The association between oral cancer distribution and TNM stages among patients with oral cancer

Abstract

Background: Head and Neck squamous cell carcinoma includes cancers of the mouth, oropharynx, throat, hypopharynx and nasopharynx, developing annually in approximately 550 000 incidence and about 304 000 people die from this type of cancer. Lip, buccal mucosa, upper and lower alveolar ridge, gingiva, retromolar trigone, floor of the mouth, palate, salivary gland, and the front two-thirds of the tongue are all potential sites for oral cavity cancer. Aim: To study the association between of oral cancer distribution and TNM stages among patients with oral cancer. Materials and Methods: Our study, based on retrospective cohort method was conducted from medical reports of 173 patients who were diagnosed with squamous cell carcinoma of oral cancer and at the Department of Head and Neck Surgery, Radio and Chemotherapy of the National Cancer Center of Mongolia between 2008-2017 years. All statistical analysis were carried out using STATA version 15.0 and we performed survival analysis using Kaplan-Meier method, and survival distribution in different variables were analyzed by the log-rank test. The study was approved by the Research Ethics Committee of the Mongolian National University of Medical Sciences on June 08, 2021 (№ 2021/3-07). Results: For almost half of the patients, the most common site of cancer was the tongue (79, 45.7%), followed by the lips (23, 13.3%) and hard and soft palate (16, 9.2%). Female patients are usually diagnosed in stage II, whereas almost half of all male patients were diagnosed in stage IV. More than half of the patients with cancer located in the gums, floor of the mouth and retromolar space were diagnosed in stage IV, whereas 77% of the patients with hard palate cancer were diagnosed in stage II (p<0.001). Conclusions: 1. In our study, the tongue cancer was most common cancer among oral cancer contributing up to 45.7% of all oral sites. It’s indicated that the high incidence of tongue cancer depends on heavy alcohol and tobacco use, chronic irritation of denture and sharp edge of broken tooth because of dental caries 2. A greater prevalence of oral cancers other than hard palate cancer diagnosed in advanced clinical stage (III, IV). It’s showed to be related to the insufÏcient knowledge about oral cancer among population and people don’t regularly undergo preventive examinations by an oncologist or a maxilla-facial surgeon.