Post-Neoadjuvant Gemcitabine and Cisplatin with Regional Hyperthermia for Patients with Triple-Negative Breast Cancer and Non-pCR after Neoadjuvant Chemotherapy: A Single-Institute Experience.

BACKGROUND: Patients with triple-negative primary breast cancer (TNBC) who have residual invasive carcinoma after neoadjuvant chemotherapy have poor prognosis. Proven adjuvant approaches to reduce the risk of recurrence and improve outcome in patients with non-pathological complete response (non-pCR) are limited.
METHODS: From our institutional registry, a consecutive case series of patients with operable, unilateral, primary invasive noninflammatory early TNBC of stage I-IIIB and pathologically verified residual cancer cells (no pathological complete response) after neoadjuvant chemotherapy underwent adjuvant treatment with gemcitabine plus cisplatin combined with regional hyperthermia. For quality assurance, we analyzed feasibility, efficacy, and toxicity of all treated patients. Outcome was evaluated for the entire group of patients as well as for the subgroups of patients with or without lymph node involvement at baseline (cN0/ cN+).
RESULTS: From August 2012 to January 2019, we offered this treatment to 53 patients at our center as part of routine care. The median follow-up was 38 months. The majority of patients (64.2%) had cT2 tumors at baseline. Twenty-four patients (45%) were clinically node positive as evaluated by sonography. Thirty-nine patients (74%) had grade 3, and 14 patients (26%) had grade 2 tumors. Forty-one patients (76%) showed a regression grade 1 according to Sinn. Patients received a median of six treatment cycles of gemcitabine and cisplatin (range 1-6) combined with 12 applications of regional hyperthermia (median 12, range 2-12). Disease-free survival (DFS) at 3 years was 57.5%. In patients with no lymph node involvement at baseline (cN0), DFS at 3 years was significantly higher than in initially node-positive (cN+) patients (80 vs. 31%; p = 0.001). Overall survival (OS) at 3 years was 81.6%. In patients with no lymph node involvement at baseline (cN0), OS at 3 years was significantly higher than in node-positive (cN+) patients (93 vs. 70.4%; p = 0.02). Overall, grade 3/4 toxicities were leukopenia (38%), thrombocytopenia (4%), and anemia (4%).
CONCLUSION: After standard neoadjuvant chemotherapy containing anthracycline plus cyclophosphamide followed by taxanes, addition of adjuvant gemcitabine plus cisplatin in combination with regional hyperthermia was safe and effective in TNBC patients with non-pCR.