EPIDERMAL GROWTH-FACTOR RECEPTOR IN VULVAR MALIGNANCIES AND ITS RELATIONSHIP TO METASTASIS AND PATIENT SURVIVAL

Objective. To evaluate the level of epidermal growth factor receptor ( EGF-R) expression in vulvar malignancies and to determine if a correla tion exists between EGF-R levels and metastasis or patient survival. M ethods. All patients with a diagnosis of invasive squamous cell carcin oma of the vulva who were treated at our institution with a primary ra dical vulvectomy and inguinal lymph node dissection from 1983 to 1993 were eligible for the study. Sixty-one patients with available tissue blocks of benign vulvar epithelium, the primary malignant vulvar lesio n, and groin node metastasis (when positive) were included in the stud y. Semiquantitative EGF-R expression was determined in a blinded fashi on utilizing immunohistochemical staining of appropriate tissue sample s. Survival was calculated utilizing Kaplan-Meier life table analysis based upon disease-free survival. Results. A significant increase (P < 0.001) in mean EGF-R levels was demonstrated in the primary tumor (67 %) versus benign vulvar epithelium (31%). In the 14 patients with lymp h node metastasis, the mean EGF-R level in the primary tumor was 65% v ersus 88% in the metastatic lesion (P < 0.001). The likelihood of lymp h node metastasis was elevated in those patients with a benign tissue EGF-R level greater than or equal to 40% (P < 0.03) and in those patie nts with a primary tumor EGF-R level greater than or equal to 90% (P < 0.025). Life table analysis revealed a cumulative disease-free surviv al of 45% for all patients. Disease-free survival in those patients wi th EGF-R levels greater than or equal to 90% in the primary tumor was 25%, contrasting with a disease-free survival of 54% in those patients with EGF-R levels <90% (P < 0.05). Conclusions. There is a progressiv e increase in EGF-R expression from benign vulvar epithelium to primar y malignant tissue to metastatic lesions within the same patient. Incr eased expression of EGF-R in the primary vulvar malignancy is signific antly associated with lymph node metastasis and decreased patient surv ival. Increased expression of EGF-R in histologically benign vulvar ep ithelium has a significant association with lymph node metastasis and may predict decreased patient survival. (C) 1997 Academic Press.