Effectiveness of a Short Duration of Neoadjuvant Endocrine Therapy in Patients with HR+ Breast Cancer-An NCDB Analysis (2004-2016).

BACKGROUND: National medical/surgical organizations have recommended the use of neoadjuvant endocrine therapy (NET) to bridge surgery delay of weeks to months for patients with hormone receptor positive (HR+) breast cancer during the ongoing coronavirus disease 2019 (COVID-19) pandemic. The effects of NET of varying durations on pathologic response are unclear. Using the National Cancer Database (NCDB), we evaluated objective response to short (< 9 weeks), moderate (9-27 weeks), and long (> 27 weeks) duration of NET. PATIENTS AND METHODS: The study cohort included female patients diagnosed with nonmetastatic invasive HR+ breast cancer, stratifying by those who received NET versus no NET between 2004 and 2016. Pathologic response was grouped into four categories (complete, downstaged, stable, upstaged) by comparing clinical and pathologic staging data. Objective response to NET included complete, downstaged, and stable pathologic response. Clinical characteristics were compared using χ2 and analysis of variance (ANOVA) tests. Multivariable logistic regression was used to determine factors associated with NET use and objective response according to NET duration. RESULTS: A minority (1.2%) received NET in our cohort. Factors associated with NET use included older age, non-Black patients, more advanced clinical stage, higher comorbidity score, government insurance, and lobular histology. Objective response rate (ORR) was 56.7%, 52.1%, and 49.0% after short, moderate, and long NET duration, respectively. CONCLUSION: Short NET duration did not result in an inferior ORR. Future study to evaluate the interaction between surgery delay and NET use on clinical outcome will provide insights into the safety of NET to bridge potential surgery delay in patients with HR+ breast cancer.

Clinical target sequencing for precision medicine of breast cancer.

Precision medicine can be defined as the customization of medical treatment based on the individual genetic profile, which enables one to identify patients who respond to therapies while sparing side effects for those who do not. Breast cancer patients have been treated based on subtyping, which is considered a prototype of precision medicine. Furthermore, the development of multigene panel testing has resulted in a paradigm shift in the treatment of breast cancer. The knowledge generated from the Human Genome Project, and subsequently The Cancer Genome Atlas, has provided the concept of precision medicine, in which cancer patients can be sub-classified based on actionable driver mutations that can be selectively targeted by molecular targeted drugs and treated by appropriate molecular targeted therapies. Development of next-generation sequencing has both dramatically advanced genomic sequencing technology and revealed actionable driver mutations for individual cancer patients when applied to a clinical setting. Clinical target sequencing by next-generation sequencing enables one to formulate treatment strategies, not only by selecting a subgroup of patients who are expected to experience more effectiveness of each drug, but also by revealing patients with drug resistance based on their actionable driver mutations.