Assessment of cervical lymph node metastasis based on total RNA from saliva and tumor tissue in patients with oral squamous cell carcinoma: An observational study

J Oral Maxillofac Pathol. 2020 May-Aug;24(2):230-236. doi: 10.4103/jomfp.JOMFP_58_20. Epub 2020 Sep 9.

Abstract

Background: In case of oral squamous cell carcinoma (OSCC) most patients die within first 2 years due to metastasis. To overcome the limitations and drawbacks of the present available methods of assessment of lymph nodes metastasis, the search for alternative method is needed.

Aim: The aim of the study is to evaluate the sensitivity, specificity and diagnostic accuracy of salivary and tumor tissue RNA for assessment of lymph node metastasis in patients with OSCC.

Methodology: Patients histologically diagnosed with OSCC were included as participants. The unstimulated saliva and tumor tissue were collected and stored at deep freeze before surgical therapy. The pretreatment lymph node metastasis assessment was done by radioimaging investigation. The posttreatment histopathological status of cervical lymph nodes was noted. The RNA was isolated and quantified from stored saliva sample and tumor tissue. The collected data were statistically analyzed for specificity and sensitivity and significance.

Results: The area under curve for salivary RNA level is 0.647 and for tumor tissue RNA level is 0.628 with moderate predictability at 95% confidence interval. It was observed that the sensitivity was 63.50% and 71.40% and specificity was 62.70% and 58.80% for saliva and tumor tissue respectively with diagnostic accuracy of 63%-65%. The Kappa statistics showed moderate degree of agreement with high statistical significance (P ≤ 0.05).

Conclusion: Saliva and tumor tissue RNA can be a good marker for pretreatment assessment of lymph node metastasis in patients with OSCC. Although the diagnostic accuracy which range from 63% to 65%, further characterization and study of specific mRNA, siRNA and miRNA may come out with high diagnostic accuracy.

Keywords: Lymph node metastasis; RNA; oral squamous cell carcinoma; saliva; tumor.