COVID-19 and early-stage lung cancer both featuring ground-glass opacities: a propensity score-matched study.

Zhang, Ya-Jie; Yang, Wen-Jie; Liu, Dong; Cao, Yu-Qin; Zheng, Yu-Yan; Han, Yi-Chao; Jin, Run-Sen; Han, Yu; Wang, Xiao-Yang; Pan, A-Shan; Dai, Jian-Yi; Sun, Qing-Feng; Zhao, Feng-Quan; Yang, Qing-Yuan; Zhang, Jia-Hao; Liu, Sheng-Jun; Da, Qian; Guo, Wei; Li, Cheng-Qiang; Zhang, Wen-Tian; Wu, Han; Chen, Xing-Shi; Ji, An-Qi; Xiang, Jie; Chen, Kai; Feng, Xi-Jia; Zhang, Xian-Fei; Cao, Qi-Qi; Qin, Le; Li, Jian; Zhou, Min; Lu, Yong; Wang, Chao-Fu; Yan, Fu-Hua; Li, He-Cheng; Qu, Jie-Ming

Background Radiological manifestations of coronavirus disease 2019 (COVID-19) featured ground-glass opacities (GGOs), especially in the early stage, which might create confusion in differential diagnosis with early lung cancer. We aimed to specify the radiological characteristics of COVID-19 and early lung cancer and to unveil the discrepancy between them. Methods One hundred and fifty-seven COVID-19 patients and 374 early lung cancer patients from four hospitals in China were retrospectively enrolled. Epidemiological, clinical, radiological, and pathological characteristics were compared between the two groups using propensity score-matched (PSM) analysis. Results COVID-19 patients had more distinct symptoms, tended to be younger (P<0.0001), male (P<0.0001), and had a higher body mass index (P=0.014). After 1:1 PSM, 121 matched pairs were identified. Regarding radiological characteristics, patients with a single lesion accounted for 17% in COVID-19 and 89% in lung cancer (P<0.0001). Most lesions were peripherally found in both groups. Lesions in COVID-19 involved more lobes (median 3.5 vs. 1; P<0.0001) and segments (median 6 vs. 1; P<0.0001) and tended to have multiple types (67%) with patchy form (54%). Early lung cancer was more likely to have a single type (92%) with oval form (66%). Also, COVID-19 and early lung cancer either had some distinctive features on computed tomography (CT) images. Conclusions Both COVID-19 and early lung cancers showed GGOs, with similar but independent features. The imaging characteristics should be fully understood and combined with epidemiological history, pathogen detection, laboratory tests, short-term CT reexamination, and pathological results to aid differential diagnosis.