This trial was to explore whether intravenous vitamin C can prolong resistance time of Tyrosine Kinase Inhibitor(TKI) on lung adenocarcinoma patients with Epidermal Growth Factor Receptor(EGFR) mutations, and can benefit NSCLC patients.

The effects of vitamin C in combination with tyrosine kinase inhibitor on tumor size, tumor markers, inflammatory factor levels, quality of life, duration of resistance, progression-free survival, and overall survival time were evaluated.

This trial is a low risk treatment, and has developed the appropriate safety measures and contingency plans to ensure patients' safety in the whole process.

Patients will be followed up after the end of the trial, and follow-up observations will be performed every month during the first year. Followed every 3 months in the second year for 3 years.

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.