard, Erika Hamilton, Suzanne Jones, Howard Burris, and David Spigel
- Subjects
Male ,Cancer Research ,Receptor, ErbB-2 ,Breast Neoplasms ,United States ,Ki-67 Antigen ,Oncology ,Chemotherapy, Adjuvant ,Biomarkers, Tumor ,Genetics ,Humans ,Female ,Receptors, Progesterone ,Retrospective Studies - Abstract
Background The National Comprehensive Cancer Network recommends that patients with hormone receptor-positive early breast cancer be considered for adjuvant endocrine therapy (ET) after primary treatment like surgical excision. Adjuvant chemotherapy (CT) use primarily depends on risk of recurrence. Biomarkers such as Ki-67 potentially have most value in patients with intermediate risk factors, such as involvement of 1–3 positive nodes. This study evaluated the use of Ki-67 testing and treatment patterns in patients with HR+, human epidermal growth factor receptor 2-negative early breast cancer. Methods This was an observational retrospective cohort study of patients with electronic medical records from January 2010 to August 2018 treated for HR+, HER2− early breast cancer at Sarah Cannon sites in the United States (US). Overall, 567 patients were randomly selected after using the eligibility criteria: female or male ≥18 years, without distant metastases, and with available physician and pathology reports. Multivariable logistic regression was used to investigate factors predicting Ki-67 testing and test results. Descriptive analyses were applied to treatment patterns. Results Multivariable logistic regression analyses found no clinical or pathological factors that predicted whether Ki-67 testing had been ordered by physicians. Of all tested patients (N = 130), having Grade-2 tumors (OR, 7.95 [95% CI: 2.05, 30.9]; p = 0.0027) or Grade-3 tumors (OR, 95.3 [95% CI, 11.9, 760.7]; p Conclusions High grade tumors predicted high Ki-67 (≥20%) expression, but Ki-67 testing was not widely used in these US patients. Most HR+, HER2− early breast cancers were treated with adjuvant ET, with or without CT.
- Published
- 2022
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