The effect of tumor spread through air spaces on the prognosis of patients with stage Ⅰ non-small cell lung cancer: a meta-analysis

Abstract

Objective: To systematically evaluate the effect of tumor spread through air spaces (STAS) on the prognosis of patients with stage Ⅰ non-small cell lung cancer (NSCLC). Methods: PubMed, Embase, Web of Science, Cochrane Library, CNKI, Wanfang Database and VIP were searched to collect papers related to NSCLC and STAS published from the establishment of aboves databases to November 2022. Papers were screened according to the inclusion and exclusion criteria, and data were extracted. The 5-year overall survival (OS) and relapse-free survival (RFS) of stage Ⅰ NSCLC patients with or without STAS were compared. HR(95%CI) was used as effective indicator to evaluate the impact of STAS positivity on the prognosis of NSCLC. The quality of each included study was assessed using the Newcast-Ottawa Scale (NOS). Results: A total of 24 papers concerning 29 studies were included according to the inclusion and exclusion criteria, and there was no significant heterogeneity among the included papers(all I2<50%). A total of 10 883 patients with stage Ⅰ NSCLC were included in the studies, of which 3 298 (30.3%) were STAS-positive. The 29 studies showed that STAS-positive patients had a higher risk of 5-year recurrence than STAS-negative patients with stage Ⅰ NSCLC [HR=1.94(95%CI:1.74-2.16)];and a meta-analysis of 17 of the studies showed that that STAS-positive patients had a higher risk of 5-year death [HR=2.09 (95%CI:1.80-2.43)]. Compared with stage Ⅰ NSCLC patients who underwent other surgeries, STAS-positive patients who underwent sublobar resection had a higher risk of 5-year recurrence than patients with other procedures (HR=3.44, 95%CI: 2.49-4.76) and a higher risk of 5-year death (HR=3.40, 95%CI:2.05-5.64); and patients with stage Ⅰ NSCLC who had the pathologic histologic type of squamous carcinoma had a higher risk of 5-year recurrence (HR=2.48,95%CI:1.71-3.60) and a higher risk of 5-year death (HR=3.04, 95%CI: 1.90-4.86) than other patients with the type of squamous lung cancer. Conclusion: STAS positivity is a risk factor of poor prognosis in patients with stage Ⅰ NSCLC, especially for patients underwent sublobar resection or with squamous lung cancer.