Figure 4. Coefficient of Growth by Tumor Diameter and Growth Curve of Tumor Volume.
A, Correlation between tumor diameter and coefficient of growth. There was a significant negative correlation between the coefficient of growth and the tumor diameter (Spearman ρ = −0.183; 95% CI, –0.354 to –0.001). The data were divided into 2 groups according to tumor size (small and large). The threshold tumor diameter YT in the screening examination was estimated as 12.4 mm. The coefficient of growth was almost zero (0.010 year−1) in the large tumor group (n = 47). B, Growth curve of tumor volume in a linear semilogarithmic progression period and a growth arrest period. The 95% CIs were estimated by Monte Carlo simulation. The mean number of years during which the tumor grew from a diameter of 5 mm until reaching the growth arrest point was calculated as approximately 8.0 (range, 5.1–17.6) years. Solid lines and broken lines represent mean and 95% CI, respectively.