Role of microscopic spread beyond gross disease as an adverse prognostic factor in oral squamous cell carcinoma

Despite meticulous surgery and proper adjuvant treatment, outcome of oral squamous cell carcinoma remains unpredictable. This shows that there may be other factors which should be considered while prognosticating these patients. Many a times there is spread of disease beyond the gross margin which can alter the margin status. We hypothesized that microscopic spread beyond gross disease may portend a poor prognosis.

This is a retrospective study of prospectively collected data of 1025 treatment naïve oral squamous cell carcinoma patients. All patients underwent surgery from January 2012 to October 2013, this was followed by appropriate adjuvant treatment. Demographic and histopathological details were noted from the electronic medical records.

Microscopic spread beyond gross disease (MSGD) is associated with higher incidence of nodal positivity (p < 0.046), peri-neural invasion (p < 0.001), thicker tumours (p < 0.024) and poor differentiation (p < 0.060). The overall survival in patients with MSGD was 32.45 months vs. 37.5 months in patients without MSGD (p < 0.002).

Tumours with MSGD tend to have a higher incidence of nodal metastasis, PNI and thicker tumours. Presence of MSGD was associated with lower overall survival as compared to those without.