Objective: To examine the expression of candidate markers for micrometastasis.
Study design: Cross-sectional analysis of subjects with oral cavity carcinomas who underwent sentinel lymph node biopsy (SLNB) and subsequent immunohistochemical (IHC) analysis.
Subjects and methods: Two groups were identified based on SLNB status: negative SLNB (19/30) and positive SLNB (11/30). Specimens underwent IHC using conjugated monoclonal antibodies for membrane type-1 matrix metalloproteinase (MT1-MMP), CD44, focal adhesion kinase-1, and E-cadherin. Staining results were evaluated to determine if a particular marker was associated with SLNB status or other histopathologic prognosticators.
Results: For MT1-MMP, 21 percent (3/14) of evaluable specimens stained positively in the SLNB(-) group and 67 percent (4/6) stained positively in the SLNB(+) group (P=0.12). No statistically significant association was seen between any marker's staining pattern and SLNB status alone. When MT1-MMP staining was evaluated in tumors with SLNB(+) or perineural invasion (PNI) present on histopathology, six of nine specimens (67%) stained positively for MT1-MMP, vs one of 11 (9%) in specimens lacking either negative prognosticator (P=0.016, RR=7.33).
Conclusion: Preliminary results suggest that MT1-MMP positivity in primary tumor specimens may identify aggressive tumor types, evidenced by the presence of micrometastasis or PNI.