Lung cancer volume doubling time by computed tomography: A systematic review and meta-analysis

Aim: Lung cancer growth rate influences screening strategies and treatment decisions. This review aims to provide an overview of primary lung cancer growth rate, quantified by volume doubling time (VDT) through computed tomography (CT) measurement. Methods: Using PRISMA-DTA guideline, PubMed, EMBASE, and Web of Science were searched until March 2024 for studies reporting CT-measured VDT of pathologically confirmed primary lung cancer before intervention. Summary data were extracted from published reports by two independent researchers. Primary outcomes were pooled mean VDT of lung cancer by nodule type and histology, distribution of indolent lung cancer (defined as VDT>400 days or negative), and correlated factors. Results: Thirty-three studies were eligible, comprising 3959 patients with primary lung cancer (mean age range:57.6–77.0 years; 60.0 % men). The pooled mean VDT for solid, part-solid, and nonsolid lung cancer were 207, 536, and 669 days, respectively (p < 0.001). When stratified by histology within solid lung cancer, the pooled mean VDT of adenocarcinoma, squamous cell carcinoma, small cell lung cancer, and others were 223, 140, 73, and 178 days, respectively (p < 0.001). Indolent lung cancer was observed in 34.9 % of lung cancer, predominantly in adenocarcinoma (68.9 %). Adenocarcinoma was associated with slower growth, whereas factors such as tumor size, solidity, TNM staging, and smoking history were positively associated with growth rates. Conclusions: Pooled mean VDT of solid lung cancer was approximately 207 days, demonstrating significant variability in histology yet remaining under the 400-day referral threshold. Key predictors of growth rate include histology, size, solidity, and smoking history, essential for tailoring early intervention strategies.