ABSTRACT
PURPOSE: To quantify the myofibroblasts in the tumor stroma of colorectal carcinomas using immunostaining with anti smooth muscle actin (SMA) as a marker for myofibroblasts. METHODS: The study was carried out on 46 surgically resected primary colorectal adenocarcinomas from the archive of the Centre for Pathology and Forensic Medicine of the Military Medical Academy in Belgrade, from 2008-2010. All samples were analysed by the scientific software "Image J". Myofibroblasts were visualized using anti-SMA antibody and quantified in order to predict tumor capacity for invasion and metastasis. Receiver Operator Characteristic (ROC) analysis was carried out, and a score of 5.72 was suggested as the score of SMA that is significant for the clinical outcome with lymph node involvement. RESULTS: Overall, the average SMA was 7.29 (range 0.39-16.84). Further analysis showed correlation of SMA with clinical and pathological tumor characteristics, i.e. SMA was significantly higher in tumors with more advanced stage, higher histological grade, greater amount of desmoplasia, smaller amount of inflammatory infiltrate, lymph node involvement, vascular and perineural invasion and infiltrative tumor growth. CONCLUSION: Our study suggests that it is possible to define the tumor capacity for invasion and metastasis by quantifying the myofibroblasts in the tumor stroma of colorectal carcinomas. Therefore, further investigations are needed to determine targeted therapies to signaling pathways in myofibroblasts.
