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.