Odontogenic Ameloblast-Associated Protein Expression in Oral Squamous Cell Carcinoma of the Tongue

Odontogenic Ameloblast-Associated Protein Expression in Oral Squamous Cell Carcinoma of the Tongue DA Gerard, ER Carlson, K Slocum

Purpose:  Odontogenic ameloblast-associated protein (ODAM) has previously been described as being a prognostic marker with possible use in the diagnosis and treatment of melanoma and breast cancers¹. In particular, nuclear expression of ODAM is evidence of increased metastatic potential of melanoma and breast cancer².  ODAM  has not been described in oral squamous cell carcinomas (OSCC). This study was undertaken to determine if ODAM is expressed in OSCC of the tongue, and whether the level of expression can be correlated with cervical lymph metastases.

Patients and methods:  A cohort of oral cancer cases treated in our institution between 2007 and 2014 were accessed in our department of pathology.  This study was reviewed and approved by the Institutional Review Board at the University of Tennessee. Four micrometer  thick, formalin-fixed paraffin embedded sections for 58 non-consecutive patients with OSCC of the tongue were mounted on charged slides and stained with anti-ODAM antibody.  Slides were examined with light microscopy and scored for the presence of ODAM expression in both the cytoplasm and nucleus.

Results: Patients ranged in age from 36 to 92 years, with 32 men and 26 women. Nineteen tumors were graded as well differentiated, 35 as moderately differentiated, and 4 as poorly differentiated. Most tumors (n=39) were staged as pTlpNO, and 13 had at least 1 cervical lymph node containing metastatic cancer. Fifty-eight tumors showed ODAM  expression in the cytoplasm.  Eighteen tumors showed positive expression of ODAM in the nucleus.  Eleven of 13 patients (85%) who had a least 1 positive  lymph node also showed nuclear staining for ODAM expression.

Conclusion: The results of this preliminary study suggest a possible correlation between nuclear ODAM expression  and cervical lymph node metastases in OSCC of the tongue. ODAM may therefore serve as a biomarker for prognosis of disease in OSCC of the tongue.

1 JS Foster, LM Fish, JE Phipps et al: Odontogenic  ameloblast-associated protein (ODAM) inhibits growth and migration of human melanoma cells and elicits PTEN elevation and inactivation of Pl3K/AKT signaling. BMC Cancer 13: 227-238, 2013.

² SS Gandhi, DP Kestler, CT Bruker et al: Nuclear odontogenic ameloblast-associated  protein (ODAM) correlates with melanoma sentinel lymph node metastasis.  J Canc Therapy 4: 1283-1289, 2013.

This study was funded by Physicians Medical Education and Research Fund, UTMCK