Ki-67, CD105, and α-smooth muscle actin expression in oral squamous cell carcinoma corresponds with different forms of tobacco consumption habits

Background: Association with variety of etiological agents is one of the characteristic features of oral squamous cell carcinoma (OSCC). We hypothesized the existence of tobacco consumption habit-based heterogeneity in the immunohistochemical expression of carcinogenesis relevant molecular markers in OSCC. Hence, the present study was conducted to investigate the carcinogenesis relevant three commonly expressed markers (Ki-67, CD105, and α-smooth muscle acting [SMA]) in various forms of tobacco consumption habits in OSCC patients. Materials and Methods: A total of 217 patients of OSCC were included in the study, and based on the habit, they were broadly categorized into tobacco lime (TL), TL and areca nut (TLAN), and areca nut (AN). Further, categorization was done on the basis of absence or presence of additional habit of smoking. Immunohistochemistry (IHC) was performed using Ki-67, CD105, and α-SMA markers on formalin-fixed paraffin-embedded tissues. Results: TLAN (62.21%) was the most common habit noted in OSCC patient followed by TL (20.73%) and AN (15.20%). The additional habit of smoking was observed in 31.11% and 25.92% of TL and TLAN habits of OSCC patients, respectively. All the three markers (Ki-67, CD105, and α-SMA) showed statistically significant differences in the habit group such as TL, TLAN, and AN (P < 0.001). Although the expression of all the three markers was increased in TL as compared with TLAN, differences were not statistically significant. When these markers were compared in with and without smoking category, only TLAN with smoking and TLAN without smoking showed statistically significant differences in the expression of all three markers. Conclusions: Ki-67 CD105 and α-SMA immunohistochemical expression in OSCC corresponds with different forms of tobacco consumption habits. Habit-related unique carcinogenesis events are reflected at IHC level thus providing proof of concept for future studies.