15: A Prospective Study of Sentinel Node Biopsy Omission in Women Age ≥ 65 with Early Invasive ER+ Breast Cancer Undergoing Breast Conserving Surgery

Saturday, March 25, 2023

8:32 AM – 8:42 AM

Location: Veterans Memorial Auditorium

Abstract Presenter(s)

Alice Chung, MD

Associate Professor of Surgery
Cedars Sinai Medical Center
Beverly Hills, California, United States

Disclosure(s): No financial relationships to disclose

First Author(s)

CD

Catherine Dang, MD, FACS

Assistant Professor of Surgery
Cedars-Sinai Medical Center, United States

Disclosure information not submitted.

Author(s)

SK

Scott Karlan, MD, FACS

Assistant Professor of Surgery
Cedars-Sinai Medical Center, United States

Disclosure information not submitted.
FA

Farin Amersi, MD

Associate Professor of Surgery
Cedars Sinai Medical Center
Los Angeles , California, United States

Disclosure information not submitted.
EP

Edward Phillips, MD, FACS

Professor of Surgery
Cedars-Sinai Medical Center, United States

Disclosure information not submitted.
YC

Yujie Cui, MS

Statistician
Cedars-Sinai Medical Center, United States

Disclosure information not submitted.
AG

Armando Giuliano, MD, FACS

Professor of Surgery
Cedars-Sinai Medical Center, United States

Disclosure information not submitted.

Disclosure(s):

Alice Chung, MD: No financial relationships to disclose

Introduction: Controversy exists over the necessity of staging the axilla with sentinel lymph node biopsy (SLNB) in older patients with breast cancer, especially in those with low-risk disease. National guidelines recommend consideration of omitting SLNB in this patient population; however, there is a lack of prospective data specifically addressing this issue. This study evaluates the outcomes of SLNB omission in clinically node-negative (cN0), hormone receptor (HR)-positive breast cancer patients aged ≥ 65 years undergoing breast conserving surgery (BCS).

Methods: The study is a prospective observational study that enrolled women ≥ 65 years with clinical T1-2N0 unifocal HR+/Her 2-neu negative invasive breast cancer who were treated with BCS with or without adjuvant radiation and systemic therapy. Patients were followed on a semi-annual basis with breast imaging and clinical breast exam for 2 years, and then annually. Recurrence and survival outcomes were evaluated using the Kaplan-Meier method and univariate analysis was performed to identify factors that were associated with recurrence or survival.

Results: From September 2016 to July 2022, 125 patients were enrolled with a median follow-up of 32.9 (95% CI, 25.2-35.3) months estimated by reverse Kaplan-Meier method. Median age was 77.0 (range 65 - 93) years. Median tumor size was 1.1 (range 0.1 - 5.0) cm. The majority of tumors had ductal histology (94/125, 75.2%), were intermediate grade (58/125, 46.4%), and ER/PR positive (114/125, 91.2%). Radiation therapy was performed in 35/125 (28.0%) patients: 3/35 (8.6%) had accelerated partial breast irradiation, and 32/35 (91.4%) had whole breast radiation. Among those recommended to have hormonal therapy, 60/125 (48%) were compliant at or beyond 2-year follow-up. Chemotherapy was administered to 6/125 (4.8%) patients. Estimated 3-year rates of regional recurrence free survival (RFS), disease-free survival (DFS) and overall survival (OS) were 98.1%, 91.0%, and 93.3%, respectively. Univariate cox regression identified hormonal therapy compliance to be marginally associated with any recurrence (p=0.055). Cardiovascular disease was the most common cause of death. There was one death due to breast cancer in a patient who declined adjuvant therapy.

Conclusions: Recurrence rates and disease-related mortality remain low in this cohort. While longer follow-up with similar findings would be corroborative, these results provide prospective data to support omission of SLNB in this patient population.

Learning Objectives:

Upon completion, participants will be able to identify patients who may safely avoid sentinel node biopsy among patients with ER+ breast cancer.
Participants will be able to describe possible risk factors for recurrence among patients who do not have a sentinel node biopsy.
Participants will be able to demonstrate that survival is minimally impacted by omission of sentinel node biopsy in this patient population.