Abstract 110P
Background
Tumor growth patterns have important implications for determining screening intervals, making treatment decisions, and predicting prognosis. Our study aimed to characterize tumor volume doubling time (VDT) or growth pattern of primary lung cancer and identify factors associated with rapid and indolent growth patterns.
Methods: We performed a systematic literature review of Medline, EMBASE, and Web of Science databases starting from 2004 until April 2022. We identified studies reporting volumetric measured tumor VDT or growth patterns of pathologically confirmed primary lung cancer without intervention, and abstracted data to calculate pooled VDT and find correlations of growth patterns (rapid defined as VDT ≤400 days, indolent as VDT >400 days, non-growth or shrinkage). Meta-analysis was performed for pooled mean VDT for overall lung cancer and for different histology subtypes. Pooled mean VDT was calculated using a random-effects model.
Results
We have identified 26 studies, including 2275 patients with primary lung cancer (mean age range from 54.6 to 72.0 years), comprising 61.6% men and 38.4% women. For overall lung cancer, median VDT ranged from 139 to 357 days and mean VDT ranged from 151 to 408 days. Pooled overall mean VDT was 213 days (95% CI 171 to 256 days, I2 = 90.0%). In subgroup analyses, pooled mean VDT of adenocarcinoma, adenocarcinoma (subsolid), squamous cell, small cell, and other lung cancer were 241, 731, 136, 71, and 183 days, respectively. Rapid growth accounted for 64.8% of overall lung cancer and 23.7% of adenocarcinoma. The most consistent correlations of rapid tumor growth included nodule solidity, non-adenocarcinoma histology subtype, and invasiveness in adenocarcinoma.
Conclusions
Median VDT in overall lung cancer is always £400 days (range 139 to 357 days) with around two-thirds being rapid; solidity and histology subtypes demonstrate the most consistent correlations.
Legal entity responsible for the study
The authors.
Funding
China Scholarship Council (CSC no. 202008440409).
Disclosure
All authors have declared no conflicts of interest.