METHODS: Primary tumor tissue microarrays (TMAs) were constructed and sections used for immunohistochemical analysis of epidermal growth factor receptor, ErbB-2, c-kit, cyclooxygenase-2, survivin, bcl-2, cyclin D1, cyclin B1, metalloproteinase (MMP)-2, and MMP-9. Univariate and multivariate analyses and unsupervised hierarchical clustering analysis of clinical pathologic and immunostaining data were performed.
RESULTS: Bcl-2 (p < 0.0001) and cyclin D1 (p = 0.015) were more highly expressed in squamous cell carcinoma (SCC), whereas MMP-2 (p = 0.009), MMP-9 (p = 0.005), and survivin (p = 0.032) had increased expression in other histologic subtypes. In univariate analysis, SCC histology and cyclin D1 expressions were favorable prognostic factors (p = 0.015 and p < 0.0001, respectively); by contrast, MMP-9 expression was associated with worse prognosis (p = 0.042). In multivariate analysis, cyclin D1 was the only positive prognostic factor (p < 0.0001). Unsupervised hierarchical clustering analysis of TMA immunostaining data identified five distinct clusters. They formed two subsets of patients with better (clusters 1 and 2) and worse (clusters 3, 4, and 5) prognoses, and median survival of 51 and 10 months, respectively (p < 0.0001). The better prognosis subset mainly comprised patients with SCC (80%).
CONCLUSIONS: Hierarchical clustering of TMA immunostaining data using a limited set of markers identifies patients with stage IIIA pN2 NSCLC at high risk of recurrence, who may benefit from more aggressive treatment.