RESUMO
HER2 is considered one of the most traditional prognostic and predictive biomarkers in breast cancer. Literature data confirmed that the addition of pertuzumab to a standard neoadjuvant chemotherapy backbone (either with or without anthracyclines), in patients with human epidermal growth factor receptor 2 (HER2)-positive early breast cancer (EBC), leads to a higher pathological complete response (pCR) rate, which is known to correlate with a better prognosis. In this retrospective analysis, 47 consecutive patients with HER2-positive EBC received sequential anthracyclines and taxanes plus trastuzumab (ATH) or pertuzumab, trastuzumab and docetaxel (THP). Despite the limited sample size, this monocentric experience highlights the efficacy (in terms of pCR) and safety of THP in the neoadjuvant setting of HER2-positive EBC as an anthracycline-free approach. Given the role of PIK3CA as a prognostic and therapeutic target in breast cancer, tumors were also analyzed to assess the PIK3CA mutational status. Thirty-eight out of forty-seven patients were evaluated, and PIK3CA variants were identified in 21% of tumor samples: overall, one mutation was detected in exon 4 (2.6%), two in exon 9 (5.3%) and four in exon 20 (10.5%). Of note, one sample showed concurrent mutations in exons 9 (codon 545) and 20 (codon 1047). Among patients reaching pCR (n = 13), 38.5% were PIK3CA mutants; on the other hand, among those lacking pCR (n = 25), just 12% showed PIK3CA variants. Regarding THP-treated mutant patients (n = 5), 80% reached pCR (three hormone-receptor-negative, one hormone-receptor-positive). Interestingly, the only patient not achieving pCR had a tumor with two co-occurring PIK3CA mutations. In conclusion, this study provides new evidence about the efficacy and good safety profile of THP, compared to the ATH regimen, as an anthracycline-free neoadjuvant treatment of HER2-positive EBC. Further studies on larger/multicentric cohorts are planned for more in-depth analysis to confirm our molecular and clinical results.
RESUMO
BACKGROUND: Dose-dense chemotherapy is one of the treatments of choice for neoadjuvant therapy in breast cancer (BC). Activating mutations in PIK3CA gene predict worse response to neoadjuvant chemotherapy for HER2-positive patients, while their role is less clearly defined for HER2-negative tumors. METHODS: We conducted a phase I/II study of neoadjuvant, sequential, dose-dense anthracycline/taxane chemotherapy, plus trastuzumab in HER2-positive patients and investigated the correlation of pre-treatment PIK3CA mutation status with pathologic complete response (pCR) and long-term outcome in a real-life setting. RESULTS: we established a dose-dense docetaxel recommended dose of 60 mg/m2 and 65 mg/m2, with or without trastuzumab, respectively, according to HER2-status, following dose-dense epirubicin-cyclophosphamide (90/600 mg/m2), every 2 weeks. The overall pCR rate was 21.4%; median disease-free survival (DFS) was 52 months and median overall survival (OS) was not yet reached. PIK3CA mutation status was not significantly associated with the pCR rate: 18% for both mutated and wild-type patients. The pCR rate was: 25% in the mutated and 24% in the wild-type (p 0.560) cohort of the HER2-positive subgroup; 33% both in the mutant and wild-type cohort of the triple-negative subgroup; no pCR neither in the mutant nor in the wild-type cohort of the HR-positive/HER2-negative subgroup. Among the HER2-positive population, a trend toward worse DFS was observed in case of mutation, as opposed to the triple negative population. CONCLUSIONS: This study proposes an effective and safe neoadjuvant dose-dense anthracycline/taxane schedule and suggests that PIK3CA mutation analysis can be usefully performed in real-life clinical practice.
RESUMO
BACKGROUND: To quantify the effect of traditional prognostic factors [nodal status, estrogen-receptor (ER), progesterone-receptor (PR), human epidermal growth factor receptor 2 (HER2)] on long-term outcome of patients with early breast cancer (EBC), treated in clinical practice over a period of about twenty years. RESULTS: 1198 consecutive patients were identified. Median DFS (disease-free survival): ER+/PR±/HER2-, 165 months (mo) if node-negative (N0) and 114mo if node-positive (N+) (p < 0.001); triple-negative (TN), 109mo if N0 and 65mo if N+ (p 0.144); ER+/PR±/HER2+ in patients not-treated with adjuvant trastuzumab (T-), not reached if N0 and 114mo if N+ (p 0.297); ER+/PR±/HER2+ in patients treated with trastuzumab (T+), 95mo if N0 and 85mo if N+ (p 0.615); ER-/PR-/HER2+ T-, not reached if N0 and 26mo if N+ (p 0.279); ER-/PR-/HER2+ T+, not reached if N0 and 66mo if N+ (p 0.014). Median OS (overall survival): ER+/ PR±/HER2-, 166mo if N0 and 144mo if N+ (p 0.028); TN, 158mo if N0 and 96mo if N+ (p 0.384); ER+/PR±/HER2+ T-, not reached if N0 and 157mo if N+ (p 0.475), ER+/PR±/HER2+ T+, not reached if N0 and 106mo if N+ (p 0.436); ER-/PR-/HER2+ T-, not reached if N0 and 34mo if N+ (p 0.273); ER-/PR-/HER2+ T+, not reached neither if N0 nor if N+ (p 0.094). MATERIALS AND METHODS: Disease-free survival (DFS) and overall survival (OS) were evaluated according to tumor characteristics, based on information retrospectively retrieved from patients' medical records. CONCLUSIONS: Pathological tumor characteristics and nodal status still represent useful tools in treatment selection and follow-up decision making of EBC patients in clinical practice.