Comparing clinicopathological features and prognosis of primary pulmonary invasive mucinous adenocarcinoma based on computed tomography findings

OBJECTIVE: To evaluate the relationship between clinicopathologic characteristics and prognosis in patients with invasive mucinous adenocarcinoma (IMA) of the lung. METHODS: A total of 68 patients who underwent surgical resection for primary lung IMA were reviewed during the period of 2009 and 2017. Tumors were classified as solitary-type or pneumonic-type according to the computed tomography (CT) findings. Cox proportional hazards model was used to assess the effects of clinicopathological characteristics on univariate and multivariable analyses of disease-free survival (DFS). RESULTS: Solitary-type was found in 54 patients, while pneumonic-type was found in 14 patients. The patients' age varied between 56 and 68 years (patients' median age was 61 years). Besides, 50 patients had T1/T2 tumor stage (73.5%). Compared with solitary-type, higher T stage, N stage, and pathological stage (P < 0.001) were found in pneumonic-type. Moreover, the survival analysis showed that the pneumonic-type had a significantly poorer DFS compared with solitary-type (P = 0.004). Univariate analysis showed that pneumonic pattern on CT scan, T stage, pathologic stage, and thyroid transcription factor-1 (TTF-1) were significant predictive factors of survival (P = 0.011, 0.014, 0.013, 0.029, respectively). Multivariate analysis further indicated that pneumonic-type was the only independent prognostic factor for poor survival [hazard ratio (HR) = 6.764, 95% confidence interval (CI): 1.563-29.269, P = 0.011]. CONCLUSIONS: Based on CT findings, the solitary-type IMA is associated with a lower stage and better prognosis compared with the pneumonic-type IMA.