AFP and hepatocellular carcinoma: The association with improved survival remained significant after lead-time bias adjustment among those with HCC detected by imaging, across sojourn times of 4 to 6 months (4 months, HR, 0.75; 95% CI, 0.62-0.90; 5 months, HR, 0.76; 95% CI, 0.63-0.92; 6 months, HR, 0.78; 95% CI, 0.64-0.94); however, there was no association among those with AFP-detected HCC.