Clinical difference between solitary and multiple pulmonary adenocarcinoma nodules

Objective: we compared and analyzed the imaging features, tumor markers, pathological immunohistochemistry, and lymph node metastasis rates of solitary and multiple lung adenocarcinoma to provide a valuable reference for clinical diagnosis and treatment. Methods: A retrospective analysis of 212 patients who underwent thoracic surgery in our hospital from 2022 to 2023, including 149 patients with a solitary lung adenocarcinoma nodule and 63 patients with multiple primary nodules. Via propensity score matching, the imaging features, tumor serological markers, pathological immunohistochemistry, and lymph node metastasis rates of the two groups were compared, and the differences in lymph node metastasis rates between solitary and multiple nodules were explored by binary logistic regression. Results: After propensity score matching, there were significant differences in the mean CT value (P = 0.001), Ki-67 expression (P < 0.001), PD-L1 expression (P = 0.002), and the lymph node metastasis rate (P = 0.030) between the two groups, but there were no significant differences in nodule type, imaging features, tumor serological marker levels, and the ALK-positive and SYN-positive rates. With lymph node metastasis as the dependent variable, solitary or multiple nodules as the categorical covariate, and the three variables were included as independent variables for binary logistic regression analysis. The probability of lymph node metastasis was 80.8% lower in patients with multiple primary lung adenocarcinoma nodules than in those with a solitary one (P = 0.042). Conclusion: Multiple primary adenocarcinoma nodules exhibit milder biological behavior than solitary adenocarcinoma nodules and carry a lower risk of lymph node metastasis.