Clinicopathological differences between lip cancers and tongue cancers

Abstract

Lip cancer is closely linked to chronic exposure to solar radiation, while tongue cancer, the most common intraoral neoplasm, is mainly related to tobacco and/or alcohol consumption. Lip cancer has a much better prognosis than tongue cancer. The objective of this study was to assess the differentiating features between squamous cell carcinomas located on both the lip and the tongue. A search for studies on lip cancer and tongue cancer was performed in the following databases: PubMed (MEDLINE and Cochrane Library), Web of Science (WoS), and Scopus. The estimated prevalence of lip and tongue cancers was calculated according to the random model of DerSimonian and Laird. For categorical outcomes, Pearson's Chi-square test was used with Fisher's exact test when required. Thirty-two studies were included in this review. Considering the whole oral tumor locations, the estimated prevalence of lip cancer was 23.43% and in tongue cancer, 27.58%. A greater number of lip cancers were found in males, were classified as T1, were well-differentiated tumors, and had a higher 5-year survival rate. In contrast, a greater number of tongue cancers were observed in younger patients, tobacco and/or alcohol users, presented lymph node metastases, and more advanced tumor stages. Although both tumors are located in the mouth, lip cancers and tongue cancers have different clinicopathological features and biological behaviors.