Study on Clinicopathological Features and Prognostic Factors of Multifocal Lung Cancer

  Objective  To analyze the clinicopathological characteristics and prognostic factors of multifocal lung cancer (MFLC) patients.

  Methods  From January 2012 to January 2018, 187 MFLC patients whose largest lesion diameter was ≤4 cm and without lymphatic involvement or systemic metastases, were retrospectively reviewed. All the patients received surgical treatment. The Kaplan-Meier method was used for survival analysis, and a multivariable Cox proportional hazards regression model was used to assess the independent prognostic factors.

  Results  Among 187 cases, 173 were simultaneous MFLC (SMFLC) and 14 were metachronous MFLC (MMFLC). The 5-year disease-free survival (DFS) and overall survival (OS) rates of this group MFLC patients were 63.5% and 89.1%, respectively. In the SMFLC group, according to the American College of Chest Physicians (ACCP) guidelines (3^rd edition), 133 patients were defined as synchronous multiple primary lung cancer (SMPLC) while 40 patients had intrapulmonary metastases, there was no statistical difference in DFS between the two subgroups (P=0.531). EGFR mutation status (same mutations, different mutations, all wild-type) had no statistically significant effect on DFS of SMFLC (P=0.388). Univariate and multivariate regression analysis revealed that radiographic feature of solid nodules (hazard ratio (HR)=7.4, P=0.008) and MMFLC (HR=5.6, P=0.001) were independent risk factors for poor prognosis.

  Conclusion  MFLC can achieve a favorable prognosis with early surgical treatment. Tumor density and metachronous lesions are two important prognostic predictors.