Performance Characteristics of the BluePrint® Breast Cancer Diagnostic Test.

The analytical performance of a multi-gene diagnostic signature depends on many parameters, including precision, repeatability, reproducibility and intra-tumor heterogeneity. Here we study the analytical performance of the BluePrint 80-gene breast cancer molecular subtyping test through determination of these performance characteristics. BluePrint measures the expression of 80 genes that assess functional pathways which determine the intrinsic breast cancer molecular subtypes (i.e. Luminal-type, HER2-type, Basal-type). Knowing a tumor's dominant functional pathway can help allocate effective treatment to appropriate patients. Here we show that BluePrint is a highly precise and highly reproducible test with correlations above 98% based on the generated index and subtype concordance above 99%. Therefore, BluePrint can be used as a robust and reliable tool to identify breast cancer molecular subtypes.

A patient- and assessor-blinded randomized controlled trial of axillary reverse mapping (ARM) in patients with early breast cancer.

BACKGROUND: Axillary lymph node dissection (ALND) in breast cancer patients is infamous for its accompanying morbidity. Selective preservation of upper extremity lymphatic drainage and accompanying lymph nodes crossing the axillary basin - currently resected during a standard ALND - has been proposed as a valuable surgical refinement. METHODS: Peroperative Axillary Reversed Mapping (ARM) was used for selective preservation of upper extremity lymphatic drainage. A multicentre patient- and assessor-blinded randomized study was performed in clinical node negative, sentinel node positive early breast cancer patients. Patients were randomized to undergo either standard-ALND or ARM-ALND. Primary outcome was the presence of surgery-related lymphedema at six, 12 and 24 months post-operatively. Secondary outcomes included patient reported and objective signs and symptoms of lymphedema, pain, paraesthesia, numbness, loss of shoulder mobility, quality of life and axillary recurrence risk. RESULTS: No significant differences were found between both groups using the water displacement method with respect to measured lymphedema. ARM-ALND resulted in less reported complaints of lymphedema at six, 12 and 24 months postoperatively (p < 0.05). No axillary recurrence was found in both groups. CONCLUSIONS: In contrast to results of volumetric measurement, patient reported outcomes support selective sparing of the upper extremity lymphatic drainage using ARM as valuable surgical refinement in case of ALND in clinically node negative, sentinel node positive early breast cancer. If completion ALND in clinically node negative, sentinel node positive early breast cancer is considered, selective sparing of upper extremity axillary lymphatics by implementing ARM should be carried out in order to reduce morbidity.