Study Limitations
esophageal cancer, cancer, CRC
CANCER, OESOPHAGEAL CANCER
Despite these intriguing findings, it is essential to acknowledge the limitations of our study:Sample size: Our analysis included a relatively small number of CRC patients in the highest sCD40L tertile subgroup, as well as in the esophageal cancer group. This limitation might increase the risk of type II errors.Timing of measurements: Serum sCD40L levels were exclusively measured postoperatively, omitting preoperative and post-supplement-initiation measurements. A comprehensive evaluation of whether vitamin D supplementation genuinely reduces sCD40L levels requires a comparison of levels before and after the initiation of vitamin D supplementation and placebo.Exploratory nature: It is crucial to recognize that our study involved exploratory analyses, which were not predefined in the original AMATERASU trial protocol. Consequently, a degree of caution is warranted when interpreting these findings.Subgroup analyses: Subgroup analyses based on tertiles might heighten the probability of type I errors due to multiple comparisons.Population specificity: The AMATERASU trial predominantly featured a Japanese population with specific cancer subtypes. Given the variation in cancer types and genetics across populations, generalizing our study’s outcomes to different populations should be undertaken with caution.