Metachronous Colorectal Neoplasms Research Articles

Gastrointestinal: Weight gain increases the risk of metachronous advanced colorectal neoplasm observed in post-polypectomy surveillance colonoscopy.

Although obesity is a known risk factor for colorectal neoplasms, the correlation between weight change and colorectal neoplasm is unclear. Thus, we aim to evaluate the association between weight change and advanced colorectal neoplasm (ACRN) recurrence during post-polypectomy surveillance colonoscopy. This retrospective cohort study included 7473 participants diagnosed with colorectal neoplasms between 2003 and 2010 who subsequently underwent surveillance colonoscopies until 2020. We analyzed the association between the risk of metachronous ACRN and weight change, defining stable weight as a weight change of <3% and weight gain as a weight increase of ≥3% from baseline during the follow-up period. During a median 8.5years of follow-up, 619 participants (8.3%) developed ACRN. Weight gain was reported as an independent risk factor for metachronous ACRN in a time-dependent Cox analysis. A weight gain of 3-6% and ≥6% had adjusted hazard ratios (AHRs) of 1.48 (95% confidence interval [CI]: 1.19-1.84) and 2.14 (95% CI: 1.71-2.69), respectively. Participants aged 30-49 and 50-75years with weight gain of ≥6% showed AHRs of 2.88 (95% CI: 1.96-4.21) and 1.90 (95% CI: 1.43-2.51), respectively. In men and women, weight gain of ≥3% was significantly correlated with metachronous ACRN. Weight gain is associated with an increased risk of metachronous ACRN. Furthermore, weight gain is associated with the recurrence of ACRN in both men and women regardless of age.

Total polyp number may be more important than size and histology of polyps for prediction of metachronous high-risk colorectal neoplasms

BackgroundTo evaluate whether the risk of metachronous high-risk colorectal neoplasm (HR-CRN) differs according to the indication for surveillance colonoscopy.MethodsPatients who underwent polypectomy or endoscopic resection of colorectal neoplasms were enrolled and classified into three groups according to the indication for surveillance colonoscopy: advanced colorectal neoplasm (ACRN: adenoma ≥ 10 mm, adenoma with high-degree dysplasia and/or villous component), advanced serrated polyps (ASP: hyperplastic polyp or sessile serrated lesion ≥ 10 mm, traditional serrated polyp), and high-risk polyps (HRP: 3 or more adenomas or serrated polyps). The primary outcome was the development of metachronous HR-CRN, defined as ACRN, ASP, or HRP at the first follow-up colonoscopy.ResultsIn total, 367 patients were enrolled (ACRN group: N = 264; ASP group: N = 33; HRP group: N = 70). Among the 160 patients who underwent follow-up colonoscopy, 28 (18%) had HR-CRN. In univariable analysis, indication for surveillance colonoscopy was not found to be associated with the development of metachronous HR-CRN. Instead, the total polyp number at index colonoscopy showed a positive association with the risk of metachronous HR-CRN in trend analysis (p = 0.001). In multivariable analysis, the presence of 5 or more polyps at index colonoscopy was found to be associated with the risk of metachronous HR-CRN (OR, 2.575, p = 0.049) after adjusting for risk factors, such as obesity, diabetes, and smoking.ConclusionsThe risk of metachronous HR-CRN did not differ according to the main indications for surveillance colonoscopy. The presence of 5 or more polyps at index colonoscopy was the only risk factor for metachronous HR-CRN.

Active exercise after polypectomy reduces the risk of metachronous advanced colorectal neoplasm.

Exercise is associated with a lower risk of colorectal neoplasm but its association with metachronous advanced colorectal neoplasm development after polypectomy remains unclear. We aimed to investigate associations between subjects' exercise habits and the risk of metachronous advanced colorectal neoplasm. This study analyzed subjects older than 40 years who received screening colonoscopy with polypectomy and surveillance colonoscopy between January 2009 and December 2016. All participants completed a standard questionnaire containing exercise habits before surveillance colonoscopy. Subjects' exercise habits were quantified as weekly exercise amounts (metabolic equivalents of task-day/week) and dichotomized (active/sedentary exercise habit) using averages as the cut-off point. The associations between incidence of metachronous advanced colorectal neoplasm and exercise habits were evaluated using Kaplan-Meier analysis and Cox regression models. A total of 1820 subjects comprised the study cohort and 86 (4.73%) of them developed metachronous advanced colorectal neoplasm during the surveillance period. An active exercise habit after polypectomy was associated with a lower risk of metachronous advanced colorectal neoplasm (adjusted hazard ratio [aHR] 0.57, 95% confidence interval [CI] 0.35-0.91). Furthermore, this protective effect from exercise was specific for subjects having advanced neoplasm at screening colonoscopy (aHR 0.32, 95% CI 0.11-0.94). An active exercise habit after polypectomy, a surrogate for a more active lifestyle, is associated with a lower risk for developing metachronous advanced colorectal neoplasm. A positive lifestyle modification, such as maintaining/establishing an active exercise habit, should be advised after polypectomy, especially for those with advanced colorectal neoplasm during screening.

Metachronous neoplasms in patients with laterally spreading tumours during surveillance

BackgroundLaterally spreading tumours represent a major challenge for endoscopic detection and resection.ObjectiveTo examine synchronous and metachronous neoplasms in patients with laterally spreading tumours.MethodsWe prospectively collected colonoscopy and histopathology data from patients who underwent colonoscopy in our centre at up to 6 years' follow‐up. Post‐resection surveillance outcomes between laterally spreading tumours, flat colorectal neoplasms 10 mm or greater, and large polypoid colorectal neoplasms, polypoid colorectal neoplasms 10 mm or greater, were compared.ResultsBetween 2008 and 2012, 8120 patients underwent colonoscopy for symptoms (84.6%), screening (6.7%) or surveillance (8.7%). At baseline, 151 patients had adenomatous laterally spreading tumours and 566 patients had adenomatous large polypoid colorectal neoplasms. Laterally spreading tumour patients had more synchronous colorectal neoplasms than large polypoid colorectal neoplasm patients (mean 3.34 vs. 2.34, p < 0.001). Laterally spreading tumour patients significantly more often developed metachronous colorectal neoplasms (71.6% vs. 54.2%, p = 0.0498) and colorectal neoplasms with high grade dysplasia/submucosal invasion than large polypoid colorectal neoplasm patients (36.4% vs. 15.8%, p < 0.001). After correction for age and gender, laterally spreading tumour patients were more likely than large polypoid colorectal neoplasm patients to develop a colorectal neoplasm with high grade dysplasia or submucosal invasion (hazard ratio 2.9, 95% confidence interval 1.8–4.6). The risk of metachronous colorectal cancer was not significantly different in laterally spreading tumours compared to large polypoid colorectal neoplasm patients.ConclusionPatients with laterally spreading tumours developed more metachronous colorectal neoplasms with high grade dysplasia/submucosal invasion than large polypoid colorectal neoplasm patients. Based on these findings endoscopic treatment and surveillance recommendations for patients with laterally spreading tumours should be optimised.

Analysis of metachronous colorectal neoplasms and survival following segmental or extended resection in patients with hereditary non-polyposis colorectal cancer.

The high incidence of metachronous colorectal tumours in patients with hereditary non-polyposis colorectal cancer (HNPCC) encourages extended resection (ER); however, the optimal surgical approach remains unclear. We evaluated the incidences of metachronous colorectal neoplasms following curative colorectal cancer segmental resection (SR) vs ER in patients with HNPCC and investigated patients' oncologic outcomes according to surgical modality and mismatch repair status. We retrospectively investigated medical records of patients with HNPCC (per the Amsterdam II criteria) treated for primary colon cancer at our institution between 2001 and 2017. All patients underwent intensive endoscopic surveillance. We included 87 patients (36 who underwent SR and 51 who underwent ER). The cumulative incidence of metachronous adenoma was higher in the SR group. One patient in the SR group (2.8%) and 3 in the ER group (5.9%) developed metachronous colon cancer; the difference was not significant (P = 0.693). Four patients in the SR group (11.1%) and 1 in the ER group (2.0%) developed distant recurrences; again, the difference was not significant (P = 0.155). Moreover, no significant differences were observed in the 5-year overall survival rates of patients in the SR and ER groups (88.2% vs 95.5%, P = 0.446); the same was true for 5-year disease-free survival rates (79.5% vs 91.0%, P = 0.147). The incidence of metachronous cancer was not significantly different between the ER and SR groups; however, that of cumulative metachronous adenoma was higher in the SR group. Hence, intensive surveillance colonoscopy may be sufficient for patients with HNPCC after non-extensive colon resection.

Risk of Metachronous Colorectal Neoplasm after a Segmental Colectomy in Lynch Syndrome Patients According to Mismatch Repair Gene Status

Because of increased risk of metachronous colorectal cancer (CRC), all patients with Lynch syndrome (LS) are offered a total colectomy. However, because metachronous CRC rate by mismatch repair (MMR) gene is uncertain, and total colectomy negatively impacts quality of life, it remains unclear whether segmental resection is indicated for lower penetrance MMR genes. We evaluated metachronous CRC incidence according to MMR gene in LS patients who underwent a segmental colectomy. Single-center, retrospective cohort study in patients with an earlier colectomy for CRC and an MMR germline mutation in MLH1, MSH2, MSH6, or PMS2 followed prospectively in a hereditary CRC family registry. All patients underwent surveillance colonoscopy. Metachronous CRC was defined as one detected more than 1 year after index resection. Primary end point was cumulative incidence of metachronous CRC overall and by MMR gene. One hundred and ten patients were included: 35 with MLH1 likely pathogenic/pathogenic (LP/P) variants (32%), 42 MSH2 (38%), 20 MSH6 (18%), and 13 PMS2 (12%). Median follow-up 4.26 years (range 0.53 to 19.92 years). Overall, metachronous CRC developed in 22 patients (20%). At 10-year follow-up, incidence was 12% (95% CI 6% to 23%), with no metachronous CRC detected in patients with a PMS2 or MSH6 LP/P variant. After index segmental resection, metachronous CRC is less likely to develop in LS patients with MSH6 or PMS2 LP/P variant than in MLH1 or MSH2 carriers. Our data support segmental resection and long-term colonoscopic surveillance rather than total colectomy in carefully selected, well-informed LS patients with MSH6 or PMS2 LP/P variant.

How to identify patients who are less likely to have metachronous neoplasms after a colon cancer: a predictive model.

Patients with prior colon cancer have increased risk of metachronous colorectal neoplasms; therefore, endoscopic surveillance is indicated. Current recommendations are not risk-stratified. We investigated predictive factors for colorectal neoplasms to build a model to spare colonoscopies for low-risk patients. This was a multicenter, retrospective study including patients who underwent surgery for colon cancer in 2001 - 2008 (derivation cohort) and 2009 - 2013 (validation cohort). A predictive model for neoplasm occurrence at second surveillance colonoscopy was developed and validated. 421 and 203 patients were included in derivation and validation cohort, respectively. At second surveillance colonoscopy, 112 (26.6 %) and 55 (27.1 %) patients had metachronous neoplasms in derivation and validation groups; three cancers were detected in the latter. History of left-sided colon cancer (OR 1.64, 95 %CI 1.02 - 2.64), ≥ 1 advanced adenoma at index colonoscopy (OR 1.90, 95 %CI 1.05 - 3.43), and ≥ 1 adenoma at first surveillance colonoscopy (OR 2.06, 95 %CI 1.29 - 3.27) were independently predictive of metachronous colorectal neoplasms at second surveillance colonoscopy. For patients without such risk factors, diagnostic accuracy parameters were: 89.3 % (95 %CI 82.0 %-94.3 %) and 78.2 % (95 %CI 65.0 %-88.2 %) sensitivity, and 28.5 % (95 %CI 23.5 %-33.9 %) and 33.8 % (95 %CI 26.2 %-42.0 %) specificity in derivation and validation group, respectively. No cancer would be missed. Patients with prior left-sided colon cancer or ≥ 1 advanced adenoma at index colonoscopy or ≥ 1 adenoma at first surveillance colonoscopy had a significantly higher risk of neoplasms at second surveillance colonoscopy; patients without such factors had much lower risk and could safely skip the second surveillance colonoscopy. A prospective, multicenter validation study is needed.

Rates of metachronous adenoma after curative resection for left-sided or right-sided colon cancer.

Background/AimsWe determined the rates of metachronous colorectal neoplasm in colorectal cancer (CRC) patients after resection for right (R)-sided or left (L)-sided cancer.MethodsConsecutive CRC patients who had undergone surgical resection for curative intent in our hospital between 2001 and 2004 were identified. R-sided colonic cancers refer to cancer proximal to splenic flexure whereas L-sided cancers include rectal cancers. Patients were included only if they had a clearing colonoscopy performed either before or within 6 months after the operation. Findings of surveillance colonoscopy performed up to 5 years after colonic resection were included in the analysis.ResultsEight hundred and sixty-three CRC patients underwent curative surgical resection during the study period. Three hundred and twenty-seven patients (107 R-sided and 220 L-sided) fulfilled the inclusion criteria and had at least 1 postoperative surveillance colonoscopy performed. The proportion of patients who had polyp and adenoma on surveillance colonoscopy was significantly higher among patients with L-sided than R-sided cancers (polyps: 30.9% vs. 19.6%, P=0.03; adenomas: 25.5% vs. 13.1%, P=0.01). The mean number of adenoma per patient on surveillance colonoscopy was also higher for patients with L-sided than R-sided tumors (0.52; 95% confidence interval [CI], 0.37–0.68 vs. 0.22; 95% CI, 0.08–0.35; P<0.01). Multivariate analysis showed that L-sided cancers, age, male gender and longer follow-up were independent predictors of adenoma detection on surveillance colonoscopy.ConclusionsPatients with Lsided cancer had a higher rate of metachronous polyps and adenoma than those with R-sided cancer on surveillance colonoscopy.

正常大腸者の経過観察にて発見される異時性大腸腫瘍の検討

正常大腸者の経過観察にて発見される異時性大腸腫瘍の検討

大腸浸潤癌切除後に発見される異時性大腸腫瘍の検討

大腸浸潤癌切除後に発見される異時性大腸腫瘍の検討

Prediction of the Risk of a Metachronous Advanced Colorectal Neoplasm Using a Novel Scoring System.

This study aimed to develop and validate a risk score model to estimate the probability of a metachronous advanced colorectal neoplasm (ACRN) at surveillance colonoscopy. A retrospective analysis of a prospectively obtained database of 11,042 asymptomatic subjects who underwent surveillance colonoscopy after a screening colonoscopy was conducted. Subjects were randomly divided into derivation (n=7730) and validation sets (n=3312). From the derivation cohort, risk factors for a metachronous ACRN were identified by a multivariable analysis. Risk points were allocated to each risk factor based on the hazard ratio to develop the Metachronous Advanced colorectal neoplasm Prediction Scoring (MAPS) model, the performance of which was assessed in the validation cohort. In the derivation cohort, age, male, sessile serrated adenoma/polyp, and a high-risk CRN (ACRN or ≥3 adenomas) at screening colonoscopy were independent risk factors for a metachronous ACRN. These variables were incorporated into the MAPS model, and the risk score ranged 0-17 (high MAPS risk arbitrarily defined as 10-17). At the 3-year surveillance colonoscopy, ACRN was found in 5.1% of the high MAPS risk group versus 3.9% of the high-risk CRN group. The colonoscopy number needed to detect one metachronous ACRN at the 3-year surveillance was 19.5 (95% CI 11.7-33.2) for the high MAPS risk group versus 25.8 (95% CI 15.4-44.0) for the high-risk CRN group. These findings were similarly confirmed in the validation cohort. Our MAPS model based on clinical and colonoscopic parameters effectively predicts the risk of a metachronous ACRN.

Nomogram prediction of metachronous colorectal neoplasms in patients with colorectal cancer.

To construct a predictive model of postoperative colorectal neoplasm development using a nomogram. Although patients with colorectal cancer (CRC) are known to be at high risk of developing metachronous adenoma or CRC, no statistical model for predicting the incidence of postoperative colorectal lesions has been reported. A total of 309 CRC patients who underwent surgical resection received regular endoscopic follow-up to detect the development of metachronous adenoma or adenocarcinoma. The patients were divided into the derivation set (n = 209) and the validation set (n = 100). The nomogram to predict the 3- and 5-year adenoma-free survival rates was constructed using the derivation set, and a calibration plot and concordance index (c-index) were calculated. The predictive utility of the nomogram was validated in the validation set. Sex, age, and number of synchronous lesions at the time of surgery for primary CRC were adopted as variables for the nomogram. The nomogram showed moderate calibration, with a c-index of 0.709 in the derivation set and 0.712 in the validation set. A nomogram based on sex, age, and number of synchronous lesions at the time of surgery has the ability to predict postoperative adenoma-free survival.

Detection of Polyps After Resection of Colorectal Cancer.

PurposeBecause colonoscopy after colorectal cancer surgery is important for detecting synchronous or metachronous colorectal neoplasms, we designed this study to investigate, by using postoperative colonoscopy, the miss rate for and the location of polyps remaining after colorectal cancer surgery.MethodsIn a prospectively-collected patient database, 264 patients were shown to have undergone a colorectal cancer resection between May 2012 and June 2013. Of these, 116 who had received a complete colonoscopy preoperatively and postoperatively were included in this study.ResultsOf these 116 patients, 68 were males and 48 were females; their mean age was 63 years. The mean time after surgery at which postoperative colonoscopy was performed was 7.1 months (range, 3-15 months). On postoperative colonoscopy, a total of 125 polyps were detected. Of these, there were no cancerous lesions; 46 (36.8%) were neoplastic polyps, and 79 (63.2%) were nonneoplastic polyps. Fifty-nine polyps (47.2%) and 15 polyps (12%) were located in the proximal and the distal parts of the anastomosis, respectively. The miss rates for the total numbers of polyps and of neoplastic polyps remaining after surgery were 37.4% and 24.2%, respectively. The incidence of neoplastic polyps increased during postoperative colonoscopy as it had during preoperative colonoscopy (r = 0.164, P = 0.048).ConclusionColonoscopic surveillance after colorectal cancer resection results in the detection of pathologic polyps in one-fourth of the cases. During postoperative colonoscopy, careful examination of the proximal colon is necessary. Patients in whom multiple neoplastic polyps had been detected during preoperative colonoscopy require careful and thorough follow-up.

Incidence and risk factors of metachronous colorectal neoplasm after curative resection of colorectal cancer in Korean patients.

Early detection and endoscopic removal of metachronous neoplasms are important preventive strategies for patients with colorectal cancer (CRC) after curative tumor resection. We aimed to determine the incidence of and the risk factors for metachronous colorectal neoplasms after curative resection for CRC. We retrospectively reviewed clinical data of patients who underwent curative resection for CRC at the National Cancer Center, Korea, from July 2004 to July 2007 and were followed up for a mean duration of 40.7 months. The incidence of and the risk factors for developing metachronous neoplasms were analyzed. A total of 1049 patients were included in this study. A follow-up colonoscopy showed that 454 (43.3%) patients developed metachronous neoplasms, including 46 (4.4%) with advanced adenoma or cancer. Univariate analyses revealed that age ≥ 60 years, male gender, diabetes mellitus, hypertension, synchronous adenoma, synchronous multiple adenoma and synchronous advanced adenoma were associated with the development of metachronous neoplasms. Baseline risk factors associated with metachronous advanced neoplasm were age ≥ 60 years, synchronous multiple adenoma and synchronous advanced adenoma. Multivariate analysis showed that age ≥ 60 years, synchronous adenoma and diabetes mellitus were risk factors for the development of metachronous neoplasms. The cumulative incidence of metachronous neoplasms was higher in patients with these risk factors than in those without. Elder age, synchronous adenoma and diabetes mellitus are risk factors for developing metachronous neoplasia. Therefore, careful surveillance colonoscopy are necessary for these patients.

Sa1514 The Findings of Surveillance Colonoscopy After Curative Treatment of Colorectal Cancer and Risk Factors of Metachronous Colorectal Neoplasm

Sa1514 The Findings of Surveillance Colonoscopy After Curative Treatment of Colorectal Cancer and Risk Factors of Metachronous Colorectal Neoplasm

Surgical treatment of hereditary nonpolyposis colorectal cancer (HNPCC, Lynch syndrome)

The surgical management of the Lynch syndrome patient with colorectal cancer needs to be individualized. Because of the increased incidence of synchronous and metachronous colorectal neoplasms, most favor an extended resection at the time of diagnosis of colorectal cancer. Age of diagnosis, stage of the tumor, co-morbidities, surgical expertise, surgical morbidity, and patient wishes should be taken into account when considering a surgical procedure. There are no prospective randomized trials or retrospective trials suggesting that patients undergoing an extended procedure have a survival advantage compared to those undergoing segmental resection. In retrospective studies it has been demonstrated that patients undergoing extended procedures will develop less metachronous colorectal neoplasms and will undergo less subsequent surgical procedures related to colorectal cancer. In females abdominal hysterectomy and bilateral salpingoophorectomy should be considered at the time of surgery for colorectal cancer.

Detection of Metachronous Neoplasms in Colorectal Cancer Patients: Identification of Risk Factors

Patients with colorectal cancer have a high risk of developing metachronous neoplasms. Identification of predictive factors associated with such conditions would allow individualized follow-up strategies in these patients. This study was designed to identify individual and familial factors associated with the development of metachronous colorectal neoplasms in patients with colorectal cancer. In the context of a prospective, multicenter, general population-based study-the EPICOLON project-all patients with colorectal cancer attended in ten Spanish hospitals during a one-year period were included. Patients with familial adenomatous polyposis or inflammatory bowel disease were excluded. All patients were monitored by colonoscopy within two years of the diagnoses. Demographic, clinical, pathologic, molecular (microsatellite instability status and immunohistochemistry for MSH2 and MLH1), and familial characteristics (fulfillment of Amsterdam I or II criteria, and revised Bethesda guidelines) were analyzed. A total of 353 patients were included in the study. At two years of follow-up, colonoscopy revealed the presence of adenomas in 89 (25 percent) patients and colorectal cancer in 14 (3.9 percent) patients, in 7 cases restricted to anastomosis. Univariate analysis demonstrated that development of metachronous neoplasm (adenoma or colorectal cancer) was associated with personal history of previous colorectal cancer (odds ratio, 5.58; 95 percent confidence interval, 1.01-31.01), and presence of previous or synchronous adenomas (odds ratio, 1.77; 95 percent confidence interval, 1.21-3.17). Although nonstatistical significance was achieved, metachronisms were associated with gender (P<0.09) and differentiation degree (P<0.08). Multivariate analysis identified previous or synchronous adenomas (odds ratio, 1.98; 95 percent confidence interval, 1.16-3.38) as independent predictive factor. Neither presence of tumor DNA microsatellite instability nor family history correlated with the presence of metachronous neoplasms. Patients with previous or synchronous colorectal adenoma have an increased risk of developing metachronous colorectal neoplasms. Accordingly, this subgroup of patients may benefit from specific surveillance strategies.

Lynch syndrome: implications for the surgeon.

Hereditary nonpolyposis colorectal cancer (HNPCC), or Lynch syndrome, is an autosomal dominant syndrome characterized by onset of colorectal cancer (CRC) at an early age, right-sided predominance, excess synchronous and metachronous colorectal neoplasms, and extracolonic neoplasms. It is the most common of the hereditary CRCs, so the practicing surgeon should expect to encounter patients with this disease. The diagnosis of HNPCC, which begins with a complete family history and a high index of suspicion by the clinician, has important implications in the management and surveillance of not only the affected individual but also for the individual's family. In this article, the diagnosis and management of Lynch syndrome will be reviewed, with emphasis on the implications for the surgeon.

Predictors of metachronous colorectal neoplasms in sporadic adenoma patients.

Our objective was to assess the overall risk of subsequent colorectal neoplasms (cancer or adenoma) in relation with the various characteristics of the index lesion in a cohort of patients who underwent endoscopic polypectomies of colorectal adenomas. A total of 1086 patients with adenomas of the large bowel were reported between 1979 and 1999 at the National Cancer Institute of Milan during a screening program for colorectal carcinoma. Data on patients who had colonoscopic examinations and treatments were collected prospectively. The relation between colorectal cancer (CRC) and adenoma features was assessed by computing the hazard ratio (HR) values and corresponding confidence intervals (95% CI) according to Cox proportional hazard models. Of the 1086 eligible patients (487 females, 579 males), 736 had single adenomas (67.7%) and 350 had multiple adenomas (32.3%). Histologic examination revealed 772 cases of tubular adenoma (73%), 205 cases of tubulovillous adenoma and 80 cases of villous adenoma (7.5%). Severe dysplasia was found in 3.3% of the cases. During the 11393 person-years of follow-up, with an average time of surveillance of 10.5 years, colorectal carcinomas developed in 10 patients (0.8%) and a new adenoma in 323 patients (29%). Multivariate analysis showed that male gender (HR 1.6; 95% CI 1.3-2.0), multiple polyps (HR 1.6; 95% CI 1.3-2.0), polyps larger than 2 cm (HR 1.5; 95% CI 1.1-2.1), tubulovillous and villous histology (HR 1.3; 95% CI 1.0-1.6 and HR 1.8; 95% CI 1.2-2.6, respectively) at index polypectomy were statistically significant risk factors for developing metachronous adenomatous polyps. The standardized incidence rates (SIR) for CRC was 0.52 (95% CI 0.25-0.95). The SIR was increased in subjects with severe dysplasia (2.8; 95% CI 0.34-1.02). Some features of large bowel adenomas are strongly correlated with an increased risk of metachronous adenomas and colorectal cancer. However, the endoscopic polypectomy is able to reduce by 50% the incidence of CRC in patients with large bowel adenomas.

Predictors of metachronous colorectal neoplasms in sporadic adenoma patients

Our objective was to assess the overall risk of subsequent colorectal neoplasms (cancer or adenoma) in relation with the various characteristics of the index lesion in a cohort of patients who underwent endoscopic polypectomies of colorectal adenomas. A total of 1086 patients with adenomas of the large bowel were reported between 1979 and 1999 at the National Cancer Institute of Milan during a screening program for colorectal carcinoma. Data on patients who had colonoscopic examinations and treatments were collected prospectively. The relation between colorectal cancer (CRC) and adenoma features was assessed by computing the hazard ratio (HR) values and corresponding confidence intervals (95% CI) according to Cox proportional hazard models. Of the 1086 eligible patients (487 females, 579 males), 736 had single adenomas (67.7%) and 350 had multiple adenomas (32.3%). Histologic examination revealed 772 cases of tubular adenoma (73%), 205 cases of tubulovillous adenoma and 80 cases of villous adenoma (7.5%). Severe dysplasia was found in 3.3% of the cases. During the 11393 person-years of follow-up, with an average time of surveillance of 10.5 years, colorectal carcinomas developed in 10 patients (0.8%) and a new adenoma in 323 patients (29%). Multivariate analysis showed that male gender (HR 1.6; 95% CI 1.3-2.0), multiple polyps (HR 1.6; 95% CI 1.3-2.0), polyps larger than 2 cm (HR 1.5; 95% CI 1.1-2.1), tubulovillous and villous histology (HR 1.3; 95% CI 1.0-1.6 and HR 1.8; 95% CI 1.2-2.6, respectively) at index polypectomy were statistically significant risk factors for developing metachronous adenomatous polyps. The standardized incidence rates (SIR) for CRC was 0.52 (95% CI 0.25-0.95). The SIR was increased in subjects with severe dysplasia (2.8; 95% CI 0.34-1.02). Some features of large bowel adenomas are strongly correlated with an increased risk of metachronous adenomas and colorectal cancer. However, the endoscopic polypectomy is able to reduce by 50% the incidence of CRC in patients with large bowel adenomas.