An evidence-based treatment algorithm for colorectal polyp cancers: results from the Scottish Screen-detected Polyp Cancer Study (SSPoCS)

Long-term outcomes after endoscopic removal of malignant colorectal polyps: Results from a 10-year cohort

BACKGROUND

Choosing an optimal post-polypectomy management strategy of malignant colorectal polyps is challenging, and evidence regarding a surveillance-only strategy is limited.

AIM

To evaluate long-term outcomes after endoscopic removal of malignant colorectal polyps.

METHODS

A single-center retrospective cohort study was conducted to evaluate outcomes after endoscopic removal of malignant colorectal polyps between 2010 and 2020. Residual disease rate and nodal metastases after secondary surgery and local and distant recurrence rate for those with at least 1 year of follow-up were investigated. Event rates for categorical variables and means for continuous variables with 95% confidence intervals were calculated, and Fisher's exact test and Mann-Whitney test were performed. Potential risk factors of adverse outcomes were determined with univariate and multivariate logistic regression models.

RESULTS

In total, 135 lesions (mean size: 22.1 mm; location: 42% rectal) from 129 patients (mean age: 67.7 years; 56% male) were enrolled. The proportion of pedunculated and non-pedunculated lesions was similar, with en bloc resection in 82% and 47% of lesions, respectively. Tumor differentiation, distance from resection margins, depth of submucosal invasion, lymphovascular invasion, and budding were reported at 89.6%, 45.2%, 58.5%, 31.9%, and 25.2%, respectively. Residual tumor was found in 10 patients, and nodal metastasis was found in 4 of 41 patients who underwent secondary surgical resection. Univariate analysis identified piecemeal resection as a risk factor for residual malignancy (odds ratio: 1.74; P = 0.042). At least 1 year of follow-up was available for 117 lesions from 111 patients (mean follow-up period: 5.59 years). Overall, 54%, 30%, 30%, 11%, and 16% of patients presented at the 1-year, 3-year, 5-year, 7-year, and 9-10-year surveillance examinations. Adverse outcomes occurred in 9.0% (local recurrence and dissemination in 4 patients and 9 patients, respectively), with no difference between patients undergoing secondary surgery and surveillance only.

CONCLUSION

Reporting of histological features and adherence to surveillance colonoscopy needs improvement. Long-term adverse outcome rates might be higher than previously reported, irrespective of whether secondary surgery was performed.

Sporadic Polyps of the Colorectum

Colorectal polyps are common, and their diagnosis and classification represent a major component of gastrointestinal pathology practice. The majority of colorectal polyps represent precursors of either the chromosomal instability or serrated neoplasia pathways to colorectal carcinoma. Accurate reporting of these polyps has major implications for surveillance and thus for cancer prevention. In this review, we discuss the key histologic features of the major colorectal polyps with a particular emphasis on diagnostic pitfalls and areas of contention.

Management after non-curative endoscopic resection of T1 rectal cancer

Since the introduction of population-based screening, increasing numbers of T1 rectal cancers are detected and removed by local endoscopic resection. Patients can be cured with endoscopic resection alone, but there is a possibility of residual tumor cells remaining after the initial resection. These can be located intraluminally at the resection site or extraluminally in the form of (lymph node) metastases. To decrease the risk of residual cells progressing towards more advanced disease, additional treatment is usually needed. However, with the currently available risk stratification models, it remains challenging to determine who should and should not be further treated after non-curative endoscopic resection. In this review, the different management strategies for patients with non-curatively treated T1 rectal cancers are discussed, along with the available evidence for each strategy and relevant considerations for clinical decision making. Furthermore, we provide practical guidance on the management and surveillance following non-curative endoscopic resection of T1 rectal cancer.

Differences in treatment of stage I colorectal cancers: a population-based study of colorectal cancers detected within and outside of a screening program

BACKGROUND

 Screen-detected colorectal cancers (CRCs) are often treated less invasively than stage-matched non-screen-detected CRCs, but the reasons for this are not fully understood. This study evaluated the treatment of stage I CRCs detected within and outside of the screening program in the Netherlands. METHODS : Data from the Netherlands Cancer Registry for all stage I CRCs diagnosed between January 1, 2008 and December 31, 2020 were analyzed, comparing patient, tumor, and treatment characteristics of screen-detected and non-screen-detected stage I CRCs. Multivariable logistic regression was used to assess the association between treatment (local excision only vs. surgical oncologic resection) and patient and tumor characteristics, stratified for T stage and tumor location.

RESULTS

 Screen-detected stage I CRCs were relatively more often T1 than T2 compared with non-screen-detected stage I CRCs (66.9 % vs. 53.3 %; P < 0.001). When only T1 tumors were considered, both screen-detected colon and rectal cancers were more often treated with local excision only than non-screen-detected T1 cancers (odds ratio [OR] 2.19, 95 %CI 1.93-2.49; and OR 1.29, 95 %CI 1.05-1.59, respectively), adjusted for sex, tumor location, lymphovascular invasion (LVI) status, and tumor differentiation. CONCLUSIONS : Less invasive treatment of screen-detected stage I CRC is partly explained by the higher rate of T1 cancers compared with non-screen-detected stage I CRCs. T1 stage I screen-detected CRCs were also more likely to undergo less invasive treatment than non-screen-detected CRCs, adjusted for risk factors such as LVI and tumor differentiation. Future research should investigate whether the choice of local excision was related to unidentified cancer-related factors or the expertise of the endoscopists.

Pathological features associated with metastasis in patients with early invasive (pT1) colorectal carcinoma in colorectal polyps

AIMS

Colorectal carcinoma (CRC) arising in a colorectal polyp with invasion limited to the submucosa is sufficiently treated by complete endoscopic resection alone in many cases. Histological features of the carcinoma including tumour size, vascular invasion and poor tumour differentiation or evidence of de-differentiation, such as tumour budding, are associated with a higher risk for metastasis such that oncological resection is recommended. However, most malignant polyps with these features do not have lymph node metastases at the time of resection, so there is a need for better refinement of the histological risk features.

METHODS AND RESULTS

A total of 437 consecutive colorectal polyps with submucosal invasive carcinoma from a single centre, 57 of which had metastatic disease, were supplemented by 30 cases with known metastatic disease from two additional centres. Clinical and histological features of the polyp cancers were reviewed looking for differences between the 87 cancers with metastatic disease and the remaining cases without metastasis. A subgroup of 204 polyps removed intact was also analysed to ensure maximum histological accuracy.

CONCLUSIONS

This study confirmed larger invasive tumour size, vascular invasion and poor tumour differentiation as adverse predictive features. Prominent peritumoral desmoplasia and high cytological grade were additional adverse features. A predictive logistic regression model comprised of (i) presence of any form of vascular invasion; (ii) presence of high tumour budding (BD3); (iii) width of invasive tumour component > 8 mm; (iv) depth of invasive tumour > 1.5 mm; and (v) the finding of prominent expansile desmoplasia located within and beyond the deep invasive edge of the carcinoma, showed excellent performance in predicting metastatic disease.

Dilemmas in the Clinical Management of pT1 Colorectal Cancer

Implementation of population-based colorectal cancer screening programs has led to increases in the incidence of pT1 colorectal cancer. These incipient invasive cancers have a very good prognosis and can be treated locally, but more than half of these cases are treated with surgery due to the presence of histological high-risk criteria. These high-risk criteria are suboptimal, with no consensus among clinical guidelines, heterogeneity in definitions and assessment, and poor concordance in evaluation, and recent evidence suggests that some of these criteria considered high risk might not necessarily affect individual prognosis. Current criteria classify most patients as high risk with an indication for additional surgery, but only 2-10.5% have lymph node metastasis, and the residual tumor is present in less than 20%, leading to overtreatment. Patients with pT1 colorectal cancer have excellent disease-free survival, and recent evidence indicates that the type of treatment, whether endoscopic or surgical, does not significantly impact prognosis. As a result, the protective role of surgery is questionable. Moreover, surgery is a more aggressive treatment option, with the potential for higher morbidity and mortality rates. This article presents a comprehensive review of recent evidence on the clinical management of pT1 colorectal cancer. The review analyzes the limitations of histological evaluation, the prognostic implications of histological risk status and the treatment performed, the adverse effects associated with both endoscopic and surgical treatments, and new advances in endoscopic treatment.

Resection margin involvement after endoscopic excision of malignant colorectal polyps: definition of margin involvement and its impact upon tumour recurrence

AIMS

Malignant polyps are examined to assess histological features which predict residual tumour in the unresected bowel and guide surgical decision-making. One of the most important of these features is resection margin involvement, although the best definition of margin involvement is unknown. In this study we aimed to investigate three different definitions and determine their impact on clinical outcomes.

METHODS AND RESULTS

One hundred and sixty-five malignant polyps removed endoscopically were identified and histological features correlated with either residual tumour in subsequent surgical resections or tumour recurrence following a period of clinical follow-up. Involvement of the polyp margin by cancer was defined in three different ways and outcomes compared. Tumour recurrence was associated with tumour grade, mucinous histology and resection margin involvement. All three definitions of margin involvement separated polyps into clinically significant categories; however, a margin ≤ 1 mm identified 73% of polyps as 'high-risk' compared with 59.1% when involvement was defined as tumour within the zone of coagulation artefact at the polyp base or 50% when tumour was present at the margin. All three 'low-risk' groups had a locoregional recurrence rate < 6.5%.

CONCLUSIONS

Definitions of margin involvement for endoscopically removed malignant polyps in the colon and rectum vary between health-care systems, but a 1-mm clearance is widely used in Europe and North America. Our results suggest that a 1-mm margin is unnecessary and should be replaced by a definition based on tumour at the margin or within coagulation artefact at the polyp base.

In comparison with polypectomy, colorectal resection is associated with improved survival for patients diagnosed with malignant polyps

AIM

Patients diagnosed with a malignant polyp generally have favourable overall survival (OS) and cancer-specific survival (CSS). However, it is unclear how choice in management for malignant polyps may affect survival.

METHODS

Data from the Queensland Oncology Repository was analysed to derive a population wide assessment of the impact of management strategy on OS and CSS for patients diagnosed with malignant polyps. Log-rank testing, Kaplan-Meier and Cox-regression models were performed. Patients were matched using propensity score and Mahalanobis distance matching.

RESULTS

A total of 1,646 patients were included with 240 deaths and 52 colorectal cancer related deaths until censor date. Following propensity score and Mahalanobis distance matching of patients undergoing polypectomy alone versus colorectal resection, there was no significant difference in the age groups (<60 years of age or ≥60 years of age), American Society of Anesthesiology score, comorbidity count or Association of ColoProctology of Great Britain and Ireland risk category. However, of note Log-rank testing demonstrated a significant difference in OS (p < 0.001) and CSS (p = 0.0061) between management strategies. Multivariable Cox-regression models in matched and un-matched patient cohorts demonstrated significantly lower hazards of death for OS with resection (p < 0.001). However, CSS was no longer significantly different between management groups in multivariable Cox-regression analysis (p = 0.073).

CONCLUSION

Patients who underwent colorectal resection had significantly improved OS and CSS compared with polypectomy alone. Improved OS was furthermore seen on multivariable analysis, and in matched cohorts. Future research should investigate why this unexpected finding may be the case and whether updates to guidelines should be considered.

Oncological outcomes after piecemeal endoscopic mucosal resection of large non-pedunculated colorectal polyps with covert submucosal invasive cancer

OBJECTIVE

Management of covert submucosal invasive cancer (SMIC) discovered after piecemeal endoscopic mucosal resection (pEMR) of large (>20 mm) non-pedunculated colorectal polyps is challenging. The residual cancer risk is largely unknown. We sought to evaluate this in a large tertiary referral cohort.

DESIGN

Cases of covert SMIC following pEMR were identified and followed. Oncological outcomes after surgery were divided based on residual intramural cancer, lymph node metastases (LNM) or both. Risk factors for residual intramural cancer and LNM were analysed based on the original pEMR histological variables. Risk parameters were analysed with respect to low and high-risk variables for residual intramural cancer and LNM.

RESULTS

Among 3372 cases of large non-pedunculated colorectal polyps, 143 cases of covert SMIC (4.2%) were identified. 109 underwent surgical resection. Histological analysis of pEMR histology was available in 98 of 109 (90%) cases. 62 cases (63%) had no residual malignancy. 36 cases had residual malignancy (residual intramural cancer n=24; LNM n=5; both n=7). All cases of residual intramural cancer could be identified by a R1 histological deep margin. Cases with poor differentiation (PD) and/or lymphovascular invasion (LVI) had a high risk of LNM (12/33), with a very low risk without these criteria (<1%; 0/65). Cases at low risk for LNM with R0 deep margin have a low risk of residual intramural cancer (<1%; 0/35).

CONCLUSION

The majority of cases of large non-pedunculated colorectal polyps with covert SMIC following pEMR will have no residual malignancy. The risk of residual malignancy can be ascertained from three key variables: PD, LVI and R1 deep margin.

Endoscopic full-thickness resection of T1 colorectal cancers: a retrospective analysis from a multicenter Dutch eFTR registry

BACKGROUND

Complete endoscopic resection and accurate histological evaluation for T1 colorectal cancer (CRC) are critical in determining subsequent treatment. Endoscopic full-thickness resection (eFTR) is a new treatment option for T1 CRC < 2 cm. We aimed to report clinical outcomes and short-term results.

METHODS

Consecutive eFTR procedures for T1 CRC, prospectively recorded in our national registry between November 2015 and April 2020, were retrospectively analyzed. Primary outcomes were technical success and R0 resection. Secondary outcomes were histological risk assessment, curative resection, adverse events, and short-term outcomes.

RESULTS

We included 330 procedures: 132 primary resections and 198 secondary scar resections after incomplete T1 CRC resection. Overall technical success, R0 resection, and curative resection rates were 87.0 % (95 % confidence interval [CI] 82.7 %-90.3 %), 85.6 % (95 %CI 81.2 %-89.2 %), and 60.3 % (95 %CI 54.7 %-65.7 %). Curative resection rate was 23.7 % (95 %CI 15.9 %-33.6 %) for primary resection of T1 CRC and 60.8 % (95 %CI 50.4 %-70.4 %) after excluding deep submucosal invasion as a risk factor. Risk stratification was possible in 99.3 %. The severe adverse event rate was 2.2 %. Additional oncological surgery was performed in 49/320 (15.3 %), with residual cancer in 11/49 (22.4 %). Endoscopic follow-up was available in 200/242 (82.6 %), with a median of 4 months and residual cancer in 1 (0.5 %) following an incomplete resection.

CONCLUSIONS

eFTR is relatively safe and effective for resection of small T1 CRC, both as primary and secondary treatment. eFTR can expand endoscopic treatment options for T1 CRC and could help to reduce surgical overtreatment. Future studies should focus on long-term outcomes.

Risk and Time Pattern of Recurrences After Local Endoscopic Resection of T1 Colorectal Cancer: A Meta-analysis

BACKGROUND & AIMS

Growing numbers of patients with T1 CRC are being treated with local endoscopic resection only and as a result, the need for optimization of surveillance strategies for these patients also increases. We aimed to estimate the cumulative incidence and time pattern of CRC recurrences for endoscopically treated patients with T1 CRC.

METHODS

Using a systematic literature search in PubMed, EMBASE, Web of Science and Cochrane Library (from inception till 15 May 2020), we identified and extracted data from studies describing the cumulative incidence of local or distant CRC recurrence for patients with T1 CRC treated with local endoscopic resection only. Pooled estimates were calculated using mixed-effect logistic regression models.

RESULTS

Seventy-one studies with 5167 unique, endoscopically treated patients with T1 CRC were included. The pooled cumulative incidence of any CRC recurrence was 3.3% (209 events; 95% CI, 2.6%-4.3%; I² = 54.9%), with local and distant recurrences being found at comparable rates (pooled incidences 1.9% and 1.6%, respectively). CRC-related mortality was observed in 42 out of 2519 patients (35 studies; pooled incidence 1.7%, 95% CI, 1.2%-2.2%; I² = 0%), and the CRC-related mortality rate among patients with recurrence was 40.8% (42/103 patients). The vast majority of recurrences (95.6%) occurred within 72 months of follow-up. Pooled incidences of any CRC recurrence were 7.0% for high-risk T1 CRCs (28 studies; 95% CI, 4.9%-9.9%; I² = 48.1%) and 0.7% (36 studies; 95% CI, 0.4%-1.2%; I² = 0%) for low-risk T1 CRCs.

CONCLUSIONS

Our meta-analysis provides quantitative outcome measures which are relevant to guidelines on surveillance after local endoscopic resection of T1 CRC.

Decision making in the management of adults with malignant colorectal polyps: An exploration of the experiences of patients and clinicians

AIM

A diagnosis of colorectal polyp cancer presents a treatment dilemma. The decision between segmental resection versus endoscopic surveillance is difficult due to a lack of good quality clinical evidence for either option. The aim of this study was to understand the decision making experiences of both clinicians and patients when faced with such a diagnosis.

METHODS

Qualitative, semi-structured interviews were undertaken with 10 clinicians involved in the care of patients diagnosed with polyp cancer and five patients who had experience of a diagnosis of polyp cancer. All clinicians and patients were from four hospital trusts across the north of England. Interviews were audio-recorded, transcribed verbatim and analysed using the principles of interpretative phenomenological analysis.

RESULTS

Analysis of the interview transcripts evidenced that clinicians and patients were supportive of a shared approach to treatment decision making in the context of a diagnosis of colorectal polyp cancer. Uncertainty, influences and information were among the themes identified to be preventing this happening at present. This study identified themes which were common to both groups. These were complexity of the risk information, lack of patient information resources, and system factors and time.

CONCLUSION

This research study has evidenced several factors such as uncertainty, complexity of risk information and influences on decisions which are preventing patients being involved in treatment decisions following a diagnosis of colorectal polyp cancer. Recommendations for improvements in practice, including a framework to assist treatment decision making in the future, are highlighted.

Oncological outcome after local treatment for early stage rectal cancer

BACKGROUND

Treatment of early rectal cancer is evolving towards organ-preserving therapy which includes endoscopic resection and transanal approaches. We aimed to explore the role of local treatments such as endoscopic polypectomy (Endoscopic Mucosal Resection (EMR) or Endoscopic submucosal dissection (ESD)) and transanal endoscopic microsurgery/ transanal minimal invasive surgery (TEM/TAMIS) in patients who had early rectal cancer. We considered these outcomes alongside conventional major surgery using total mesorectal excision (TME) for early stage disease.

METHODS

All patients identified at MDT with early stage rectal cancer at our institution between 2010 and 2019 were included. Long-term outcomes in terms of local recurrence, survival and procedure-specific morbidity were analysed.

RESULTS

In total, 536 patients with rectal cancer were identified, of which 112 were included based on their pre-operative identification at the MDT on the basis that they had node-negative early rectal cancer. Among these, 30 patients (27%) had the lesion excised by flexible endoscopic polypectomy techniques (EMR/ESD), 67 (60%) underwent TEM/TAMIS and 15 (13%) had major surgery. There were no differences in patient demographics between the three groups except for TEM/TAMIS patients being more likely to be referred from another hospital (p < 0.001) and they were less active (WHO performance status p = 0.04). There were no significant differences in overall survival rates and cancer-specific survival between the three treatment groups. The 5-year overall survival rate for endoscopic polypectomy, TEM/TAMIS or major resection was 96% versus 90% and 88%, respectively (p = 0.89). The 5- year cancer-specific survival rate was 96%, versus 96% and 100%, respectively (p = 0.74).

CONCLUSION

Endoscopic polypectomy by EMR/ESD is an appropriate local treatment for early stage rectal cancer in selected patients. It is possible to achieve good oncological outcomes with a polypectomy similar to TEM/TAMIS and major surgery; however, a multidisciplinary approach is necessary enabling close surveillance and the use of adjuvant radiotherapy.

International validation of a risk prediction algorithm for patients with malignant colorectal polyps

AIM

The optimal management strategy for patients with endoscopically resected malignant colorectal polyps (MCP) has yet to be defined. The aim of this study was to validate a published decision-making tool, termed the Scottish Polyp Cancer Study (SPOCS) algorithm, on a large international population.

METHODS

The SPOCS algorithm allocates patients to risk groups based on just two variables: the polyp resection margin and the presence of lymphovascular invasion (LVI). The risk groups are termed low (clear margin, LVI absent), medium (clear margin, LVI present) or high (involved/non-assessable margin). The International Polyp Cancer Collaborative was formed to validate the algorithm on data from Australia, Denmark, UK and New Zealand.

RESULTS

In total, 1423 patients were included in the final dataset. 680/1423 (47.8%) underwent surgical resection and 108/680 (15.9%) had residual disease (luminal disease 8.8%, lymph node metastases 8.8%). The SPOCS algorithm classified 602 patients as low risk (in which 1.5% had residual disease), 198 patients as medium risk (in which 7.1% had residual disease) and 484 as high risk (in which 14.5% had residual disease) (P < 0.001, χ² test). Receiver operating characteristic curve analysis demonstrated good accuracy of the algorithm in predicting residual disease (area under the curve 0.732, 95% CI 0.687-0.778, P < 0.001). When patients were designated as low risk, the negative predictive value was 98.5%.

CONCLUSION

The SPOCS algorithm can be used to predict the risk of residual disease in patients with endoscopically resected MCPs. Surgery can be safely avoided in patients who have a clear margin of excision and no evidence of LVI.

Long-term Outcomes of Primary Endoscopic Resection vs Surgery for T1 Colorectal Cancer: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

There is controversy over the best therapeutic approach for T1 colorectal cancer. We performed a systematic review and meta-analysis of long-term outcomes of endoscopic resection (ER) vs those of primary or additional surgery.

METHODS

We performed a systematic review of the PubMed, Embase, and Cochrane databases through October 2019 for studies that reported outcomes (overall survival, disease-specific survival, recurrence-free survival at 5 years, recurrence, and metastasis) of ER vs surgery in patients with colorectal neoplasms. Hazard ratios (HR) were calculated based on time to events.

RESULTS

In total, 17 published studies with 19,979 patients were included. The median follow-up time among the studies was 36 months. The meta-analysis found no significant differences between primary ER and primary surgery in overall survival (79.6% vs 82.1%, HR, 1.10; 95% CI, 0.84-1.45), recurrence-free survival (96.0% vs 96.7%, HR, 1.28; 95% CI, 0.87-1.88), or disease-specific survival (94.8% vs 96.5%; HR, 1.09; 95% CI, 0.67-1.78). Additional surgery and primary surgery did not produce significant differences in recurrence-free survival (HR, 1.27; 95% CI, 0.85-1.89). A significantly lower proportion of patients who underwent primary ER had procedure-related adverse events (2.3%) than patients who underwent primary surgery (10.9%) (P < .001). Lymphovascular invasion and rectal cancer, but not depth of submucosal invasion, were independently associated with recurrence for all T1 colorectal cancers.

CONCLUSIONS

In a systematic review and meta-analysis, we found that ER should be considered as the first-line treatment for endoscopically resectable T1 colorectal cancers. In cases of noncurative resection, additional surgery can have comparable outcomes to primary surgery.

Endoscopic full-thickness resection (eFTR) of colorectal lesions: results from the Dutch colorectal eFTR registry

BACKGROUND

Endoscopic full-thickness resection (eFTR) is a minimally invasive resection technique that allows definite diagnosis and treatment for complex colorectal lesions ≤ 30 mm unsuitable for conventional endoscopic resection. This study reports clinical outcomes from the Dutch colorectal eFTR registry.

METHODS

Consecutive patients undergoing eFTR in 20 hospitals were prospectively included. The primary outcome was technical success, defined as macroscopic complete en bloc resection. Secondary outcomes were: clinical success, defined as tumor-free resection margins (R0 resection); full-thickness resection rate; and adverse events. RESULTS : Between July 2015 and October 2018, 367 procedures were included. Indications were difficult polyps (non-lifting sign and/or difficult location; n = 133), primary resection of suspected T1 colorectal cancer (CRC; n = 71), re-resection after incomplete resection of T1 CRC (n = 150), and subepithelial tumors (n = 13). Technical success was achieved in 308 procedures (83.9 %). In 21 procedures (5.7 %), eFTR was not performed because the lesion could not be reached or retracted into the cap. In the remaining 346 procedures, R0 resection was achieved in 285 (82.4 %) and full-thickness resection in 288 (83.2 %). The median diameter of resected specimens was 23 mm. Overall adverse event rate was 9.3 % (n = 34/367): 10 patients (2.7 %) required emergency surgery for five delayed and two immediate perforations and three cases of appendicitis. CONCLUSION : eFTR is an effective and relatively safe en bloc resection technique for complex colorectal lesions with the potential to avoid surgery. Further studies assessing the role of eFTR in early CRC treatment with long-term outcomes are needed.

High practice variation in risk stratification, baseline oncological staging, and follow-up strategies for T1 colorectal cancers in the Netherlands

Background and study aims  Based on pathology, locally resected T1 colorectal cancer (T1-CRC) can be classified as having low- or high-risk for irradicality and/or lymph node metastasis, the latter requiring adjuvant surgery. Reporting and application of pathological high-risk criteria is likely variable, with inherited variation regarding baseline oncological staging, treatment and surveillance. Methods  We assessed practice variation using an online survey among gastroenterologists and surgeons participating in the Dutch T1-CRC Working Group. Results  Of the 130 invited physicians, 53 % participated. Regarding high-risk T1-CRC criteria, lymphangio-invasion is used by 100 %, positive or indeterminable margins by 93 %, poor differentiation by 90 %, tumor-free margin ≤ 1 mm by 78 %, tumor budding by 57 % and submucosal invasion > 1000 µm by 47 %. Fifty-two percent of the respondents do not perform baseline staging in locally resected low-risk T1-CRC. In case of unoperated high-risk patients, we recorded 61 different surveillance strategies in 63 participants, using 19 different combinations of diagnostic tests. Endoscopy is used in all schedules. Mean follow-up time is 36 months for endoscopy, 26 months for rectal MRI and 30 months for abdominal CT (all varying 3-60 months). Conclusion  We found variable use of pathological high-risk T1-CRC criteria, creating risk for misclassification as low-risk T1-CRC. This has serious implications, as most participants will not proceed to oncological staging in low-risk patients and adjuvant surgery nor radiological surveillance is considered. On the other hand, oncological surveillance in patients with a locally resected high-risk T1-CRC who do not wish adjuvant surgery is highly variable emphasizing the need for a uniform surveillance protocol.

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.

Revising the definition of vertical margin involvement following endoscopic polypectomy may reduce unnecessary surgery in patients with malignant colorectal polyps

Background and Study Aims

Endoscopically resected malignant colorectal polyps (MCPs) present a dilemma regarding whether the risk of residual disease justifies a major bowel resection. Overtreatment is common, and the vast majority of patients who undergo resection have no residual tumor. The aim of this study was to investigate whether revising the definition of vertical margin involvement following MCP polypectomy could reduce unnecessary surgery.

Patients and Methods

This was a cohort study of consecutive patients with MCPs treated at a tertiary hospital between 2004 and 2018. Data on demographics, index colonoscopy, polyp pathology, and any subsequent surgical resection were analyzed. Polypectomy resection margins were reviewed and measured to the nearest decimal place. The ability of existing guidelines (requiring a margin clearance of ≥ 1 mm) to predict residual disease was compared to a revised version requiring a margin clearance of ≥ 0.1 mm.

Results

A total of 129 patients with an MCP were included. Of these 129 patients, 77 (60%) underwent surgical resection, of which 62 (81%) had no residual tumor. Existing guidelines, requiring a margin clearance of ≥ 1 mm, classified 28 patients as being at “low risk” for residual disease. Of these, four underwent surgery, but none had residual tumor (P = 0.031). Revised guidelines, requiring a margin clearance of ≥ 0.1 mm, classified 44 patients as “low risk.” Of these, in the 13 that had surgery, no residual tumor was found (P = 0.003).

Conclusions

Revising the definition of vertical margin involvement leads to more patients being correctly classified as being at low risk of residual disease. This has the potential to reduce unnecessary surgery in patients with MCPs.

Pedunculated Morphology of T1 Colorectal Tumors Associates With Reduced Risk of Adverse Outcome

BACKGROUND & AIMS

Risk stratification for adverse events, such as metastasis to lymph nodes, is based only on histologic features of tumors. We aimed to compare adverse outcomes of pedunculated vs nonpedunculated T1 colorectal cancers (CRC).

METHODS

We performed a retrospective study of 1656 patients diagnosed with T1CRC from 2000 through 2014 at 14 hospitals in The Netherlands. The median follow-up time of patients was 42.5 months (interquartile range, 18.5-77.5 mo). We evaluated the association between tumor morphology and the primary composite end point, adverse outcome, adjusted for clinical variables, histologic variables, resection margins, and treatment approach. Adverse outcome was defined as metastasis to lymph nodes, distant metastases, local recurrence, or residual tissue. Secondary end points were tumor metastasis, recurrence, and incomplete resection.

RESULTS

Adverse outcome occurred in 67 of 723 patients (9.3%) with pedunculated T1CRCs vs 155 of 933 patients (16.6%) with nonpedunculated T1CRCs. Pedunculated morphology was independently associated with decreased risk of adverse outcome (adjusted odds ratio [OR], 0.59; 95% CI, 0.42-0.83; P = .003). Metastasis, incomplete resection, and recurrence were observed in 5.8%, 4.6%, and 3.9% of pedunculated T1CRCs vs 10.6%, 8.0%, and 6.6% of nonpedunculated T1CRCs, respectively. Pedunculated morphology was independently associated with a reduced risk of metastasis (adjusted OR, 0.62; 95% CI, 0.41-0.94; P = .03), incomplete resection (adjusted OR, 0.57; 95% CI, 0.36-0.91; P = .02), and recurrence (adjusted hazard ratio, 0.52; 95% CI, 0.32-0.85; P = .009). Metastasis, incomplete resection, and recurrence did not differ significantly between low-risk pedunculated vs nonpedunculated T1CRCs (0.8% vs 2.9%, P = .38; 1.5% vs 0%, P = .99; 1.5% vs 0%; P = .99). However, incomplete resection and recurrence were significantly lower for high-risk pedunculated vs nonpedunculated T1CRCs (6.5% vs 12.5%; P = .007; 4.4% vs 8.6%; P = .03).

CONCLUSIONS

In a retrospective study of patients with T1CRC, we found pedunculated morphology to be associated independently with a decreased risk of adverse outcome in a T1CRC population at high risk of adverse outcome. Incorporating morphologic features of tumors in risk assessment could help predict outcomes of patients with T1CRC and help identify the best candidates for surgery.

Securing the Appendiceal Stump During Emergency Appendicectomy: Options and Influencing Factors in Current UK Surgical Practice

INTRODUCTION

The aim of our study was to identify the most commonly employed methods and influencing factors for securing the appendiceal stump in current NHS practice.

METHODS

An electronic survey of the Scottish Surgical Research Group network, invitation extended to the UK National Research Collaborative.

RESULTS

A total of 111 responses were received from 32 surgical centers; 28 (25.2%) consultants, 66 (59.5%) specialty trainees and 12 (10.8%) core trainees. Endoscopic ligatures were the preferred method in 96 (86.5%) with no difference in those with the greatest operative experience (P=0.79), 12 (10.8%) preferred polymeric clips. Ease of application (70.3%) and severity of stump inflammation (65.8%) had the greatest influence on the method chosen. Cost was a factor in 36.0%.

CONCLUSIONS

The preferred method for securing the appendiceal stump in UK practice is endoscopic ligatures regardless of operative experience. Factors with the greatest influence on the method employed include the ease of application and severity of stump inflammation. Our findings are likely to be representative of current NHS practice in Scotland.

A National Bowel Cancer Screening Programme using FIT: Achievements and Challenges

Colorectal cancer accounts for 11% of all cancer-related deaths in Ireland. With the aim of diagnosing these cancers at an earlier stage, and detecting premalignant lesions, the National Screening Service (NSS) offered a fecal immunochemical test (FIT) to all individuals aged 60 to 69. All individuals in the age range were contacted by post and invited to participate in the programme. Those with a positive FIT result were offered a colonoscopy in an internationally accredited unit. From an eligible population of 488,628, 196,238 individuals participated giving an uptake of 40.2%. Commencing at a FIT threshold of 20 μg Hg/g feces, the positivity rate was 8.6%, which overwhelmed colonoscopy capacity and, thus, the threshold was increased to 45 μg, resulting in an overall 5% positivity rate. A total of 520 individuals had cancer detected (68.3% stage I or II), of which 104 were removed endoscopically (pT1s). Adenomas were present in 54.2% of all colonoscopies, 17.4% deemed high risk. Despite a lower uptake, males were twice as likely to have colorectal cancers as females and had a 59% increased rate of high-risk adenomas diagnosed. Challenges facing the programme include increasing participation, especially among males, and increasing colonoscopy capacity. The ability to alter the sensitivity of FIT to match colonoscopy capacity is a valuable option for such a programme as it ensures that the maximum public health benefit can be achieved within available resources.

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.

The role of imaging and biopsy in the management and staging of large non-pedunculated rectal polyps

Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are often used for benign and Sm1 large non-pedunculated rectal polyps (LNPRPs), although other surgical techniques including transanal endoscopic microsurgery (TEMS) and transanal minimal invasive surgery remain available. This review covers the role of pre-excisional imaging and selective biopsy of LNPRPs. Areas covered: Polyps between 2 and 3 cm with favorable features (Paris 1, Kudo III/IV pit patterns, and non-lateral spreading type [LST]) may have a one-stage EMR without biopsy and imaging, provided adequate expertise is available with other technologies such as magnifying chromoendoscopy. Higher-risk polyps (moderate/severe dysplasia, 0-IIa+c morphology, nongranular LST, Kudo pit pattern V or submucosal carcinoma, or those >3 cm) should have pre-EMR/ESD imaging with magnetic resonance imaging (MRI) and/or endorectal ultrasound (ERUS) ± biopsies and photographs prior to multidisciplinary team discussion. Expert commentary: In some centers, EMR and ESD are considered the primary modality of treatment, with TEMS as a back-up, while elsewhere, TEMS is the main modality for excision of significant polyps and early colorectal cancer lesions. Likewise, the exact roles of ERUS and MRI will depend on availability of local expertise, although it is suggested that the techniques are complementary.

Histologic Factors Associated With Need for Surgery in Patients With Pedunculated T1 Colorectal Carcinomas

BACKGROUND & AIMS

Most patients with pedunculated T1 colorectal tumors referred for surgery are not found to have lymph node metastases, and were therefore unnecessarily placed at risk for surgery-associated complications. We aimed to identify histologic factors associated with need for surgery in patients with pedunculated T1 colorectal tumors.

METHODS

We performed a cohort-nested matched case-control study of 708 patients diagnosed with pedunculated T1 colorectal tumors at 13 hospitals in The Netherlands, from January 1, 2000 through December 31, 2014, followed for a median of 44 months (interquartile range, 20-80 months). We identified 37 patients (5.2%) who required surgery (due to lymph node, intramural, or distant metastases). These patients were matched with patients with pedunculated T1 colorectal tumors without a need for surgery (no metastases, controls, n = 111). Blinded pathologists analyzed specimens from each tumor, stained with H&E. We evaluated associations between histologic factors and patient need for surgery using univariable conditional logistic regression analysis. We used multivariable least absolute shrinkage and selection operator (LASSO; an online version of the LASSO model is available at: http://t1crc.com/calculator/) regression to develop models for identification of patients with tumors requiring surgery, and tested the accuracy of our model by projecting our case-control data toward the entire cohort (708 patients). We compared our model with previously developed strategies to identify high-risk tumors: conventional model 1 (based on poor differentiation, lymphovascular invasion, or Haggitt level 4) and conventional model 2 (based on poor differentiation, lymphovascular invasion, Haggitt level 4, or tumor budding).

RESULTS

We identified 5 histologic factors that differentiated cases from controls: lymphovascular invasion, Haggitt level 4 invasion, muscularis mucosae type B (incompletely or completely disrupted), poorly differentiated clusters and tumor budding, which identified patients who required surgery with an area under the curve (AUC) value of 0.83 (95% confidence interval, 0.76-0.90). When we used a clinically plausible predicted probability threshold of ≥4.0%, 67.5% (478 of 708) of patients were predicted to not need surgery. This threshold identified patients who required surgery with 83.8% sensitivity (95% confidence interval, 68.0%-93.8%) and 70.3% specificity (95% confidence interval, 60.9%-78.6%). Conventional models 1 and 2 identified patients who required surgery with lower AUC values (AUC, 0.67; 95% CI, 0.60-0.74; P = .002 and AUC, 0.64; 95% CI, 0.58-0.70; P < .001, respectively) than our LASSO model. When we applied our LASSO model with a predicted probability threshold of ≥4.0%, the percentage of missed cases (tumors mistakenly assigned as low risk) was comparable (6 of 478 [1.3%]) to that of conventional model 1 (4 of 307 [1.3%]) and conventional model 2 (3 of 244 [1.2%]). However, the percentage of patients referred for surgery based on our LASSO model was much lower (32.5%, n = 230) than that for conventional model 1 (56.6%, n = 401) or conventional model 2 (65.5%, n = 464).

CONCLUSIONS

In a cohort-nested matched case-control study of 708 patients with pedunculated T1 colorectal carcinomas, we developed a model based on histologic features of tumors that identifies patients who require surgery (due to high risk of metastasis) with greater accuracy than previous models. Our model might be used to identify patients most likely to benefit from adjuvant surgery.