Table 1. The characters of included trials.
| Author | Year | No patients | Country | Dukes’ stage | Intervention group | Control group | Follow-up (months) |
|---|---|---|---|---|---|---|---|
| Augestad | 2013 | 110 | Norway | Dukes' A: 24; Dukes' B: 55; Dukes' C: 32 | Surgeon follow-up | GP follow-up | 24 |
| COLOFOL | 2018 | 2555 | Sweden | Unclear | CT (thorax and abdomen) and CEA at 6, 12, 18, 24, and 36 months | CT (thorax and abdomen) and CEA at 12 and 36 months | 60 |
| GILDA | 2016 | 1228 | Italy, Spain, US | Dukes' B: 617; Dukes' C: 611 | 4, 8, 12, 16, 20, 24, 30, 36, 42, 48, and 60 monthly office visits and history and clinical examination, FBC, CEA, and CA 19–9; Colonoscopy and CXR at 12, 24, 36, 48, and 60 months; Liver ultrasound at 4, 8, 12, 16, 24, 36, 48, and 60 months; For rectal participants, pelvic CT at 4, 12, 24, and 48 months | 4, 8, 12, 16, 20, 24, 30, 42, 48, and 60 monthly office visits, including history, examination, and CEA; Colonoscopy at 12 and 48 months; Liver ultrasound at 4 and 16 months; Rectal cancer participants in addition had rectoscopy at 4 months, CXR at 12 months, and liver US at 8 and 16 months. A single pelvic CT was allowed if a radiation oncologist required it as baseline following adjuvant treatment | 96 |
| Kjeldsen | 1997 | 597 | Denmark | Dukes' A 138; Dukes' B: 293; Dukes' C: 166 | At 6, 12, 18, 30, 36, 48, 60, 120, 150 and 180 months, digital rectal examination, colonoscopy, CXR: the same in both groups. | At 60, 120, 180 months, digital rectal examination, colonoscopy, CXR: the same in both groups. | 132 |
| Mäkelä | 1995 | 106 | Finland | Dukes' A: 28; Dukes' B: 48; Dukes' C: 30 | participants who had rectal or sigmoid cancers had flexible sigmoidoscopy with video imaging every 3 months, colonoscopy at 3 months (if it had not been done pre-operation), then annually. They also had ultrasound of the liver and primary site at 6 months, then annually. | participants who had rectal and sigmoid cancers had rigid sigmoidoscopy and barium enema annually | 60 |
| Ohlsson | 1995 | 107 | Finland | Dukes' A: 19; Dukes' B: 47; Dukes' C: 41 | at 3-, 6-, 9-, 12-, 15-, 18-, 21-, 24-, 30-, 36-, 42-, 48-, and 60-month intervals. Performed at each visit were clinical exam, rigid proctosigmoidoscopy, CEA, alkaline phosphatase, gamma-glutaryl transferase, faecal haemoglobin, and CXR. Examination of anastomosis (flexible sigmoidoscopy or colonoscopy, as dictated by the lesion) was performed at 9, 21, and 42 months. Colonoscopy was performed at 3, 15, 30, and 60 months. CT of the pelvis was performed at 3, 6, 12, 18, and 24 months. | no follow-up visits planned. They received written instructions recommending that they leave faecal samples with the district nurse for examination every third month during the first 2 years after surgery then once a year. They were instructed to contact the surgical department if they had any symptoms. | 66–105.6 |
| Pietra | 1998 | 207 | Italy | Dukes' A: 0; Dukes' B: 122; Dukes' C: 85 | At 3, 6, 9, 12, 15, 18, 21, 24, 30, 36, 42, 48, 54, and 60 months, then annually thereafter. At each visit, clinical examination, ultrasound, CEA, and CXR were performed. Annual CT and colonoscopy were performed. | At 6 and 12 months, then annually. At each visit, clinical examination, CEA, and ultrasound were performed. Annual CXR, colonoscopy, and CT were performed. | 60 |
| FACS | 2017 | 1202 | UK | Dukes' A: 254; Dukes' B: 553; Dukes' C: 354 | (1) CEA follow-up: measurement of blood CEA every 3 months for 2 years, then every 6 months for 3 years, with a single chest, abdomen, and pelvis CT scan at 12–18 months if requested at study entry by hospital clinician (n = 300). (2) CT follow-up: CT of the chest, abdomen, and pelvis every 6 months for 2 years, then annually for 3 years (n = 299). (3) CEA and CT follow-up: both blood CEA measurement and CT imaging as above (n = 302). | no scheduled follow-up except a single CT scan of the chest/abdomen/pelvis if requested at study entry by a clinician | 106 |
| Rodriguez-Moranta | 2006 | 259 | Spain | Unclear | Seen with history, examination, and bloods (including CEA) at 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45, 48, 51, 54, 57, and 60 months. US/CT at 6, 12, 18, 24, 30, 36, 42, 48, and 56 months. CXR and colonoscopy at 12, 24, 36, 48, and 56 months | Seen with history, examination, and bloods (including CEA) at 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45, 48, 51, 54, 57, and 60 months | 48 |
| Schoemaker | 1998 | 325 | Australia | Dukes' A: 71; Dukes' B: 153; Dukes' C: 101 | Participants in the experimental arm underwent yearly CXR, CT of the liver, and colonoscopy. | These investigations were only performed in the control group if indicated on clinical grounds or after screening test abnormality, and at 5 years of follow-up, to exclude a reservoir of undetected recurrences. | 60 |
| Secco | 2002 | 227 | Italy | Unclear | They had clinic visits and serum CEA, abdomen/pelvic US scans, and CXR. Participants with rectal carcinoma had rigid sigmoidoscopy and CXR. | Minimal follow-up programme performed by physicians | 61.5 48 |
| Sobhani | 2008 | 130 | French | Unclear | PET performed at 9 and 15 months and conventional follow-up | conventional follow-up | 24 |
| Strand | 2011 | 110 | Sweden | Unclear | surgeon-led follow-up | nurse-led follow-up | 60 |
| Treasure | 2014 | 216 | UK | Dukes' A: 10; Dukes' B: 95; Dukes' C: 74 | Second-look laparotomy | No further action was taken | 300 |
| Wang | 2009 | 326 | China | Dukes' A: 53; Dukes' B: 186; Dukes' C: 93 | Colonoscopy at 3-month intervals for 1 year, at 6-month intervals for the next 2 years, and once a year thereafter | Colonoscopy at six months, 30 months, and 60 months postoperatively | 64–79 |
| Wattchow | 2006 | 203 | Australia | Dukes' A: 47; Dukes' B: 96; Dukes' C: 60 | Follow by surgeons: more ultrasound, colonoscopy and sigmoidoscopy. CEA, CT, Rx, endoscopy: the same in both groups. | Follow-up by general practitioners: more fecal occult blood. CEA, CT, Rx, endoscopy: the same in both groups. | 24 |