Vitamin C and Tyrosine Kinase Inhibitor in Lung Cancer Patients With Epidermal Growth Factor Receptor Mutations

Inclusion Criteria: * Primary non-small cell lung cancer (adenocarcinoma) with EGFR mutations on exons 19 and 21. * 18 years old to 75 years old. * During the trial, patients were prescribed TKI drugs(received initial treatment within 2 months, or change medication within 2 months) and did not receive chemotherapy or radiotherapy at the same time. * Eastern Cooperative Oncology Group (ECOG) performance status are 0 to 2. * Expected survival over 3 months. * Household registration is Guangdong Province. Exclusion Criteria: * Co-morbid conditions that affect survival: end stage congestive heart failure, unstable angina, myocardial infarction (within the past 6 weeks), and uncontrolled blood sugars of greater than 300 mg/dL, known chronic active hepatitis or cirrhosis. * Glucose-6-phosphate dehydrogenase deficiency (G6PD) (a relative contraindication). * Patients who are allergic to vitamin C. * Patients with HIV and other infectious diseases. * Patients who are taking anticoagulants and have coagulopathy; * Combine dysfunction of important organs such as heart, lung, liver and kidney; * Patients with impaired renal function (serum creatinine content \> 1.2 mg/dL) * Compromised liver function with evidence of Serum total bilirubin content, Serum alanine aminotransferase(ALT) and aspartate transaminase(AST)\> 2 times normal reference value. * Pregnant or lactating female. * Smoking and alcohol abuse patients; * Anti-infective treatment is required for systemic or localized serious infections; * Patients with hyperuricacidemia (normal: 91-456 μmol / 24h (8-40mg / 24h)); * Wilson's disease. * Evidence of significant psychiatric disorder by history or examination that would prevent completion of the study or preclude informed consent. * Any condition that impairs the patients' ability to swallow, which impairs drug absorption or drug kinetic parameters, including any kind of gastrointestinal resection or surgery; * History of surgery of visceral organs within 6 weeks before the study.