Mutation Analysis of Second Primary Tumors in Oral Cancer in Taiwanese Patients through Next-Generation Sequencing

Abstract

Head and neck cancer has poor overall survival. Patients with head and neck cancer more frequently develop second primary tumors than do patients with other cancers, leading to a poor prognosis. In this study, we used next-generation sequencing to analyze and compare mutations between first tumors and second tumors in oral cancer. We retrieved tumor tissues collected from 13 patients who were diagnosed twice as having cancer. We used driver gene and trunk mutations to distinguish between recurrent cancer and primary cancer in oral cancer. We observed unique driver gene mutations in three patients with an initial clinical diagnosis of recurrent cancer; hence, we believe that the corresponding patients had primary cancer. Four patients with an initial clinical diagnosis of primary cancer were found to actually have recurrent cancer according to our results. Genetic testing can be used to enhance the accuracy of clinical diagnosis.

Genomic alterations in oral multiple primary cancers

“…The number of trunk mutations varied among MPCs cases, while recurrent patients exhibited completely duplicated mutated genes. 1 However, the study did not differentiate between synchronous and metachronous MPCs, nor did it consider prognosis.…”

“…The clinical manifestations of OSCC vary depending on the specific cancer type, with some patients presenting with nonhealing nodules or sores in the oral mucosa. 1 Others with tumors located in the pharynx or floor of the mouth may experience difficulties in swallowing or changes in vocal quality. 2 Approximately 75% of OSCC are attributed to alcohol and tobacco use.…”

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“…Oral cancers are caused by a long-term accumulation of mutations that eventually transform normal mucosa into dysplasia and then invasive carcinoma. Early detection of high-risk oral premalignant condition is essential for reducing mortality and morbidity while maintaining the most effective method of preventing cancer transformation [20,21]. Despite the accessible histopathologic examination, more than 60% of all OSCCs are diagnosed when metastatic condition is already present [22].…”