ALK Protein Expression Patterns in Squamous Cell Carcinoma of the Oral Cavity

Background: Oral squamous cell carcinoma (OSCC) is characterized by a broad spectrum of genomic imbalances, including gross chromosomal (polysomy/aneuploidy) ones as well as specific gene alterations. Aberrant expression of anaplastic lymphoma kinase (ALK) seems to be a useful molecular marker for discriminating patients based on genetic signatures in a variety of solid malignancies, such as lung carcinoma. Our aim was to analyze ALK protein expression patterns in a series of OSCCs.

Materials and methods: Fifty (n=50) OSCC tissue sections were analyzed by implementing an ALK-based immunohistochemistry protocol. Digital image analysis was performed for measuring the corresponding protein expression levels.

Results: ALK overexpression was observed in 14/50 (28%) OSCC tissue sections, whereas the rest 36/50 (72%) demonstrated low expression levels. ALK expression was negatively associated with grade (p=0.027) and stage (p=0.0028) of the examined cases.

Conclusion: Abnormal ALK expression in subsets of patients with OSCC seems to be related to an aggressive phenotype (advanced stage/progressive dedifferentiation). ALK protein overexpression may be used as a significant marker for applying targeted therapeutic regimens.