Detection of micrometastasis in lymph nodes of oral squamous cell carcinoma: A comparative study

Evaluation of micrometastasis and isolated tumor cells in node-negative early-stage oral tongue squamous cell carcinoma: a cross-sectional study in tertiary-level hospitals in eastern India

OBJECTIVE

The present study aimed to investigate the incidence of micrometastasis (MMs) and isolated tumor cells (ITCs) in node-negative early-stage oral tongue squamous cell carcinoma (T1-T2 N0). The secondary objective was to correlate the incidence with the clinicopathologic parameters of age, sex, depth of invasion, pattern of invasion, host lymphocytic response, and size and grade of primary tumor.

STUDY DESIGN

Micrometastasis and ITCs in cervical nodes of 30 patients with early-stage oral tongue squamous cell carcinoma were detected and compared using 3 methods: routine hematoxylin and eosin staining, serial-sectioning at intervals of 150 microns employing hematoxylin and eosin, and serial sectioning pan-cytokeratin immunostaining. Associations with clinicopathological variables were analyzed.

RESULTS

Metastatic tumor cells were detected in the cervical nodes of 2 patients using serial sectioning and immunohistochemistry, resulting in upstaging of 6.6% of all cases. Level I and II lymph nodes were primarily involved.

CONCLUSIONS

Early-stage oral tongue squamous cell carcinoma has a significant potential for MMs that frequently go undetected in routine histopathologic examination. However, laborious and technique-sensitive, serial sectioning in combination with pan-cytokeratin staining (AE1/AE3) may aid in detecting MMs and ITCs in patients with early-stage OTSCC.

Molecular immuno-imaging improves tumor detection in head and neck cancer

Detection and accurate delineation of tumor is important for the management of head and neck squamous cell carcinoma (HNSCC) but is challenging with current imaging techniques. In this study, we evaluated whether molecular immuno-imaging targeting myeloperoxidase (MPO) activity, an oxidative enzyme secreted by many myeloid innate immune cells, would be superior in detecting tumor extent compared to conventional contrast agent (DTPA-Gd) in a carcinogen-induced immunocompetent HNSCC murine model and corroborated in human surgical specimens. In C57BL/6 mice given 4-nitroquinoline-N-oxide (4-NQO), there was increased MPO activity in the head and neck region as detected by luminol bioluminescence compared to that of the control group. On magnetic resonance imaging, the mean enhancing volume detected by the MPO-targeting agent (MPO-Gd) was higher than that by the conventional agent DTPA-Gd. The tumor volume detected by MPO-Gd strongly correlated with tumor size on histology, and higher MPO-Gd signal corresponded to larger tumor size found by imaging and histology. On the contrary, the tumor volume detected by DTPA-Gd did not correlate as well with tumor size on histology. Importantly, MPO-Gd imaging detected areas not visualized with DTPA-Gd imaging that were confirmed histopathologically to represent early tumor. In human specimens, MPO was similarly associated with tumors, especially at the tumor margins. Thus, molecular immuno-imaging targeting MPO not only detects oxidative immune response in HNSCC, but can better detect and delineate tumor extent than nonselective imaging agents. Thus, our findings revealed that MPO imaging could improve tumor resection as well as be a useful imaging biomarker for tumor progression, and potentially improve clinical management of HNSCC once translated.

Prospective evaluation of the impact of human papilloma virus status and small node size on the diagnostic accuracy of 18F-fluorodeoxyglucose positron emission tomography/computed tomography for primary head and neck squamous cell carcinoma

BACKGROUND

Fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) is well validated in the staging of pre-treatment head and neck squamous cell carcinoma (HNSCC), although the impact of human papilloma virus (HPV) status and node size on accuracy remains unclear. The aim of this study was to assess the diagnostic accuracy of PET/CT based on HPV status and node size and determine the effects of maximum standardized uptake value thresholds on sensitivity, specificity and positive predictive value.

METHODS

A total of 38 patients with primary HNSCC were recruited. All patients underwent primary tumour resection and cervical node dissection following FDG-PET/CT.

RESULTS

A total of 38 patients including 68 dissected necks, representing 353 nodal levels and a total of 2701 lymph nodes were included. Histopathological analysis revealed lymph node metastases in 4.3% (116/2701) of dissected lymph nodes. Forty-four percent of patients had HPV-positive tumours. Sixty-four percent of involved lymph nodes were <1 cm. The sensitivity and specificity for HPV-positive nodes were 67.2% and 99.3% versus 35.6% and 98.2% in HPV-negative nodes, respectively (P < 0.001). Mean maximum standardized uptake value in HPV-positive nodes was 6.3 versus 3.5 in HPV-negative nodes (P < 0.001). Sensitivity and specificity were 30.7% and 99.2% in <1 cm nodes versus 90.2% and 84.8% in ≥1 cm nodes, respectively (P < 0.001).

CONCLUSION

FDG-PET/CT has significantly higher diagnostic accuracy in determining nodal metastases in HPV-positive HNSCC versus HPV-negative disease. Accuracy was lower in <1 versus ≥1 cm nodes.

Let-7b-5p inhibits proliferation and motility in squamous cell carcinoma cells through negative modulation of KIAA1377

KIAA1377 has been found to be linked with lymph node metastasis in esophageal squamous cell carcinoma (SCC) in our previous study; however, the regulation of KIAA1377 remains far from understood. Herein, to understand the regulation of KIAA1377 from the angle of microRNA (miRNA)-messenger RNA (mRNA) modulation in the setting of SCC cells, the basal level of KIAA1377 was determined by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot analysis in KYSE-150 and HeLa cells; biological roles of KIAA1377 contributing in the proliferation, migration, and invasion were evaluated using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT), wound-healing and Transwell assays, respectively, after KIAA1377 was knocked out mediated by the CRISPR-Cas9 system. Bioinformatic prediction revealed that let-7b-5p was a putative miRNA regulating KIAA1377, which was ensuingly validated by the luciferase reporter assay; after which, variation of KIAA1377 expression was further verified by qRT-PCR and western blot analysis. Moreover, the biological roles of let-7b-5p in proliferation, migration, and invasion of KYSE-150 and HeLa cells were also evaluated. It was exhibited that KIAA1377 was able to promote the proliferation and motility of both KYSE-150 and HeLa cells, which can be reverted by re-expression of let-7b-5p. The luciferase reporter assay verified that let-7b-5p can diametrically target KIAA1377. Collectively, our data demonstrated that let-7b-5p can directly but negatively regulate KIAA1377 in SCC cell lines, Ecal109, and HeLa cells.

Intramuscular vaccination targeting mucosal tumor draining lymph node enhances integrins-mediated CD8+ T cell infiltration to control mucosal tumor growth

Purpose: Mucosal immunization is suggested to be crucial for controlling tumors in the mucosal region; however, therapeutic DNA vaccination with electroporation in various mucosal sites has yet to become clinically adaptable. Since tumor-draining lymph nodes (tdLNs) have been suggested as immune-educated sites that can be utilized to mount a potent antitumor immune response, we examined whether intramuscular DNA vaccination with electroporation at sites that target the mucosal tdLNs could elicit mucosal immune response to restrict tumor growth. Experimental Design: The efficacy and mechanism of intramuscular administration of a therapeutic DNA vaccine with electroporation at different sites was examined by lymphocyte analysis, tumor growth, mouse survival, as well as integrin expression, in mice bearing orthotopic HPV16 E6/E7+ syngeneic TC-1 tumors in various mucosal areas. Results: While provoking comparable systemic CD8+ T cell responses, intramuscular hind leg vaccination generated stronger responses in cervicovaginal-draining LNs to control cervicovaginal tumors, whereas intramuscular front leg vaccination generated stronger responses in oral-draining LNs to control buccal tumors. Surgical removal of tdLNs abolished the antitumor effects of therapeutic vaccination. Mucosal-tdLN-targeted intramuscular vaccination induced the expression of mucosal-homing integrins LPAM-1 and CD49a by tumor-specific CD8+ T cells in the tdLNs. Inhibition of these integrins abolished the therapeutic effects of vaccination and the infiltration of tumor-specific CD8+ T cells into mucosal tumors. Conclusions: Our findings demonstrate that tumor draining lymph nodes targeted intramuscular immunization can effectively control mucosal tumors, which represents a readily adaptable strategy for treating mucosal cancers in humans.

A comprehensive study of smoking-specific microRNA alterations in head and neck squamous cell carcinoma

OBJECTIVE

While tobacco smoking is a well-known risk factor for head and neck squamous cell carcinoma (HNSCC), the molecular mechanisms underlying tobacco-induced HNSCC remain unclear. This study sought to comprehensively identify microRNA (miRNA) alterations and evaluate their clinical relevance in smoking-induced HNSCC pathogenesis and progression.

MATERIALS AND METHODS

Using small RNA-sequencing data and clinical data from 145 HNSCC patients, we performed a series of differential expression and correlation analyses to identify a panel of tobacco-dysregulated miRNAs associated with key clinical characteristics in HNSCC. We then examined the expression patterns of these miRNAs in normal epithelial cell lines following exposure to cigarette smoke extract.

RESULTS

Our analyses revealed distinct panels of miRNAs to be dysregulated with smoking status and associated with additional clinical features, including tumor stage, metastasis, anatomic site, and patient survival. The differential expression of key miRNAs, including miR-101, miR-181b, miR-486, and miR-1301, was verified in cigarette-treated epithelial cell lines, suggesting their potential roles in the early development of smoking-related HNSCCs.

CONCLUSION

Specific alterations in miRNA expression may be traced to tobacco use and are associated with important HNSCC clinical characteristics. Future studies of these miRNAs may be valuable for furthering the understanding and targeted treatment of smoking-associated HNSCC.

A nomogram for predicting the risk of neck node metastasis in pathologically node-negative oral cavity carcinoma

OBJECTIVE

To generate a nomogram for predicting the risk of neck node metastasis in pathologically node-negative patients using a combination of variables comprising of protein expression, ultrastructural alterations and clinicopathological parameters.

MATERIALS AND METHODS

Surgically removed oral tumours (n = 103) were analysed for the expression of desmosomal and hemidesmosomal assembly proteins by immunohistochemistry and ultrastructural alterations by transmission electron microscopy (TEM). Protein expression, ultrastructural alterations and clinicopathological variables were used to construct nomogram from the training set in 75 patients. Clinical utility of the nomogram was validated in a discrete set of 28 patients.

RESULTS

Univariate and multivariate analyses were performed on the training set, and obtained significant variables comprising of integrin β4 expression (p = .027), number of hemidesmosomes (p = .027)/desmosomes (p = .046), tumour differentiation grade (p = .033) and tumour thickness (p = .024) were used for construction of the nomogram. The area under the curve was calculated for both training 0.821 (95% CI 0.725-0.918) and validation sets 0.880 (95% CI 0.743-1.000). The nomogram demonstrated a predictive accuracy of 73.3% and 78.6% with the sensitivity of 81.4% and 83.3% in the training and validation sets, respectively.

CONCLUSIONS

The nomogram constructed on postsurgical tumour samples will be a value addition to histopathology for the detection of neck node metastasis in pathologically node-negative patients.

Micrometastasis Detection using Special Stains in Nodal Tissues of Oral Squamous Cell Carcinoma - A Histochemical Study

INTRODUCTION

Micrometastasis to the lymph node is an important prognostic factor in survival and recurrence and even in making critical decisions regarding postoperative radiation treatment. Methods like Immunohistochemistry (IHC), serial sectioning and Polymerase Chain Reaction (PCR) are very sensitive; however, they are expensive and time consuming. Hence, there is a need for the detection of micrometastasis by method which is easily feasible and inexpensive.

AIM

This study was undertaken to identify if special stains (Modified Papanicolaou stain and Ayoub Shklar stain) are valuable in detecting micrometastasis which are routinely missed in Haematoxylin and Eosin stain and also to compare their efficacy over Haematoxylin and Eosin stain in detection of metastatic tumour cells in non-metastatic lymph nodes.

MATERIALS AND METHODS

This study constituted a total of 300 histopathologically proven non metastatic lymph node sections. Other than Haematoxylin and Eosin stain, Modified Papanicalaou and Ayoub Shklar stain were used for identification of micrometastatic deposit.

RESULTS

Papanicolaou stain was the only stain useful in detecting micrometastasis which accounted to 7% of non metastatic lymph node sections used in our study.

CONCLUSION

Papanicolaou stain has definitely proved valuable in detecting micrometastasis over routine Haematoxylin and Eosin and Ayoub Shklar stain with an added advantage of being economical, easily available and technique insensitive.

Determining the potential of desmoglein 3 as a sensitive and specific immunohistochemical marker for the detection of micrometastasis in patients with primary oral squamous cell carcinoma

Aim of the study

Despite advances in surgical and radiotherapy techniques, the presence of lymph node metastasis drastically decreases the survival rate of patients with primary oral squamous cell carcinoma (OSCC). Thus the accurate pathological staging of the neck is critical. Desmoglein 3 (DSG3), a desmosomal cadherin protein is said to be highly expressed in head and neck squamous cell carcinoma (HNSCC) and in metastatic cervical lymph nodes, but absent in non-invaded nodes. With an aim to improve the sensitivity of tumour cell detection, we investigated the potential of DSG3 as an immunohistochemical marker for the detection of occult lymph node metastasis in patients with primary OSCC.

Material and methods

Forty-seven lymph node specimens from 10 patients who underwent neck dissection for primary OSCC were immunostained with DSG3.

Results

The DSG3 positivity was noted in the six positive lymph nodes. However, when using DSG3 as an immunohistochemical marker, no additional micrometastatic deposits were evident in the histologically negative nodes. Interestingly, tumour marker DSG3-positive macrophages could be identified within the subcapsular sinuses, medullary sinuses, and the interfollicular areas.

Conclusions

Our findings suggest that although DSG3 is overexpressed in HNSCC, it is not specific and may not prove to be a potent immunohistochemical marker to detect micrometastasis. The role of tumour marker-positive macrophages within the lymph nodes needs to be investigated further.