Increased incidence of colorectal adenomas in follow-up evaluation of patients with newly diagnosed hyperplastic polyps

Intraoperative colonoscopy in laparoscopic colorectal surgery: A review of recent publications

INTRODUCTION

Laparoscopic colorectal resection is becoming the gold standard for treating colorectal cancers because it offers superior short-term and comparable long-time outcomes compared to open surgery. Intraoperative colonoscopy (IOC) is increasingly performed for tumor localization and mucosal assessment. The aim of this report was to review the safety and efficacy of IOC in laparoscopic colorectal surgery.

METHOD

A MEDLINE search of studies of IOC in laparoscopic colorectal surgery was performed. We focused on three aspects of IOC use: (i) IOC for intraoperative tumor localization; (ii) colonic irrigation and IOC for obstructive left-sided colorectal cancers; and (iii) IOC for assessing colorectal anastomosis.

RESULTS

During laparoscopic colorectal surgery, IOC enables accurate localization of early mucosal tumors, detection of lesions in the proximal unexamined colon for obstructive left-sided cancer, and visual assessment of anastomosis. Additionally, IOC allows for proper surgical resection, management of concomitant lesions, immediate maintenance of hemostasis, suture repair of leaks, and the creation of a protective stoma as necessary.

CONCLUSIONS

Intraoperative colonoscopy is beneficial in laparoscopic colorectal surgery. Experienced surgical endoscopists should be trained to safely perform IOC.

Sex-influenced association of non-alcoholic fatty liver disease with colorectal adenomatous and hyperplastic polyps

AIM

To investigate the relationship between non-alcoholic fatty liver disease (NAFLD) and colorectal adenomatous and hyperplastic polyps.

METHODS

A retrospective cross-sectional study was conducted on 3686 individuals undergoing health checkups (2430 males and 1256 females). All subjects underwent laboratory testing, abdominal ultrasonography, colonoscopy, and an interview to ascertain the baseline characteristics and general state of health. Multinomial logistic regression analysis was performed to examine the association between NAFLD and the prevalence of colorectal adenomatous and hyperplastic polyps. Furthermore, the relationship was analyzed in different sex groups. Subgroup analysis was performed based on number, size, and location of colorectal polyps.

RESULTS

The prevalence of colorectal polyps was 38.8% in males (16.2% for adenomatous polyps and 9.8% for hyperplastic polyps) and 19.3% in females (8.4% for adenomatous polyps and 3.9% for hyperplastic polyps). When adjusting for confounding variables, NAFLD was significantly associated with the prevalence of adenomatous polyps (OR = 1.28, 95%CI: 1.05-1.51, P < 0.05) and hyperplastic polyps (OR = 1.35, 95%CI: 1.01-1.82, P < 0.05). However, upon analyzing adenomatous and hyperplastic polyps in different sex groups, the significant association remained in males (OR = 1.53, 95%CI: 1.18-2.00, P < 0.05; OR = 1.42, 95%CI: 1.04-1.95, P < 0.05) but not in females (OR = 0.44, 95%CI: 0.18-1.04, P > 0.05; OR = 1.18, 95%CI: 0.50-2.78, P > 0.05).

CONCLUSION

NAFLD is specifically associated with an increased risk of colorectal adenomatous and hyperplastic polyps in men. However, NAFLD may not be a significant factor in the prevalence of colorectal polyps in women.

The clinical effectiveness of different surveillance strategies to prevent colorectal cancer in people with intermediate-grade colorectal adenomas: a retrospective cohort analysis, and psychological and economic evaluations

BACKGROUND

The UK guideline recommends 3-yearly surveillance for patients with intermediate-risk (IR) adenomas. No study has examined whether or not this group has heterogeneity in surveillance needs.

OBJECTIVES

To examine the effect of surveillance on colorectal cancer (CRC) incidence; assess heterogeneity in risk; and identify the optimum frequency of surveillance, the psychological impact of surveillance, and the cost-effectiveness of alternative follow-up strategies.

DESIGN

Retrospective multicentre cohort study.

SETTING

Routine endoscopy and pathology data from 17 UK hospitals (n = 11,944), and a screening data set comprising three pooled cohorts (n = 2352), followed up using cancer registries.

SUBJECTS

Patients with IR adenoma(s) (three or four small adenomas or one or two large adenomas).

PRIMARY OUTCOMES

Advanced adenoma (AA) and CRC detected at follow-up visits, and CRC incidence after baseline and first follow-up.

METHODS

The effects of surveillance on long-term CRC incidence and of interval length on findings at follow-up were examined using proportional hazards and logistic regression, adjusting for patient, procedural and polyp characteristics. Lower-intermediate-risk (LIR) subgroups and higher-intermediate-risk (HIR) subgroups were defined, based on predictors of CRC risk. A model-based cost-utility analysis compared 13 surveillance strategies. Between-group analyses of variance were used to test for differences in bowel cancer worry between screening outcome groups (n = 35,700). A limitation of using routine hospital data is the potential for missed examinations and underestimation of the effect of interval and surveillance.

RESULTS

In the hospital data set, 168 CRCs occurred during 81,442 person-years (pys) of follow-up [206 per 100,000 pys, 95% confidence interval (CI) 177 to 240 pys]. One surveillance significantly lowered CRC incidence, both overall [hazard ratio (HR) 0.51, 95% CI 0.34 to 0.77] and in the HIR subgroup (n = 9265; HR 0.50, 95% CI 0.34 to 0.76). In the LIR subgroup (n = 2679) the benefit of surveillance was less clear (HR 0.62, 95% CI 0.16 to 2.43). Additional surveillance lowered CRC risk in the HIR subgroup by a further 15% (HR 0.36, 95% CI 0.20 to 0.62). The odds of detecting AA and CRC at first follow-up (FUV1) increased by 18% [odds ratio (OR) 1.18, 95% CI 1.12 to 1.24] and 32% (OR 1.32, 95% CI 1.20 to 1.46) per year increase in interval, respectively, and the odds of advanced neoplasia at second follow-up increased by 22% (OR 1.22, 95% CI 1.09 to 1.36), after adjustment. Detection rates of AA and CRC remained below 10% and 1%, respectively, with intervals to 3 years. In the screening data set, 32 CRCs occurred during 25,745 pys of follow-up (124 per 100,000 pys, 95% CI 88 to 176 pys). One follow-up conferred a significant 73% reduction in CRC incidence (HR 0.27, 95% CI 0.10 to 0.71). Owing to the small number of end points in this data set, no other outcome was significant. Although post-screening bowel cancer worry was higher in people who were offered surveillance, worry was due to polyp detection rather than surveillance. The economic evaluation, using data from the hospital data set, suggested that 3-yearly colonoscopic surveillance without an age cut-off would produce the greatest health gain.

CONCLUSIONS

A single surveillance benefited all IR patients by lowering their CRC risk. We identified a higher-risk subgroup that benefited from further surveillance, and a lower-risk subgroup that may require only one follow-up. A surveillance interval of 3 years seems suitable for most IR patients. These findings should be validated in other studies to confirm whether or not one surveillance visit provides adequate protection for the lower-risk subgroup of intermediate-risk patients.

STUDY REGISTRATION

Current Controlled Trials ISRCTN15213649.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Activation of pro-oncogenic pathways in colorectal hyperplastic polyps

Background

In contrast to sessile serrated adenomas and traditional serrated adenomas which are associated with a significant cancer risk, the role of hyperplastic polyps (HP) in colorectal carcinogenesis as well as the molecular mechanisms underlying their development remain controversial and still need to be clarified. Several reports suggest that a subset of HP may represent precursor lesions of some colorectal cancers. However, biomarkers are needed to identify the subset of HP that may have a malignant potential. The hormone precursor, progastrin (PG) has been involved in colon carcinogenesis and is known to activate pro-oncogenic pathways such as the ERK or the STAT3 pathway. We therefore analyzed PG expression and the activation of these signaling factors in HP.

Methods

We retrospectively analyzed PG expression as well as the phosphorylation of ERK and STAT3 by immunohistochemistry in HP from 48 patients.

Results

Mean percentages of epithelial cells positive for PG or phospho-ERK were respectively, 31% and 33% in HP and were significantly higher in these lesions compared to normal colon (3%, p = 0.0021 and 7%, p = 0.0008, respectively). We found a significant correlation between PG and phospho-ERK expression in HP with ERK activation significantly stronger in lesions with high progastrin expression (p = 0.015). In contrast, STAT3 was not significantly activated in HP compared to normal colon and we did not observe a significant correlation with PG expression.

Conclusions

HP overexpressing PG that have the highest activation of the ERK pathway might reflect less latent lesions that might have a malignant potential.

Progastrin Peptides Increase the Risk of Developing Colonic Tumors: Impact on Colonic Stem Cells

Pre-neoplastic lesions (ACF, aberrant-crypt-foci; Hp, hyperplastic/dysplastic polyps) are believed to be precursors of sporadic colorectal-tumors (Ad, adenomas; AdCA, adenocarcinomas). ACF/Hp likely originate due to abnormal growth of colonic-crypts in response to aberrant queues in the microenvironment of colonic-crypts. Thus identifying factors which regulate homeostatic vs aberrant proliferation/apoptosis of colonocytes, especially stem/progenitor cells, may lead to effective preventative/treatment strategies. Based on this philosophy, role of growth-factors/peptide-hormones, potentially available in the circulation/microenvironment of colonic-crypts is being examined extensively. Since the time gastrins were discovered as trophic (growth) factors for gastrointestinal-cells, the effect of gastrins on the growth of normal/cancer cells has been investigated, leading to many discoveries. Seminal discoveries made in the area of gastrins and colon-cancer, as it relates to molecular pathways associated with formation of colonic tumors will be reviewed, and possible impact on diagnostic/preventative/treatment strategies will be discussed.

Serrated lesions of the colorectum: review and recommendations from an expert panel

Serrated lesions of the colorectum are the precursors of perhaps one-third of colorectal cancers (CRCs). Cancers arising in serrated lesions are usually in the proximal colon, and account for a disproportionate fraction of cancer identified after colonoscopy. We sought to provide guidance for the clinical management of serrated colorectal lesions based on current evidence and expert opinion regarding definitions, classification, and significance of serrated lesions. A consensus conference was held over 2 days reviewing the topic of serrated lesions from the perspectives of histology, molecular biology, epidemiology, clinical aspects, and serrated polyposis. Serrated lesions should be classified pathologically according to the World Health Organization criteria as hyperplastic polyp, sessile serrated adenoma/polyp (SSA/P) with or without cytological dysplasia, or traditional serrated adenoma (TSA). SSA/P and TSA are premalignant lesions, but SSA/P is the principal serrated precursor of CRCs. Serrated lesions have a distinct endoscopic appearance, and several lines of evidence suggest that on average they are more difficult to detect than conventional adenomatous polyps. Effective colonoscopy requires an endoscopist trained in the endoscopic appearance of serrated lesions. We recommend that all serrated lesions proximal to the sigmoid colon and all serrated lesions in the rectosigmoid > 5 mm in size, be completely removed. Recommendations are made for post-polypectomy surveillance of serrated lesions and for surveillance of serrated polyposis patients and their relatives.

Prevalence of colorectal polyps in pediatric colonoscopy

BACKGROUND

The available data regarding the prevalence, types, and clinical determinants of colonic polyps in children is limited.

AIMS

We aimed to estimate the prevalence of colorectal polyps in a large cohort of children.

METHODS

We conducted a cross-sectional study to determine the presence, number, and location of colorectal polyps reported in all children (0-20 years) who underwent colonoscopy at 14 pediatric facilities between January 2000 and December 2007 recorded in Pediatric Endoscopy Database System Clinical Outcomes Research Initiative (PEDS-CORI). We compared procedures with and without polyps with respect to procedure indication, age, sex, and race. We also reviewed a sample of histopathologic reports from one participating center.

RESULTS

We analyzed 13,115 colonoscopy procedures performed in 11,637 patients. Colorectal polyps were reported in 810 procedures (6.1%; 95% CI: 5.7-6.5%) performed in 705 patients, and in 12% of patients with lower GI bleeding. Children with colorectal polyps were significantly younger (8.9 years vs. 11.9 years; p < 0.0001), male (58.3% vs. 49.0%; p < 0.001), non-white race (27.5% vs. 21.9%; p < 0.001), and had lower GI bleeding (54.4% vs. 26.6%; p < 0.001) as compared to children without polyps. In a sample of 122 patients with polyps from a single center, the histological types were solitary juvenile in 91 (70.5%), multiple juvenile in 20 (15.5%), adenoma in 14 (10.9%) and hyperplastic polyps in four patients (3.1%).

CONCLUSIONS

Colorectal polyps are detected in 6.1% overall and in 12.0% among those with lower gastrointestinal bleeding during pediatric colonoscopy. Approximately 26% are multiple juvenile or adenoma.

A new biomarker that predicts colonic neoplasia outcome in patients with hyperplastic colonic polyps

The most frequently occurring lesions in the colon are the hyperplastic polyps. Hyperplastic polyps have long been considered as lesions with no malignant potential and colonoscopy for these patients is not recommended. However, recent works suggest that hyperplastic polyps may represent precursor lesions of some sporadic colorectal cancers. Until now, no biomarker allows to identify the subset of hyperplastic polyps that may have a malignant potential. Because the hormone precursor progastrin has been involved in colon carcinogenesis, we investigated whether its expression in hyperplastic polyps predicts the occurrence of colonic neoplasm after resection of hyperplastic polyps. We retrospectively analyzed progastrin expression in hyperplastic polyps from 74 patients without history of colorectal pathology. In our study, 41% of patients presenting an initial hyperplastic polyp subsequently developed adenomatous polyps, recognized as precursor lesions for colorectal adenocarcinomas. Progastrin was overexpressed in the hyperplastic polyps in 40% of the patients. We showed a significant association between progastrin overexpression and shortened neoplasm-free survival (P = 0.001). Patients with high overexpression of progastrin had a 5-year neoplasm-free survival rate of 38% as compared with 100% for the patients with low progastrin expression. In addition, we established a predictive test on the basis of progastrin staining and patients' age that predicts occurrence of neoplasm after developing a first hyperplastic polyp with a sensitivity of 100% [95% confidence interval (CI), 79%-100%] and a specificity of 74% (51%-90%). We show that progastrin expression evaluation in hyperplastic polyps is an efficient prognostic tool to determine patients with higher risk of metachronous neoplasms who could benefit from an adapted follow-up.

Do guidelines improve clinical practice? - a national survey on surveillance colonoscopies

BACKGROUND

Colonoscopic services are increasingly being utilized in surveillance of conditions predisposing to colorectal cancers (CRC). The ACPGBI/BSG guidelines are the most commonly followed recommendations. Numerous retrospective studies have shown poor compliance with them. We conducted a national survey of colonoscopic practitioners investigating attitudes, awareness and implementation of surveillance guidelines.

METHOD

A postal questionnaire was sent to a random population of 250 ACPGBI and 200 BSG members. Questions assessed practice as regards colorectal polyp surveillance, family screening and surveillance for past history of CRC.

RESULTS

The ACPGBI/BSG guidelines were the most commonly followed recommendations. Only 17.2% of practitioners used the criteria that would ensure accurate implementation of guidelines for colorectal adenoma surveillance. With regards to familial surveillance for CRC, 53.5% respondents assessed familial risk accurately, while 69.3% recommended surveillance incorrectly. A total of 48.8% of ACPGBI members recommended five yearly colonoscopies following curative treatment for CRC.

CONCLUSION

This study has revealed the widespread ignorance of guidelines, which will potentially translate into the gross over utilization of colonoscopic resources. Strategies to improve and audit guideline implementation must be integral to guideline formation. Methods to improve accurate guideline implementation need to be explored.

Colonic adenoma patients have higher incidence of hyperplastic polyps on surveillance colonoscopy

OBJECTIVES

To determine the incidence of hyperplastic polyps in patients undergoing surveillance colonoscopy and to compare with the prevalence in individuals undergoing index colonoscopy.

PATIENTS AND METHODS

This prospective observational study included patients with index colonoscopy findings of adenomas, adenoma with concomitant hyperplastic polyps and advanced neoplasia who subsequently underwent surveillance colonoscopy. Patient characteristics, indications for colonoscopy, interval between examinations and findings were recorded. These findings were compared with our control group that comprised of patients who underwent index colonoscopy during the same period.

RESULTS

Study group consisted of 108 patients (median age 61.5 years) who underwent index colonoscopy for indications including, weight loss, rectal bleeding, altered bowel habits and anaemia. On index colonoscopy, adenomas, adenoma with concomitant hyperplastic polyps and advanced neoplasia were present in 61, 35 and 12 patients, respectively. Surveillance colonoscopy was performed after a mean follow-up period of 29 +/- 17 months. Findings on surveillance examination included hyperplastic polyps in 35 and 57% of patients with past adenomas and adenoma with concomitant hyperplastic polyps, respectively. Control group included 3852 symptomatic patients who had index colonoscopy (median age, 65 years). Hyperplastic polyps, adenomas and advanced neoplasia were found in 155 (4%), 388 (10%) and 60 (1.5%) of patients, respectively. Hyperplastic polyps and adenoma were significantly higher in study group as compared with control group (P >0.5).

CONCLUSION

Incidence of hyperplastic polyps is significantly higher on surveillance colonoscopy as compared with the prevalence on index colonoscopy. This may signify a continuous spectrum of biological evolution between hyperplastic polyps and adenomas.

Charity Colonoscopy Event to Commemorate the 185th Anniversary of Singapore General Hospital

Introduction: Colorectal cancer is now the cancer with the highest incidence in Singapore. However, the overall mortality rate is still about 50% because the majority of the patients present at a late stage of disease. A charity event of screening colonoscopy was offered to the public in conjunction with the 185th anniversary of Singapore General Hospital. The aim of this event was to raise awareness about early detection of colorectal cancer and the safety of colonoscopy. Materials and Methods: We conducted a one-off free screening event for colorectal cancer using colonoscopy. Four hundred and ninety individuals responded to a multimedia advertisement for the event. Of these, 220 individuals were selected for the screening based on National Guidelines for colorectal cancer screening and financial status. Results: One hundred and fifty-two individuals turned up for the colonoscopy. The median age was 55 years (range, 22 to 82), with 84 males. Significant pathology was found in 33% of the individuals (n = 51). Colorectal polyps were detected in 34 individuals (22%). A total of 45 polyps were removed, with 20 hyperplastic polyps and 25 adenomas. Eight out of 25 adenomas were located proximal to the splenic flexure. Rectal cancer was diagnosed in 1 individual (0.6%). One individual had a large dysplastic rectosigmoid ulcer and refused further intervention. There were no significant complications from any of the colonoscopies. Conclusions: Colonoscopy is an invaluable screening modality as it has a high pick-up rate for colorectal polyp and cancer in an asymptomatic population. It is also proven to be safe in our study. It has the added advantage over flexible sigmoidoscopy of detecting a significant number of proximal lesions. Also, therapeutic polypectomy can be performed in the same setting. Colorectal cancer is now the cancer with the highest incidence in Singapore. Similar to many developed countries, individuals here have a moderate to high risk of developing colorectal cancer in their lifetime. Key words: Cancer screening, Colonoscopy, Colorectal cancer, Colorectal polyps, Polypectomy

Association of large serrated polyps with synchronous advanced colorectal neoplasia

OBJECTIVES

Serrated polyps of the colorectum are a histologically and genetically heterogeneous group of lesions, which include classic hyperplasic polyps, sessile serrated adenomas (SSAs), and traditional serrated adenomas. Accumulating evidence suggests that they may have different malignancy potentials. This study sought to determine the association between the presence of large serrated colorectal polyps and synchronous advanced colorectal neoplasia.

METHODS

Among 4,714 asymptomatic subjects who underwent screening colonoscopy, cases of advanced colorectal neoplasia (tubular adenoma > or =1 cm, adenoma with any villous histology, adenoma with carcinoma in situ / high-grade dysplasia, or invasive adenocarcinoma) were compared with controls without advanced neoplasia with respect to candidate predictors, including age, sex, family history of colorectal cancer, body mass index, the presence and number of small tubular adenomas (<1 cm), the presence of multiple small serrated polyps (<1 cm), and the presence of large serrated polyps (> or =1 cm). Independent predictors of advanced neoplasia were determined by multivariate logistic regression analysis.

RESULTS

Among 467 cases and 4,247 controls, independent predictors of advanced colorectal neoplasia were increasing age (odds ratio (OR)=4.51; 95% confidence interval (CI), 1.43-14.3; P=0.01 for subjects > or =80 years vs. 50-54 years of age); non-advanced tubular adenomas (OR=2.33; 95% CI 1.37-3.96, P=0.0017 for 3 or more); and large serrated polyps (OR=3.24; 95% CI 2.05-5.13, P<0.0001). In total, 109 subjects (2.3% of the study population) had large serrated polyps. Right- and left-sided large serrated polyps had a similar association with advanced colorectal neoplasia (OR=3.38 vs. 2.66, P=0.62).

CONCLUSIONS

Large serrated polyps are strongly and independently associated with synchronous advanced colorectal neoplasia. Our results suggest that large serrated polyps may be a marker for advanced colorectal neoplasia. Further studies are needed to determine whether the association with advanced neoplasia differs among subsets of serrated polyps, particularly SSAs and classic hyperplastic polyps.

Hyperplastic polyps and the risk of adenoma recurrence in the polyp prevention trial

BACKGROUND AND AIMS

Recent studies have suggested that some hyperplastic polyps may be associated with an increased risk of colorectal cancer. Prospective information on the risk of adenoma recurrence associated with hyperplastic polyps is limited. We sought to investigate whether the coexistence of hyperplastic polyps with adenomas increases the risk of adenoma recurrence.

METHODS

We used unconditional logistic regression models to examine the association between baseline hyperplastic polyps and subsequent adenoma recurrence during a 3-year follow-up evaluation, among 1637 participants in the Polyp Prevention Trial.

RESULTS

A total of 437 participants (26.7%) had hyperplastic polyps coexisting with adenomas at baseline. Of these, 132 (30.2%) had at least one hyperplastic polyp in the proximal colon, whereas 305 (69.8%) had only distal hyperplastic polyps. When compared with subjects without any hyperplastic polyps at baseline, there was no statistically significant association between the presence of baseline hyperplastic polyps and recurrence of any adenoma (odds ratio [OR], 1.19; 95% confidence interval [CI], 0.94-1.51) or advanced adenoma (OR, 1.25; 95% CI, 0.78-2.03). Also, there was no association between hyperplastic polyp location and adenoma recurrence (OR, 1.01; 95% CI, 0.69-1.48) for any proximal hyperplastic polyp (OR, 1.26; 95% CI, 0.96-1.65) and for distal hyperplastic polyps.

CONCLUSIONS

The coexistence of hyperplastic polyps with adenomas, irrespective of location, does not confer an increased risk of adenoma recurrence beyond that of adenomas alone within 3 years of follow-up evaluation. Prospective long-term studies on adenoma recurrence risk associated with hyperplastic polyps in screening populations are needed.

High prevalence of colonic polyps in white males with esophageal adenocarcinoma

PURPOSE

There is ongoing discussion regarding Barrett's esophagus and the prevalence of colonic neoplasms. The goal of this investigation was to evaluate colonoscopic findings in patients with esophageal carcinoma.

METHODS

In this case-control study, we used the data of patients with esophagectomy. These patients underwent routine preoperative endoscopy of the entire colon to exclude pathologic findings pending the need for colonic bridging graft reconstruction. A total of 171 patients with esophageal cancer (78 adenocarcinomas, 93 squamous-cell carcinomas, and 168 control subjects) who underwent screening colonoscopy were included. Univariate analysis and multinomial logistic regression were used to calculate odds ratios for colonic polyps.

RESULTS

The age of the three groups of patients was comparable (median age: adenocarcinoma = 62 years, squamous-cell carcinoma = 58 years, control subjects = 59 years). The male to female ratio differed significantly (adenocarcinoma = 71:7, squamous-cell carcinoma = 65:28, control subjects = 86:82; P < 0.001). Patients with adenocarcinoma had more findings on colonoscopy than patients with squamous-cell carcinoma (45 and 25 percent, respectively; P < 0.01) or control subjects (14 percent; P < 0.001). Analyzing the male data only, the difference was more pronounced. The histologic type of the esophageal tumor significantly impacted the presence of colorectal polyps even with age-adjusted and sex-adjusted data (P < 0.001), with an odds ratio of 4.03 for adenocarcinoma.

CONCLUSION

These results demonstrate a significant relationship between the development of Barrett's carcinoma and colonic polyps.

Association between cigarette smoking and colorectal cancer in the Women's Health Initiative

The evidence linking cigarette smoking to the risk of colorectal cancer is inconsistent. We investigated the associations between active and passive smoking and colorectal cancer among 146,877 Women's Health Initiative participants. Women reported detailed smoking histories at enrollment. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated for the association between smoking and overall and site-specific risk of colorectal cancer. Invasive colorectal cancer was diagnosed in 1242 women over an average of 7.8 years (range = 0.003-11.2 years) of follow-up. In adjusted analyses, statistically significant positive associations were observed between most measures of cigarette smoking and risk of invasive colorectal cancer. Site-specific analyses indicated that current smokers had a statistically significantly increased risk of rectal cancer (HR = 1.95, 95% CI = 1.10 to 3.47) but not colon cancer (HR = 1.03, 95% CI = 0.77 to 1.38), compared with never smokers. Passive smoke exposure was not associated with colorectal cancer in adjusted analyses. Thus, active exposure to cigarette smoking appears to be a risk factor for rectal cancer.

The Association Between Cigarette Smoking and Colorectal Polyp Recurrence (United States)

OBJECTIVE

Although evidence exists linking smoking to precancerous colorectal adenomatous polyps, few studies have examined the association between cigarette smoking and recurrence of colorectal polyps. This association was investigated prospectively with data from the Polyp Prevention Trial.

METHODS

Cigarette smoking data were collected through baseline interviews. The study was completed by 1872 men and women with presence of adenomas at baseline colonoscopy. Multiple logistic regression analysis was used to examine the association between cigarette smoking and polyp recurrence (adenomatous and hyperplastic) up to four years from baseline.

RESULTS

Adenoma recurrence was not related to cigarette smoking. Current smokers had increased odds of hyperplastic polyps at follow-up compared to never smokers (OR 2.88, 95% CI 2.06-4.01). Current smoking was associated with subsequent distal (OR 3.44, 95% CI 2.38-4.95) and rectal (OR 3.53, 95% CI 2.15-5.78) hyperplastic polyps, but not subsequent proximal hyperplastic polyps. Cigarette smoking was associated with subsequent multiple and small size (4 mm) hyperplastic polyps. Significant linear trends were observed between development of subsequent hyperplastic polyps and all smoking variables.

CONCLUSIONS

Although no association with recurrent adenomas was observed, cigarette smoking was significantly associated with hyperplastic polyp development, except for those in the proximal colon. This prospective study confirms that cigarette smoking has a significant effect on the development of hyperplastic colorectal polyps.

Colorectal polyps and other precursor lesions. Need for an expanded view

The traditional understanding of adenomas serving as precursors for a homogeneous group of adenocarcinomas is being assailed from all sides. Clearly, the relationship between precursor lesions and adenocarcinomas with defective DNA mismatch repair is much more complex and appears to include right-sided hyperplastic polyps as precursor lesions in some cases. Additional data will be forthcoming regarding this risk of adenocarcinoma development in right-sided hyperplastic polyps, both through defective DNA mismatch repair and methylation of the MGMT gene. This will likely be accompanied by an attempt to reclassify at least some larger hyperplastic polyps as serrated adenomas either on subtle morphologic or molecular grounds.