Tumour cells at the deep margin are characterised by poorer differentiation, greater cellular dissociation, and higher probabilities of formation of tumour satellites (separate islands of tumour cells with intervening normal tissue at the tumour and non-tumour interface). Epithelial mesenchymal transition (EMT), indicative of change of phenotype from epithelial to mesenchymal, is indicated by loss of epithelial adhesion (that contributes to tumour satellite formation) and acquisition of mesenchymal phenotype (that is beneficial for spread of tumour satellites). This transition may aid in the progression and invasion of tumour cells into the surrounding connective tissue and therefore may also be associated with increased incidence of lymph node metastasis and recurrence in patients with Oral Squamous Cell Carcinoma.
To immunohistochemically assess and correlate tumour satellite distance (TSD) and EMT-related biomarkers (E-cadherin and Vimentin) with prognosis of OSCC.
Micrometric (measurement of TSD) and Immunohistochemical assessment of tumour satellites using E-cadherin and Vimentin was done in 40 archival cases of OSCC at the tumour proper, invasive tumour front and in normal oral mucosa. Â Expressions were then correlated with clinicopathological parameters like nodal metastasis, clinical staging, recurrence of tumour and survival in 3 year follow-up period.
There was significantly higher concomitant reduction of E-cadherin and gain in Vimentin at the invasive tumour front. Cases with higher TSD showed increased vimentin and decreased E-Cadherin, besides exhibiting lymph node metastasis, recurrence and decreased three-year post-operative survival. Correlation of TSD and EMT parameters with prognosticators was done using independent t test and Pearson’s correlation test.
Cancer cells located in tumour satellites further away from the overlying epithelium underwent EMT, which is associated with enhanced metastatic potential and can be used as a good prognostic tool.