Evaluation of  premetastatic changes in lymph nodes(pN0) of oral tongue tumour: A prospective observational Study [version 1; peer review: 2 approved]

Background: Tongue tumors show intra and inter-tumoral heterogenicity with high incidence, relapse and mortality rates necessitating further research. Recurrence/metastasis that occurs after surgical resection of primary cancer is often the reason for poor survival in these patients. Lymph nodes are the most common site of metastasis in tongue tumors. Therefore, premetastatic molecular changes can be best evaluated in lymph nodes which may epitomize the earliest events in the metastasis cascades. The presence of circulating tumor cells(CTCs) in the absence of nodal disease (N0) may represent tumor aggressiveness, suggesting an immune escape which may have high metastatic potential. This trial was developed to investigate the earliest pre-metastatic changes which may regulate tumor dormancy and predict metastasis. A better understanding of organotropism or pre-metastatic changes can help in theragnostic, thereby preventing the outbreak of overt metastasis. Methods: A single-institutional prospective observational cohort study. This trial will be conducted at a tertiary care Centre (Amrita Institute of Medical Sciences Kochi). Eligible patients will be enrolled after obtaining informed consent. The dissected lymph nodes will be subjected to histopathological and immunohistochemical analyses for premetastatic niche (PMN) formation. In addition, circulating tumor cells will be evaluated before treatment and 6 months after treatment. The patients will be followed up for a period of two years to correlate the findings with the recurrence-free survival. Expected results: The pre-metastatic changes, if detected will be a predictive biomarker. It may help to define future drug targets for metastasis chemoprevention . CTCs may define the tumor aggressiveness ,there by prognostication and helps in better disease management. Ethics and dissemination: The study has received the following approval: Ethics Committee of Amrita School of Medicine (ECASM-AIMS-2022-048).Trial Registered Prospectively( CTRI/2022/03/041256 ) on 22/03/2022 under Clinical Trial Registry of India