Clinical outcomes and impact of prognostic factors following adjuvant radiotherapy in oral tongue cancer patients

Abstract

Abstract Background The purpose of the study was to evaluate survival outcomes in post-operative oral tongue cancer patients undergoing adjuvant radiotherapy (RT) at a tertiary cancer care center and to critically review the impact of various clinical-pathological factors on recurrence and survival. Demographic factors, stage of all the histology proven oral tongue cancer, and treatment details were documented. Overall survival (OS) and recurrence-free survival (RFS) were analyzed along with the potential prognostic factors affecting outcome. Results One hundred forty-four post-operative oral tongue cancer patients referred to our department for adjuvant treatment were evaluated. Median age at presentation was 45 years. Forty-seven patients had pathological early stage disease (stages I and II) and 95 had locally advanced (stages III and IV) disease while post-op details were not present in 2 patients. At a median follow-up of 87 months (60–124) of alive patients, the median RFS for entire cohort was 62 months while median OS was 74 months respectively. Age, perineural invasion (PNI), and grade of the tumor emerged as independent prognostic factors for OS and RFS. Among patients with early stage disease, depth of invasion (DOI), age, and PNI were found as independent prognostic factors for RFS and OS. In locally advanced disease, higher grade, age, and PNI independently impacted the respective survival end points. Conclusions Age (> 45 years), higher grade, and presence of PNI showed inferior survival outcomes across the sub-groups (early versus locally advanced disease). This may warrant adjuvant treatment intensification. DOI > 10 mm was particularly found to worsen survival in early node negative SCC oral tongue patients.