Correlation between CT Features and Patient's Prognosis of Multiple Primary Lung Cancer

Objective: To study the clinical, pathological and CT features of patients with multiple primary lung cancer (MPLC), analyze its prognosis and survival related factors, and provide theoretical basis for its clinical diagnosis, treatment and prognosis evaluation. Methods: A total of 93 MPLC patients diagnosed in our hospital from 2009-01-01 to 2014-12-31 with at least 3 years of follow-up data were reviewed. The clinical, pathological and CT data of the patients were analyzed, and survival analysis was performed. Results: Among the 93 patients, 86(92.5%) had synchronous multiple primary lung cancer and 7(7.5%) had metachronous multiple primary lung cancer. There were 47 males (50.5%) and 46 females (49.5%) with ages from 39 to 79 years ($\tilde x$=58 years). Of the 93 patients, 33 cases (35.5%) had a history of smoking; 22 cases of emphysema (23.7%) 62 cases (66.7%) were in stageⅠ, 12 cases (12.9%) in stageⅡ, 15 cases (16.1%) in stage Ⅲ, 4 cases (4.3%) in stage Ⅳ. A total of 205 primary tumor lesions were found in 93 patients, mainly adenocarcinoma (94.2%), with diameters of 0.4~8.3cm ($\tilde x$=1.9cm). CT mainly manifested as double primary lung cancer (81.7%), 48 cases (51.6%) showed solid nodules/masses with GGN, and 30 cases (32.3%) were multiple GGN. Lobulation were found in 72.2% cases, speculation sign in 57.6% cases, vascular bundle sign in 56.1% cases, and pleural indentation in 61.0% cases. The 3-year overall survival rate after surgery was 94.6% and the disease free survival rate was 84.9%. Smoking history (P=0.016), maximum tumor diameter (P=0.036), pleural indentation (P=0.045) and bronchial truncation sign (P=0.024) were independent risk factors for disease-free survival of MPLC patients. Conclusion: Adenocarcinoma was the main pathological type among MPLC. The largest lesion had the malignant characteristics of primary lung cancer, particularly the presence of single or multiple GGN. The overall prognosis of MPLC is good. Smoking history, tumor size, pleural indentation and bronchial truncation sign are independent risk factors influencing the prognosis of patients. Early diagnosis and surgical treatment may achieve better prognosis.