Surufatinib Combined With Tislelizumab in Advanced Lung Cancer With Neuroendocrine Differentiation

Inclusion Criteria: * Histopathologically confirmed locally advanced or metastatic unresectable lung cancer (IIIB-IV) with an abnormal NED or NE phenotype (without neuroendocrine morphologic features and positive immunohistochemical expression of at least one neuroendocrine marker (CD56, CgA, Syn)); * Have at least one measurable lesion according to RECIST v1.1; * ECOG performance status: 0-1; * Patients who were deemed by the investigator to be eligible for first-line single-agent immunotherapy or who progressed on first-line standard therapy; * Urine protein \< ++ . If Urine protein ≥ ++ ,the amount of urine protein in 24 hours ≤1.0g; * Expected survival time \> 3 months; Exclusion Criteria: * Pulmonary neuroendocrine tumors (typical carcinoid, atypical carcinoid, small cell carcinoma, large cell neuroendocrine carcinoma); * Prior anti-VEGF/VEGFR-targeted therapy or anti-PD (L)1 antibody; * Have uncontrolled hypertension, defined as systolic blood pressure \>150 mmHg or diastolic blood pressure \>90 mm Hg, while under anti-hypertension treatment; * Patients with active ulcer, intestinal perforation and intestinal obstruction; * With active bleeding or bleeding tendency; * Severe history of cardiovascular and cerebrovascular diseases; * Other malignancies diagnosed within the previous 5 years, except basal cell carcinoma or cervical carcinoma in situ after radical resection.