Nanozoomer ht digital pathology scanning system

All routine H&E stained sections of primary breast tumours and uninvolved and involved LNs were reassessed histopathologically. A minimum of 6 sections of the primary tumour and 1–12 (mean = 6) LNs per case were available for evaluation of immune and stromal features. All sections were reviewed by a specialist Consultant Breast Pathologist (SEP) and Pathology Research Scientist (PG). Analyses of the tumour microenvironment were performed using conventional microscopy of H&E whole sections. The NanoZoomer HT Digital Pathology Scanning System (Hamamatsu, Japan), was used to scan H&E sections with a spatial resolution of 0.46 μm/pixel for the measurement of LN germinal centres (GCs). According to recommendations by the International Tumour Infiltrating Lymphocytes Working Group 12, morphological features initially assessed as continuous variables (e.g. stromal TILs) were discretised for statistical analysis. All features and their associated categories described below in detail are summarised in supplementary material, Tables S1A and S1B.