Temporal and spatial patterns of recurrence in oral squamous cell carcinoma, a single-center retrospective cohort study in China

BACKGROUND: Oral squamous cell carcinoma (OSCC) is an invasive cancer with a high recurrence rate. Most clinical studies have focused on the prognosis of patients with OSCC, few have investigated the causes and interventions that affect the recurrence. Our study is to explore the temporal and spatial patterns of recurrence in OSCC. METHODS: 234 OSCC patients with recurrence in our hospital and 64 OSCC patients with recurrence in TCGA database were included in the study. Log-rank test and Multivariate Cox Regression Analysis were used to determine whether there was a significant difference between each selected demographic or clinical factors and recurrence. The Kaplan–Meier method was used to plot survival curves for each recurrence interval. RESULTS: The proportion of OSCC patients in clinical and TCGA with early recurrence was 93.6% and 84.4%, respectively. Age, chewing betel nut, previous radiotherapy, histopathological grading of the primary tumor (poorly differentiated), lymph node metastasis and postoperative infection were found to be associated with the timing of recurrence. It was found that tongue cancer has more regional recurrences, while buccal cancer is mostly local and loco-regional recurrences. The earlier the recurrence, the greater the possibility of local-regional recurrence and the worse the prognosis. CONCLUSION: Most of recurrent OSCC patients present early recurrence (< 18 months) with poor prognosis, and early recurrence is more prone to local recurrence. Moreover, recurrence site is related with primary site of OSCC.