No abstract

Background: Next generation sequencing and broadened genetic testing guidelines have made it possible to perform multi-gene testing upfront for patients at risk for hereditary breast cancer. Breast surgeons and oncologists are ideally situated at the forefront of cancer treatment to initiate these tests since results can impact treatment decisions. This study evaluates the utility of multi-gene testing in a multidisciplinary breast practice. Methods: Data was collected retrospectively from 500 consecutive patients who underwent multi-gene panel testing July 2013 – September 2014. Patients were evaluated at time of visit if they met criteria for genetic testing based on NCCN guidelines. Results: Most patients had no prior genetic testing; 28.8% of patients had previous negative BRCA1 and BRCA2 (BRCA1/2) tests. All patients had a personal and/or family history of breast or ovarian cancer. All patients were evaluated with a multi-gene panel consisting of a minimum of 5 breast-cancer related genes (BRCA1, BRCA2, PTEN, TP53, and CDH1) and most (68.0%) had extended panel testing of up to 43 cancer-associated genes. Pathogenic mutations were identified in 32 (6.4%) patients. The majority of patients (79.0%) were not found to carry any mutations, while 16.2% had at least one genetic variant of uncertain significance. Of the patients with pathogenic mutations, 37.5% had a mutation in BRCA1/2 while most patients had mutations in non-BRCA1/2 genes. PatientMutationPersonal History of CancerBreast CancerAge at Breast Cancer DxType of Breast CancerOther Cancer1ATMyes47DCIS 2ATMyes77IDC 3BARD1, CHEK2yes39IDC 4BRCA1yesno Ovarian, age 515BRCA1yes46IDC 6BRCA2yes42IDC 7BRCA2yes76ILCOvarian, age 558BRCA2yes43DCIS 9BRCA2yes46IDC 10BRCA2yes54IDC 11BRCA2yes36ILC 12BRCA2yes38ILC 13BRCA2yes64IDC 14BRCA2yes35IDC 15BRCA2nono  16CHEK2yes35not availableThyroid, age 6017CHEK2yes66IDC 18CHEK2yes65DCIS 19CHEK2yes44IDC 20CHEK2yes43IDC 21CHEK2nono  22MRE11Anono  23MSH2nono  24MUTYHyes41DCIS 25MUTYHyes53DCIS 26MUTYHnono  27NBNyes72IDC 28PALB2yes59IDC 29PALB2yes42IDC 30PALB2yes53IDC 31RAD51Cyesno Ovarian, age 6532TP53yes46DCIS  The majority of patients with mutations had a personal history of cancer including breast, ovarian, and thyroid cancer. There was no significant difference between age of breast cancer diagnosis and having a BRCA1/2 mutation compared to having a non-BRCA gene mutation. The majority of gene-positive patients with cancer had hormone-positive invasive ductal carcinoma(IDC) while only two patients had triple negative breast cancer. Compared to patients with BRCA1/2 mutations, patients with non-BRCA mutations were more likely to have a family history of non-breast or ovarian cancer(58.3% vs 90%, respectively, p=0.0735). Conclusions: Multi-gene panel testing will identify more patients with risk of breast and ovarian cancer than routine BRCA1/2 testing alone, and may have an impact on screening for other cancers as well. Obtaining a thorough personal and family cancer history is necessary to provide optimal counseling and screening. Citation Format: Kapoor NS, Curcio LD, Patrick M, Swisher J, West JD, Banks K. Multi-gene panel testing and the cancers identified in patients at risk for hereditary breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr PD7-05.

Background: The purpose of this study was to evaluate bioelectrical impedance spectroscopy's (BIS) ability to detect and monitor extracellular fluid accumulation of the upper limb as it relates to the extent of loco-regional therapy. Methods: A total of 125 patients with breast cancer from 4 clinical practices were evaluated with BIS at baseline and following loco-regional procedures. In order to assess the ability of BIS to detect subclinical changes by treatment modality, the change in L-Dex score from baseline to measurements taken within 180 days following surgery were calculated. Results: Mean age was 55 years with 68 patients (54.4%) undergoing sentinel lymph node (SLN) sampling while 57 (45.6%) underwent an axillary dissection (ALND). Sixty-five patients (52%) underwent radiation therapy (RT). Patients receiving RT had a significantly increased change in L-Dex score (0.8 v.-2.5, p=0.03) compared with those patients not receiving RT. For all patients, ALND was associated with a significantly increased change in L-Dex score (5.0 v. 0.3, p=0.003) compared with SLN. When stratifying by the number of nodes removed, a statistically significant increase in the change in L-Dex score was noted (0.4 v. 0.4 v. 4.3 v. 6.4, p=0.04) for 0-3, 4-6, 7-10 and greater than 10 lymph nodes removed. Conclusions: In this limited analysis, L-Dex scores paralleled the extent of axillary sampling and the addition of radiation therapy; these results demonstrate that BIS can be used to monitor patients for the early onset of edema as differences emerged within 180 days of surgery.

#5141 Purpose/Objective(s): With the new ConturaTM Multi-Lumen Balloon (MLB) catheter (SenoRx, Inc, Aliso Viejo, CA), one may achieve 2 dosimetric advantages over a MammoSiteTM catheter: 1) avoidance of a radiation “hot spot” in the skin which may improve cosmetic results, and 2) reduction of the size of an air/fluid pocket in the planning target volume for plan evaluation (PTV_EVAL) which may improve local control by increasing the radiation dose delivered to breast tissue at risk. The purpose of this study was to analyze the frequency with which a Contura catheter can satisfy the above 2 dosimetric goals relative to a MammoSite catheter.
 Materials/Methods: From October 2007 to June 2008, 23 patients between the ages of 43 and 88 years (median, 57 years) with unifocal AJCC pathological T0, T1, or T2 (maximum, 3.0 cm; median, 1.0 cm), N0 ductal, papillary, or tubular carcinomas of the breast at least 1 mm from the inked edge of the lumpectomy specimen were treated with high-dose-rate iridium-192 brachytherapy using a Contura MLB catheter. Sixty-five percent of the cancers were estrogen-receptor positive. Brachytherapy was delivered to a total dose of 34 Gy in 10 fractions bid over 5-7 days. We prescribed the dose to a depth of 1.0 cm from the balloon surface. The Contura applicator allows one to load up to 5 source lumens: 4 lumens that are offset 0.5 cm circumferentially from a central lumen. The ability to choose from multiple lumens allows for greater control over where radiotherapy is delivered. The Contura catheter also has a sixth lumen through which air/fluid can be removed from around the balloon. This feature helps to improve tissue-balloon conformance. The minimum balloon-to-skin distance was 0.5 cm. In 39% of patients, the balloon-to-skin distance was 0.5-0.9 cm. The balloon volume was 30-55 cc, V150 was ≤ 33 cc, and V200 was ≤ 10 cc. Hypothetical MammoSite treatment plans were created using a CT scan of the breast prior to air/fluid removal. Only the central lumen was loaded for the hypothetical MammoSite plan. The 2 treatment planning goals were to keep the: 1) maximum skin dose ≤ 100% of the prescribed dose, and 2) volume of air/fluid around the balloon ≤ 3.0% of PTV_EVAL. A one-sided McNemar test was used to compare the % of Contura plans that satisfied both goals vs the % of MammoSite plans that satisfied both goals.
 Results: The maximum skin dose was 100% of the prescribed dose with the Contura catheter vs 145% of the prescribed dose with a MammoSite catheter. The volume of air/fluid around the balloon was 4.4% ± 1.0% (mean ± standard error) of PTV_EVAL prior to suctioning vs 1.2% ± 0.3% after suctioning. Ninety-one percent of Contura plans satisfied both treatment planning goals vs only 48% of MammoSite plans (p=0.08).
 Conclusion: A Contura applicator resulted in a trend towards dosimetric improvement over a MammoSite catheter. Patients will be followed long-term in order to determine their local control, disease-free survival, cosmetic results, and treatment-related toxicities. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5141.