TP53 and in situ carcinoma: The absence of p53 expression was associated with warty tumors (p = 0.001), presence of carcinoma in situ (p = 0.0.41), HPV-associated histology (p < 0.0001), absence of perineural invasion (p = 0.036), koilocytosis (p = 0.002), and tumors with an expansive growth pattern (p = 0.002).