MKI67 and neuroendocrine carcinoma: Higher Ki‐67 levels (OR 1.05, 95% CI 1.03–1.07, p < 0.001), NEC histology (OR 7.84, 95% CI 2.84–24.61, p < 0.001), and Grade 3 tumors (OR 9.56, 95% CI 3.07–36.96, p < 0.001) were also significantly associated with mortality.