Zee, Kimberly J. Van

ImportanceBreast cancer–related lymphedema (BCRL) is a common complication of axillary lymph node dissection (ALND) but can also develop after sentinel lymph node biopsy (SLNB). Several models have been developed to predict the risk of disease development before and after surgery; however, these models have shortcomings that include the omission of race, inclusion of variables that are not readily available to patients, low sensitivity or specificity, and lack of risk assessment for patients treated with SLNB.ObjectiveTo create simple and accurate prediction models for BCRL that can be used to estimate preoperative or postoperative risk.Design, Setting, and ParticipantsIn this prognostic study, women with breast cancer who underwent ALND or SLNB from 1999 to 2020 at Memorial Sloan Kettering Cancer Center and the Mayo Clinic were included. Data were analyzed from September to December 2022.Main Outcomes and MeasuresDiagnosis of lymphedema based on measurements. Two predictive models were formulated via logistic regression: a preoperative model (model 1) and a postoperative model (model 2). Model 1 was externally validated using a cohort of 34 438 patients with an International Classification of Diseases diagnosis of breast cancer.ResultsOf 1882 included patients, all were female, and the mean (SD) age was 55.6 (12.2) years; 80 patients (4.3%) were Asian, 190 (10.1%) were Black, 1558 (82.8%) were White, and 54 (2.9%) were another race (including American Indian and Alaska Native, other race, patient refused to disclose, or unknown). A total of 218 patients (11.6%) were diagnosed with BCRL at a mean (SD) follow-up of 3.9 (1.8) years. The BCRL rate was significantly higher among Black women (42 of 190 [22.1%]) compared with all other races (Asian, 10 of 80 [12.5%]; White, 158 of 1558 [10.1%]; other race, 8 of 54 [14.8%]; P < .001). Model 1 included age, weight, height, race, ALND/SLNB status, any radiation therapy, and any chemotherapy. Model 2 included age, weight, race, ALND/SLNB status, any chemotherapy, and patient-reported arm swelling. Accuracy was 73.0% for model 1 (sensitivity, 76.6%; specificity, 72.5%; area under the receiver operating characteristic curve [AUC], 0.78; 95% CI, 0.75-0.81) at a cutoff of 0.18, and accuracy was 81.1% for model 2 (sensitivity, 78.0%; specificity, 81.5%; AUC, 0.86; 95% CI, 0.83-0.88) at a cutoff of 0.10. Both models demonstrated high AUCs on external (model 1: 0.75; 95% CI, 0.74-0.76) or internal (model 2: 0.82; 95% CI, 0.79-0.85) validation.Conclusions and RelevanceIn this study, preoperative and postoperative prediction models for BCRL were highly accurate and clinically relevant tools comprised of accessible inputs and underscored the effects of racial differences on BCRL risk. The preoperative model identified high-risk patients who require close monitoring or preventative measures. The postoperative model can be used for screening of high-risk patients, thus decreasing the need for frequent clinic visits and arm volume measurements.

PURPOSE Breast-conserving therapy (BCT) is the preferred treatment for unifocal breast cancer (BC). The oncologic safety of BCT for multiple ipsilateral breast cancer (MIBC) has not been demonstrated in a prospective study. ACOSOG Z11102 (Alliance) is a phase II, single-arm, prospective trial designed to evaluate oncologic outcomes in patients undergoing BCT for MIBC. PATIENTS AND METHODS Women age 40 years and older with two to three foci of biopsy-proven cN0-1 BC were eligible. Patients underwent lumpectomies with negative margins followed by whole breast radiation with boost to all lumpectomy beds. The primary end point was cumulative incidence of local recurrence (LR) at 5 years with an a priori rate of clinical acceptability of <8%. RESULTS Among 270 women enrolled between November 2012 and August 2016, there were 204 eligible patients who underwent protocol-directed BCT. The median age was 61 years (range, 40-87 years). At a median follow-up of 66.4 months (range, 1.3-90.6 months), six patients developed LR for an estimated 5-year cumulative incidence of LR of 3.1% (95% CI, 1.3 to 6.4). Patient age, number of sites of preoperative biopsy–proven BC, estrogen receptor status and human epidermal growth factor receptor 2 status, and pathologic T and N categories were not associated with LR risk. Exploratory analysis showed that the 5-year LR rate in patients without preoperative magnetic resonance imaging (MRI; n = 15) was 22.6% compared with 1.7% in patients with a preoperative MRI (n = 189; P = .002). CONCLUSION The Z11102 clinical trial demonstrates that breast-conserving surgery with adjuvant radiation that includes lumpectomy site boosts yields an acceptably low 5-year LR rate for MIBC. This evidence supports BCT as a reasonable surgical option for women with two to three ipsilateral foci, particularly among patients with disease evaluated with preoperative breast MRI.

Abstract Background Breast conserving therapy (BCT) is accepted as a preferred option for unifocal breast cancer. However, 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 &lt; 5cm in size with at least 1 site invasive) separated by &gt;2-3 cm of normal breast tissue and disease limited to two quadrants of the breast with cN0 or cN1 disease were eligible. All patients had pre-operative mammogram and breast MRI was initially required and subsequently made optional. Neoadjuvant therapy was not allowed. Patients were treated with lumpectomy resected to negative margins followed by whole breast radiation with boost to all lumpectomy beds. The primary endpoint of Z11102 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 (treating death and distant and nodal/regional recurrence as competing risks) 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. Of these, 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 who completed breast conserving surgery and radiation therapy. With median follow-up of alive patients of 66.6 months (range: 4.1, 90.6), 6 patients have developed LR (5 ipsilateral breast and 1 chest wall), corresponding to an estimated cumulative incidence of local recurrence of 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. Conclusion The Z11102 clinical trial demonstrates that for women with MIBC breast conserving surgery with adjuvant radiation with lumpectomy site boosts has an acceptably low LR rate (3.2% at 5 years), making this a reasonable consideration for women with 2-3 ipsilateral foci. The LR rate was significantly higher in the small cohort of patients without preoperative breast MRI. Support: U10CA180821, U10CA180882; https://acknowledgments.alliancefound.org. ClinicalTrials.gov Identifier: NCT01556243 Table 1: Factors associated with LR after BCT for MIBC Citation Format: Judy C. Boughey, Kari M. Rosenkranz, Karla V. Ballman, Linda McCall, Bruce G. Haffty, Laurie W. Cuttino, Charlotte D. Kubicky, H. T. Carisa Le-Petross, Kimberly Van Zee, Armando E. Giuliano, Olwen M. Hahn, Kelly K. Hunt, Lisa Carey, Ann Partridge. Impact of Breast Conservation Therapy on Local Recurrence in Patients with Multiple Ipsilateral Breast Cancer – Results from ACOSOG Z11102 (Alliance) [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr GS4-01.