Prevalence of invasive lung cancer in pure ground glass nodules less than 30 mm: A systematic review
Abdullah Alshammari, Akshay J. Patel, Mark Boyle, Chiara Proli, Jose Alvarez Gallesio, Anuj Wali, Paulo De Sousa, Eric Lim
Abstract
BACKGROUND: The IASLC TNM proposal suggests that pure ground glass nodules less than 30 mm should be classified as cTis corresponding to pathologic adenocarcinoma in situ implying no invasive malignancy potential. We sought to ascertain the proportion of pure ground glass nodules that harbour tissue confirmed minimally invasive or invasive adenocarcinoma. METHODS: We analyzed data from 3874 individuals with pure ground glass nodules less than 30 mm, reported in 28 observational studies identified through a systematic search of electronic databases. The primary outcome was the prevalence of invasive malignancy by random effects meta-analysis, and we used meta-regression to determine the impact of baseline risk, size, and country of investigation on overall effect size. The study was registered with PROSPERO (CRD42021286261). RESULTS: =99 %) and patient selection was the most significant contribution, accounting for 73 % of the observed heterogeneity (p < 0.0001). Meta-regression based on size selection and country of investigation revealed no significant contribution to effect size effect or heterogeneity. CONCLUSIONS: Pure ground glass nodules less than 30 mm harbour a high proportion of invasive malignancy, contrary to the IASLC staging proposals and opinions from numerous guidelines across the world.