Effect of selective lymph node dissection on immune function in patients with T1 stage non-small cell lung cancer: a randomized controlled trial

Background: Many lymph nodes resected from early-stage non-small cell lung cancer (NSCLC) patients haven't metastasis. Selective lymph node dissection (SLND) can reduce surgical trauma by retaining non-metastatic lymph nodes, we aimed to investigate whether SLND could reduce immune impairment compared with systematic lymph node dissection.

Methods: According to the selection criteria, patients with no metastasis in hilar and regional lymph nodes were selected as the research subjects. The patients were randomly divided into 2 groups: the SLND group (Group SD) and the systematic lymph node dissection group (Group CD). At 24 hours before surgery and on the 1st and 3rd postoperative days (POD), fasting venous blood was sampled to detect cytokine indicators [interleukin-6 (IL-6), C-reactive protein (CRP)], cellular immune indicators [lymphocytes, natural killer cells (NK cells), CD4⁺, CD8⁺, CD4⁺/CD8⁺], and humoral immune indicators (IgG, IgA, IgM). At the same time, clinically indicators of the patients were recorded. All indicators between the 2 groups were compared.

Results: The comparison of clinical indicators between the two groups showed that SLND is more conducive to patients' rapid recovery after surgery. CRP and IL-6 levels in Group CD were significantly higher than those in Group SD after surgery (P<0.05). There were no statistical differences between the 2 groups in the proportions of lymphocytes and NK cells after surgery (P>0.05). The proportions of CD4⁺ cells and CD4⁺/CD8⁺ in Group CD were significantly lower than those in Group SD at POD1 (P<0.05). The proportion of CD8⁺ cells was significantly higher in Group CD than in Group SD at POD3 (P<0.05). There were no significant differences in IgG, IgA, and IgM levels between the 2 groups at the same point in time (P>0.05).

Conclusions: Compared with systematic lymph node dissection, SLND has the following advantages: (I) it is more conducive to patients' rapid recovery after surgery; (II) it can reduce the body's acute inflammatory response and non-specific immune damage; (III) it can reduce the damage to cellular immune function caused by surgery.

Trial registration: Chinese Clinical Trial Registry ChiCTR2100045893.