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 :