What should be the follow-up colonoscopy for patients after CRC resection?

From Cancer Guidelines Wiki

Recommendations about the timing of colonoscopy after CRC resection should be based upon the “natural history” of metachronous colonic neoplasia, in order to meet the objectives of surveillance, namely early detection of metachronous cancer and timely polypectomy for metachronous adenomas. .

The natural history of metachronous cancer and polyps is best estimated by studies of the yields of colonoscopy at various time points after surgery, when pre- or peri-operative colonoscopy has excluded synchronous cancer and cleared synchronous polyps.

In the US Guidelines for Colonoscopy Surveillance after Cancer Resection[1], the literature to 2005 was summarised with regard to metachronous cancer development. In studies incorporating more than 9000 patients, 137 metachronous cancers were detected, 57 of which were found within 24 months of surgery. It could be argued that second cancers found so soon after surgery were in many instances missed synchronous (rather than metachronous) lesions but the importance of detecting them remains undiminished. The authors argued that such a rate of cancer detection (157 colonoscopies per metachronous cancer found) was comparable to the rate of prevalent cancer detection in the setting of screening colonoscopy (as practised in the US). It was this relatively high incidence of metachronous cancers within two years of surgery that led to the Guidelines’ recommendation to perform post-operative colonoscopy at an interval of one year (with subsequent colonoscopies after an interval of three years and then five years, if all surveillance examinations were normal).

In the literature prior to 2005, Barillari[2] and Neugut[3] found that more than one-half of metachronous adenomas and cancers arose within the first twenty four months after surgery. In a 2000 study, Togashi et al[4] detected twenty-two metachronous colorectal cancers in 19 out of 341 patients after CRC surgery, 14 (64 %) of them within five years of surgery. Most were small, 10 mm or less in size, and many had a flat endoscopic appearance. In a study of 174 patients reported by Juhl et al in 1990[5], three-quarters of the colonoscopically detected neoplasms (adenomatous polyps and cancers) occurred within the first 24 months. In the period 12-30 months after surgery, four metachronous cancers and 37 advanced adenomas were detected. A retrospective review by Khoury et al[6] concluded that annual follow-up colonoscopy for two years after CRC surgery was beneficial and that the interval between subsequent examinations be increased depending on the result of the most recent examination[6].

However, not all of these earlier studies advocated colonoscopy within one to two years of surgery. Among 175 patients who underwent a curative resection for CRC between 1986 and 1992, colonoscopies performed one year after surgery and then at two-year intervals revealed no metachronous cancers or advanced adenomas .The authors suggested that only patients who had had synchronous adenomas at pre-operative colonoscopy should undergo follow-up colonoscopy at three years.[7] Similarly, Stigliano et al[8] conducted a retrospective study of 322 patients and found no metachronous cancers within the first two years after surgery. In their 2002 review, Berman et al[9] suggested that there were insufficient data to support the routine use of annual or more frequent colonoscopy to identify metachronous or recurrent CRC and they suggested post-operative colonoscopy be limited to every three to five years. The value of a large retrospective audit of patients after CRC resection by McFall et al, which concluded that most patients are at very low risk of developing significant colonic pathology in the five years after resection, was limited by the fact that less than one-third of the patients underwent post-operative colonoscopy[10] and the mean interval between surgery and colonoscopy was more than four years. Similar reservations about the need for follow-up colonoscopy earlier than two to three years were expressed by Mathew et al[11], even though 10 out of 14 patients with neoplastic findings at surveillance colonoscopy were detected two years post-operatively.

A Western Australian study by Yusoff et al audited all patients who underwent surgical resection of CRC from 1989 to 2001[12] and found that no metachronous cancers (and only 1 of 11 recurrent anastomotic cancers) were found by surveillance of asymptomatic patients. The three metachronous cancers were all detected in symptomatic patients, at four, eight and nine years after surgery. In a subset of their patients, the yields for adenoma were 10 % at one year post-operatively, 28 % at two years and none at three years.

Another Australian study published in 2005 by Platell et al specifically evaluated the clinical utility of performing a colonoscopy 12 months after curative resection for CRC[13]. In 253 patients who had undergone complete colonoscopy prior to resection, 90 % received their first post-operative colonoscopy at a mean of 1.1 years. Although no recurrent or metachronous cancers were found, 149 polyps were detected in 30 % of patients, 42 % of which were adenomas and 13 % of which were villous or tubulovillous adenomas. Having observed such a high prevalence of advanced adenomas at 12 months (7.9 % of patients), the authors raised the possibility that, in contrast to recommendations in the Clinical Practice Guidelines for the Prevention, Early Detection and Management of Colorectal Cancer 2005[14],(that post-operative colonoscopy be performed at three to five years), a variably intense colonoscopy surveillance schedule might be justifiable. Similarly, the large study from Taipei mentioned earlier[15] concluded that a lifelong schedule of post-operative colonoscopic surveillance was necessary.

According to Hassan et al[16], who used a decision analysis model, early surveillance colonoscopy performed one year following CRC resection was clinically efficient and cost-effective in terms of cancer detection and prevention of cancer-specific death[16]. Compared to “no early colonoscopy” following surgery, the number of one-year colonoscopies required to find one CRC was 143 and the number needed to prevent one CRC-related death was 926. In a 2007 analysis of 1002 operated CRC patients, Rulyak et al[17] concluded that surveillance colonoscopy within one year of surgery was warranted because (i) 9 of the 20 metachronous cancers detected during the study period were found within 18 months of surgery and (ii) the rate of metachronous advanced neoplasia was significantly lower if colonoscopy was performed within 18 months of surgery (6.9 %) than if colonoscopy was delayed for three years or more (15.5 %).

In a 2009 study from China, Wang et al compared “intensive colonoscopic surveillance” (three monthly colonoscopy for the first year after surgery, then six monthly for the following two years and annually thereafter) with “routine colonoscopic surveillance” (at six, thirty and sixty months after surgery).[18] In the intensive surveillance group, one metachronous cancer was detected in the second year of surveillance, one in the fourth year and the third more than five years after initial surgery. In the routine surveillance group, no metachronous cancers were found at six months, four were found at 30 months, one was found at five years and one was found thereafter. The authors concluded that the routine schedule of surveillance was acceptable, with follow-up colonoscopy at one and two years after surgery and then three to five years thereafter.

Thus, while not all of the published evidence is in agreement, most studies demonstrate a significant incidence of metachronous cancers, advanced adenomas and other types of polyps after curative resection for CRC. In many studies, a high proportion of the metachronous neoplasia was detected within the first two years after surgery. Careful, high-quality colonoscopy at 12 months after surgery would be expected to detect the vast majority of this metachronous neoplasia. In turn, this should improve survival in patients operated on for CRC, by finding second cancers at a stage early enough to be cured by re-operation, and by removing metachronous adenomas while still benign. As a result, the weight of evidence from the literature would seem to support performing the initial post-operative surveillance colonoscopy at an interval of one year. If this examination does not reveal a metachronous cancer, the intervals between subsequent colonoscopies should probably be three and five years, depending on the number, size and histologic type of polyps (if any) removed.

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Evidence summary and recommendations

Evidence summary Level References
Follow-up colonoscopy reduces the mortality rate of patients after CRC resection. Most studies demonstrate a significant incidence of metachronous cancers, advanced adenomas and other types of polyps after curative resection for CRC. II [15], [17], [12], [2], [6], [4], [19], [20], [21], [22], [23], [3], [13], [16], [18]
In many studies, a high proportion of the metachronous neoplasia occurred within the first two years after surgery. IV [24]
Evidence-based recommendationQuestion mark transparent.png Grade
Colonoscopy should be performed one year after the resection of a sporadic cancer, unless a complete post-operative colonoscopy has been performed sooner.
Evidence-based recommendationQuestion mark transparent.png Grade
If the peri-operative colonoscopy or the colonoscopy performed at one year reveals advanced adenoma, then the interval before the next colonoscopy should be three years.
Evidence-based recommendationQuestion mark transparent.png Grade
If the colonoscopy performed at one year is normal or identifies no advanced adenomas, then the interval before the next colonoscopy should be five years.

Practice pointQuestion mark transparent.png

Patients undergoing either local excision (including transanal endoscopic microsurgery) of rectal cancer or advanced adenomas or ultra-low anterior resection for rectal cancer should be considered for periodic examination of the rectum at six monthly intervals for two or three years using either digital rectal examination, rigid proctoscopy, flexible proctoscopy, and/or rectal endoscopic ultrasound. These examinations are considered to be independent of the colonoscopic examination schedule described above.

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  1. Rex DK, Kahi CJ, Levin B, Smith RA, Bond JH, Brooks D, et al. Guidelines for colonoscopy surveillance after cancer resection: a consensus update by the American Cancer Society and the US Multi-Society Task Force on Colorectal Cancer. Gastroenterology 2006;130(6):1865-1871.
  2. 2.0 2.1 Barillari P, Ramacciato G, Manetti G, Bovino A, Sammartino P, Stipa V. Surveillance of colorectal cancer: effectiveness of early detection of intraluminal recurrences on prognosis and survival of patients treated for cure. Dis Colon Rectum 1996 Apr;39(4):388-93 [Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/8878497].
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  9. Berman JM, Cheung RJ, Weinberg DS. Surveillance after colorectal cancer resection. Lancet 2000 Jan 29;355(9201):395-9 [Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/10665570].
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  13. 13.0 13.1 Platell C, Salama P, Barwood N, Makin G. Performing a colonoscopy 12 months after surgery for colorectal neoplasia. ANZ J Surg 2005 May;75(5):282-5 [Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/15932437].
  14. Australian Cancer Network Colorectal Cancer Guidelines Revision Committee. Clinical practice guidelines for the prevention, early detection and management of colorectal cancer. The Cancer Council Australia and Australian Cancer Network 2005.
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