MKI67 and neuroendocrine carcinoma: The median OS following first-line palliative therapy was 18.7 months (95% CI 13.2–24.7 months), with a statistically significant difference (p < 0.001) between NET G3 (median OS of 43.9 months, 95% CI 24.7–NA months) and NEC (12.7 months, 95% CI 8.5–16.4 months) and between high (12.7 months, 95% CI 7.9–17.8 months) and low Ki-67 index (39.0 months, 95% CI 20.4–88.6 months).