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 patients who achieved and those who did not achieve pathological complete remission (pCR), and (III) analyze the accuracy of different clinical-imaging modalities in tumor response monitoring. METHODS: 188 patients who received PST between 2008 and 2014 were reviewed and 43 Her2 overexpressing breast cancer 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 trastuzumab-containing PST (Group 2). We compared the concordance between pCR and complete remission (CR) defined by breast-ultrasound, CR defined by standard 18F-fluoro-deoxy-glucose positron emission tomography and computerized 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=%, 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 trastuzumab-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 response by our novel, breast cancer specific FDG-PET/CT criteria accurately differentiated pCR from non-pCR patients

Comparison of immunophenotypes of primary breast carcinomas and multiple corresponding distant metastases: an autopsy study of 25 patients

Phenotypical change in metastatic breast carcinoma has widely been accepted as an inherent biological feature rather than technical fault. We analyzed the immunohistochemical phenotype and histopathological features of 25 primary breast carcinomas and 90 corresponding distant metastases in 23 organs retrospectively. Histological slides were reviewed for prognostic and predictive factors. Overall, metastases were more similar to each other and often differed from the primary tumor. We created a 3-step grouping system based on the localization of metastases. Regions: tumors metastasizing to the abdominal region were likely to lose ER (p = 0.002); we detected loss of PR in metastases to the thorax (p = 0.039) and abdomen (p < 0.001). Organ systems: loss of ER and PR was observed in metastases to the gastrointestinal system (p = 0.026 and p = 0.001, respectively), in the respiratory system only the loss of PR was significant (p = 0.05). Individual organs: the primaries were likely to lose the hormone receptors in liver metastases (ER p = 0.026; PR p = 0.004). In lung metastases only loss of PR was apparent (p = 0.049). We did not observe significant change in HER2 status, regarding Ki67 change occurred only in bone metastases compared to the primary (p = 0.048). 7/25 patients' distant metastases had heterogeneous immunoprofiles. The later the metastasis was discovered the more likely it had a differing IHC profile compared to the primary tumor, patients who had longer OS had a higher chance to develop a discordant metastasis. Immunoprofile of metastases may differ from primary breast cancer and from each other, probably resulting in different response to therapy