2.5. Follow-Up and Outcomes
colorectal cancer, fractures, death
COLORECTAL CANCER, OSTEOPOROSIS, CANCER RELAPSE
As part of the study protocol, patients underwent regular outpatient examinations utilizing CT, MRI, PET scans, and other necessary procedures to monitor for any signs of cancer relapse, as determined by the attending surgeon. Typically, the examinations were conducted monthly during the initial 6 months postoperatively, bi-monthly during the subsequent 6 months, and then every 3 months for the remaining 4 years. After the initial 5 years, the follow-up frequency was adjusted to every 3–6 months, based on the patient’s condition, as assessed by the responsible surgeon.A clinical research coordinator was actively involved in patient follow-up, conducting interviews during each outpatient clinic visit at the International University of Health and Welfare Hospital. The research coordinator contacted participants via telephone to inquire about their health status and adherence to the treatment regimen. Further, adherence to the trial supplement was reconfirmed when a new bottle was provided to the participants every six months.In all patients in both the vitamin D and placebo groups, blood 25(OH)D levels were measured annually to monitor changes in their levels. In addition to the assigned supplementation, patients diagnosed with stage II and III esophageal, gastric, or colorectal cancer were given pre- and postoperative chemotherapy.In select cases of relapse, local radiation or molecular targeting therapy was combined with chemotherapy. In situations where vitamin D supplementation became medically necessary, such as for conditions like bone fractures or osteoporosis, trial supplementation was discontinued. However, these patients continued to be monitored until the conclusion of the study.The outcome of this study was prespecified as relapse or all-cause death. The elapsed time was defined as the time from starting the supplement to the date the outcome occurred or was censored.