RESULTS:
There were 150 patients in the planned OPS group, 75 patients in the unplanned OPS group, and 340 patients in the mastectomy group. Thirty-eigth patients in the unplanned OPS group completed their NAC in external centers, and no preoperative tumor marking was performed in these patients. Although 32 patients did not accept BCS in the pre-treatment period, they requested BCS after NAC. Tumor marking with a titanium clip before neoadjuvant treatment could not be performed in five patients due to technical reasons. When all three groups were evaluated in terms of patient and tumor characteristics, the patients in the mastectomy group were found to be significantly older and the number of those in the postmenopausal period was higher. There was no difference between the groups in terms of pre-NAC stage, grade, and biological characteristics of the tumor. Patient and tumor characteristics of the groups are summarized in Table 1.
In the planned OPS group, complete clinical response was observed in 40 (26%) of the patients whereas 110 (74%) achieved a partial response. These numbers were 29.3% and 70.7% in the planned OPS group, respectively. Twenty-six patients (7.6%) in the mastectomy group were considered to be stable after NAC. Complete clinical response was achieved in 72 patients (21.2%) whereas 242 (71.2%) patients achieved a partial response in the mastectomy group. Mastectomy was performed in 10 patients who were scheduled for OPS before NAC but achieved an inadequate response. Pathologic complete response rate was 9.4% in the whole series.
In the planned OPS group, re-excision was required in 16 (10.6%) patients due to positive or close surgical margins. Eight (5.3%) patients were required re-operation and mastectomy. In the unplanned OPS group, nine (12%) and six (8%) patients underwent re-excision and mastectomy, respectively. The mean distance between the tumor and closest surgical margin was 14±0.6 mm in the planned OPS group and 18±0.4 mm in the unplanned OPS group. There was no significant difference between the groups in terms of surgical margin status, re-excision requirement, and mastectomy rates (Table 2).
Axillary dissection was performed in patients with positive SLNB and patients with clinical suspicious lymph nodes after neoadjuvant therapy. While axillary dissection was performed in 110 (74%) patients in the planned OPS group, 77% of the patients in the unplanned OPS group underwent axillary dissection whereas SLNB alone was performed in 13%. In the mastectomy group, 79% of patients underwent axillary dissection. There was no significant difference between the groups.
During an average follow-up period of 43 months, 5.3% and 4% of the patients in the planned OPS group developed IBTR and axillary recurrence, respectively, whereas these rates were 6.6% and 5.3% in the unplanned OPS group, respectively. In the mastectomy group, the rates of IBTR and axillary recurrence were found to be 4.1% and 3.8%, respectively. There was no significant difference between the three groups in terms of IBTR (p: 0.06) and axillary recurrence (p: 0.08) rates. The rate of patients developing distant metastasis during the follow-up period was 26%, 29.3%, and 25.2% in the planned, unplanned OPS, and mastectomy groups, respectively (p: 0.2) (Table 2). The mean five-year LRFS was 90.1% in the planned OPS group whereas it was 91.2% in the unplanned OPS group and 93% in the mastectomy group. There was no significant difference between the groups in terms of LRFS (p: 0.6) (Figure 1). Five-year OS was found to be 92% in the planned OPS group, 90.3% in the unplanned OPS group, and 89.8% in the mastectomy group. There was no significant difference between the groups in terms of OS (p: 0.9).