Statistical Analysis
The SEER*Stat 8.3.5 is a statistical software designed specifically for the analysis of SEER and other cancer-related databases. The software was used to analyze incidence rates (1/100,000), 95% confidence intervals for incidence rates, relative risk (RR), 95% confidence interval for RR and annual percentage change (APC) of incidence rate. The male-female incidence rate ratios (M/F) were also calculated. SPSS (version 25; Chicago, IL, USA) was used for survival data analysis, including relative survival (RS), a net survival measure that estimates the probability of avoiding death due to a particular cancer relative to the general population. RS is defined as the ratio of the proportion of observed survivors in a cohort of cancer patients to the proportion of expected survivors in a comparable set of cancer free individuals. The Kaplan-Meier method was used to calculate the overall survival rate. The log-rank rest was used to formally test the differences for survival. A p value <0.05 was considered statistically significant for incidence rate, APC and survival.
Results :