In a phase II trial (ACOSOG Z11102/Alliance) reported in the Journal of Clinical Oncology, Judy C. Boughey, MD, and colleagues found that breast-conserving therapy was associated with a low rate of local recurrence in women with multiple ipsilateral breast cancer sites.
Study Details
A total of 204 eligible patients were enrolled in the U.S. multicenter trial between July 2012 and August 2016; they were aged ≥ 40 years (median = 61 years), with two or three foci of biopsy-proven cN0-1 disease. Patients underwent lumpectomies with negative margins followed by whole-breast radiation with a boost to all lumpectomy beds. The primary endpoint was cumulative incidence of local recurrence at 5 years, with an a priori clinical acceptability rate < 8%.
Judy C. Boughey, MD
Key Findings
Over a median follow-up of 66.4 months (range = 1.3–90.6 months), six patients developed local recurrence, with an estimated 5-year cumulative incidence of 3.1% (95% confidence interval [CI] = 1.3%–6.4%). Among the six patients with local recurrence, four had in-breast tumor recurrence, one had ipsilateral breast skin recurrence, and one had chest wall recurrence with an intrapectoral mass.
Exploratory analysis showed a 5-year local recurrence rate of 22.6% among 15 patients who did not have preoperative magnetic resonance imaging (MRI) vs 1.7% among 189 patients with preoperative MRI (P = .002). No associations with local recurrence risk were observed for age, number of sites of preoperative biopsy-proven disease, estrogen receptor status, HER2 status, or pathologic T and N categories.
With regard to other recurrence sites, no patients developed regional recurrence, and four developed distant recurrence (none with concurrent local recurrence), with sites consisting of bone only in two patients, bone and bone marrow in one, and lungs in one. Contralateral breast cancer occurred in six patients. Non–breast cancer malignancies developed in three patients, consisting of gastric, lung, and ovarian cancer in one patient each. One patient died due to breast cancer.
The investigators concluded, “The Z11102 clinical trial demonstrates that breast-conserving surgery with adjuvant radiation that includes lumpectomy site boosts yields an acceptably low 5-year local recurrence rate for multiple ipsilateral breast cancer. This evidence supports breast-conserving therapy as a reasonable surgical option for [patients] with two to three ipsilateral foci, particularly among patients with disease evaluated with preoperative breast MRI.”
Dr. Boughey, of Mayo Clinic, Rochester, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was supported by grants from the National Cancer Institute. For full disclosures of the study authors, visit ascopubs.org.
