Tech Coloproctol (2004) 8:S72–S75 DOI 10.1007/s10151-004-0117-x
H. Demetriades • I. Kanellos • K. Blouhos • T. Tsachalis • K. Vasiliadis • M.G. Pramateftakis • D. Betsis
Synchronous polyps in patients with colorectal cancer
Abstract Background The aim of this study is to underscore the incidence of synchronous polyps in patients with colorectal cancer and to emphasise the importance of their perioperative detection and management. Patients and methods Three hundred and seven patients underwent a potentially curative resection for colorectal cancer during the last ten years. A total of 129 synchronous polyps were detected in 72 of the patients (23.5%). Complete preoperative colonoscopy was performed in 62 of the patients. Fortythree polyps (33.4%) in 37 patients were removed preoperatively, while 69 polyps (53.4%) in 25 patients were included in the surgical specimen. In 10 patients the colon was evaluated postoperatively and 17 polyps (13.1%) were removed via endoscopy. Results A total of 81 polyps were detected in different surgical segments than the index cancer. Furthermore, 15 polyps were detected in the right colon of 55 patients with left colon cancer. Conclusions Synchronous polyps in patients with colorectal cancer are a frequent event. Thus, all patients should undergo a perioperative colonoscopy and endoscopic polypectomy, if feasible. The planned surgical procedure may alter as a consequence of the colonoscopic findings in some of the patients. Key words Colorectal cancer Colonoscopy
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Synchronous polyps
H. Demetriades • I. Kanellos • K. Blouhos • T. Tsachalis K. Vasiliadis • M.G. Pramateftakis • D. Betsis 4th Surgical Department Aristotle University, Thessaloniki, Greece I. Kanellos () Antheon 1, Panorama 55236 Thessaloniki, Greece E-mail:
[email protected]
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Introduction Routine preoperative colonoscopy has been recommended for patients diagnosed with colorectal cancer in order to identify synchronous polyps and/or cancers, that otherwise might have remained undetected at the time of the operation [1]. It has been suggested, but not clearly demonstrated, that this approach may alter surgical therapy or follow-up regimen [2]. The aim of this study is to underscore the incidence of synchronous polyps in patients with colorectal cancer and to emphasise the importance of their perioperative detection and management.
Patients and methods Three hundred and sixty-eight consecutive patients have been admitted to our department with a diagnosis of colorectal cancer during the last ten years. Out of these patients, 307 (83.5%) underwent a potentially curative resection. This is defined as the absence of apparent local or metastatic tumour at the end of the operation and the absence of tumour at the margins of resection. In all patients, a total colonoscopy had been attempted prior to operation. Synchronous polyps were detected in 72 patients (23.5%), including 42 males and 30 females (mean age 64.9 years, range 38–82 years). Adenomatous polyps were the only findings considered as positive. Attention was given to their size and location. Site and pathologic stage (according to the Astler-Coller classification) of the primary cancers in these 72 patients are given in Table 1. In 62 (86%) of the 72 patients with synchronous polyps, the entire colon was inspected prior to the operation; data from these colonoscopies were recorded. In the remaining 10 patients (14%), five did not undergo any endoscopic examination, chiefly because they had been operated on as an emergency, while in the other five patients the colonoscopy was incomplete because of tumoral stenosis or ineffective bowel preparation. Thus, according to preoperative evaluation, patients were classified into two groups: patients who had undergone a successful total colonoscopy (“known preoperative bowel status”; n=62) and patients who had
H. Demetriades et al.: Synchronous polyps in CRC patients
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Table 1 Distribution of primary carcinoma by stage and site Site
Stage
Ascending colon Transverse colon Descending colon Sigmoid colon Rectum Total
A
BI
BII
CI
CII
Total
– 1 – 6 3 10
– – – 4 4 8
5 1 – 8 13 27
1 1 2 2 1 7
7 1 1 2 9 20
13 4 3 22 30 72
not undergone a successful total colonoscopy (“unknown preoperative bowel status”; n=10). In patients with “unknown preoperative bowel status”, the entire colon was evaluated with postoperative colonoscopy within three months of surgery.
Operative management of these 72 patients with synchronous polyps included 61 standard segmentectomies and 11 extended colectomies (extended left or right hemicolectomy in 7, subtotal colectomy in 3, right hemicolectomy and sigmoidectomy in 1 patient). Thus, planned resection was altered by the results of preoperative colonoscopy in 11 patients (15.3%).
Results Table 2 Polyps
One hundred and twenty-nine adenomatous polyps were detected in 72 patients. Multiple polyps were detected in 27 of them. These were distributed along the whole length of the large bowel. Thirty polyps were greater than 10 mm and, therefore, of significant malignant potential (Table 2). Out of the 62 patients in the “known preoperative bowel status” group, 43 polyps (33.4%) in 37 patients were removed preoperatively via endoscopic polypectomy, while 69 polyps (53.4%) in 25 patients were included in the surgical specimen. Out of the 10 patients in the “unknown preoperative bowel status” group, 17 polyps (13.1%) were removed via postoperative endoscopic polypectomy within three months of surgery (Table 3).
Total number of polyps Size of polyps, mm 20 Location of polyps Ascending Transverse Descending Sigmoid Rectum
129 47 52 19 8 3 7 12 18 71 21
Table 3 Management of synchronous polyps Endoscopically/surgically Preoperative polypectomy Postoperative polypectomy Surgical specimen Total
Number of patients
Polyps removed
37 10 25 72
43 17 69 129
Table 4 Location of primary cancer and synchronous polyps Primary cancer Site Ascending colon Transverse colon Descending colon Sigmoid colon Rectum Total
Synchronous polyps Number
Number of right-sited
Number of left-sited
13 4 3 22 30 72
9 1 3 7 5 25
12 4 7 31 50 104
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In 55 patients with left colon cancer, 88 polyps were detected in the left colon and 15 in the right colon (27.3%). The location of the index cancer and the synchronous polyps, described as left-sided or right-sided, are included in Table 4.
Discussion Our results confirmed the profitability of perioperative colonoscopy. The observed synchronous polyps rate (23.5%) is in agreement with previous studies [2, 3]. Thirty polyps were greater than 10 mm in size, thus, of significant malignant potential. Cases of “missed early synchronous cancers” have been reported in the past [3, 4]. This suggests clearly that there is no alternative to a perioperative colonoscopy [5]. In fact, the only question is to determine whether the perioperative colonoscopy has better results if performed before or soon after the operation. When colonoscopy is performed prior to the operation, inspection of the entire colon is often impossible due to tumoral stenosis, ineffective bowel preparation or patient intolerance. Given the necessity of a perioperative colonoscopy, the consequence of an unsuccessful preoperative procedure is to repeat the examination soon after operation. For this reason and in order to avoid multiple invasive and expensive investigations, Barlow et al. [6] proposed performing colonoscopy only after surgery. At this time, colonoscopy is more likely to be successful, with a reported failure rate of 10%. This policy involves the risk of re-operation. In our experience, planned resections were altered because of the preoperative colonoscopy findings in 11 out of 72 patients (15.3%). Given the lack of sensitivity of operative palpation, it is possible that some of these 11 patients would have required re-operation if preoperative colonoscopy had not been performed. These avoided reoperations are a decisive argument for preoperative colonoscopy. In our view, preoperative colonoscopy should be performed whenever possible. When colonoscopy is unsuccessful or not feasible (patients operated as an emergency), an early postoperative colonoscopy within 3 months of surgery is mandatory. After total colonoscopy and curative perioperative resection, the follow-up may begin with a patient assuming to have a clear colon. A significant minority (1.5–3%) of patients surviving after resection of a colorectal cancer will develop a second, metachronous cancer, while approximately 50% will develop metachronous adenomatous polyps [1, 3]. These possibilities are the second reason advocated for a perioperative colonoscopic evaluation. This expectation is based on the acceptance of the theory of the polyp-cancer sequence, which postulates that virtually all colorectal cancers develop progressively and gradually from a benign adenomatous precursor [6].
H. Demetriades et al.: Synchronous polyps in CRC patients
It is often reported in the relevant literature that routine colonoscopy enables one to diagnose metachronous cancers in the first 2 or 3 postoperative years [6]. Indeed, as was suggested by the studies of Heald et al. [7], two types of metachronous cancers must be distinguished: the “early” ones are in fact “missed synchronous cancers”, whereas the “late” ones represent “true metachronous cancers”. The reported mean time for a “real” metachronous cancer to develop is about 10 years [3]. Hence, once the entire colon has been perioperatively inspected and all polyps found have been removed, routine colonoscopy should not be expected to detect metachronous cancers in the early postoperative years. In our series, the adenomatous polyps that were detected at perioperative colonoscopies were distributed along the whole length of the large bowel. The ascending colon was a common location, especially in patients with left colorectal cancer. These right-sided polyps would have been overlooked if an incomplete preoperative or an absent early postoperative colonoscopy had been performed. Therefore, we concur with other authors [2, 6] who have recommended total postoperative colonoscopy for detection of “missed” synchronous polyps or tumour within three months after the operation. Even though there is still controversy regarding the degree of malignant potential of polypoid lesions of the colon, the current consensus is that most cancers arise from preexisting neoplastic polyps [2]. It is impossible to detect which lesions are or will become malignant. The incidence of malignancy in a polyp rises as the size and villous component of the polyp increases. As single and even multiple forceps biopsies frequently miss malignant changes in polyps, histologic evaluation should be based on examination of the completely excised polyp. In general, all polypoid lesions greater than 1 cm in diameter should be totally excised and recovered for histologic examination. Even though removing polyps less than 1 cm in diameter is still considered to be controversial and occurrence of carcinoma in a lesion under 0.5 cm is rare, it is reasonable to destroy or remove all such diminutive lesions [2, 5]. In conclusion, all colorectal cancer patients must undergo preoperative colonoscopy. The planned surgical procedure may alter in some patients as a consequence of the colonoscopic findings. When stenosis or obstruction prevents colonoscopic scrutiny of all parts of the large bowel, the examination should be performed within 3 months of the initial operation, to ensure that no synchronous polyps or tumours have been missed.
References 1. Langevin JM, Nivatrongs S (1984) The true incidence of synchronous cancer of the large bowel: a prospective study. Am J Surg 147:330–333
H. Demetriades et al.: Synchronous polyps in CRC patients 2. Barrier A, Houry S, Huguier M (1998) The appropriate use of colonoscopy in the curative management of colorectal cancer. Int J Colorect Dis 13:93–98 3. Chen F, Stuart M (1994) Colonoscopic follow-up of colorectal carcinoma. Dis Colon Rectum 37:568–572 4. Bensen S, Mott LA, Dain B, Rothstein R, Baron J (1999) The colonoscopic miss rate and true one-year recurrence of colorectal neoplastic polyps. Polyp Prevention Study Group. Am J Gastroenterol 94:194–199
S75 5. Linburg PJ, Ahlouist DA (2002) Second primary colorectal cancer: the consequence of management failure at several potential levels. Ann Intern Med 136:335–337 6. Barlow AP, Thompson MH (1993) Colonoscopic follow-up after resection for colorectal cancer: a selective policy. Br J Surg 80:781–784 7. Heald RJ, Bussey HJ (1975) Clinical experiences at St Mark’s Hospital with multiple synchronous cancers of the colon and rectum. Dis Colon Rectum 18:6–10
