MTA1 as negative prognostic marker in vulvar carcinoma

PURPOSE: Vulvar cancer is the fourth most common malignancy of the female genital tract after endometrial, ovarian, and cervical carcinoma and affects mainly elderly women. In 2020 there were registered more than 17,000 deaths worldwide related to vulvar carcinoma. Data about target-based therapies and predictive biomarkers for vulva carcinomas are rare so far. The metastasis-associated gene MTA1 is a transcriptional repressor with a potential effect on cancer. Expression of MTA1 was found to be significantly enhanced in gynecological malignancies as breast or ovarian cancer tissues with advanced cancer stages and higher FIGO grading, indicating an important role of MTA1 in the progression of those tumor entities. Due to the lack of information around MTA1 and its significance regarding vulvar carcinoma, this study focuses on the expression of MTA1 in vulvar carcinoma and its correlation to clinicopathological characteristics and prognosis. METHODS: A total of 157 paraffin-embedded vulvar cancer tissues were immunohistochemically stained and examined for MTA1 expression by using the immunoreactive score. Subsequently, the values were correlated with clinicopathological parameters. RESULTS: MTA1 was found to be expressed in 94% of the patients in the cytoplasm and 91% in the nucleus. Cytoplasmatic expression of MTA1 was significantly increased in non-keratinizing squamous cell carcinoma and in vulvar carcinoma of the condylomatous type, compared to keratinizing squamous cell carcinoma and vulvar carcinoma of the verrucous type. High MTA1 expression in the nucleus was associated with advanced tumor size as well as higher FIGO grading. In addition, p16 negative vulvar carcinomas showed a higher nuclear expression of MTA1 compared to p16 positive vulvar carcinomas. Suprisingly, Kaplan–Meier analysis showed a significantly lower disease-free survival in tumor samples without a nuclear expression of MTA1. CONCLUSIONS: MTA1 was identified as a negative prognostic marker for vulvar carcinoma associated with advanced tumor stage and FIGO grading. A possible explanation could be that the antibody used for this study does not bind to a possible mutation in the C terminal region of MTA leading to negative immunohistochemical staining and this can be correlated with early recurrence in patients with vulvar carcinoma.