Response evaluation after primary systemic therapy of Her2 positive breast cancer – an observational cross-sectional study

Aim To evaluate (I) trastuzumab-containing primary systemic therapy (PST) in human epidermal growth factor receptor 2 (Her2) overexpressing breast carcinomas.; (II) compare the pa - tients who achieved and those who did not achieve pathologi - cal complete remission (pCR), and (III) analyze the accuracy of different clinical-imaging modalities in tumor response moni - toring. Methods 188 patients who received PST between 2008 and 2014 were reviewed and 43 Her2 overexpressing breast can - cer patients (28 Luminal B/Her2-positive and 15 Her2-positive) were enrolled. 26 patients received mostly taxane-based PST without trastuzumab (Group 1) and 17 patients received tras - tuzumab-containing PST (Group 2). We compared the con - cordance between pCR and complete remission (CR) defined by breast-ultrasound, CR defined by standard 18F-fluoro-de - oxy-glucose positron emission tomography and computer - ized tomography (FDG-PET/CT) criteria (Method 1) and CR defined by a novel, breast cancer specific FDG-PET/CT criteria (Method 2). Sensitivity (sens), specificity (spec), and positive (PPV ) and negative predictive values (NPV ) were calculated. Results Ten patients (38.5%) in Group 1 and eight (47%) in Group 2 achieved pCR. pCR was significantly more frequent in Her2-positive than in Luminal B/Her2-positive tumors in both Group 1: ( P = 0.043) and Group 2: ( P = 0.029). PET/CT evaluated by the breast cancer specific criteria (Method 2) differentiated pCR from non-pCR more accurately in both groups (Group 1: sens = 77.8%, spec = 100%, PPV = 100%, NPV = 71.4%; Group 2: sens = 87.5%, spec = 62.5%, PPV = 70%, NPV = 83.3%) than standard PET/CT criteria (Method 1) (Group 1: sens = 22.2% spec = 100% PPV = 100% NPV = 41.7%; in Group 2: sens = 37.5%, spec = 87.5%, PPV = 75% NPV = 58.3%) or breast ultrasound (Group 1, sens = 83.3% spec = 25% PPV = 62.5% NPV = 50%; Group 2, sens = 100% spec = 12.5% PPV = 41.6% NPV = 100%). Conclusion The benefit of targeted treatment with trastu - zumab-containing PST in Her2 overexpressing breast cancer was defined in terms of pCR rate. Luminal B/Her2-positive subtype needs further subdivision to identify patients who would benefit from PST. Combined evaluation of tumor re - sponse by our novel, breast cancer specific FDG-PET/CT crite - ria accurately differentiated pCR from non-pCR patients

Az FDG-PET-CT szerepe az emlőrák primer szisztémás kezelése során: a metabolikus változások és a patológiai remisszió összefüggései = The Role of FDG-PET-CT in the Evaluation of Primary Systemic Therapy in Breast Cancer: Links Between Metabolic and Pathological Remission

Introduction: FDG-PET-CT is highly sensitive in detection of viable tumour tissue, giving an importance for that in oncological diagnostics. Aim: The authors analysed retrospectively the relationship between metabolic response and changes in Ki-67, a proliferation marker. Methods: Staging FDG-PET-CT scans (before and after therapy) SUVs (Standardized Uptake Value), and morphological changes in the primary tumour and axillary lymph node region were evaluated in 30 patients with breast cancer. Calculated ΔSUV were compared with Ki-67 proliferation marker (measured in biopsies and surgical specimens). Results: The decrease of SUV and size were significant in the primary tumour and the axillary lymph node region. Decrease of Ki-67 was significant. Significant correlation was found between Ki-67 and SUV before therapy, initial Ki-67 and ΔSUV, and ΔKi-67 and ΔSUV. Conclusions: The metabolic changes were more sensitive in the measurement of the therapeutic response than morphological remission, and they correlated well with the pathological response, in not standardized clinical conditions even. Orv. Hetil., 2012, 153, 1958–1964. </jats:p