Weaker staining of cathepsin K in the invasive front correlates with shorter recurrence-free survival and increased mortality.

<p>Survival analyses show a shorter overall recurrence-free interval in patients with a lower cathepsin K staining gradient (cat-K gradient −) compared with those with either higher (cat-K gradient +) or no gradient (gradient 0) of cathepsin K staining intensities in the invasive front compared with the upper part of the tumor (A), especially seen in patients with stage 1 or 2 OTSCC (B). Disease-specific survival of patients with stages 1 and 2 OTSCC tumors was better in patients with a positive or no gradient of cathepsin K staining compared with those with a negative gradient (C).