Abstract / Summary
Objective: To investigate the pattern of lymph node metastasis (LNM) in multiple primary lung cancers (MPLC) and related influencing factors. Methods: We retrospectively analyzed the lymph node status of 215 patients with MPLC diagnosed by pathological and imaging examinations at Guangdong Jiangmen Central Hospital between January 2015 and December 2021, evaluating the relationship between age, smoking history, tumor markers, primary lesion diameter (PLD), pathological type, lesion location and LNM. Results: There were no statistically significant differences in age, smoking history, Cyfra 21– 1, tumor location, or the number of lesions between groups regarding LNM. Binary logistic regression analysis demonstrated that CEA (OR=0.129, 95% CI=0.039– 0.426), PLD (OR=0.377, 95% CI=0.207– 0.689), and pathological type (OR=1.303, 95% CI=1.019– 1.665) were independent risk factors. ROC analysis demonstrated that CEA and PLD could serve as potential predictive indicators for LNM, but a comprehensive model integrating multiple risk factors provided higher clinical predictive value. The LNM rate was significantly higher in patients with CEA > 5ng/mL than those with CEA ≤ 5ng/mL ( P < 0.05) and was associated with a poorer prognosis. LNM rates and prognosis varied across pathological subtypes ( P < 0.05), with higher incidences observed in Solid Predominant Adenocarcinoma (SPA), Micropapillary Predominant Adenocarcinoma (MPA), and Acinar Predominant Adenocarcinoma (ACI), while no LNM occurred in Papillary Predominant Adenocarcinoma (PAP), Lepidic Predominant Adenocarcinoma (LPA), or Minimally Invasive Adenocarcinoma (MIA). The incidence of LNM is positively correlated with prognosis. The LNM rate was positively correlated with PLD. Conclusion: LNM in MPLC is associated with CEA, PLD and pathological type. Systematic lymph node dissection may be considered appropriate when PLD > 20mm, CEA > 5ng/mL, or when the tumor is SPA or MPA, whereas systematic lymph node sampling may be considered for ACI and other pathological types. These findings provide a preliminary framework that requires prospective validation. Keywords: lung cancer, multiple primary lung cancer, lymph node metastasis