Maintenance tegafur-uracil versus observation following an adjuvant oxaliplatin-based regimen in patients with stage III colon cancer after radical resection: study protocol for a randomized controlled trial

Table 3 Flowchart for pretreatment and post-treatment investigations

Study period	Screening	Study treatment	Treatment completion	Post treatment
Day/month/year	−28 to 0 days	Clinical visit	Any time	2nd year	3rd–5th years
Informed consent	X
Medical history	X
Demography	X
Pregnancy test, if appropriate	X
Physical examination, ECOG, vital signs	X	X^a	X
Hematology	X	X^a	X
Biochemistry	X	X^a	X
CT or MRI^b	X		X	X
Abdominal echo^c		X^c		Every 6 months	Every 6 months
Carcinoembryonic antigen (CEA)	X	X^a	X	Every 3 months	Every 6 months
Study treatment^d		X
Adverse events		X	X^e

^aIt will be repeated once every 3 months, including the assessment of physical status, Eastern Cooperative Oncology Group (ECOG) status, vital signs, hematological and biochemical data, and CEA, during the study treatment
^bComputed tomography (CT) or magnetic resonance imaging (MRI) will be repeated every 12 months for the first 2 years or on suspecting disease recurrence. Thereafter, CT or MRI will be performed only on suspected disease recurrence
^cAbdominal echo will be repeated every 6 months. However, actual implementation will be based on clinical practice. The schedule of CT or MRI and abdominal echo are crossed over; the examinations are typically performed at an interval of 6 months. CT or MRI is the main examination used when the schedule is duplicated
^dTreatment in arm A will be started within 7 days after the randomization
^eThe patients will be followed for the occurrence of serious adverse events (SAEs) until 30 days after the last dose of study medication or introduction of an additional antitumor therapy, whichever occurs first

ISSN: 1745-6215