Research On Quantitative Management Of Invasion-Associated Risk Factors Of Lung Adenocarcinoma With Pure Ground Glass Opacity

Objective To find the invasion-associated clinical and CT risk factors of lung adenocarcinoma presenting as pure ground glass opacity nodule (pGGN) and to calculate the total risk value for the management stratification of pGGN. Methods This study consisted of 265 patients with 274 lesions pathologically confirmed lung adenocarcinoma with pGGN on CT who had undergone curative resection between January 2014 and December 2016. All clinical data and CT imaging findings and histopathologic subtypes were collected and analyzed retrospectively. All lesions were divided into preinvasive (AAH+AIS) group and invasive (MIA+ILA) group. Patient’s clinical data (patient age, gender, respiratory symptoms, family tumor history,smoking history) and CT characteristics (lesion size, location, CT value, bubble-like sign, air bronchogram, vessel convergence sign, margin, tumor-lung interface) of pGGN were collected and compared between two groups. Quantitative data (patient age, lesion size and density) were compared between preinvasive and invasive groups using t test or variance analysis (ANOVA) or nonparametric test. Qualitative data(gender, respiratory symptom, family tumor history, smoking history, location,bubble-like sign, air bronchogram, vessel convergence sign, margin, tumor-lung interface) were compared between two groups using chi-square test. Logistic regression analysis was performed to evaluate the clinical and imaging independent risk factors of invasiveness. The OR value of each independent risk factor was considered as risk value of pGGN and the total risk value (TRV) of each lesion was calculated. Receiver operating characteristics curve analysis was used to get the optimal cutoff value (warning value) for lesion invasiveness and the warning value was verified for its validity. A P-value less than 0.05 was considered statistically significant. Results There were 74 preinvasive lesions and 200 invasive lesions. There were statistically significant differences in patient age, lesion size, bubble-like sign,air bronchogram, vessel convergence sign, tumor-lung interface between preinvasive and invasive groups (P=0.012, 0.000, 0.000, 0.000, 0.002, 0.004, respectively). There were no significant differences in gender, respiratory symptom, family tumor history,smoking history, lesion density, location, margin between two groups (P=0.477, 0.535,0.125, 0.158, 0.229, 0.244, 0.930, respectively). Logistic regression analysis showed that bubble-like sign, air bronchogram, tumor-lung interface and lesion size were the independent risk factors of invasiveness and the OR values were 2.145, 3.167, 3.253,1.175, respectively. The round-off numbers of the OR values were added to the total risk value (TRV) of lung adenocarcinoma with pGGN. The ROC curve demonstrated the optimal cutoff of TRV for invasiveness was 3.5 with the sensitivity of 85.5% and specificity of 69.0%. Conclusion The TRV can predict the invasiveness of pGGN.The surgical treatment is recommended if TRV is ≥3.5, otherwise the follow-up is recommended.