Abstract P5-14-07: Noninfectious Wound Complications after Mastectomy with and without Immediate Breast Reconstruction

Background: Noninfectious wound complications, including tissue necrosis and dehiscence, may complicate healing of the breast surgical incision after mastectomy. Breast cancer patients may be at increased risk of noninfectious wound complications due to adjuvant chemo-and radiotherapy. Objective: To identify independent risk factors for noninfectious wound complications (necrosis and/or dehiscence), including the impact of neo-and adjuvant chemotherapy, and previous and adjuvant radiotherapy after mastectomy alone or with immediate breast reconstruction. Methods: We performed a prospective cohort study of all mastectomy patients with invasive or in situ breast cancer at a tertiary care academic medical center from 8/2005 — 7/2008. Data were collected from the original surgical admission and all hospital readmissions and surgery and oncology clinic visits within 1 year of surgery. Follow-up data included documented signs and symptoms of wound complications, microbiology cultures, additional surgical procedures, and chemo-and radiation therapy dates. Extended Cox proportional hazards models were used to determine independent risk factors for wound complications, controlling for underlying comorbidities, previous chest irradiation and neoadjuvant chemotherapy, and with adjuvant radiotherapy and chemotherapy included as time-dependent covariates. Results: 777 women had a mastectomy (408 (52.5%) mastectomy only, 325 (41.8%) mastectomy plus implant, and 44 (5.7%) mastectomy plus autologous tissue reconstruction). 173/777 women (22.3%) received neoadjuvant chemotherapy. 105 women had breast wound complications within 180 days after surgery (13.5%). Repeat surgery (incision and drainage, debridement, and/or implant removal) was required in 40/105 (38.1%) women with wound complication. 13/105 (12.4%) women had subsequent infection after wound complication, while 9/105 (8.6%) had infection diagnosed before the wound complication. Independent risk factors for noninfectious wound complication within 180 days after surgery included autologous tissue reconstruction (hazard ratio (HR) 5.6, 95% CI: 2.9-10.5), implant reconstruction (HR 4.3, 95% CI: 2.8-6.8), smoking (HR 3.3, 95% CI: 2.2-4.9), higher ASA class (HR 1.7 (95% CI: 1.0-2.9), and morbid obesity (BMI > 35, HR 2.6, 95% CI: 1.7-4.0). Preadmission anticoagulant therapy was marginally associated with increased risk of necrosis/dehiscence (HR 1.8, 95% CI: 0.9-3.7). Diabetes (p = .365), neoadjuvant chemotherapy (p = .254), adjuvant chemotherapy (p = .222), previous radiotherapy (p = .195), and adjuvant radiotherapy (p = .106) were not associated with increased risk of necrosis/dehiscence within 180 days of surgery after accounting for other risk factors for wound complication. Discussion: Immediate breast reconstruction, smoking, and morbid obesity were associated with increased risk of tissue necrosis/dehiscence within 180 days after mastectomy. Neo-and adjuvant chemotherapy and adjuvant radiotherapy were not associated with increased risk of noninfectious wound complications after controlling for underlying comorbidities and other risk factors. These results emphasize the important of smoking cessation in women undergoing mastectomy, particularly with immediate breast reconstruction. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-14-07.