The management of malignant polyps in colorectal cancer screening programmes: A retrospective Italian multi-centre study

Factors affecting treatment decisions for endoscopically resected low- and high-risk malignant colorectal polyps in a screening setting

INTRODUCTION

The European Guidelines for colorectal cancer screening of 2006 state that only high-risk endoscopically resected malignant colorectal polyps (MCPs), defined as poor/no differentiation or positive resection margins or lymphovascular invasion, require colonic resection.

METHODS

A multicentre series of 954 patients with screen-detected MCP (northern Italy, 2005-2016, age 50-69) was studied to identify (1) the factors affecting the choice of colonic resection, and (2) the factors associated with deviation from the European Guidelines for low- and high-risk patients. Data analysis was based on multilevel logistic regression models.

RESULTS

Five hundred sixty-four (59.1 %) patients underwent colonic resection. The factors significantly associated with surgical referral included: distal and rectal versus proximal tumour site (inverse association); sessile and flat versus pedunculated morphology (direct association); tumour size (direct); moderate/poor versus good differentiation (direct); adenocarcinoma of not otherwise specified type versus adenocarcinoma with a residual adenoma component (direct); positive versus negative resection margins (direct); lymphovascular invasion (direct); and high-grade versus low-grade/absent tumour budding (direct). In low-risk MCPs, tumour budding encouraged strongly the decision for surgery. In high-risk MCPs, a distal/rectal tumour site encouraged the follow-up option.

CONCLUSION

The identification of factors associated with treatment choices other than those currently recommended may help prioritise the clinical questions in the development of future guidelines.

Oncologic outcomes of screen-detected and non-screen-detected T1 colorectal cancers

BACKGROUND

The incidence of T1 colorectal cancer (CRC) has increased with the implementation of CRC screening programs. It is unknown whether the outcomes and risk models for T1 CRC based on non-screen-detected patients can be extrapolated to screen-detected T1 CRC. This study aimed to compare the stage distribution and oncologic outcomes of T1 CRC patients within and outside the screening program.

METHODS

Data from T1 CRC patients diagnosed between 2014 and 2017 were collected from 12 hospitals in the Netherlands. The presence of lymph node metastasis (LNM) at diagnosis was compared between screen-detected and non-screen-detected patients using multivariable logistic regression. Cox proportional hazard regression was used to analyze differences in the time to recurrence (TTR), metastasis-free survival (MFS), cancer-specific survival (CSS), and overall survival. Additionally, the performance of conventional risk factors for LNM was evaluated across the groups.

RESULTS

1803 patients were included (1114 [62%] screen-detected), with median follow-up of 51 months (interquartile range 30). The proportion of LNM did not significantly differ between screen- and non-screen-detected patients (12.6% vs. 8.9%; odds ratio 1.41; 95%CI 0.89-2.23); a prediction model for LNM performed equally in both groups. The 3- and 5-year TTR, MFS, and CSS were similar for patients within and outside the screening program. However, overall survival was significantly longer in screen-detected T1 CRC patients (adjusted hazard ratio 0.51; 95%CI 0.38-0.68).

CONCLUSIONS

Screen-detected and non-screen-detected T1 CRCs have similar stage distributions and oncologic outcomes and can therefore be treated equally. However, screen-detected T1 CRC patients exhibit a lower rate of non-CRC-related mortality, resulting in longer overall survival.

Management of high and low risk malignant polyps: a population-wide analysis

AIM

The management of malignant polyps is a treatment dilemma in selecting between polypectomy and colorectal resection. To assist clinicians, guidelines have been developed by the Association of Coloproctology of Great Britain and Ireland (ACPGBI) to provide treatment recommendations.

METHODS

This study compared management strategy based on the ACPGBI risk categorization for malignant polyps. Univariable and multivariable statistical analysis was undertaken to assess the factors predicting management strategy. A population-wide analysis was performed of 1646 malignant polyps and the factors that predicted their management strategy, from Queensland, Australia, from 2011 to 2019.

RESULTS

Overall, 31.55% of patients with very low or low risk disease proceeded to resection. Of those with high or very high risk disease, 36.69% did not proceed to resection. In very low and low risk polyps, age (P = 0.003) and polyp location (P < 0.001) were significantly different between the colorectal resection group and the polypectomy alone group. In those with very high or high risk polyps age (P < 0.001), type of facility (public or private) for the colonoscopy (P = 0.037), right colonic polyps compared to left colonic polyps (P = 0.015) and rectal polyps (P < 0.001) and mismatch repair mutations present (P = 0.027) were predictive of resection in high risk disease using a multivariable model.

CONCLUSION

Over 30% of patients with very low and low risk malignant polyps proceeded to resection, against the advice of guidelines. Furthermore, over 35% of patients with very high or high risk malignant polyps did not proceed to resection. Education strategies may improve management decision choices. Furthermore, improvements in data collation will improve the understanding of management choices in the future.

Patient and pathological predictors of management strategy for malignant polyps following polypectomy: a systematic review and meta-analysis

PURPOSE

Malignant polyps present a treatment dilemma for clinicians and patients. This meta-analysis sought to identify the factors that predicted the management strategy for patients diagnosed with a malignant polyp.

METHODS

A literature search was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and the Cochrane Collaboration prognostic studies guidelines. Reports from 1985 onwards were included, data on patient and pathological factors were extracted and random effects meta-analysis models were used.

RESULTS

Fifteen studies were included. Seven studies evaluated lymphovascular invasion (LVI). The odds of surgery were significantly higher in malignant polyps with LVI (OR 2.20, 95% CI 1.36-3.55). Ten studies revealed the odds of surgery were significantly higher with positive polypectomy margins (OR 8.09, 95% CI 4.88-13.40). Tumour differentiation was compared in eight studies. There were significantly lower odds of surgery in malignant polyps with well/moderate differentiation compared with poor differentiation (OR 0.31, 95% CI 0.21-0.46). There were non-significant trends favouring surgical resection in younger patients, males and Haggitt 4/Kikuchi Sm3 lesions. There was considerable heterogeneity in the meta-analyses for the variables age, gender, polyp morphology and Haggitt/Kikuchi level (I² > 75%).

CONCLUSION

This meta-analysis has demonstrated that LVI, positive polypectomy resection margins, and poor tumour differentiation significantly predict malignant polypectomy patients who underwent subsequent surgery. Age and gender were important factors predicting management, but not consistently across studies, whilst polyp morphology and Haggitt/Kikuchi levels did not significantly predict the management strategy. Further research may assist in understanding the management preferences.

Factors predicting occurrence and therapeutic choice in malignant colorectal polyps: a study of 13 years of colonoscopic polypectomy

Colorectal carcinoma represents a major cause of mortality and 0.2–12% of resected colonic polyps have malignant cells inside. We performed a retrospective study of patients with resected polyps during a period of 13 years. A total of 905 patients had 2033 polyps removed; 122 polyps (109 patients) had malignant cells. Prevalence of malignant polyps with submucosal invasion was 1.23% and for all polyps with malignant cells was 6%; malignant polyps had a larger size (23.44 mm mean diameter) vs benign polyps (9.63 mm); the risk of malignancy was increased in polyps larger than 10 mm, in lateral spreading lesions and in Paris types 0-Ip, 0-Isp, in sigmoid, descending colon and rectum, in sessile serrated adenoma and traditional serrate adenoma subtypes of serrated lesions and in tubulovillous and villous adenoma. In 18 cases surgery was performed, in 62 patients only colonoscopic follow-up was made and in 35 patients no colonoscopic follow-up was recorded. From initially endoscopic resected polyps, recurrence was noted in seven (11.3%) cases; there was a trend toward association with depth of invasion, piecemeal resection, right and rectum location, sessile and lateral spreading type and pathological subtype. In surgical group, post-therapeutic staging was available in 11 cases; nodal involvement was noted in three (27.27%) cases; none had lymphatic or vascular invasion in endoscopically resected polyps. Four patients with no macroscopic local recurrence underwent surgery with no residual tumor. The rate of metastasis was 16.67% in surgical group and 1.61% in endoscopic group. Evaluation of lymph node (LN) invasion was available for 11 operated patients, with LN invasion (N1) in three patients, local residual tumoral tissue in one patient with incomplete resection and no residual tumor (R0 resection) in four patients with endoscopic resection before surgery.

Management of T1 colorectal cancers detected at screening colonoscopy: A study from the French national screening programme

AIM

The main aim of this study was to examine the management strategies that were used and to determine the outcomes (survival and recurrence rate) of screen-detected T1-CRC.

METHODS

Medical records from 207 patients with T1-CRC diagnosed through the French national screening programme in one district from 2003 to 2015 were analysed. The 5-year overall, CRC-specific and CRC-free survival were calculated for the whole cohort and for the 3 groups treated by endoscopic resection (ER) alone, ER followed by subsequent surgery (ERSS), and primary surgery (PS).

RESULTS

Of the 207 patients, 81 (39%) underwent PS, and 126 (61%) underwent primary ER, of whom 82 (64%) underwent subsequent surgery. The 5-year overall and cancer-specific survival rates were 95.5% (95% CI, 90.8; 97.9) and 98.8% (95% CI, 95.4; 99.7%), respectively. Long-term cancer-specific mortality and recurrence crude rates were 2.4% and 5.6%, respectively. The 5-year CRC-free survival rate was 96.1% (95% CI, 91.8; 98.1%) and did not differ amongst the 3 groups (ER alone, ERSS and PS).

CONCLUSION

This study demonstrates the good prognosis of screen-detected T1-CRC, regardless of the treatment strategy used. But, there is a room to improve the screening programme quality with regard to the management of screen-detected CRC.

Clinical management of endoscopically resected pT1 colorectal cancer

Background  Implementation of colorectal cancer (CRC) screening programs increases endoscopic resection of polyps with early invasive CRC (pT1). Risk of lymph node metastasis often leads to additional surgery, but despite guidelines, correct management remains unclear. Our aim was to assess the factors affecting the decision-making process in endoscopically resected pT1-CRCs in an academic center. Methods  We retrospectively reviewed patients undergoing endoscopic resection of pT1 CRC from 2006 to 2016. Clinical, endoscopic, surgical treatment, and follow-up data were collected and analyzed. Lesions were categorized according to endoscopic/histological risk-factors into low and high risk groups. Comorbidities were classified according to the Charlson comorbidity index (CCI). Surgical referral for each group was computed, and dissociation from current European CRC screening guidelines recorded. Multivariate analysis for factors affecting the post-endoscopic surgery referral was performed. Results  Seventy-two patients with endoscopically resected pT1-CRC were included. Overall, 20 (27.7 %) and 52 (72.3 %) were classified as low and high risk, respectively. In the low risk group, 11 (55 %) were referred to surgery, representing over-treatment compared with current guidelines. In the high risk group, nonsurgical endoscopic surveillance was performed in 20 (38.5 %) cases, representing potential under-treatment. After a median follow-up of 30 (6 - 130) months, no patients developed tumor recurrence. At multivariate analysis, age (OR 1.21, 95 %CI 1.02 - 1.42; P  = 0.02) and CCI (OR 1.67, 95 %CI 1.12 - 3.14; P  = 0.04) were independent predictors for subsequent surgery. Conclusions  A substantial rate of inappropriate post-endoscopic treatment of pT1-CRC was observed when compared with current guidelines. This was apparently related to an overestimation of patient-related factors rather than endoscopically or histologically related factors.

Management of Pt1 tumours removed by endoscopy during colorectal cancer screening: Outcome and treatment quality indicators

INTRODUCTION

Limited information is available about outcomes of patients with malignant adenomas endoscopically resected at screening. The aim of the study was to evaluate diagnostic and therapeutic quality indicators and to correlate them with clinical and surgical outcomes.

MATERIALS AND METHODS

We reviewed endoscopic and histology characteristics of all pT1 tumours endoscopically removed at the time of colonoscopy assessment in subjects with a positive screening test result in the context of a population-based program.

RESULTS

392 pT1 tumours were completely removed by endoscopy (en-bloc = 86.7%, piecemeal = 13.3%) and the histology report was considered complete in 83.2% of cases. Treatment was limited to endoscopic excision for 120 patients (30.7%, Group 1), 272 (69.3%, Group 2) underwent radicalisation surgery. In patients who had at least 1 lymph node examined, the rate of nodal involvement was 5.4% (13/239); no metastatic node was found in the 21 (27.6%) out of 76 patients with low-risk adenomas, who underwent surgery.

CONCLUSION

Risk of nodal involvement in colorectal pT1 tumours is well predicted by known histologic features also in a screening setting, although it was lower than among patients from clinical series. Surgical overtreatment is still significantly present and there is ample room for improvement regarding diagnostic and therapeutic flow-chart.

Malignant colorectal polyps: endoscopic polypectomy and watchful waiting is not inferior to subsequent bowel resection. A nationwide propensity score-based analysis

BACKGROUND AND AIMS

The optimal treatment of patients with malignant colorectal polyps is unsettled. The surgical dilemma following polypectomy is selecting between watchful waiting (WW) and subsequent bowel resection (SBR), but the long-term survival outcomes have not been established yet. This nationwide study compared survival of patients after WW or SBR.

METHODS

Danish nationwide study with 100% follow-up of all patients with malignant colorectal polyps (the Danish Colorectal Cancer Group database) in a 10-year period from 2001 to 2011. All patients' charts and histological reports were individually reviewed. Survival rates were calculated with Cox proportional hazard model after propensity score matching.

RESULTS

A total of 692 patients were included (WW, 424 (61.3%), SBR, 268 (38.7%)) with a mean follow-up of 7.5 years (3-188 months). Following propensity score matching, there was no significant difference in overall or disease-free survival (p = 0.344 and p = 0.184) or rate of local recurrence (WW, 7.2%, SBR, 2%, p = 0.052) or distant metastases (WW, 3.3%, SBR, 4.6%, p = 0.77). In the SBR group, there was no residual tumor or lymph node metastases in the resected specimen in 82.5% of the patients.

CONCLUSION

Subsequent bowel resection may not be superior to endoscopic polypectomy and watchful waiting with regard to overall and disease-free survival in patients with malignant colorectal polyps.