1: Impact of Breast Conservation Therapy on Local Recurrence in Patients with Multiple Ipsilateral Breast Cancer – Results from ACOSOG Z11102 (Alliance)

Friday, March 24, 2023

1:13 PM – 1:25 PM

Location: Veterans Memorial Auditorium

Abstract Presenter(s)

Kari Rosenkranz, MD

Associate Professor
Dartmouth Health
Norwich, Vermont, United States

Disclosure(s): No financial relationships to disclose

First Author(s)

Kari Rosenkranz, MD

Associate Professor
Dartmouth Health
Norwich, Vermont, United States

Disclosure(s): No financial relationships to disclose

Author(s)

Judy C. Boughey, MD, FACS, FSSO (she/her/hers)

Professor of Surgery, W.H. Odell Professor in Individualized Medicine, Chair-Division of Breast and Melanoma Surgical Oncology, Department of Surgery
Mayo Clinic
Rochester, Minnesota, United States

Disclosure(s): Cairns Surgical: Other (Ongoing); Eli Lilly: Research Grant (Ongoing); OncLive: Speaker (Terminated); Peer View: Speaker (Terminated); PER: Speaker (Terminated); SymBioSis: Research Grant (Ongoing); UptoDate: Royalties (Ongoing)
BH

Bruce Haffty, MD. MS

Chair, Radiation Oncology
Rutgers Cancer Institute of New Jersey, United States

Disclosure information not submitted.
KB

Karla Ballmam, PhD

Chief of Biostatistics and Epidemiology
Weill Cornell MMedical Center, United States

Disclosure information not submitted.
LM

Linda McCall, MS

Statistician
Alliance Statistics and Data Center, United States

Disclosure information not submitted.
LC

Laurie Cuttino, MD

Radiation Oncologist
Sarah Cannon Cancer Institute, United States

Disclosure information not submitted.
CK

Charlotte Kubicky, MD

Radiation Oncologist
Sutter Health, United States

Disclosure information not submitted.
HL

H. Clarissa LePetross, MD

Radiologist
MD Anderson Cancer 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.
KV

Kimberly J. Van Zee, MS, MD

Breast Service, Department of Surgery
Memorial Sloan Kettering Cancer Center, United States

Disclosure information not submitted.
Kelly K. Hunt, MD (she/her/hers)

Chair, Department of Breast Surgical Oncology
The University of Texas MD Anderson Cancer Center
Houston, Texas, United States

Disclosure(s): Armada Health: Advisor (Ongoing); Astra Zeneca: Consultant (Ongoing); Cairn Surgical: Research Grant (Ongoing); Eli Lilly & Company: Research Grant (Ongoing); Lumicell: Research Grant (Ongoing)
OH

Olwen Hahn, MD

Associate Professor of Medicine
University of Chicago, United States

Disclosure information not submitted.
LC

Lisa Anne Carey, MD

Professor of Breast Cancer Research
University of North Carolina, United States

Disclosure information not submitted.
AP

Ann Partridge, MD, MPH

Professor of Medicine, Chair in Breast Cancer Research
Dana Farber Cancer Institute, United States

Disclosure information not submitted.

Disclosure(s):

Kari Rosenkranz, MD: No financial relationships to disclose

Judy C. Boughey, MD, FACS, FSSO: Cairns Surgical: Other (Ongoing); Eli Lilly: Research Grant (Ongoing); OncLive: Speaker (Terminated); Peer View: Speaker (Terminated); PER: Speaker (Terminated); SymBioSis: Research Grant (Ongoing); UptoDate: Royalties (Ongoing)

Kelly K. Hunt, MD: Armada Health: Advisor (Ongoing); Astra Zeneca: Consultant (Ongoing); Cairn Surgical: Research Grant (Ongoing); Eli Lilly & Company: Research Grant (Ongoing); Lumicell: Research Grant (Ongoing)

Introduction: Breast conserving therapy (BCT) is an accepted treatment for unifocal breast cancer. The oncologic safety of BCT for multiple ipsilateral breast cancer (MIBC), has not been demonstrated in a prospective study. The ACOSOG (Alliance) Z11102 phase II single arm prospective trial was designed to evaluate outcomes with BCT for MIBC.

Methods: Women age 40+ with 2 or 3 foci of biopsy proven breast cancer (BC) (each site < 5cm in size with with cN0 or cN1 disease) treated with up front surgery were eligible. All patients had pre-operative mammogram. Breast MRI was optional for the majority of the trial. Patients were treated with lumpectomy resected to negative margins followed by whole breast radiation with boost to all lumpectomy beds. The primary endpoint is the cumulative incidence of local recurrence (LR, defined as histologic evidence of ductal carcinoma in situ or invasive BC in the ipsilateral breast or chest wall) at 5 years to assess whether the rate is greater than 8%. Data were frozen 5/25/2022.

Results: From 11/2012-8/2016, 270 women were enrolled. 33 were ineligible, 14 converted to mastectomy, 11 were unable to meet protocol-specific radiation endpoints, 1 had no definable tumor, 1 had 4 sites of cancer and 16 withdrew before completing surgery and radiation, leaving 194 patients [median age 61 (range 40-87)] eligible. With median follow-up of alive patients of 66.6 months (range: 4.1, 90.6), 6 patients developed LR (5 ipsilateral breast and 1 chest wall). Estimated cumulative incidence of local recurrence is 3.2% (95% CI: 1.3, 6.4) at 5 years. No patients have developed regional recurrence, 5 patients developed distant recurrence, 0 patients developed local and distant recurrence, 5 patients developed contralateral BC, 3 new non-BC primaries and 8 patients have died (1 related to BC). The rate of local recurrence in patients without a breast pre-op MRI (n=14) was 22.6% at 5 years compared to 1.7% among the 180 patients with a preop MRI (p=0.002). Patient age, number of sites of preoperative biopsy proven BC, HER2 status, pathologic T and N category were not statistically significantly associated with risk of LR.

Conclusions: The Z11102 clinical trial demonstrates breast conserving surgery with radiation (with boosts) in women with MIBC has an acceptably low LR rate (3.2% at 5 years). BCT is a reasonable consideration for women with 2-3 ipsilateral foci.

Support: U10CA180821, U10CA180882; https://acknowledgments.alliancefound.org. ClinicalTrials.gov Identifier: NCT01556243

Learning Objectives:

Understand surgical management options for patients with multiple ipsilateral breast cancer
Discuss local recurrence rates for patients with MIBC
Consider risk factors for local recurrence in patients with MIBC