Surgical prognosis of lung invasive mucinous and non-mucinous adenocarcinoma: propensity score matched analysis

OBJECTIVES: Invasive mucinous adenocarcinoma exhibits distinct prognostic outcomes compared to non-mucinous adenocarcinoma (ADC). This study investigated and compared the clinical outcomes and prognostic factors of invasive mucinous and non-mucinous ADC patients. METHODS: This retrospective study included patients who underwent curative surgery for ADC between 2011 and 2021. Patient characteristics were balanced using propensity score matching. Cumulative incidence was analysed to evaluate cancer recurrence incidence, and the Kaplan-Meier method was used to calculate overall survival (OS) for each group. RESULTS: A total of 6101 patients were included. After matching, the non-mucinous group and mucinous groups comprised 798 and 408 patients, respectively. The patients in the mucinous group had a lower recurrence incidence than those in the non-mucinous group (P = 0.014). The recurrence incidence in the mucinous group was between those of grades 1 (P = 0.011) and 2 (P = 0.012) and the OS rates were comparable to those of grades 2 (P = 0.6) and 3 (P = 0.2). Multivariable analysis revealed that the maximal standardized uptake value [hazard ratio (HR): 1.13, P = 0.11] and progressed pathological stages (pStage II, HR: 3.9, P = 0.028; pStage III, HR: 8.33, P = 0.038) served as adverse prognostic factors for the mucinous group. CONCLUSIONS: Patients with mucinous ADC demonstrated lower recurrence incidence and similar OS rates compared to those with non-mucinous ADC. The recurrence incidence of mucinous ADC was between those of International Association for the Study of Lung Cancer grades 1 and 2, with the OS rates comparable to those of grades 2 and 3.