This study aims to identify key clinicopathological variables which predict recurrence
in those undergoing curative resection of oral squamous cell carcinoma (OSCC) with
emphasis on initial treatment failure patterns.
Between February 2006 to May 2020, clinicopathological data on 833 patients who underwent
curative resection of OSCC were gathered. Outcomes of interest included local, regional,
distant and overall recurrence. Univariate analysis was performed to identify significant
clinicopathological variables for each recurrence type, where a multivariate regression
analysis was utilised to generate predictive models.
187 patients (22.4%) developed recurrent disease; 79 local, 63 regional and 46 distant.
For local recurrence: tumour depth of invasion (DOI) >5-10mm, tumour DOI >10mm and
modified Glasgow Prognostic Score (mGPS) 2 were independently predictive (c-index
0.708). For regional recurrence: primary OSCC of hard palate/maxilla, pN1, pN3b and
non-cohesive invasive front were independently predictive (c-index 0.738). For distant
recurrence: pN1 pN2a, pN2b, pN2c, pN3b and tumour DOI >10mm were independently predictive
(c-index 0.809). For recurrence at any site; pN1, pN2a, pN2b, pN2c, pN3b, tumour DOI
>5-10mm, tumour DOI >10mm, mGPS 2 and involved surgical margins were independently
predictive (c-index 0.750).
Recurrence events after curative treatment for OSCC are relatively predictable on
the basis of available clinicopathological characteristics. It seems likely that trials
of adjuvant systemic therapy in high-risk OSCC will continue to be designed with emerging
therapeutic agents. Trials should focus on those of highest risk of relapse and this
study adds clarity to the selection of the correct target population.