EGFR and αvß6 as Promising Targets for Molecular Imaging of Cutaneous and Mucosal Squamous Cell Carcinoma of the Head and Neck Region.

R0 resection is paramount in cutaneous squamous cell carcinoma (CSCC) and head and neck squamous cell carcinoma (HNSCC). However, in the setting of recurrence, immunocompromised patients, or non-keratinizing squamous cell carcinoma (SCC) with a spindle growth pattern, tumor borders are difficult, if not impossible, to determine. Fluorescence-guided surgery (FGS) aids in this differentiation. Potential targets for FGS of CSCC and HNSCC were evaluated. Most sections stained intensely for αvß6 and epidermal growth factor receptor (EGFR) on tumor cells. Normal epithelium stained less for αvß6 than for EGFR. In addition, soft tissue and stroma stained negative for both, allowing for clear discrimination of the soft tissue margin. Tumor cells weakly expressed urokinase plasminogen activator receptor (uPAR) while expression on stromal cells was moderate. Normal epithelium rarely expressed uPAR, resulting in clear discrimination of superficial margins. Tumors did not consistently express integrin ß3, carcinoembryonic antigen, epithelial cell adhesion molecule, or vascular endothelial growth factor A. In conclusion, αvß6 and EGFR allowed for precise discrimination of SSC at the surgically problematic soft tissue margins. Superficial margins are ideally distinguished with uPAR. In the future, FGS in the surgically challenging setting of cutaneous and mucosal SCC could benefit from a tailor-made approach, with EGFR and αvß6 as targets.

MicroRNA-143 and -205 expression in neosquamous esophageal epithelium following Argon plasma ablation of Barrett's esophagus.

INTRODUCTION: Ablation of Barrett's esophagus using Argon plasma coagulation (APC) is usually followed by the formation of a neosquamous epithelium. Investigating simple columnar or stratified squamous epithelium associated cytokeratin and microRNA (miRNA) expression in neo-squamous epithelium could help determine the identity and stability of the neosquamous epithelium. METHODS: Nine patients underwent ablation of Barrett's esophagus with APC. Biopsies were collected from Barrett's esophagus mucosa and proximal normal squamous epithelium before ablation, and from neosquamous and normal squamous epithelium after ablation. Additional esophageal mucosal biopsies from ten nonrefluxing subjects were used as a reference. RNA was extracted and real-time polymerase chain reaction was used to measure the expression of the cytokeratins CK-8 and CK-14 and the microRNAs miR-143 and miR-205. RESULTS: CK-8 and miR-143 expression were significantly higher in Barrett's esophagus mucosa, compared to neosquamous and normal squamous epithelium before and after APC, whereas miRNA-205 and CK-14 expression was significantly lower in Barrett's esophagus mucosa compared to all categories of squamous mucosa. The expression of CK-8, CK-14, miR-205, and miR-143 was similar between neosquamous epithelium compared to normal squamous epithelium in patients with Barrett's esophagus. Only miR-143 expression was significantly higher in neosquamous and normal squamous epithelium before and after APC compared to normal squamous epithelium from control subjects (p < 0.004). CONCLUSIONS: The expression levels of cytokeratins and miRNAs studied in post-ablation neosquamous epithelium and normal squamous epithelium in patients with Barrett's esophagus are similar. In patients with Barrett's esophagus, miR-143 expression is still elevated in both neosquamous mucosa, and the squamous mucosa above the metaplastic segment, suggesting that this mucosa may not be normal; i.e., it is different to that seen in subjects without Barrett's esophagus. miR-143 could promote a Barrett's epithelium gene expression pattern, and this could have a role in development of Barrett's esophagus.

Accuracy of identification of tissue types in endoscopic esophageal mucosal biopsies used for molecular biology studies.

OBJECTIVES: To determine if histopathologic assessment of esophageal biopsies harvested for research study is justified due to the heterogeneity of tissues in the esophagus, and the consequent histopathologic mis-matches with the clinical histopathology of biopsies taken at the same level. METHODS: Since 2004, patients undergoing upper endoscopy for a variety of clinical conditions were invited to provide additional esophageal biopsies; those were collected for research purpose at the same level as biopsies collected for clinical histopathology. Research biopsies were cut in two parts: one part was submitted to research histopathology and the other stored for molecular analysis. Results of clinical histopathology for each patient were summarized per biopsy level and compared to results obtained from research biopsies at the corresponding level. RESULTS: A total of 377 level summaries were obtained from 137 patients. Clinical histopathology summaries classified 123 levels (32.6%) as squamous epithelium, 84 levels (22.3%) as metaplastic columnar-lined epithelium, 135 levels (35.8%) as columnar-lined epithelium with intestinal metaplasia, 30 levels (8%) as dysplasia, and 5 levels (1.3%) as adenocarcinoma. Research histopathology matched to clinical summaries on 120 of 123 (97.5%) levels for squamous epithelium, 52 of 84 (61.9%) for metaplastic columnar-lined epithelium, and 94 of 135 (69.5%) for columnar-lined epithelium with intestinal metaplasia. There were no matches for dysplasia between the groups; however, they agreed on all five cases of AC. On 59 (70.2%) metaplastic columnar-lined epithelium levels and on 62 (46%) columnar-lined epithelium with intestinal metaplasia levels, tissue heterogeneity was observed in clinical histopathology, with portions of squamous epithelium within the samples. Matches with pure tissue samples in both clinical and research histopathology levels were observed on 22 (26.2%) levels of metaplastic columnar-lined epithelium and in 55 (40.7%) levels of columnar-lined epithelium with intestinal metaplasia. CONCLUSIONS: The high proportion of mismatches and tissue heterogeneity observed, especially among columnar-lined epithelium with intestinal metaplasia and dysplasia, points to the necessity of determining the histopathology of the research samples to avoid sampling errors during molecular studies.