Available studies suggest that regional anesthesia-analgesia may decrease the occurrence of recurrence/metastasis in patients after cancer surgery. However, evidences from prospective studies are still lacking. The purpose of this randomized controlled trial is to investigate the effect of epidural anesthesia-analgesia on recurrence-free survival in patients undergoing lung cancer surgery.

Lung cancer is increasing and is the leading cause of cancer death. Surgical resection is the mainstay of treatment for early stage non-small cell lung cancer. However, long-term survival after lung cancer surgery is far from optimal, and cancer recurrence or metastasis is the main reason leading to cancer death in these patients.

The development of cancer recurrence/metastasis largely depends on the balance between tumor-promoting factors and immune function of the body. Studies showed that surgical manipulation releases cancer cells into circulation; and stress response induced by surgery inhibits the cell-mediated immunity. In addition, volatile anesthetics and opioids may also aggravate immunosuppression and potentially worsen long-term outcome. On the other hand, regional anesthesia can blunt surgical stress and reduce anesthetic consumption. These effects may help to preserve immune function and reduce recurrence/metastasis. However, existing evidences are insufficient to draw conclusion in this topic.

The purpose of this randomized controlled trial is to test the hypothesize that regional anesthesia-analgesia may reduce recurrence/metastasis and improve long-term survival in patients after lung cancer surgery.

Inclusion Criteria:

1. Adult patients (aged 18-80 years);
2. Clinically diagnosed as primary non-small cell lung cancer of stage IA to IIIA, and scheduled for radical surgery;
3. Agreed to receive patient-controlled analgesia after surgery.

Exclusion Criteria:

1. Distant metastasis, malignant tumor in other organs, or chemo-/radiotherapy or other anti-cancer therapy before surgery;
2. Comorbid with autoimmune diseases, or glucocorticoid/immunosuppressant therapy within 1 year;
3. History of schizophrenia, epilepsy or Parkinson disease, or unable to complete preoperative assessment due to severe dementia, language barrier, or end-stage disease;
4. Severe hepatic disease (Child-Pugh classification C), renal failure (serum creatinine >442 umol/L or receiving renal replacement therapy), or American Society of Anesthesiologists classification IV or higher;
5. History of anesthesia and/or surgery within 1 year;
6. Contraindications to epidural anesthesia, including spinal deformity, coagulation dysfunction, local infection, and history of spinal trauma/surgery;
7. Allergic to any medications used during the study.