ALDH1 expression in primary and recurrent vulvar carcinoma.

Abstract

e17573 Background: Our aim was to evaluate ALDH1 expression as a stem cell marker in primary and recurrence vulvar squamous cell carcinoma. Methods: 27 patients aged 27-80 years with vulvar squamous cell carcinomas, together with their verified histopathological and clinical data were included in the study. All of them underwent treatment the first stage of which was surgery in National Research Centre for Oncology in 2015-2020. In 10 of them I stage of vulvar squamous cell carcinomas was diagnosed, in 13 – II stage, 4 had relapses after complex treatment and 2-10 years` remission. All paraffin-embedded samples of the primary and recurrent vulvar carcinoma were recruited. The presence of ALDH1 was detected by immunohistochemistry using murine monoclonal antibodies to ALDH1 (clone B-5 Santa Cruz Biotechnology) diluted 1:800 and Reveal Polyvalent HRP-DB Detection System. Positively stained cells were counted among all the tumor cells as well as a part of tumors positive for ALDH1 ( > 10% of cells). Statistics analysis was performed by program STATISTICA 13.0 (StatSoftInc., the USА). Results: By immunohistochemical staining, the expression of ALDH1 was observed in 5 patients with I stage of vulvar squamous cell carcinomas, in 5 patients with II stage and in all the patients with recurrence. Mean values of ALDH1 expression in patients with I stage were 14.1±4.3%, in patients with II stage – 16.0±3.6%, in patients with recurrence – 29.6±3.6%. Maximal ALDH1 accumulation was observed in tumor cells of patients with recurrence, it was 1.9 times higher than in the II stage (p = 0.03) and 2.1 times exceeded ones of the I stage (p = 0.027). All the differences were statistically significant according to Student`s t-test (p < 0.05). The was no statistically significant difference between values of the patients with I and II stages (p = 0.738), but it is noteworthy that ALDH1-expressing cells prevailed in tumor stroma especially in II stage. Conclusions: There is some discrepancy in the assessment of ALDH1 prognostic value in vulvar carcinoma patients as well as in understanding if it is related predominantly to cancer stem cells or to normal stem cells either. Our results though obtained on a few cases of vulvar squamous cell carcinomas show that ALDH1 expression in recurrent carcinomas markedly exceeds that in primary tumors and is related to tumor cells while in primary tumors is related rather to stromal cells.