MicroRNA Alterations and Associated Aberrant DNA Methylation Patterns across Multiple Sample Types in Oral Squamous Cell Carcinoma

Background: MicroRNA (miRNA) expression is broadly altered in cancer, but few studies have investigated miRNA deregulation in oral squamous cell carcinoma (OSCC). Epigenetic mechanisms are involved in the regulation of .30 miRNA genes in a range of tissues, and we aimed to investigate this further in OSCC. Methods: TaqManH qRT-PCR arrays and individual assays were used to profile miRNA expression in a panel of 25 tumors with matched adjacent tissues from patients with OSCC, and 8 control paired oral stroma and epithelium from healthy volunteers. Associated DNA methylation changes of candidate epigenetically deregulated miRNA genes were measured in the same samples using the MassArrayH mass spectrometry platform. MiRNA expression and DNA methylation changes were also investigated in FACS sorted CD44high oral cancer stem cells from primary tumor samples (CSCs), and in oral rinse and saliva from 15 OSCC patients and 7 healthy volunteers. Results: MiRNA expression patterns were consistent in healthy oral epithelium and stroma, but broadly altered in both tumor and adjacent tissue from OSCC patients. MiR-375 is repressed and miR-127 activated in OSCC, and we confirm previous reports of miR-137 hypermethylation in oral cancer. The miR-200 s/miR-205 were epigenetically activated in tumors vs normal tissues, but repressed in the absence of DNA hypermethylation specifically in CD44high oral CSCs. Aberrant miR-375 and miR-200a expression and miR-200c-141 methylation could be detected in and distinguish OSCC patient oral rinse and saliva from healthy volunteers, suggesting a potential clinical application for OSCC specific miRNA signatures in oral fluids. Conclusions: MiRNA expression and DNA methylation changes are a common event in OSCC, and we suggest miR-375, miR- 127, miR-137, the miR-200 family and miR-205 as promising candidates for future investigations. Although overall activated in OSCC, miR-200/miR-205 suppression in oral CSCs indicate that cell specific silencing of these miRNAs may drive tumor expansion and progression

Sentinel node in oral cancer: the nuclear medicine aspects: a survey from the sentinel european node trial

PURPOSE: Nuclear imaging plays a crucial role in lymphatic mapping of oral cancer. This evaluation represents a subanalysis of the original multicenter SENT trial data set, involving 434 patients with T1-T2, N0, and M0 oral squamous cell carcinoma. The impact of acquisition techniques, tracer injection timing relative to surgery, and causes of false-negative rate were assessed. METHODS: Three to 24 hours before surgery, all patients received a dose of Tc-nanocolloid (10-175 MBq), followed by lymphoscintigraphy. According to institutional protocols, all patients underwent preoperative dynamic/static scan and/or SPECT/CT. RESULTS: Lymphoscintigraphy identified 723 lymphatic basins. 1398 sentinel lymph nodes (SNs) were biopsied (3.2 SN per patient; range, 1-10). Dynamic scan allowed the differentiation of sentinel nodes from second tier lymph nodes. SPECT/CT allowed more accurate anatomical localization and estimated SN depth more efficiently. After pathological examination, 9.9% of the SN excised (138 of 1398 SNs) showed metastases. The first neck level (NL) containing SN+ was NL I in 28.6%, NL IIa in 44.8%, NL IIb in 2.8%, NL III in 17.1%, and NL IV in 6.7% of positive patients. Approximately 96% of positive SNs were localized in the first and second lymphatic basin visualized using lymphoscintigraphy. After neck dissection, the SN+ was the only lymph node containing metastasis in approximately 80% of patients. CONCLUSIONS: Best results were observed using a dynamic scan in combination with SPECT/CT. A shorter interval between tracer injection, imaging, and surgery resulted in a lower false-negative rate. At least 2 NLs have to be harvested, as this may increase the detection of lymphatic metastases

Sentinel European Node Trial (SENT): 3-year results of sentinel node biopsy in oral cancer.

PURPOSE: Optimum management of the N0 neck is unresolved in oral cancer. Sentinel node biopsy (SNB) can reliably detect microscopic lymph node metastasis. The object of this study was to establish whether the technique was both reliable in staging the N0 neck and a safe oncological procedure in patients with early-stage oral squamous cell carcinoma. METHODS: An European Organisation for Research and Treatment of Cancer-approved prospective, observational study commenced in 2005. Fourteen European centres recruited 415 patients with radiologically staged T1-T2N0 squamous cell carcinoma. SNB was undertaken with an average of 3.2 nodes removed per patient. Patients were excluded if the sentinel node (SN) could not be identified. A positive SN led to a neck dissection within 3 weeks. Analysis was performed at 3-year follow-up. RESULTS: An SN was found in 99.5% of cases. Positive SNs were found in 23% (94 in 415). A false-negative result occurred in 14% (15 in 109) of patients, of whom eight were subsequently rescued by salvage therapy. Recurrence after a positive SNB and subsequent neck dissection occurred in 22 patients, of which 16 (73%) were in the neck and just six patients were rescued. Only minor complications (3%) were reported following SNB. Disease-specific survival was 94%. The sensitivity of SNB was 86% and the negative predictive value 95%. CONCLUSION: These data show that SNB is a reliable and safe oncological technique for staging the clinically N0 neck in patients with T1 and T2 oral cancer. EORTC Protocol 24021: Sentinel Node Biopsy in the Management of Oral and Oropharyngeal Squamous Cell Carcinoma

Implications of a positive sentinel node in oral squamous cell carcinoma

The results are preliminary but suggest that both the number and the position of positive sentinel nodes may identify different prognostic groups that may allow further tailoring of management plans

Sentinel Node in Oral Cancer:The Nuclear Medicine Aspects. A Survey from the Sentinel European Node Trial

Purpose: Nuclear imaging plays a crucial role in lymphatic mapping of oral cancer. This evaluation represents a subanalysis of the original multicenter SENT trial data set, involving 434 patientswith T1-T2, N0, and M0 oral squamous cell carcinoma. The impact of acquisition techniques, tracer injection timing relative to surgery, and causes of false-negative rate were assessed. Methods: Three to 24 hours before surgery, all patients received a dose of 99mTc-nanocolloid (10-175 MBq), followed by lymphoscintigraphy. According to institutional protocols, all patients underwent preoperative dynamic/ static scan and/or SPECT/CT. Results: Lymphoscintigraphy identified 723 lymphatic basins. 1398 sentinel lymph nodes (SNs) were biopsied (3.2 SN per patient; range, 1-10). Dynamic scan allowed the differentiation of sentinel nodes from second tier lymph nodes. SPECT/CT allowed more accurate anatomical localization and estimated SN depth more efficiently. After pathological examination, 9.9% of the SN excised (138 of 1398 SNs) showed metastases. The first neck level (NL) containing SN+ was NL I in 28.6%, NL IIa in 44.8%, NL IIb in 2.8%, NL III in 17.1%, and NL IV in 6.7% of positive patients. Approximately 96% of positive SNs were localized in the first and second lymphatic basin visualized using lymphoscintigraphy. After neck dissection, the SN+ was the only lymph node containing metastasis in approximately 80% of patients. Conclusions: Best results were observed using a dynamic scan in combination with SPECT/CT. A shorter interval between tracer injection, imaging, and surgery resulted in a lower false-negative rate. At least 2 NLs have to be harvested, as this may increase the detection of lymphatic metastases