Epithelial-mesenchymal transition (EMT) in vulvar cancer with and without inguinal lymph node metastases
During process of invasion cancer cells may usurp a normal embryological process, epithelial-mesenchymal transition (EMT), as a means of acquiring migratory capacity (Stewart & Mccluggage 2013). The knowledge of EMT in vulvar cancer is very limited (Rodrigues et al. 2013), especially in comparing cases with and without inguinal metastatic disease.
15 cases with and 15 cases without inguinal metastatic disease were obatiend from our vulval cancer registry. Representative tumor block was immunohistochemically satined against vimentin, p53 and cyclin D1.
An immunoreactive score (IRS) was calculated by summarizing the percent of positive stained cells and their staining intensity. Staining intensity (SI) was scores as weak, moderate and strong. The percent of positive stained tumor cells at the front of invasion was scored as 0 = 0% positive stained tumor cells, 1 = 1% positive cells, 2 = 2- < 10% positive cells,3 = 10- < 33% positive cells, 4 = 33- < 66% positive cells, 5 = 66 – 100% positive cells. The median values of IRS in the group with and without metastatic disease were compared for statistical analyses. The zonal staining comparing the front of invasion and centre of the tumor was evaluated as well. Additionally the pattern of invasion and the grade of peritumoral desmoplastic change (DSR) and peritumoral inflammatory response (PER) was compared within the cases with and without pelvic lymph node involvement.
There was a pronounced staining at the front of invasion within the tumor cells for vimentin and cyclin D1. But there were no differences in IRS when cases with and without inguinal lymph node metastases were compared. The median IRS-values were for vimentin 2.5 for pN0 versus 4 for pN+ (p = 0.87), for p53 6 for pN0 versus 6.5 for pN+ p = 0.93) and for cyclin D1 5 for pN0 versus 7 for pN+ (p > 0.05). There were no differences in the pattern of invasion (spray-like versus finger-like) between the cases with and without inguinal lymph node involvement (p = 0.1), as was for DES (p = 0.1) and PER (p = 0.28).
Conclusions: EMT occurs in vulva cancer and may be highlighted by different staining for vimentin, p53 and cyclin D1 at the front of invasion. There were no differences in EMT and peritumoral stromal remodelling as well as for tumor cell dissociation analysing cases with and without inguinal lymph node metastases.