Study of Anlotinib as the Maintenance Therapy for Extensive-stage Small Cell Lung Cancer

Inclusion Criteria:

* Histologic or cytologic diagnosis of small cell lung caner
* Advanced small cell lung cancer who had no prior cisplatin-based chemotherapy or radiotherapy,at least one measurable lesion (by RECIST1.1)
* Males or females between 18 Years to 75 Years.
* Performance status of 0～2 on the ECOG criteria.
* Main organs function is normal
* Expected survival is above three months.
* with asymptomatic brain metastases.
* At least one measurable lung tumor lesion (according to RECIST criteria, the application of conventional technology, diameter length of the lesion \>= 20mm or spiral CT \>=10mm).
* Adequate hematologic (Leukocyte count \>= 4.0×109/L, neutrophil count\>=2.0×109/L, hemoglobin\>=95g/L, platelets\>=100×109/L), hepatic function (aspartate transaminase (AST) \& alanine transaminase(ALT)

  =\<upper normal limit(UNL) x1.5, bilirubin level =\< UNL x 1.5).
* Patient can take oral medicine.
* Patients have the ability to understand and voluntarily sign the informed consent, and allow adequate follow-up.

Exclusion Criteria:

* History of cardiovascular disease: congestive heart failure (CHF) \> New York Heart Association (NYHA) II, active coronary artery disease(patients with myocardial infarction six months ago can be recruited), arrhythmias need to be treated (allow taking beta blockers or digoxin).
* Serious clinical infection (\> NCI-CTCAE version 4.0 ,infection standard II).
* Patients with epilepsy who need to take medicine (such as steroids or anti epilepsy agents).
* The patients had accepted allogeneic organ transplantation.
* Bleeding tendency or coagulation disorders.
* patients who need renal dialysis.
* suffered from other tumor within 5 years( Except: cervical carcinoma in situ, cured basal cell carcinoma, cured bladder epithelial tumor).
* uncontrolled hypertension (systolic pressure\>150 mmHg , or diastolic pressure\> 90 mmHg).
* thrombosis or embolism(cerebrovascular accidents including transient ischemic attack within the last 6 months).
* pulmonary hemorrhage \>CTCAE grade 2 within 4 weeks before first use of drugs.
* Other organ hemorrhage \>CTCAE grade 3 within 4 weeks before first use of drugs.
* severe uncured wounds, ulcers or fracture.
* uncured dehydration.
* Drugs abuse and medical, psychological or social conditions may interfere with the patient's participation in research or the results of the evaluation effect.
* Patients are allergic to drugs used in research.
* Factors influencing the safety and compliance of patients.
* Inability to comply with protocol or study procedures.
* Pregnant or breast-feeding.
* The researcher believe that the Patient is not suitable to participate in the study.