Prognostic significance of polo-like kinase (PLK) expression in squamous cell carcinomas of the head and neck

Previously, we demonstrated that the mammalian polo-like kinase (PLK), whic h participates in the regulation of the cell cycle, is a novel marker of ce llular proliferation. Because current prognostic tools for the evaluation o f patients with head and neck squamous cell canter (HNSCC) need to be impro ved, we analyzed 89 patients and found elevated PLK expression in most tumo rs, Nodal stage as a crucial prognostic factor in HNSCC also correlated to PLK transcript levels (P = 0.0043), A Kaplan-Meier analysis showed that HNS CC patients with moderate I versus high PLK expression survived significant ly longer (5-year survival rates, 43% versus 12%; P = 0.0047). Interestingl y, a combination of nodal stage and PLK expression contributed to discrimin ate patients with a better prognosis in the pN(0/1) and pN(2/3) groups, whi ch could improve the definition of a suitable therapy.