Correction to: Comparative analysis of confocal microscopy on fresh breast core needle biopsies and conventional histology.

Following publication of the original article [1], the authors reported an added data on Table 1 in their paper. The original article [1] has been updated.

Prognostic impact of PIK3CA protein expression in triple negative breast cancer and its subtypes.

BACKGROUND: Triple negative breast cancer (TNBC) harbors a heterogeneous group of carcinomas with poor prognosis and high genetic variability. As a potential aim for targeted therapy, genetic mutations leading to an activation of the phosphoinositide 3-kinase pathway in a catalytic subunit (PIK3CA) in breast cancer have been analyzed currently. Little is known about the clinical impact and prognostic or predictive value of this marker in TNBC subtypes. METHODS: Samples from 119 TNBC cases were submitted to immunohistochemical PIK3CA protein expression analysis and scored semi-quantitatively as negative, weak (1 +), or strongly expressed (2 +). Expression scores were correlated to patient's characteristics, imaging features, and TNBC subtypes. TNBC subtypes were categorized into four subtypes: basal like, mesenchymal like, luminal androgen receptor (LAR), and immunomodulatory. RESULTS: We did not observe differences in clinical aspects and imaging features between TNBC with and without PIK3CA expression. PIK3CA expression was in general higher in the LAR subtype. The disease-free survival and overall survival were significantly better in TNBC with PIK3CA protein expression, independent of TNBC subtypes. CONCLUSION: Despite conflicting results in the literature, our study clearly shows a better outcome of PIK3CA-expressing TNBC, independent of TNBC subtypes. PIK3CA expression in TNBC is not associated with specific clinical or diagnostic features. Further molecular studies and meta-analysis are warranted to clarify the prognostic and predictive role of PIK3CA protein expression.

Comparative analysis of confocal microscopy on fresh breast core needle biopsies and conventional histology.

BACKGROUND: Evaluation of core needle biopsies (CNB) is a standard procedure for the diagnosis of breast cancer. However, tissue processing and image preparation is a time- consuming procedure and instant on-site availability of high-quality images could substantially improve the efficacy of the diagnostic procedure. Conventional microscopic methods, such as frozen section analysis (FSA) for detection of malignant cells still have clear disadvantages. In the present study, we tested a confocal microscopy scanner on fresh tissue from CNB with intention to develop an alternative device to FSA in clinical practice. PATIENTS AND METHODS: In 24 patients with suspicious breast lesions standard of care image-guided biopsies were performed. Confocal images have been obtained using the Histolog™ Scanner and evaluated by two independent pathologists. Hematoxylin-Eosin (H&E) histological sections of the biopsies were routinely processed in a blinded fashion with respect to the confocal images. RESULTS: In total 42 confocal images were generated from 24 biopsy specimens, and available for analysis within a few minutes of taking the biopsy. This resulted in 2 × 42 = 84 pathologic evaluations. In four cases, a pathologic diagnosis was not possible with confocal microscopy. An exact correlation based on the B-classification was reached in 41 out of 80 examinations and in another 35 cases in a broader sense of correspondence definition (i.e. malignant vs. benign). CONCLUSIONS: As a reliable on-site method, the Histolog™ Scanner provides a visualization of cellular details equivalent to the H&E standards, permitting rapid and accurate diagnosis of malignant and benign breast lesions. Furthermore, this device offers great potential for immediate margin analysis of specimen in breast conserving therapy.

The impact of distinct triple-negative breast cancer subtypes on misdiagnosis and diagnostic delay.

BACKGROUND: Triple-negative breast cancer (TNBC) includes mostly aggressive types of breast cancer with poor prognosis. Due to its growth pattern, misinterpretation in clinical imaging is more frequent than in non-TNBC. As the group of TNBC contains heterogeneous types of tumors, marker expression-based subtypes have recently been established. We analyzed clinical features and false-negative imaging findings that could potentially lead to diagnostic delay within the subtypes. METHODS: An exploratory analysis compared the imaging features across the a priori defined subtypes and related these findings to molecular subtype, disease stage, potential diagnostic delay, and patient outcome. RESULTS: TNBC cases were categorized into basal-like (BL; 38.6%), mesenchymal-like (ML; 19.9%), luminal androgen receptor (LAR; 28.3%), and immunomodulatory (IM; 13.3%) subtype. In almost every third patient, malignant classification was missed in at least one imaging method. Misclassification in mammogram was more frequent in ML, while benign ultrasound features were reported more often in the BL subtype. Diagnostic delay due to misclassification in imaging led to tumor growth and/or upgrading of the tumor stage in 8.9% of BL tumors, which had the lowest overall survivals. Despite misclassification rate was higher in the ML subtype it showed better outcomes. Misdiagnosis of axillary lymph node metastasis was higher in LAR; however, this subtype showed a higher percentage of affected axillary lymph nodes. CONCLUSION: TNBC subtypes have different clinical features, benign appearances, and diagnostic delay, which can lead to tumor stage upgrade. Future clinical studies on TNBC outcomes might consider the confounder of clinical delay in the subtypes.