From the secondary multivariate regression model investigating significant factors associated with SFT among different comparisons, we found that when analyzing the subgroup of cancer vs. non-cancer (n = 136), positive associations were found for SFT and education years (β = 0.76, 95% CI: 0.43~1.10, p < 0.001) and anxiety (β = 0.9, 95% CI: 0.19~0.99, p = 0.005); negative associations were found for the group indicator of ‘cancer vs. non-cancer’ (β = −7.04, 95% CI: −10.34~−3.74, p < 0.001) and log IL-4 (β = −3.31, 95% CI: −6.51~−0.11, p = 0.043). Here, IL4 is linked to cancer.