ABSTRACT
Background: Increasing incidence of Squamous Cell Carcinoma (SCC) has emphasized the challenges of managing this condition. Traditional microscopic information often fails, especially when based on H & E methods. Immunohistochemistry (IHC) and molecular studies in combination with traditional histopathology may fill this gulf. Aims: The study was conducted to introduce new a grading system based on both histopathological and biological correlation of SCC. Settings and Design: A descriptive study included 180 cases of SCC of the skin (all regions of skin and oral mucosa). Cellular proliferation index (Ki‑67 and p53 expression) was studied in SCC by immunohistochemistry (IHC). This study was carried out in the Department of Pathology from January 2006 to December 2008. Methods and Material: The clinicopathological information regarding age, sex, primary tumor site, tumor size, local recurrence, distance metastasis and follow‑up status was collected for each case. Patient outcome was verified and updated through the medical records. Five micron thick (5μm) sections were cut from archival formalin fixed, paraffin embedded specimens. The first section was stained with haematoxylin and eosin (H&E) for histopathological analysis. Other sections were stained immunohistochemically with p53 and Ki‑67 and then independently scored for the expression of p53 proteins and Ki‑67 index. Results: SCC was designated low, intermediate, and high tirade grades based on the sum of point values assigned to each 4 scores of histological differentiation, staging, expression of p53 protein and Ki‑67 index. Expression of P53 was found to be related to the Ki‑67 and the scores of histology and stages of SCC. A significant correlation was found among the newly assigned grades, stages (Spearman correlation = 0.721, P value = 0.000). The grades were also significantly correlated with other prognostic factors like local invasion, lymph node and distance metastasis (Kendall’s Tau‑b = 0.394;p‑value = 0.00). Tumor recurrence was also significantly based on grades of SCC (Kendall’s Tau–b = 0.966, P value = 0.025). Conclusion: It was concluded that a new grading system is an important prognostic indicator of squamous cell carcinoma. This practical approach has potential to improve clinical evaluation of SCC in understanding the pathological as well as clinical behavior of SCC.