MATERIALS and METHODS:
This study examined a retrospective series of patients with breast cancer who underwent surgical treatment after NAC between 2012 and 2017. The planned OPS group consisted of patients who were scheduled to undergo OPS before NAC between the specified dates. Tumors of patients in the planned OPS group were marked with metallic clips before neoadjuvant therapy. The unplanned OPS group consisted of patients who underwent OPS after NAC although OPS was not scheduled. Therefore, tumor marking was not performed in these patients. Patients undergoing mastectomy after NAC constituted the mastectomy group. Anthracycline- and taxane-based chemotherapies were applied to patients receiving NAC. Patients with HER2-positive breast cancer received NAC with trastuzumab. For local staging; mammography (MG), breast ultrasonography (USG), axillary USG were performed as standard in the pre-NAC period. Magnetic Resonance Imaging (MRI) was used in the pre and post NAC period in the unplanned OPS group. Post-NAC clinical response was classified as unresponsive, partial, and complete clinical response. Absence of radiological and clinical signs of tumor in the breast and axilla was considered a complete response. A reduction of more than 50% compared to pre-NAC was considered as a partial response whereas a reduction of less than 50% was considered a stable condition.
Patients with minimal edema or skin shrinkage around the tumor were considered to have T4 breast cancer and they had the opportunity to undergo OPS after NAC. Mastectomy was performed in patients who were considered to be at the T4 stage due to diffuse edema, ulceration, peau d’orange appearance, and chest wall invasion. The most common reasons for mastectomy were patient’s request, inadequate response to chemotherapy, multicentricity, tumor-to-breast ratio mismatch, complete radiological disappearance of the tumor, and no residual radiological findings. Although OPS was not scheduled initially, it was possible to be performed after NAC in patients with palpable tumors or radiological (MG, MRI, or USG) residual disease (e.g. structural distortion or microcalcification). Patients with radiological residual disease in the unplanned OPS group were operated on after these areas were marked with a wire. Tumors were labeled with titanium clips before the NAC was initiated in the planned OPS group. Fine needle aspiration biopsy (FNAB) was performed for radiologically suspicious axillary lymph nodes. Surgical margins in patients in the unplanned OPS group were determined considering the areas containing microcalcification and structural distortion (residual radiological disease) surrounding the tumor, which were identified through the local staging investigations performed following NAC. If necessary, the areas to be resected were marked with a wire before surgery. Radio-guided occult lesion localization (ROLL) method was used for this purpose in some patients. After resection, specimen radiographs were taken in all patients to determine whether adequate resection was achieved. Routine frozen section examination was not performed for surgical margins; however, when deemed necessary, additional resections were made from the suspicious margins. Sentinel lymph node biopsy (SLNB) was performed in patients without clinical signs of metastasis in axillary lymph nodes before and/or after NAC. The closest surgical margins were used to calculate the average length of the surgical margins. No tumor on ink was considered a negative surgical margin.
Level II OPS techniques were used for the planned and unplanned OPS groups. Techniques were chosen according to tumor localization and tumor-to-breast volume. Racquet and fusiform mammoplasty techniques were used for tumors located in the upper outer quadrant. Radial mammoplasties were preferred for inner quadrant tumors. Vertical mammoplasty techniques were used for tumors located in the upper or lower midline. Furthermore, reduction mammoplasty techniques with superior or inferior flap (wise pattern) were applied to patients who required reduction. Superior flap techniques were used for lower quadrant tumors whereas inferior flap techniques were used for upper quadrant tumors. Batwing and round block techniques were most commonly used for tumors close to the areola. Patients undergoing OPS received radiotherapy (RT) with 5 Gy + 1 Gy boost dose to the tumor bed. The RT needs of patients who underwent mastectomy were also discussed in the tumor board. Patients were invited for follow-ups at three-month intervals for the first two years and at six-month intervals for the next three years. After five years, the patients were followed at one-year intervals. In addition to physical examinations, annual MG and breast USG examinations were performed as standard. Breast MRI was performed when needed.
Age, body mass index (BMI), menopause status, and tumor characteristics (stage, grade, hormone receptor status, and CerbB2 status) of the patients were recorded. Surgical margin status, re-operation and re-excision requirements, axillary intervention results, ipsilateral breast tumor recurrence (IBTR), and axillary recurrence rates were also recorded. Long-term local recurrence-free survival (LRFS), disease-free survival (DFS), and overall survival (OS) were evaluated. The IBTR (invasive or in-situ) and regional recurrence were accepted as the events that ended LRFS.
STATISTICAL ANALYSIS: :
Statistical analyses were performed using SPSS version 25 (SPSS Inc; Chicago, IL, USA). Mann-Whitney U test was used for inter-group comparisons. Qualitative data for each group were analyzed using the Student’s t-test. Chi-square test was used for quantitative data. Kaplan-Meier analysis was used to determine recurrence rates, LRFS, and OS. A p value of <0.05 was considered statistically significant.