Abstract OT3-06-01: Prevention and management of residual breast tissue following radical mastectomy and skin-sparing and nipple-sparing mastectomy in oncologic and high-risk breast cancer patients - A multicentre questionnaire study
Authors: Deutschmann Christine , Pfeiler Georg 
Published: March 2020

Abstract
1. Background
As the presumed oncological risk of skin-sparing (SSM) and nipple-sparing mastectomy (NSM) putatively relies on remaining fibroglandular tissue within the nipple-areolar-complex and the skin flap complete resection of breast parenchyma is of uttermost importance. Contrary, residual fibroglandular tissue has been detected in up to 50% of breast specimens following NSM and 13% after SSM. Studies focusing on the prevention and management of residual breast tissue (RBT) are scarce.
2. Trial design and eligibility criteria
A prospective multicenter questionnaire study addressing the subjects preventive measures, targeted flap thickness and detection and management of RBT will be performed. Certified breast care centres in Austria, Germany, Switzerland, England and the United States of America will be contacted via E-mail and asked to participate in the study. The following questions will be asked via a web-based questionnaire:
I. General data including institution, profession, number of operations the institution/ the participating surgeon performs in 1 year
II. Preventive Measures
i. In case of NSM/SSM do you determine the thickness of the subcutaneous tissue preoperatively?
ii. In case of NSM or SSM do you mark sites where fibroglandular breast tissue approximates closely to the skin preoperatively?
iii. Do you perform a frozen subareolar biopsy in the course of NSM?
iv. What do you use for breast tissue preparation to separate breast tissue from the pectoralis major muscle/from the skin?
III.Flap thickness
i. What is your target flap thickness when you perform NSM/SSM in patients with breast cancer/in high-risk patients?
ii. Are there factors that influence your target flap thickness?
IV. Detection of residual breast tissue
i. Do you screen for residual breast tissue following radical ME/NSM/SSM?
ii. What imaging modality do you use for aftercare?
iii. Is the imaging modality you use for aftercare patient-dependent or standardized?
iv. When do you perform the first breast imaging in the course of aftercare after the completion of reconstruction in patients with breast cancer/in high-risk patients?
V. Management of residual breast tissue
i. Is residual breast tissue an indication for reoperation in a patient with breast cancer and negative resection margins/in a high-risk patient?
ii. Is residual breast tissue an indication for post-mastectomy radiotherapy in a patient with breast cancer and negative resection margins?
iii. In case of residual breast tissue do you intensify your follow-up care?
3. Aims
The primary objective of the study is to assess the applied preventive and treatment measures of RBT following mastectomy in oncologic and high-risk breast cancer patients in certified breast care centres in Austria, Germany, Switzerland, England and the USA. Based on these expert opinions guidelines for the course of action regarding RBT will be developed.
4. Statistical methods
Descriptive statistics will be performed.
Citation Format: Christine Deutschmann, Georg Pfeiler. Prevention and management of residual breast tissue following radical mastectomy and skin-sparing and nipple-sparing mastectomy in oncologic and high-risk breast cancer patients - A multicentre questionnaire study [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr OT3-06-01.