Invasive lobular carcinoma of the breast is the most common ‘special’ morphological subtype of breast cancer, comprising up to 15% of all cases. Tumours are generally of a good prognostic phenotype, being low histological grade and low mitotic index, hormone receptor positive and HER2, p53 and basal marker negative, and with a generally good response to endocrine therapy. Despite this, clinicians face countless challenges in the diagnosis and long-term management of patients, as they encounter a tumour that can be difficult to detect through screening, elicits a very invasive nature, a propensity for widespread metastatic colonisation and, consequently, in some studies a worse long-term poor outcome compared with invasive carcinoma of no special type. Here we review the morphological and molecular features that underpin the disparate biological and clinical characteristics of this fascinating tumour type.

After initiating breastfeeding, some African American mothers find adjusting to the demands challenging and discontinue breastfeeding. To learn about decisions switching to formula, we conducted a secondary analysis of qualitative interviews with African American mothers ≥ 18 years old. Data were analyzed using thematic analysis guided by the social cognitive theory. We identified four key themes that reflect personal, behavioral, and environmental factors: (1) simplicity of formula, (2) diverse support networks, (3) early breastfeeding is most important, and (4) lack of access to breastfeeding support resources. To increase breastfeeding duration among African American mothers, it is essential for interventions to be comprehensive including various strategies such as education regarding the physical aspects of breastfeeding, exposure to African American breastfeeding mothers, and active involvement of support persons. More research among African American mothers is needed to identify effective opportunities for change in cultural, social, and structural systems that impede successful breastfeeding.

<p>PDF file - 31K, Supplemental Table S1: Correlation between mRNA expression and status of protein expression, promoter CpG island methylation, or other tumor biomarker status.</p>

<p>PDF file - 1787K, Supplemental Figure S1: Immunohistochemistry for selected proteins. Supplemental Figure S2: Pairwise scatterplots of technical variables for 1,003 DASL arrays from the NHS/HPFS study, including median value of Illumina control probes, sample age, RNA concentration, fraction of probes called present (p<0.05), and Interquartile Range (IQR). Supplemental Figure S3: Spatial distribution of sample-independent positive control probes (CY3_HYB) across the 12 96-well plates of the NHS/HPFS experiment. Supplemental Figure S4: Spearman correlation of expression profiles of individual technical replicates to the median pseudochip decreases with Interquartile Range (IQR), particularly for samples with IQR less than 1. Supplemental Figure S5: CAT-boxplots for six covariates available in the NHS/HPFS study, showing reproducibility of ranked lists of differentially expressed between two independent samples by plotting fractional concordance of the top n genes in each list on the y-axis, against n on the x-axis. Supplemental Figure S6: Examples of two of the "best" (0.1% and 0.2% quantile) and "worst" (99.8% and 99.9% quantile) probes for reproducibility as assessed by Spearman correlation, Euclidian Distance, and Manhattan Distance. Supplemental Figure S7: Reproducibility of individual probe intensity measurements. For samples passing quality control in the BC/A experiment, Spearman correlation between technical replicates was calculated for each probe, as a function of four different measures of probe activity. Supplemental Figure S8: Analysis of probe reproducibility measured by Euclidian distance, and relationships between different probe filtering criteria. Supplemental Figure S9: t-statistics using samples passing strict QC and permissive QC for the molecular markers considered in Supplemental Table 1. Supplemental Figure S10: validation of MSI-associated mRNA transcripts previously reported from fresh-frozen tissues(24). Supplemental Figure S11: Distribution of presence calls (fraction of samples in which a probe is called present, p<0.01) for all 24,526 probes on the DASL� assay, and for probes involved in validation of previously identified MSI-associated gene transcripts(24).</p>

<div>Abstract<p><b>Purpose:</b> More than 20 million archival tissue samples are stored annually in the United States as formalin-fixed, paraffin-embedded (FFPE) blocks, but RNA degradation during fixation and storage has prevented their use for transcriptional profiling. New and highly sensitive assays for whole-transcriptome microarray analysis of FFPE tissues are now available, but resulting data include noise and variability for which previous expression array methods are inadequate.</p><p><b>Experimental Design:</b> We present the two largest whole-genome expression studies from FFPE tissues to date, comprising 1,003 colorectal cancer (CRC) and 168 breast cancer samples, combined with a meta-analysis of 14 new and published FFPE microarray datasets. We develop and validate quality control (QC) methods through technical replication, independent samples, comparison to results from fresh-frozen tissue, and recovery of expected associations between gene expression and protein abundance.</p><p><b>Results:</b> Archival tissues from large, multicenter studies showed a much wider range of transcriptional data quality relative to smaller or frozen tissue studies and required stringent QC for subsequent analysis. We developed novel methods for such QC of archival tissue expression profiles based on sample dynamic range and per-study median profile. This enabled validated identification of gene signatures of microsatellite instability and additional features of CRC, and improved recovery of associations between gene expression and protein abundance of MLH1, FASN, CDX2, MGMT, and SIRT1 in CRC tumors.</p><p><b>Conclusions:</b> These methods for large-scale QC of FFPE expression profiles enable study of the cancer transcriptome in relation to extensive clinicopathological information, tumor molecular biomarkers, and long-term lifestyle and outcome data. <i>Clin Cancer Res; 18(22); 6136–46. ©2012 AACR</i>.</p></div>