PIK3CA and neoplasm of hypopharynx: According to these data, the risk for nodal metastasis was estimated to be 5.8-fold higher in patients with hypopharyngeal tumors (HR = 5.82; CI 95% 1.32-25.64; P = 0.02), 4.7-fold higher in patients with positive PTEN expression (HR = 4.7; CI 95% 1.17-18.78; P = 0.028), 13.65-fold higher in patients without PIK3CA (H1047R) mutation (HR = 13.65; CI 95% 1.36-137.38; P = 0.026), and remarkably 49.6-fold higher in patients with negative p-S6 (Ser235/236) tumors (HR = 49.61; CI 95% 3.43-716.11; P = 0.004).