Nab-paclitaxel Versus Topotecan As Second-Line Treatment for Patients With Extensive Stage Small Cell Lung Cancer

Inclusion Criteria:

1.18 to 75years, male or female; 2.Histological or pathological diagnosis of small cell lung caner; 3.Progression or relapse after first-line chemotherapy, extensive disease; 4.ECOG performance status of 0-2; 5.Life expectancy of 3 months or more; 6.Patient must be accessible for treatment and follow-up; 7.For women of child-bearing age, the pregnancy test results (serum or urine) within 72 hours before enrolment must be negative. They will take appropriate methods for contraception during the study; 8.Signed informed consent.

Exclusion Criteria:

1. symptomatic brain metastases;
2. Uncontrolled serious medical conditions that, in the opinion of the investigator, would affect the ability of the subject to receive the study regimen, such as concomitant serious medical conditions, including severe heart disease, cerebrovascular disease, uncontrolled diabetes mellitus, uncontrolled hypertension, uncontrolled infection, active peptic ulcer, etc.;
3. Have dementia, altered mental state or any mental illness that would prevent understanding or informed consent or fill out questionnaires;
4. Received any investigational drug within 30 days of the planned first dose of this study treatment.
5. Prior Grade ≥ 2 peripheral neuropathy(according to (NCI CTCAE), version 5.0);
6. Known to be hypersensitive, highly sensitive, or intolerant to study-related medications or their excipients;
7. Have malignant tumors in the past 5 years, except for clinically cured basal cell or squamous cell skin cancer, local prostate cancer after radical operation, and ductal carcinoma in situ after radical operation;
8. Bone marrow function: Neutrophils \< 1.5×109/L, platelets \< 100×109/L, hemoglobin \< 90 g/L; Hepatic and renal function: Serum creatinine \> 1.5×ULN; AST and ALT \> 2.5×ULN or \> 5×ULN in the presence of hepatic metastasis; Total bilirubin \>1.5×ULN;
9. Patients need other anti-tumor drugs;
10. Known HIV, hepatitis B/C virus positive ;
11. The researchers considered the patients who were not suitable for enrollment.