BMC Cancer 2009, 9:254 http://www.biomedcentral.com/1471-2407/9/254 Background Breast-conserving surgery (BCS) followed by whole-breast radiation therapy is a well-established standard of care for the treatment of early-stage invasive breast cancer [1,2]. This has been shown to be essentially equivalent to mas- tectomy with regards to local control and survival [3-8]. The primary goal of BCS is to completely excise the tumor and achieve "adequate" or "negative" surgical resection margins while maintaining an acceptable level of postop- erative cosmetic outcome to the affected breast. Neverthe- less, the precise determination of the adequacy of surgical resection margins during BCS has long been debated [8- 17]. There have been two major questions that have been central to this ongoing debate. First, what represents the most appropriate definition of an "adequate" or "nega- tive" surgical margin? Second, what is the most optimal manner in which to assess the adequacy of the surgical margins? In this regard, the aim of the current paper was to describe a standardized and reproducible methodology for the comprehensive and systematic assessment of surgical resection margins during BCS for invasive breast cancer. This methodology attempts to limit the volume of addi- tional breast tissue excised, yet it attempts to optimize the determination of which individual patients may need fur- ther tissue resection from the affected breast in order to minimize the potential risk of local recurrence following BCS. Methods This study protocol was approved by the Clinical Scien- tific Review Committee (protocol number OSU 07016) and by the Cancer Institutional Review Board (protocol number 2007C0009) of the Arthur G. James Cancer Hos- pital and Richard J. Solove Research Institute and Com- prehensive Cancer Center of The Ohio State University. All patients who underwent BCS for invasive breast cancer were identified from a prospectively maintained operative log of a single surgeon (SPP). Prior to August 2003, each BCS procedure was done without the use of any standard- ized methodology of assessing the surrounding perimeter of the resultant BCS resection bed cavity. Starting in August 2003, such a standardized and reproducible meth- odology of assessment of surgical resection margins (for both the BCS specimen itself and for the surrounding perimeter of the resultant BCS resection bed cavity) dur- ing BCS for invasive breast cancer was initiated by the sur- geon (SPP). Therefore, all BCS cases from August 2003 to June 2007 for invasive breast cancer were selected for the current analysis. All BCS procedures performed for a diag- nosis of ductal carcinoma in situ (DCIS) alone were not included in the current analysis. BCS was not offered or undertaken in patients that had any additional suspicious lesions within the affected breast that were demonstrated on preoperative mammogram, ultrasound, or magnetic resonance imaging (MRI) unless those additional suspi- cious lesions were first biopsied and proven not to repre- sent additional foci of breast malignancy within the affected breast. In those cases in which those additional suspicious lesions were first biopsied and proven to repre- sent additional foci of breast malignancy within the affected breast or in those cases in which patients elected not to have those additional suspicious lesions biopsied within the affected breast, only mastectomy was offered to those patients. All cases were performed in the operating room at the Arthur G. James Cancer Hospital and Richard J. Solove Research Institute of The Ohio State University. These pro- cedures were generally done under general anesthesia along with concomitant evaluation of the axillary lymph nodes with sentinel lymph node biopsy and axillary lymph node dissection, when indicated. For all non-pal- pable or questionably-palpable tumors, pre-resection tumor localization was accomplished by either mammo- graphic guidance or sonographic guidance. A standardized rationale was consistently utilized for the determination of the extent of tissue resection during each BCS procedure. For each BCS procedure, an overlying skin ellipse was incised with a #10 surgical blade. Division of the breast parenchymal was performed with the coagula- tion mode of the electrocautery (Force 4B Electrosurgical Generator, Valleylab™, Boulder, Colorado). In all cases, wide local excision of breast parenchyma around the tumor was undertaken, along with en bloc removal of an ellipse of overlying skin (Figure 1). As is a standard of practice for BCS, all attempts were made by the operating surgeon to remove the tumor with what grossly appeared at the time of surgery to be at least a 1 cm rim of surround- ing normal-appearing breast tissue around all aspects of the tumor. Additionally, concomitant excision of underly- ing breast parenchyma all the way down to and including the pectoralis major muscle fascia was performed for all tumors located within the posterior two-thirds of the breast parenchyma and was performed only selectively for tumors located within the anterior one-third of the breast parenchyma. Conversely, such a concomitant excision of breast parenchyma all the way down to and including the pectoralis major muscle fascia was generally excluded for tumors located very superficially within the breast paren- chyma in a location just under the skin of the breast. Lastly, for very deeply placed tumors abutting or involving the underlying pectoralis major muscle fascia, concomi- tant en bloc excision of a portion of the directly underly- ing pectoralis major muscle was generally performed. No percentage criteria for the minimum required amount of breast tissue that was necessary to be resected from the Page 2 of 23 (page number not for citation purposes)