Digital Analysis of BCL2 Expression in Laryngeal Squamous Cell Carcinoma

Background: Deregulation of apoptosis is critical regarding the development and progression of malignancies, including laryngeal squamous cell carcinoma (LSCC). B-Cell lymphoma 2 (BCL2) (gene locus:18q21.33), located on the outer mitochondrial membrane, acts mainly as an anti-apoptotic factor suppressing and blocking apoptotic signal transduction.

Materials and methods: Fifty (n=50) primary LSCC tissue sections were used. Immunohistochemistry and digital image analysis were implemented for evaluating BCL2 protein expression levels.

Results: High BCL2 protein expression levels were observed in 21/50 (42%) LSCC tissue sections, whereas the remaining cases (n=29) demonstrated a low expression. Overall, BCL2 expression was associated with grade (p=0.046) and anatomical region of the examined malignancies (transglottic, p=0.047). Interestingly, high BCL2 expression levels were strongly associated with radiotherapy-based only regimens (p=0.01) in corresponding patients.

Conclusion: BCL2 overexpression was found to be correlated with an aggressive phenotype (advanced grade of differentiation) in LSCC, also demonstrating a potential selective anatomic localization (transglotic region). Additionally, BCL2 overexpression appears to be a negative regulator for successful radiotherapy implementation by reducing the apoptotic process in patients.