Diagnostic pathology of early systemic cancer: ERBB2 gene amplification in single disseminated cancer cells determines patient survival in operable esophageal cancer.

Early metastatic dissemination and evolution of disseminated cancer cells (DCCs) outside the primary tumor is one reason for the failure of adjuvant therapies because it generates molecular genotypes and phenotypes different from primary tumors, which still underlie therapy decisions. Since ERBB2 amplification in esophageal DCCs but not in primary tumor cells predict outcome, we aimed to establish an assay with diagnostic reliability for single DCCs or circulating tumor cells. For this, we evaluated copy number alterations of more than 600 single DCCs from multiple cancer types to define reference regions suitable for quantification of target regions, such as ERBB2. We then compared ERBB2 quantitative PCR (qPCR) measurements with fluorescent in situ hybridization (FISH) data of various breast cancer cell lines and identified the aberration-calling threshold. The method was applied to two independent cohorts of esophageal cancer patients from Hamburg (n = 59) and Düsseldorf (n = 53). We found a high correlation between the single cell qPCR assay and the standard FISH assay (R = 0.98) and significant associations between amplification and survival for both patient cohorts (Hamburg (HH), p = 0.033; Düsseldorf (D), p = 0.052; pooled HH + D, p = 0.002) when applied to DCCs of esophageal cancer patients. Detection of a single ERBB2-amplified DCC was the most important risk factor for death from esophageal cancer (relative risk = 4.22; 95% CI = 1.91-9.32; p < 0.001). In our study, we detected ERBB2-amplified cells in 7% of patients. These patients could benefit from anti-ERBB2 targeting therapies.

Sweet Christmas: Do overweight and obese children associate special events more frequently with food than normal weight children?

This study examined children's spontaneous associations of special events with food. Children in primary education (N = 111, age between 10 and 13 years) at a school in Germany wrote down their first five associations with five special or festive events (Christmas, holidays, weekend, carnival and birthday). After completing the free-word association test, they were offered a choice between a candy and a toy. Finally, their body mass index (BMI) was measured. The first prediction was that overweight and obese children would associate special events more often with food than normal weight and leaner children. The second prediction was that choice for a candy would be predicted by a higher number of food-related associations. The first hypothesis was not supported: BMI was negatively related to number of food-related associations (the lower the BMI, the more food-related associations). The second hypothesis was also not supported: There was no relation between number of food-related associations and choice for a candy or toy. A possible explanation for the finding that leaner children reported more food-related associations is that for them specific sweets and snack food are more exclusively connected to special occasions than for overweight children. Speculatively, this may be the result of differences in food parenting styles between parents of heavier and leaner children. Parents of leaner children often have a more restrictive style, i.e., reserving specific foods for specific, relatively rare occasions whereas parents of overweight children adopt more liberal food rules.

Molecular profiling of single circulating tumor cells with diagnostic intention.

Several hundred clinical trials currently explore the role of circulating tumor cell (CTC) analysis for therapy decisions, but assays are lacking for comprehensive molecular characterization of CTCs with diagnostic precision. We therefore combined a workflow for enrichment and isolation of pure CTCs with a non-random whole genome amplification method for single cells and applied it to 510 single CTCs and 189 leukocytes of 66 CTC-positive breast cancer patients. We defined a genome integrity index (GII) to identify single cells suited for molecular characterization by different molecular assays, such as diagnostic profiling of point mutations, gene amplifications and whole genomes of single cells. The reliability of > 90% for successful molecular analysis of high-quality clinical samples selected by the GII enabled assessing the molecular heterogeneity of single CTCs of metastatic breast cancer patients. We readily identified genomic disparity of potentially high relevance between primary tumors and CTCs. Microheterogeneity analysis among individual CTCs uncovered pre-existing cells resistant to ERBB2-targeted therapies suggesting ongoing microevolution at late-stage disease whose exploration may provide essential information for personalized treatment decisions and shed light into mechanisms of acquired drug resistance.