Abstract P2-12-12: Identifying optimal candidates for three-dimensional bioabsorbable marker placement during breast cancer treatment: Incidence and predictors of postoperative complications
Authors: Foster BC , Graves TA , Taneja C , Wiggins DL , Hepel JT , Wazer DE , Leonard KL 
Published: February 2018

Abstract
OBJECTIVES: Radiation therapy (RT) is often an integral component of postoperative breast cancer management. Three dimensional (3D) bioabsorbable markers have been designed to assist CT-based tumor bed targeting during the RT process. There have been limited reports detailing complications following placement of such devices. This retrospective analysis attempts to identify demographic and treatment characteristics associated with complications after 3D bioabsorbable marker placement in a cohort of breast cancer patients treated at an academic medical center. METHODS: Records of 160 patients receiving a 3D bioabsorbable marker during initial breast surgery for DCIS or breast cancer were reviewed. Ten devices were removed at subsequent re-excision or mastectomy; therefore, 150 patients were ultimately evaluable. Demographic, tumor and operative/treatment characteristics were collected. Variables including body mass index (BMI), diabetes mellitus (DM), smoking, chemotherapy or RT use and excision volume (EV) were analyzed using multivariable logistic regression analysis (MVA). Endpoints included reoperation for wound complications (re-op), receipt of postoperative antibiotics (abx) and clinically palpable 3D bioabsorbable marker. RESULTS: Median follow-up was 8.2 months. Six (6/150, 4%) patients required re-op for wound complications and 5 required 3D bioabsorbable marker removal due to complications. Twenty (20/150, 13.3%) patients received abx for clinically detected postoperative wound infections. At last follow-up, 61 (61/150, 40.6%) patients noted persistent perceived fullness of the device at the lumpectomy site, and the 3D bioabsorbable marker remained palpable by the physician in 95 (95/150, 63.3%) patients. On MVA, DM and larger EV were associated with greater rates of re-op (p=0.020 and 0.012, respectively, Table 1). Mean EV was 279 cc among the re-op cohort and 85.5 cc among the no re-op cohort. DM, receipt of chemotherapy and larger EV were associated with postoperative abx prescription (p=0.005, 0.009 and 0.005, respectively, Table 2). Mean EV was 169.6 cc among those who received abx and 81.5 cc among those who did not. Larger EV was the only statistically significant predictor of a clinically palpable bioabsorbable marker during follow-up (p=0.044).
Table 1. Multivariable Analysis: Reoperation for Wound ComplicationsVariablep-valueBMI0.986Diabetes0.020Smoking0.999Excision Volume0.012Chemotherapy0.079Radiation0.113

Table 2. Multivariable Analysis: Prescription of AntibioticsVariablep-valueBMI0.571Diabetes0.005Smoking0.099Excision Volume0.005Chemotherapy0.009Radiation0.958
CONCLUSIONS: Rates of re-op for wound complications (4%) and postoperative infection (13.3%) were higher than expected among this cohort receiving 3D bioabsorbable markers, and were relatively high compared to historical surgical series managed without such devices. The present analysis suggests that those with larger EV, DM or receiving chemotherapy may be at greater risk for post-operative complications when a 3D bioabsorbable marker is placed. These factors should be considered when assessing candidacy for device placement.
Citation Format: Foster BC, Graves TA, Taneja C, Wiggins DL, Hepel JT, Wazer DE, Leonard KL. Identifying optimal candidates for three-dimensional bioabsorbable marker placement during breast cancer treatment: Incidence and predictors of postoperative complications [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-12-12.