Distinct clinical characteristics and prognosis of ground-glass opacity-type lung cancer: A systematic review and meta-analysis.
Authors: Ren Chongxi, Yin Ruisheng, Wang Hongqiao, Wang Hongchen, Zhou Tong, Li Fengying, Wang Xin, Li Meng, Qi Hongxia, Li Sheng, Ren Haixia, Li Xuefeng, Li Fengyan, Wang Juan, Yang Fengshuo
Journal: Journal of Clinical Oncology (2021)

e20505 Background: Lung ground-glass opacity (GGO), a hazy increased opacity on computed tomography with preservation of bronchial and vascular margins, has been shown to be associated with early-stage lung cancer. With the increasing prevalence of ground-glass opacity-type lung cancer (GGO-LC), more researches have focused on the diagnosis and treatment of this early stage lung cancer; however, the clinical characteristics and survival outcomes of this disease has not yet been fully elucidated. Aim: To analyze and review the clinicopathological characteristics for GGO-LC and to identify the optimal treatment strategies in this select population. A systematic review and meta-analysis of the literature were carried out. The study was registered (CRD42021228774). Methods: We did a systematic review and meta-analysis of observational studies published from database inception to June 30, 2020, which reported on clinicopathological characteristics, management and survival outcomes in patients with GGO-LC. Studies were identified by searches in PubMed, MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, and by hand searching of previous publications. We extracted the general information to perform the meta-analysis, mainly focusing on age, gender, and smoking status. We also extracted treatment and prognosis information to assess the effect of treatment strategies on overall survival (OS). Robustness of pooled estimates from random-effects models was considered with sensitivity analyses, meta-regression, and subgroup analyses. All statistical analyses were performed with Stata 16.0. Results: Data on 9444 patients in 27 observational studies were included. GGO-type lung cancer was typically characterized as non-invasively or minimally invasively low-grade adenocarcinomas. Therapeutic intervention for these early stage lung cancers was an important opportunity for decreasing overall mortality of lung cancer. The final pooled analysis showed that the average age at diagnosis, female proportion and non-smoking proportion of patients with GGO-LC was 57.7 (95% CI, 53.9-61.5, P &lt; 0.001, I2 = 92.9%), 0.591 (95% CI, 0.563-0.619, P &lt; 0.001, I2 = 86.7%), and 0.631 (95% CI, 0.556-0.706, P &lt; 0.001, I2 = 98.3%), respectively. The pooled overall survival rate was 96.2% (95% CI, 0.954 to 0.970, P &lt; 0.001, I2 = 78.9%). The results showed that the majority of GGO-LC patients had good survival outcomes, presenting a significant proportion of young, female and non-or light smokers. Conclusions: From our analysis, it demonstrates that the patients with GGO-LC may be relatively young females and non-or light smoking history, and had better prognosis. However, there are some limitations in the present study, and more evidence is necessary to wait for more results from RCT to draw a valid conclusion.