Lung cancer metastasis to oral soft tissues; Systematic review of 122 cases.

Background: Lung cancer metastasis to oral region is very rare. Studies have been published analysing the cases of metastatic tumours to the oral cavity by many researchers. But very few research work has been conducted till date to analyse only the oral soft tissue metastasis from Lung cancer as the primary source. The goal of this study was to examine published cases of oral soft tissue metastasis from lung cancer as the only primary source from 1st August 1977 to 31st December 2021. Material and Methods: An electronic search of the published English literature was performed in PubMed/ Medline, Scopus, Google Scholar, and Research gate databases, using keywords like 'Lung cancer', OR/ AND 'Lung carcinoma' OR/ AND 'Oral cavity', OR/AND 'Metastasis', OR/AND 'Primary', OR/AND 'Source', OR/AND 'Initial', OR/AND 'Tongue', OR/AND 'Palate', OR/ AND 'Tonsil', OR/AND 'Lip', OR/AND 'Buccal mucosa', OR/AND 'Floor of mouth', OR/AND 'Salivary glands', OR/ AND 'Parotid', OR/ AND 'Submandibular', OR/ AND 'Sublingual' OR/ AND 'Mandible', OR/AND 'Maxilla. We also searched all related journals manually. Reference list of all articles was also checked. Results: Our research revealed total 122 patients. The most prevalent diagnosed metastatic lung cancer was adenocarcinoma. Gingiva, tongue and tonsils were the most common site of metastasis. 54% patients died of metastasis with a survival time of 1 week to 2.5 years. Conclusions: Oral soft tissue metastasis from lung cancer has a bad prognosis. More cases need to be published in order to raise awareness of these lesions and gain a better understanding of their characteristics.