Management and outcome of patients with invasive carcinoma arising in colorectal polyps

A Retrospective Multicenter Study of Risk Factors, Stratification, and Prognosis of Lymph Node Metastasis in T1 and T2 Colorectal Cancer

BACKGROUND

The objective of this study was to compare the long-term prognosis of patients with T1 and T2 colorectal cancer (CRC) according to lymph node metastasis (LNM) and to identify risk factors for LNM.

METHODS

We retrospectively reviewed patients who underwent curative resection for T1 or T2 CRC at five University-affiliated hospitals between January 2012 and December 2021. The patients were divided into several groups depending on the presence of LNM or the number of risk factors.

RESULTS

Of the total 765 patients, 87 (11.3%) patients had LNM. These patients had poorer recurrence-free survival (RFS) than patients without LNM (72.6% vs. 88.6%). The multivariable analysis showed that high-grade tumors (p = 0.003), lymphovascular invasion (p < 0.001), and rectal location (p = 0.049) were independent predictors of LNM. When divided into groups according to the number of the three risk factors, the risk of LNM increased from 5.4% (ultralow-risk group; no risk factor) to 60.0% (high-risk group; all three risk factors) and the 5-year RFS rate decreased from 96.3% in the ultralow-risk group to 60% in the high-risk group (p < 0.001).

CONCLUSION

Radical surgery should be considered for T1 and T2 CRC patients with these risk factors.

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.

Late Recurrence of Colorectal Carcinoma in Patients with Malignant Polyp and Risk Factors

Malignant polyps are polypoid lesions that appear benign endoscopically but harbor invasive adenocarcinoma microscopically. Patient with diagnosis of malignant polyp can be managed by surgical resection or endoscopic surveillance. Current literature on long term recurrence is sparse. A total of 76 patients with malignant polyp and follow-up period of over one year are included. Of these, 28 patients underwent endoscopic polypectomy followed by surveillance (group 1). Forty-eight patients underwent segmental colectomy (group 2). In group 1, three patients developed local recurrent pT3 adenocarcinoma (5.9 to 9.7 years) and one patient developed liver metastasis (7.3 years). One patient presented with malignant polyp in another segment of colon (4.0 years). Two of the malignant polyps with local recurrence do not have commonly reported high-risk features, including tumor ≤ 1 mm from resection margin, presence of lymphovascular invasion and high grade tumor, they had invasion depth of >4 mm and harbored a TP53 missense mutation. In group 2, during the follow-up period (1.0-21.8 years, median 9.3 years), none of the patients developed local recurrence. In this study, surveillance group had a local late recurrence rate of 10.7% versus no local recurrence in surgical resection group (0%). Our study shows that depth of invasion of over 4 mm in malignant polyp is a risk factor for late local recurrence if managed by endoscopic surveillance. Further study is needed to explore whether certain molecular alterations, such as TP53 mutation, is a risk factor for late recurrence.

Impact of Salvage Surgery following Colonic Endoscopic Polypectomy for Patients with Invasive Neoplasia

BACKGROUND

Invasive neoplasia (Tis-T1) are increasingly being encountered in the daily routine of endoscopic polypectomy. However, the need for salvage surgery following endoscopic therapy for invasive neoplasia is controversially discussed.

PATIENTS AND METHODS

Patients with endoscopic removal of invasive neoplasia were identified from the national Surveillance Epidemiology and End Results (SEER) Database 2005 to 2015. Survival analysis and Cox proportional hazard regression analysis in cancer-specific mortality and overall survival rate was used, which were stratified by T stage and polyp size.

RESULTS

A total of 5805 patients with endoscopic removal of invasive neoplasia were included in the analysis, of whom 1214 (20.9%) underwent endoscopic treatment alone and 4591 (79.1%) underwent endoscopic resection plus surgery. The survival analysis revealed that patients undergoing salvage surgery had a significantly better cancer-specific survival (97.4% vs. 95.8%, p-value = 0.017). In patients with T1 stage, additional salvage surgery led to a significantly higher cancer-specific survival (92.1% vs. 95.0%, p value = 0.047).

CONCLUSION

Salvage surgery following endoscopic polypectomy may improve the oncological survival of patients with invasive neoplasia, especially in patients with T1 stage. Furthermore, the T stage, size, and localization of polyps, as well as the level of CEA, could be identified as significant predictors for lymphonodal and distant metastases.

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.

Invasive carcinoma versus pseudoinvasion: interobserver variability in the assessment of left-sided colorectal polypectomies

OBJECTIVES

Misplaced epithelium in adenomas can occasionally be difficult to distinguish from invasive adenocarcinoma. We evaluated interobserver variability in the assessment of left-sided colon polypectomies for pseudoinvasion versus invasive adenocarcinoma and further investigated relevant histological findings.

METHODS

28 consecutive left-sided colon polyps with the keywords "pseudoinvasion", "epithelial misplacement", "herniation", "prolapse" or "invasive adenocarcinoma" were collected from 28 patients and reviewed by eight gastrointestinal pathologists. Participants assessed stromal hemosiderin, lamina propria/eosinophils surrounding glands, desmoplasia, high grade dysplasia/intramucosal adenocarcinoma and margin status and rendered a diagnosis of pseudoinvasion, invasive adenocarcinoma, or both.

RESULTS

Agreement among pathologists was substantial for desmoplasia (κ=0.70), high grade dysplasia/intramucosal adenocarcinoma (κ=0.66), invasive adenocarcinoma (κ=0.63) and adenocarcinoma at the margin (κ=0.65). There was moderate agreement for hemosiderin in stroma (κ=0.53) and prolapse/pseudoinvasion (κ=0.50). Agreement was low for lamina propria/eosinophils around glands (κ=0.12). For invasive adenocarcinoma, seven or more pathologists agreed in 24 of 28 cases (86%), and there was perfect agreement in 19/28 cases (68%). For pseudoinvasion, seven or more pathologists agreed in 19 of 28 cases (68%), and there was perfect agreement in 16/28 cases (57%).

CONCLUSION

Moderate to substantial, though imperfect, agreement was achieved in the distinction of pseudoinvasion from invasive carcinoma.

The Detection of Lymphatic Invasion in Colorectal Polyp Cancer Using D2-40 Immunohistochemistry and Its Association With Prognosis

Introduction

The aim of this study was to compare the detection of lymphatic invasion using haematoxylin and eosin (H&E) staining versus D2-40 immunostaining on specimens from a retrospective cohort of patients with colorectal polyp cancer and to investigate the association of lymphatic invasion, detected by either method, with survival.

Methods

Specimens from patients with pathologically diagnosed colorectal polyp cancer were selected from the Greater Glasgow and Clyde Bowel Cancer Screening Registry for D2-40 immunohistochemistry staining. Clinicopathological information was retrieved from patient electronic records including analysis of pathology reports to determine if a lymphatic invasion was detected using H&E staining.

Results

Over 100 patients were included in this study with a median age at polypectomy of 66 years (range 50-76). All patients were followed up for a minimum of four years and five patients died due to colorectal cancer. The lymphatic invasion was detected in 8% of cases by H&E staining and 23% of cases with D2-40 immunostaining. Only D2-40-detected lymphatic invasion showed a statistically significant relationship with colorectal cancer-specific mortality using univariate analysis (p=0.01). Survival analysis performed separately by Cox regression demonstrated that lymphatic invasion detected by D2-40 immunostaining was associated with worse disease-specific survival (hazard ratio [HR] 14.07, 95% CI 1.57-125.97, p=0.018).

Conclusion

This study shows that D2-40 immunostaining can improve the detection of lymphatic invasion in colorectal polyp cancer when compared to H&E staining. In addition, the lymphatic invasion detected by D2-40 immunostaining significantly associates with survival allowing it to be used as a prognostic indicator in colorectal polyp cancer.  

A Focused Review on Advances in Risk Stratification of Malignant Polyps

Colorectal cancer is the third most common cancer in both men and women in the United States, with most cases arising from precursor adenomatous polyps. Colorectal malignant polyps are defined as cancerous polyps that consist of tumor cells invading through the muscularis mucosae into the underlying submucosa (pT1 tumor). It has been reported that approximately 0.5-8.3% of colorectal polyps are malignant polyps, and the potential for lymph node metastasis in these polyps ranges from 8.5% to 16.1%. Due to their clinical significance, recognition of malignant polyps is critical for clinical teams to make treatment decisions and establish appropriate surveillance schedules after local excision of the polyps. There is a rapidly developing interest in malignant polyps within the literature as a result of an increasing number of identifiable adverse histologic features and recent advancements in endoscopic treatment techniques. The purpose of this paper is to have a focused review of the recent histopathologic literature of malignant polyps.

Risk factors for lymph node metastasis in early colon cancer

BACKGROUND

The aim of the study was to determine factors predicting lymph node metastasis in patients with T1 or T2 colon cancer.

METHODS

A total of 906 patients with T1 or T2 colon cancer who underwent colon resection with regional lymphadenectomy in a tertiary hospital, from January 2008 to December 2013, were analyzed. The prognostic factors for LN metastasis and the risk factors for survival were analyzed.

RESULTS

There were 728 patients (80.4%) without lymph node metastasis (LN-negative group) and 178 patients (19.6%) with lymph node metastasis (LN-positive group). Tumor invasion depth (P < 0.001), lymphatic invasion (P < 0.001), and perineural invasion (P = 0.008) were significantly different between the two groups. During the median follow-up period of 69 months, the 5-year disease-free survival rate was 98.6% for the LN-negative group and 92.8% for the LN-positive group (P ≤ 0.001). In multivariate analysis, influencing factors associated with disease-free survival rate were LN metastasis (P = 0.001) and perineural invasion (P = 0.040). Female, depth of tumor invasion (P = 0.001), and lymphatic invasion (P < 0.001) were significant independent predictive factors for lymph node metastasis in multivariate analysis.

CONCLUSION

Positive LN status predicted poor disease-free survival in patients with early cancer. This suggests that depth of tumor invasion ≥ sm2 and the presence of lymphatic invasion in early colon cancer provide useful information to determine which patients would benefit from radical surgery.

Malignant Colorectal Polyp Pathology: Are We Getting Sufficient Information to Make Decisions?

The College of American Pathologists has published guidelines for malignant colorectal polyp pathology reports that list histopathological features that are "core elements" and "optional." Lack of element reporting may result in inaccurate tumor risk stratification.This study aimed to perform a population-based assessment of pathology reporting for T1 colorectal cancers and determine the completeness of reporting for core and optional histopathological elements.This is a retrospective cohort study.This study reviews the pathology reports of endoscopically resected malignant colorectal polyps in Alberta, Canada between 2014 and 2016.Individuals aged 18 years or older with T1 colorectal polyps were selected.Histopathological elements were dichotomized into core and optional. Malignant polyps were classified as high risk or low risk for lymph node metastases and local intraluminal recurrence. Addendum reports were compared with first reports.After applying exclusion criteria, 431 polyps were analyzed. The mean age of patients was 65.5 years; 59.4% were male. Histological grade, deep margin, and lymphovascular invasion were reported in 82.4%, 86.8% and 75.6%; all 3 were reported in only 66.4%. Tumor budding (not in the 2016 guidelines) was reported in 14.4%. One hundred ninety polyps (44.1%) were high risk. Thirty-seven polyps (8.3%) had an addendum report. Following the addendum, 1 polyp was downgraded to low risk, and 9 polyps were upgraded to high risk.The main limitation of the study is its retrospective nature. The decision making surrounding treatment for T1 cancers is complex, and factors other than histopathological tumor features may have been part of treatment decisions.There is a high rate of incomplete reporting of core and optional elements for malignant colorectal polyp pathology reports in Alberta. Several variables used by colorectal surgeons for decision making, such as tumor budding and depth of submucosal invasion, are not considered core elements and are infrequently reported. A pathology review by a second pathologist often results in a change in risk stratification. See Video Abstract at http://links.lww.com/DCR/B98. PATOLOGÍA DEL PÓLIPO COLORRECTAL MALIGNO: ¿ESTAMOS OBTENIENDO INFORMACIÓN SUFICIENTE PARA TOMAR DECISIONES?: El Colegio de Patólogos Americanos publico pautas para informes de patología de pólipos colorrectales malignos que enumeran características histopatológicas como "elementos centrales" y "opcionales". La falta de información elemental puede resultar en una estratificación de riesgo tumoral imprecisa.Valoración basada en una población de los informes de patología para los cánceres colorrectales T1 y determinar la precisión de los informes en cuanto los elementos histopatológicos centrales y opcionales.Estudio de cohorte retrospectivo.Este estudio revisa los informes de patología de pólipos colorrectales malignos resecados endoscópicamente en Alberta, Canadá, entre 2014 y 2016.personas mayores de 18 años con pólipos colorrectales T1.Los elementos histopatológicos se dicotomizaron entre elementales y opcionales. Pólipos malignos se clasificaron como de alto riesgo o bajo riesgo de metástasis en los ganglios linfáticos y recurrencia intraluminal local. Los informes enmendados se compararon con los informes originales.Después de aplicar los criterios de exclusión, se analizaron 431 pólipos. La edad media fue 65.5 años, con 59.4% masculinos. El grado histológico, el margen profundo y la invasión linfovascular se informaron confirmaron en 82.4%, 86.8% y 75.6% respectivamente; las tres características se demostraron en solo 66.4%. Un patrón tumoral en ciernes se reporto en 14.4-una característica que no se usaba en las guías de 2016. Ciento noventa pólipos (44.1%) eran de alto riesgo. Treinta y siete pólipos (8.3%) requirieron de un informe enmendado. Aplicación de los nuevos criterios resulto en que 1 pólipo se redujo a bajo riesgo y 9 pólipos se actualizaron como a alto riesgo.La principal limitación del estudio es el diseño retrospectivo. La toma de decisiones en torno al tratamiento de los cánceres T1 es compleja y otros factores además de las características histopatológicas del tumor pueden haber sido parte de las decisiones terapéuticas.Hay una alta tasa de informes incompletos de elementos centrales y opcionales para informes de patología de pólipos colorrectales malignos en Alberta. Algunas variables utilizadas por los cirujanos colorrectales para la toma de decisiones, como el patrón tumoral en ciernes y la profundidad de la invasión submucosa, no se consideran elementos centrales y se informan con poca frecuencia. Una revisión de patología realizada por un segundo patólogo a menudo resulta en un cambio en la estratificación del riesgo. Consulte Video Resumen en http://links.lww.com/DCR/B98. (Traducción-Dr. Adrian E. Ortega).

Re-examining the 1-mm margin and submucosal depth of invasion: a review of 216 malignant colorectal polyps

Malignant colorectal polyps have a risk of lymph node metastases between 9 and 24%, but patients who are negative for certain histologic poor prognostic factors have the potential to be treated with polypectomy alone. Retrospective cohort of 216 malignant polyps from 213 patients identified through the British Columbia Colon Screening Program. Complete pathologic reporting (reporting of tumor grade, lymphovascular invasion, margin status, and tumor budding) was present in only 43% of patients. Sixty-one patients had no poor prognostic factors on polypectomy, and 23 (37%) of those underwent surgery. A positive margin cutoff of tumor at cautery showed significantly increased rates of lymph node metastases (p = 0.04) compared to a margin of greater than 0 mm, and polyps with a margin of greater than 0 mm had no risk of residual carcinoma. A submucosal depth of ≥ 2000 μm had an increased rate of lymph node metastases compared to < 2000 μm (p = 0.01). Malignant polyps with either tumor at cautery or a submucosal depth of ≥ 2000 μm, compared to polyps without these risk factors, had a relative risk for lymph node metastases of 16.3. Adoption of submucosal depth and refinement of the cutoffs for positive margin and submucosal depth have the potential to identify high-risk patients and reduce the number of surgeries required in patients with malignant polyps, a group that continues to grow significantly in part due to the introduction of colon screening programs.

Clinical outcomes of positive resection margin after endoscopic mucosal resection of early colon cancers

BACKGROUND/AIMS

When determining the subsequent management after endoscopic resection of the early colon cancer (ECC), various factors including the margin status should be considered. This study assessed the subsequent management and outcomes of ECCs according to margin status.

METHODS

We examined the data of 223 ECCs treated by endoscopic mucosal resection (EMR) from 215 patients during 2004 to 2014, and all patients were followed-up at least for 2 years.

RESULTS

According to histological analyses, the margin statuses of all lesions after EMR were as follows: 138 cases (61.9%) were negative, 65 cases (29.1%) were positive for dysplastic cells on the resection margins, and 20 cases (8.9%) were uncertain. The decision regarding subsequent management was affected not only by pathologic outcomes but also by the endoscopist's opinion on whether complete resection was obtained. Surgery was preferred if the lesion extended to the submucosa (odds ratio [OR], 25.46; 95% confidence interval [CI], 7.09-91.42), the endoscopic resection was presumed incomplete (OR, 15.55; 95% CI, 4.28-56.56), or the lymph system was invaded (OR, 13.69; 95% CI, 1.76-106.57). Fourteen patients (6.2%) had residual or recurrent malignancies at the site of the previous ECC resection and were significantly associated with presumed incomplete endoscopic resection (OR, 4.59; 95% CI, 1.21-17.39) and submucosal invasion (OR, 5.14; 95% CI, 1.18-22.34).

CONCLUSIONS

Subsequent surgery was associated with submucosa invasion, lymphatic invasion, and cancer-positive margins. Presumed completeness of the resection may be helpful for guiding the subsequent management of patients who undergo endoscopic resection of ECC.

Predictive Factors for Lymph Node Metastasis in Submucosal Invasive Colorectal Carcinoma: A New Proposal of Depth of Invasion for Radical Surgery

BACKGROUND

Patients with lymph node metastasis (LNM) in submucosal invasive colorectal carcinoma (SM cancer) require additional surgical treatment after endoscopic dissection. However, because additional radical resection after endoscopic local resection may be unnecessary for cases without LNM, more specific criteria are required in order to diminish the incidence of further radical resection after endoscopic dissection.

METHODS

A total of 492 patients with biopsy-proven SM cancer who underwent curative surgery between January 2008 and December 2012 were collected and were divided into LNM group and no LNM group. The cutoff value for the depth of submucosal invasion was analyzed by a receiver operating characteristic (ROC) curve. In this retrospective study, the association between LNM and clinicopathologic factors was analyzed by logistic regression analysis.

RESULTS

The depth of submucosal invasion of 1900 μm was determined as the cutoff value by ROC curve. Significant, independent predictive factors for LNM included the depth of submucosal invasion >1900 μm (odds ratio [OR] 7.5; 95% confidence interval [CI] 3.1-18.3; p < 0.001), venous invasion (OR 2.4; 95% CI 1.1-5.5; p = 0.03), and poorly differentiated/mucinous adenocarcinoma (OR 6.3; 95% CI 1.3-30.8; p = 0.02).

CONCLUSIONS

Our study demonstrates that the depth of submucosal invasion (>1900 μm), vascular invasion and poorly differentiated/mucinous carcinoma were predictive factors of LNM in patients with SM cancer. These predictors may help to reduce the incidence of unnecessary surgery after endoscopic resection.

Surgical or endoscopic management of malignant colon polyps

BACKGROUND

To evaluate indications for colectomy in T1 polyps and possible risk factors for lymph node metastasis.

METHODS

Between 2004 and 2017, 40 patients underwent colectomy after endoscopic removal of malignant polyps with T1 carcinoma. Resection was done based on at least one of the unfavourable histopathological criteria. We collected and prospectively studied histopathologic features, short-term results and the benefit-risk balance. Complications were assessed by Clavien-Dindo classification.

RESULTS

Twenty-five patients (62.5%) underwent laparoscopic bowel resection. Twenty-nine patients (63.0%) had more than two unfavourable criteria in the polyp that justified colorectal resection. Thirty-five patients (76%) had G2 (moderately differentiated) cancer, 11 (24%) had G1 (well-differentiated). Five patients (12.5%) had lymph node metastases and one (2.5%) had residual adenocarcinoma. All five patients with lymph node metastasis had G2 cancer. Nine patients (22.5%) had residual adenoma. Overall complications were identified in six (15.0%) patients. Oncologic benefit (or risk factors for lymph node metastasis) was significantly associated with polyp size ≥18 mm (P = 0.006), lymphovascular invasion (P = 0.05) and budding (P = 0.02).

CONCLUSIONS

Female gender, lymphovascular invasion, desmoplastic reaction, criteria for surgery ≥2 and polyp size ≥18 mm were all in complex significant risk factors for lymph node metastasis in T1 colorectal cancer. Acting as a single factor, these variables had no effect to increased risk of metastasis.

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.

The American Society of Colon and Rectal Surgeons Clinical Practice Guidelines for the Treatment of Colon Cancer

The American Society of Colon and Rectal Surgeons is dedicated to ensuring high-quality patient care by advancing the science, prevention, and management of disorders and diseases of the colon, rectum, and anus. The Clinical Practice Guidelines Committee is composed of society members who are chosen because they have demonstrated expertise in the specialty of colon and rectal surgery. This committee was created to lead international efforts in defining quality care for conditions related to the colon, rectum, and anus. This is accompanied by developing Clinical Practice Guidelines based on the best available evidence. These guidelines are inclusive and not prescriptive. Their purpose is to provide information on which decisions can be made, rather than to dictate a specific form of treatment. These guidelines are intended for the use of all practitioners, health care workers, and patients who desire information about the management of the conditions addressed by the topics covered in these guidelines. It should be recognized that these guidelines should not be deemed inclusive of all proper methods of care or exclusive of methods of care reasonably directed to obtaining the same results. The ultimate judgment regarding the propriety of any specific procedure must be made by the physician in light of all the circumstances presented by the individual patient.

Association of Poor Differentiation or Positive Vertical Margin with Residual Disease in Patients with Subsequent Colectomy after Complete Macroscopic Endoscopic Resection of Early Colorectal Cancer

In the presence of unfavorable pathologic results after endoscopic resection of colorectal cancer, colectomy is routinely performed. We determined the risk factors for residual diseases in patients with colectomy after complete macroscopic endoscopic resection of early colorectal cancer. We identified consecutive patients who underwent endoscopic resection of early colorectal cancer and subsequently underwent colectomy, from January 2011 to December 2014. Clinicopathologic risk factors related to the residual disease were analyzed. In total, 148 patients underwent endoscopic resection and subsequent colectomy. Residual disease on colectomy was noted in 16 (10.9%) patients. The rates of poorly differentiated/mucinous histology (p = 0.028) and of positive or unknown vertical resection margin (p = 0.047) were higher in patients with residual disease than in those without. In multivariate analysis, a poorly differentiated/mucinous histology and positive or unknown vertical resection margin were significantly associated with residual disease (odds ratio = 7.508 and 2.048, p = 0.015 and 0.049, resp.). After complete macroscopic endoscopic resection of early colorectal cancer, there is a greater need for additional colectomy in cases with a positive or unknown vertical resection margin or a poorly differentiated/mucinous histology, because of their higher risk of residual cancer and lymph node metastasis.

Risk for Incomplete Resection after Macroscopic Radical Endoscopic Resection of T1 Colorectal Cancer: A Multicenter Cohort Study

OBJECTIVES

The decision to perform secondary surgery after endoscopic resection of T1 colorectal cancer (CRC) depends on the risk of lymph node metastasis and the risk of incomplete resection. We aimed to examine the incidence and risk factors for incomplete endoscopic resection of T1 CRC after a macroscopic radical endoscopic resection.

METHODS

Data from patients treated between 2000 and 2014 with macroscopic complete endoscopic resection of T1 CRC were collected from 13 hospitals. Incomplete resection was defined as local recurrence at the polypectomy site during follow-up or malignant tissue in the surgically resected specimen in case secondary surgery was performed. Multivariate regression analysis was performed to analyze factors associated with incomplete resection.

RESULTS

In total, 877 patients with a median follow-up time of 36.5 months (interquartile range 16.0-68.3) were included, in whom secondary surgery was performed in 358 patients (40.8%). Incomplete resection was observed in 30 patients (3.4%; 95% confidence interval (CI) 2.3-4.6%). Incomplete resection rate was 0.7% (95% CI 0-2.1%) in low-risk T1 CRC vs. 4.4% (95% CI 2.7-6.5%) in high-risk T1 CRC (P=0.04). Overall adverse outcome rate (incomplete resection or metastasis) was 2.1% (95% CI 0-5.0%) in low-risk T1 CRC vs. 11.7% (95% CI 8.8-14.6%) in high-risk T1 CRC (P=0.001). Piecemeal resection (adjusted odds ratio 2.60; 95% CI 1.20-5.61, P=0.02) and non-pedunculated morphology (adjusted odds ratio 2.18; 95% CI 1.01-4.70, P=0.05) were independent risk factors for incomplete resection. Among patients in whom no additional surgery was performed, who developed recurrent cancer, 41.7% (95% CI 20.8-62.5%) died as a result of recurrent cancer.

CONCLUSIONS

In the absence of histological high-risk factors, a 'wait-and-see' policy with limited follow-up is justified. Piecemeal resection and non-pedunculated morphology are independent risk factors for incomplete endoscopic resection of T1 CRC.

Long-term results of transanal endoscopic microsurgery after endoscopic polypectomy of malignant rectal adenoma

BACKGROUND

There is no consensus on the treatment and prognosis of malignant rectal polyps. The aim of the present study was to determine the role of transanal endoscopic microsurgery (TEM) after endoscopic complete polypectomy of malignant rectal adenomas with long-term follow-up.

METHODS

Of 105 patients with pT1 rectal carcinoma in 32 patients TEM followed complete endoscopic polypectomy while 73 had primary TEM. Local recurrence (LR), distant metastasis, overall and cancer-specific survival were determined by the Kaplan-Meier method.

RESULTS

Median follow-up was 9.1 years. In 32 patients with TEM following complete polypectomy no residual cancer was found. LR occurred in 3/28 (11%) patients with low-risk carcinoma (pT1 G1/2/X, L0/X, R0) and in 1/4 (25%) with high-risk carcinoma (pT1 G3/4 or L1). After primary TEM with complete resection (minimal distance >1 mm) LR occurred in 6/60 (10%) with low-risk carcinoma. After incomplete TEM resection (minimal distance ≤1 mm) LR occurred in 3/8 (38%) patients with low-risk and in 1/5 (20%) patients with high-risk carcinoma. Grading was the only significant risk factor for LR after endoscopic polypectomy followed by TEM (p = 0.002). At all outcomes did not differ between postpolypectomy TEM and primary TEM.

CONCLUSIONS

Patients with malignant rectal polyps removed by endoscopic polypectomy have a substantial risk of LR even if TEM of polyp site is cancer free. Risk of LR depends on tumor characteristics. In low-risk carcinoma long-term follow-up is necessary. The high LR rate in patients with high-risk rectal carcinoma restricts the use of TEM alone.

Colorectal carcinomas with submucosal invasion (pT1): analysis of histopathological and molecular factors predicting lymph node metastasis

Submucosally invasive colorectal carcinoma (pT1) has the potential to be cured by local excision. In US surgical intervention is reserved for tumors with high-grade morphology, lymphvascular invasion, and close/positive margin. In other countries, particularly Japan, surgical therapy is also recommended for mucinous tumors, tumors with >1000 μm of submucosal invasion, and those with high tumor budding. These histological features have not been well evaluated in a western cohort of pT1 carcinomas. In a cohort of 116 surgically resected pT1 colorectal carcinomas, high tumor budding (P<0.001), lymphatic invasion (P=0.003), depth of submucosal invasion >1000 μm (P=0.04), and high-grade morphology (P=0.04) were significantly associated with lymph node metastasis on univariate analysis. Mucinous differentiation, tumor location, tumor growth pattern, and size of invasive component were not significant. On multivariate analysis, only high tumor budding was associated with lymph node metastasis with an odds ratio of 4.3 (P=0.004). A subset of 48 tumors (22 node-positive and 26 node-negative) was analyzed for mutations in 50 oncogenes and tumor suppressors. No statistically significant molecular alterations in these 50 genes were associated with lymph node status. However, lymphatic invasion was associated with BRAF mutations (P=0.01). Furthermore, high tumor budding was associated with mutations in TP53 (P=0.03) and inversely associated with mutations in the mTOR pathway (PIK3CA and AKT, P=0.02). In conclusion, this study demonstrates the importance of identifying high tumor budding in pT1 carcinomas when considering additional surgical resection. Molecular alterations associated with adverse histological features are identified.

Diagnosis of T1 colorectal cancer in pedunculated polyps in daily clinical practice: a multicenter study

T1 colorectal cancer can be mimicked by pseudo-invasion in pedunculated polyps. British guidelines are currently one of the few which recommend diagnostic confirmation of T1 colorectal cancer by a second pathologist. The aim of this study was to provide insights into the accuracy of histological diagnosis of pedunculated T1 colorectal cancer in daily clinical practice. A sample of 128 cases diagnosed as pedunculated T1 colorectal cancer between 2000 and 2014 from 10 Dutch hospitals was selected for histological review. Firstly, two Dutch expert gastrointestinal pathologists reviewed all hematoxylin-eosin stained slides. In 20 cases the diagnosis T1 colorectal cancer was not confirmed (20/128; 16%). The discordant cases were subsequently discussed with a third Dutch gastrointestinal pathologist and a consensus diagnosis was agreed. The revised diagnoses were pseudo-invasion in 10 cases (10/128; 8%), high-grade dysplasia in 4 cases (4/128; 3%), and equivocal in 6 cases (6/128; 5%). To further validate the consensus diagnosis, the discordant cases were reviewed by an independent expert pathologist from the United Kingdom. A total of 39 cases were reviewed blindly including the 20 cases with a revised diagnosis and 19 control cases where the Dutch expert panel agreed with the original reporting pathologists diagnosis. In 19 of the 20 cases with a revised diagnosis the British pathologist agreed that T1 colorectal cancer could not be confirmed. Additionally, amongst the 19 control cases the British pathologist was unable to confirm T1 colorectal cancer in a further 4 cases and was equivocal in 3 cases. In conclusion, both generalist and expert pathologists experience diagnostic difficulty distinguishing pseudo-invasion and high-grade dysplasia from T1 colorectal cancer. In order to prevent overtreatment, review of the histology of pedunculated T1 colorectal cancers by a second pathologist should be considered with discussion of these cases at a multidisciplinary meeting.

Tumor Budding Detection by Immunohistochemical Staining is Not Superior to Hematoxylin and Eosin Staining for Predicting Lymph Node Metastasis in pT1 Colorectal Cancer

BACKGROUND

Tumor budding is recognized as an important risk factor for lymph node metastasis in pT1 colorectal cancer. Immunohistochemical staining for cytokeratin has the potential to improve the objective diagnosis of tumor budding over detection based on hematoxylin and eosin staining. However, it remains unclear whether tumor budding detected by immunohistochemical staining is a significant predictor of lymph node metastasis in pT1 colorectal cancer.

OBJECTIVE

The purpose of this study was to clarify the clinical significance of tumor budding detected by immunohistochemical staining in comparison with that detected by hematoxylin and eosin staining.

DESIGN

This was a retrospective study.

SETTINGS

The study was conducted at Niigata University Medical & Dental Hospital.

PATIENTS

We enrolled 265 patients with pT1 colorectal cancer who underwent surgery with lymph node dissection.

MAIN OUTCOME MEASURES

Tumor budding was evaluated by both hematoxylin and eosin and immunohistochemical staining with the use of CAM5.2 antibody. Receiver operating characteristic curve analyses were conducted to determine the optimal cutoff values for tumor budding detected by hematoxylin and eosin and CAM5.2 staining. Univariate and multivariate analyses were performed to identify the significant factors for predicting lymph node metastasis.

RESULTS

Receiver operating characteristic curve analyses revealed that the cutoff values for tumor budding detected by hematoxylin and eosin and CAM5.2 staining for predicting lymph node metastases were 5 and 8. On multivariate analysis, histopathological differentiation (OR, 6.21; 95% CI, 1.16-33.33; p = 0.03) and tumor budding detected by hematoxylin and eosin staining (OR, 4.91; 95% CI, 1.64-14.66; p = 0.004) were significant predictors for lymph node metastasis; however, tumor budding detected by CAM5.2 staining was not a significant predictor.

LIMITATIONS

This study was limited by potential selection bias because surgically resected specimens were collected instead of endoscopically resected specimens.

CONCLUSIONS

Tumor budding detected by CAM5.2 staining was not superior to hematoxylin and eosin staining for predicting lymph node metastasis in pT1 colorectal cancer.

Pathology of premalignant colorectal neoplasia

Colorectal cancer is a heterogeneous oncological disease that develops through several molecular pathways. Each pathway is associated with specific neoplastic precursor lesions. Classification of colorectal polyps and the molecular features of associated colorectal cancers have undergone significant changes. An understanding of colorectal carcinogenesis and the molecular features of colorectal carcinomas is now regarded as necessary for personalized treatment and management of patients with colon cancer, and even for patients undergoing screening colonoscopy for early detection and prevention of colorectal cancer. In the present review, we describe the pathological and molecular features of epithelial precursor lesions involved in the early phases of colorectal carcinogenesis.

Management of colorectal T1 carcinoma treated by endoscopic resection from the Western perspective

Detection of early colorectal cancer is expected to rise in light of national colorectal cancer screening programs. This The present review article delineates current endoscopic risk assessments, differentiating invasive from non-invasive neoplasia, for high likelihood of lymph node metastasis in early colorectal cancer, also termed high-risk early colorectal cancer, and endoscopic and surgical resection methods from a Western hemisphere perspective.

Practice parameters for early colon cancer management: Italian Society of Colorectal Surgery (Società Italiana di Chirurgia Colo-Rettale; SICCR) guidelines

Early colon cancer (ECC) has been defined as a carcinoma with invasion limited to the submucosa regardless of lymph node status and according to the Royal College of Pathologists as TNM stage T1 NX M0. As the potential risk of lymph node metastasis ranges from 6 to 17% and the preoperative assessment of lymph node metastasis is not reliable, the management of ECC is still controversial, varying from endoscopic to radical resection. A meeting on recent advances on the management of colorectal polyps endorsed by the Italian Society of Colorectal Surgery (SICCR) took place in April 2014, in Genoa (Italy). Based on this material the SICCR decided to issue guidelines updating the evidence and to write a position statement paper in order to define the diagnostic and therapeutic strategy for ECC treatment in context of the Italian healthcare system.

Long-Term Outcomes of Endoscopic Versus Surgical Resection of Superficial Submucosal Colorectal Cancer

BACKGROUND

The long-term outcomes of endoscopic resection of superficial submucosal colorectal cancer (CRC) had not been adequately compared with those of surgical resection.

AIMS

We aimed to compare the long-term clinical outcomes of endoscopic resection of superficial submucosal CRC to those of surgical resection.

METHODS

Submucosal CRC patients with a tumor depth of sm1 or less than 1 mm from the muscularis mucosa were enrolled. Patients with unfavorable histology, such as poorly differentiated cancer or lymphovascular invasion, were excluded. Recurrence-free survival and overall survival were investigated in 87 patients who underwent endoscopic resection and in 171 patients who underwent surgical resection.

RESULTS

The mean ages of the endoscopic and surgical resection groups were 59.7 and 59.8 years, respectively. Hospital stay was shorter in the endoscopic resection group (1.7 ± 1.6 vs. 8.6 ± 3.8 days; p < 0.001). The 3- and 5-year recurrence-free survival rates were 98.7 and 96.7 % in the endoscopic resection group and 98.7 and 97.5 % in the surgical resection group, respectively (p = 0.837). The 3- and 5-year overall survival rates were 100.0 and 95.2 % in the endoscopic resection group and 98.7 and 92.8 % in the surgical resection group, respectively (p = 0.928). Recurred cases showed an unfavorable histology that was overlooked at the time of initial resection.

CONCLUSIONS

Long-term outcomes after endoscopic resection of superficial submucosal CRC are comparable to those after surgical resection. Thorough initial histopathological evaluations are needed to guarantee the correct indication for endoscopic resection of submucosal CRC.

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

BACKGROUND

Although recognition of colorectal malignant polyps is increasing, treatment plans lack the evidence of randomised trials.

AIM

To retrospectively evaluate presentation, management and outcomes of screen-detected colorectal malignant polyps, with special focus on the role of histological factors in therapeutic decision-making.

METHODS

We retrospectively analysed data regarding malignant polyps detected during faecal immuno-chemical test-based screening programmes in five centres in North-Eastern Italy between April 2008 and April 2013.

RESULTS

306 malignant polyps in 306 patients were included; 72 patients underwent surgery directly (23.6%). Of 234 patients treated endoscopically, 133 subsequently underwent radicalisation surgery (56.8%) and in 17 there was evidence of residual disease (12.8%). Involved, unsafe (<1mm) or invaluable resection margins and sessile morphology represented the most frequent determinants of subsequent surgery. The mean number of nodes harvested during radicalisation surgery was 7.1±6.4 (range 0-29). Histological diagnosis was re-evaluated according to new guidelines in 125 cases (41%); in 18 this led to modification of the risk class (14.4%).

CONCLUSIONS

Although the rate of surgical treatment following endoscopic resection is similar to other studies, residual disease at surgery was lower than most international series. Adhering to the new histological reporting system and respecting guidelines on node harvesting may favourably influence prognosis.

The Ueno method for substaging pT1 colorectal adenocarcinoma by depth and width measurement: an interobserver study

AIM

Early pT1 polyp colorectal cancers (CRCs) present challenges for accurate pathology substaging. Haggitt and Kikuchi stages depend on polyp morphology and are often difficult to apply due to suboptimal orientation or fragmentation, or absence of the muscularis propria in polypectomy or submucosal resection specimens. European guidelines for quality assurance suggest using Ueno's more objective approach, using depth and width measurements beyond muscularis mucosae. We have investigated interobserver variation using Ueno's approach.

METHOD

Ten consecutive pT1 polyp CRCs were identified and the slides assessed by six gastrointestinal pathologists for depth and width of invasion. A further 60 polyps were studied by a group of specialist and general pathologists. Agreement was assessed by analysis of variance. A polyp CRC is classified as high risk if it has a depth ≥ 2000 μm or a width ≥ 4000 μm and low risk with a depth < 2000 μm or a width < 4000 μm. Concordance for the dichotomized values was assessed using the kappa statistic.

RESULTS

The intraclass correlation coefficient (ICC) for depth was 0.83 and for width 0.56 in the 10-polyp group. The ICC for the 60-polyp CRCs was 0.67 for depth and 0.37 for width. In both groups, when polyp CRCs are divided into high- and low-risk categories based on depth, there was substantial and moderate agreement (κ = 0.80 and 0.47) but only fair agreement when based on width (κ = 0.34 and 0.35).

CONCLUSION

Ueno's method has the advantage of being independent of polyp morphology. Our study shows better concordance for depth measurement and reproducibility in nonfragmented specimens, with poorer agreement when based on width.

Systematic review and meta-analysis of histopathological predictive factors for lymph node metastasis in T1 colorectal cancer

BACKGROUND

In this study we examined whether histopathological findings, specifically lymphatic vessel invasion identified by an anti-human podoplanin antibody, and several other factors are associated with lymph node metastasis in T1 colorectal cancer.

METHODS

We searched PubMed and Cochrane Library, and also handsearched relevant journals, for reports written in English and published between 1998 and 2012, utilizing combination headings, such as 'colorectal cancer,' 'lymph node metastasis,' and 'risk factors.' For the report to be included in our study, the following criteria had to be met: (1) data on the frequency of lymph node metastasis in T1 colorectal cancer in relation to histopathological factors were reported; (2) patients had undergone bowel resection and had histologically diagnosed T1 colorectal cancer; (3) lymphatic vessel invasion was identified by immunohistochemistry with an anti-human podoplanin antibody rather than by hematoxylin and eosin staining; (4) univariate and multivariate analyses were conducted. Studies investigating molecular markers were excluded. The independent predictive factors were confirmed in at least one study included in the meta-analysis in the present systematic review. Microsoft Excel 2013 for Windows was used for the statistical analysis.

RESULTS

Initially, 369 publications were identified in the database searches and handsearches, of which five ultimately met all of the inclusion criteria and selected for this systematic review. The meta-analysis revealed that only two factors were significantly associated with T1 colorectal cancer lymph node metastasis: (1) lymphatic vessel invasion identified by an anti-human podoplanin antibody [Mantel-Haenszel odds ratio (OR) 5.19; (95% confidence interval (CI) 3.31-8.15; P = 0.01]; (2) tumor budding (OR 7.45; 95 % CI 4.27-13.02; P = 0.0077).

CONCLUSION

Our meta-analysis revealed that lymphatic vessel invasion identified by an anti-human podoplanin antibody and tumor budding were significantly associated with T1 colorectal cancer lymph node metastasis.

A clinical model for predicting lymph node metastasis in submucosal invasive (T1) colorectal cancer

BACKGROUND

No single histopathological feature of submucosal invasive colorectal cancer (T1-CRC) can reliably predict the risk for lymph node metastasis (LNM).

AIM

The purpose of the study was to develop a prediction model of LNM in T1-CRC.

METHODS

Ninety-seven surgically resected T1-CRC at our institution were retrospectively evaluated. Morphology, localization, grading, mode of growth, presence of background adenoma, lymphoid infiltration, angiolymphatic invasion, budding, and depth of invasion were assessed. Mortality and morbidity related to surgery were also evaluated. Benefit-risk balance was assessed according to the presence of severe complications and to the presence of LNM.

RESULTS

Fourteen cases had LNM (14%). Eight patients (8%) presented severe surgical complications and there were two deaths (2 %). Infiltrative growth pattern (OR 31.91, 95% CI 2.37-428.36; p = 0.009) and the absence of lymphoid infiltrate (OR 28.75; 95% CI 2.13-388.37; p = 0.011) were the only variables independently associated with LNM in the multivariate analysis. Both variables were included in the prediction model together with sessile morphology (OR 4.88; 95% CI 0.81-29.3; p = 0.083) and poorly differentiated carcinoma (OR 11.77; 95% CI 0.77-179.83; p = 0.076). A 0-100 score was developed (infiltrative growth pattern: no = 0, yes = 33; lymphoid infiltrate: no = 29, yes = 0; sessile morphology: no = 0, yes = 15; poorly differentiated: no = 0, yes = 23). Cutoff point to indicate additional surgery was set in 35 points (i.e., 10% risk LNM). Discrimination of the prediction model was excellent (AUC 0.90; 95% CI 0.81-0.99).

CONCLUSION

Combined evaluation of infiltrative growth pattern, lymphoid infiltration, poorly differentiated carcinoma, and sessile appearance showed good performance for discriminating T1-CRC patients with LNM. The benefit-risk balance was in favor of surgery when at least two of these criteria were present.

Endoscopic and surgical treatment of malignant colorectal polyps: a population-based comparative study

BACKGROUND

Long-term population-based data comparing endoscopic therapy (ET) and surgery for management of malignant colorectal polyps (MCPs) are limited.

OBJECTIVE

To compare colorectal cancer (CRC)-specific survival with ET and surgery.

DESIGN AND SETTING

Population-based study.

PATIENTS

Patients with stage 0 and stage 1 MCPs were identified from the Surveillance Epidemiology and End Results (SEER) database (1998-2009). Demographic characteristics, tumor size, location, treatment modality, and survival were compared. Propensity-score matching and Cox proportional hazards regression models were used to evaluate the association between treatment and CRC-specific survival.

INTERVENTIONS

ET and surgery.

MAIN OUTCOME MEASUREMENTS

Mid-term (2.5 years) and long-term (5 years) CRC-free survival rates and independent predictors of CRC-specific mortality.

RESULTS

Of 10,403 patients with MCPs, 2688 (26%) underwent ET and 7715 (74%) underwent surgery. Patients undergoing ET were more likely to be older white men with stage 0 disease. Surgical patients had more right-sided lesions, larger MCPs, and stage 1 disease. There was no difference in the 2.5-year and 5-year CRC-free survival rates between the 2 groups in stage 0 disease. Surgical resection led to higher 2.5-year (97.8% vs 93.2%; P < .001) and 5-year (96.6% vs 89.8%; P < .001) CRC-free survival in stage 1 disease. These results were confirmed by propensity-score matching. ET was a significant predictor for CRC-specific mortality in stage 1 disease (hazard ratio 2.40; 95% confidence interval, 1.75-3.29; P < .001).

LIMITATIONS

Comorbidity index not available, selection bias.

CONCLUSIONS

ET and surgery had comparable mid- and long-term CRC-free survival rates in stage 0 disease. Surgical resection is the recommended treatment modality for MCPs with submucosal invasion.

Management of sessile malignant polyps: is colonoscopic polypectomy enough?

BACKGROUND

The role of endoscopy in the management of malignant-pedunculated polyps has been well studied, but endoscopic management of malignant sessile polyps has not. Sometimes patients with malignant sessile polyps have comorbidities that make surgery exceptionally risky, and endoscopy beckons as a definitive management option. The aim of this study is to evaluate the potential role of endoscopy in the management of malignant sessile polyps.

METHODS

Patients undergoing colonoscopic polypectomy for malignant sessile polyps by a single endoscopist from 1997 to 2010 were evaluated. Demographic data, clinicopathological variables as well as long-term outcomes were recorded.

RESULTS

Sixteen patients had malignant sessile polyps. Six (37.5 %) were male and 10 (62.5 %) were female. Mean age at diagnosis was 72.9 ± 12.2 years. Six polyps were proximal to the splenic flexure (37.5 %) and 10 (62.5 %) were distal. The mean size of the polyps was 30.5 ± 15.9 mm. All polyps were removed endoscopically but 7 patients (43.8 %) had formal colectomy following colonoscopic resection. There were no demographic differences between patients with and without surgery. Piecemeal polypectomy was necessary in 8 patients, 4 from the surgery group, and 4 from the endoscopy group. More patients in the surgery group had poorly differentiated cancers (4/6 vs. 0/6) and incomplete margins (5/6 vs. 1/6) and more patients in the endoscopically treated group had serious comorbidity (5/9 vs. 3/7). There was no procedure-related morbidity or mortality. After a mean follow-up of 48.4 ± 27.2 months, one patient from the polypectomy group patient had a local recurrence and a liver metastasis, after originally declining surgery. In the surgery group, one patient had lung metastasis. The two patients who recurred with distant metastasis died.

CONCLUSION

Endoscopic management of sessile colorectal polyps appears to be feasible and safe in patients with well/moderately differentiated cancer and negative margins. Larger studies are needed to confirm these findings.

Biological ablation of sentinel lymph node metastasis in submucosally invaded early gastrointestinal cancer

Currently, early gastrointestinal cancers are treated endoscopically, as long as there are no lymph node metastases. However, once a gastrointestinal cancer invades the submucosal layer, the lymph node metastatic rate rises to higher than 10%. Therefore, surgery is still the gold standard to remove regional lymph nodes containing possible metastases. Here, to avoid prophylactic surgery, we propose a less-invasive biological ablation of lymph node metastasis in submucosally invaded gastrointestinal cancer patients. We have established an orthotopic early rectal cancer xenograft model with spontaneous lymph node metastasis by implantation of green fluorescent protein (GFP)-labeled human colon cancer cells into the submucosal layer of the murine rectum. A solution containing telomerase-specific oncolytic adenovirus was injected into the peritumoral submucosal space, followed by excision of the primary rectal tumors mimicking the endoscopic submucosal dissection (ESD) technique. Seven days after treatment, GFP signals had completely disappeared indicating that sentinel lymph node metastasis was selectively eradicated. Moreover, biologically treated mice were confirmed to be relapse-free even 4 weeks after treatment. These results indicate that virus-mediated biological ablation selectively targets lymph node metastasis and provides a potential alternative to surgery for submucosal invasive gastrointestinal cancer patients.

Novel risk factors for lymph node metastasis in early invasive colorectal cancer: a multi-institution pathology review

BACKGROUND

Novel risk factors for lymph node metastasis (LNM) in T1 colorectal cancer (CRC) have been recently proposed, but most have not been implemented because of the lack of validation. Here we determined the value of poorly differentiated clusters (PDCs) in a multi-institutional cohort of T1 CRC cases.

METHODS

A pathology review involving 30 institutions was conducted for 3556 T1 CRCs. PDC was defined as malignant clusters comprising ≥5 cells and lacking a glandular formation. The ability to identify LNM risk was compared using Akaike's information criterion (AIC).

RESULTS

PDC was observed in 1401 tumors (39.4 %), including 94 (17.8 %) with <1000 µm submucosal invasion and 1307 (43.2 %) with ≥1000 µm submucosal invasion (P < 0.0001). The incidence of LNM was higher in PDC-positive tumors (17.4 %) than in PDC-negative tumors (6.9 %; P < 0.0001), and PDCs had an adverse impact on LNM irrespective of the degree of submucosal invasion. Grade 3, vascular invasion, budding, and submucosal invasion depth were also significant factors (all, P < 0.0001). AIC of risk factor to identify LNM risk was most favorable for vascular invasion (2273.4), followed by PDC (2357.4); submucosal invasion depth (2429.1) was the most unfavorable. Interinstitutional judgment disparities were smaller in PDC (kappa, 0.51) than vascular invasion (0.33) or tumor grade (0.48).

CONCLUSIONS

PDC is a promising new parameter with good ability to identify LNM risk. Use of its appropriate judgment criteria will enable us determine whether an observational policy can be safely applied following local tumor excision in T1 CRC cases.

Oncologic colorectal resection after endoscopic treatment of malignant polyps: does endoscopy have an adverse effect on oncologic and surgical outcomes?

BACKGROUND

Early colorectal cancer is increasingly treated by endoscopic removal. In cases of incomplete resection or high-risk carcinoma, additional surgery is necessary.

OBJECTIVE

To evaluate the frequency of subsequent oncologic surgery after endoscopic resection of colorectal cancer, the rate of lymph node metastasis, residual cancer, and morbidity and mortality rates of the operation. Any eventual adverse effect of the prior endoscopic therapy on the surgical and oncologic outcome was assessed.

DESIGN

Retrospective review of prospectively collected data.

SETTING

University hospital.

PATIENTS

Sixty-six consecutive patients with incomplete endoscopic treatment and need for additional surgery between 2004 and 2011.

INTERVENTION

The data of these patients were compared with those of a group of patients with surgery for early colorectal cancer during the same period without prior endoscopic resection as the control group.

MAIN OUTCOME MEASUREMENTS

Rate of lymph node metastasis and residual cancer, perioperative morbidity and mortality.

RESULTS

The lymph node metastasis rate after oncologic resection was 8.6%, and the residual cancer rate was 41%. Risk factors for residual cancer were macroscopic incomplete resection (P < .0001), positive resection margins (P = .03), and piecemeal resection (P = .004). No mortality was observed. Perioperative morbidity, mortality, and oncologic outcome were not significantly different in the group with prior endoscopic resection compared with the primarily operated group.

LIMITATIONS

Retrospective study.

CONCLUSION

Endoscopic treatment of malignant polyps does not worsen surgical and oncologic outcomes in cases of subsequent surgery. Because mortality and morbidity are low, oncologic resection generally should be done in the presence of risk factors for residual cancer.

Mismatch repair system and p53 expression in patients with T1 and T2 colorectal cancer: predictive role of lymph node metastasis and survival

BACKGROUND

The aim of this study was to evaluate the predictive role of the mismatch repair (MMR) system and p53 expression for lymph node metastasis and long-term survival in patients with T1 and T2 colorectal cancer.

METHODS

A total of 543 patients with T1 or T2 colorectal cancers who underwent radical surgery with regional lymphadenectomy from December 2007 to December 2009 were analyzed. Predictive factors for lymph node metastasis and prognostic factors were analyzed.

RESULTS

During the median follow-up period of 4 years, the 5-year disease-free survival rate for patients without lymph node metastasis was 94.8%, which was significantly higher than that for those with lymph node metastases (85.2%; P < 0.001). On multivariate analysis, gender, tumor location, N category, lymphatic invasion, vascular invasion, and perineural invasion were independent prognostic factors for disease-free survival; however MMR defect, p53 expression, and microsatellite instability (MSI) were not. The presence of lymphatic invasion, vascular invasion, and tumor budding were independent predictors of lymph node metastasis.

CONCLUSIONS

In patients with T1 or T2 colorectal cancer, lymphatic invasion, vascular invasion, and tumor budding were predictive of lymph node metastasis; however, MMR defect, p53 expression, and MSI were not predictive.

Clinical outcome of low- and high-risk malignant colorectal polyps: results of a population-based study and meta-analysis of the available literature

Some histological features of malignant polyps have been used to classify patients into low- and high-risk groups. This study proposed to evaluate the impact of this classification on the clinical outcome of patients with malignant polyps. Through the Colorectal Cancer Registry, 105 patients with endoscopically removed malignant polyps were selected. The presence of one of the following histological features defined malignant polyps as high-risk: infiltrated resection-margin, poorly differentiated carcinoma, lymphatic/vascular invasion and tumour budding and depth of submucosal invasion. Available literature was reviewed by applying a similar classification. Most of the malignant polyps were pedunculated and were localized in the left colon. Fifty-five malignant polyps were classified as low-risk lesions and 50 as high-risk. None of the patients at low-risk died of colorectal cancer. Of the patients at high-risk, three died of cancer; all three cases showed lymphatic/vascular invasion. Review of the literature reveals that an unfavourable clinical outcome is significantly more prevalent in the high-risk compared with the low-risk group (p > 0.005). Moreover, all histological risk factors show a specific predictive value of clinical adverse outcome. Our study and the pooled data analysis confirmed the usefulness of the subdivision into low- and high-risk malignant polyps for management of patients with endoscopically removed colorectal carcinoma.

Long-term follow-up of patients with malignant pedunculated colon polyps after colonoscopic polypectomy

BACKGROUND

Previously published studies have suggested that patients with resected colon cancer have an increased risk for early metachronous colon cancer. Current screening guidelines recommend intense surveillance by colonoscopy for the initial five years after the initial colon cancer has been resected. Information regarding endoscopically removed malignant polyps is limited.

METHODS

In the present study, 25 consecutive patients (14 male, 11 female) with malignant pedunculated colon polyps treated with snare cautery polypectomy were followed for more than one decade up to 20 years. Five patients required an additional resection to ensure that removal of the original cancer was complete. Annual colonoscopies were planned for five years. If an adenoma was detected in the fifth year, colonoscopy was performed annually until no adenomas were detected. Otherwise, colonoscopy was planned every three years after five years.

RESULTS

In the present study, there was no mortality from colon cancer and no patient developed either recurrent colon cancer or an early metachronous colon cancer during the initial five-year period of surveillance. Two patients (one male, one female) ultimately developed late cecal cancers almost one decade after the original colon cancers were resected. One had an early stage cancer that was resected, while the other had an infiltrating mucinous carcinoma complicating a small tubulovillous adenoma with extension to a single lymph node. After surgical removal and adjuvant chemotherapy, no further neoplastic disease has been detected.

CONCLUSIONS

Overall, patients with malignant pedunculated polyps do extremely well if appropriately managed at the time of the initial polypectomy. Short-term outcomes after removal of a malignant polyp(s) appear to be similar to those with a nonmalignant polyp. However, late metachronous colon cancer may still occur. Long-term follow-up should be considered in each patient, assuming reasonable life expectancy, because risk of additional adenomas and metachronous colon cancer persists even after the initial five years of currently recommended surveillance. Patients with resected malignant polyps may represent a special patient subgroup that requires surveillance for more extended periods than current guidelines have recommended.

Factors associated with risk for colorectal cancer recurrence after endoscopic resection of T1 tumors

BACKGROUND & AIMS

More information is needed on the long-term outcomes of patients who undergo endoscopic resection of colorectal tumors. We evaluated recurrence of colorectal cancer (CRC) after endoscopic resection or a combination of endoscopic research and surgery for T1 colorectal tumors.

METHODS

We conducted a retrospective study of 389 patients with T1 CRC treated by endoscopic resection from January 1989 to December 2008 in Sapporo, Japan. We compared outcomes between patients who underwent subsequent surgery (ER + SURG, n = 205) and those who did not (ER only, n = 184) and statistically adjusted baseline differences between the groups according to the propensity scores.

RESULTS

There was almost no risk of cancer recurrence among patients without indications for surgery recommended by the Japanese Society for Cancer of the Colon and Rectum (these indications include tumors with vertical margins, deep submucosal invasion, lymphatic or venous invasion, poor differentiation, or high-grade budding). Among patients with indications for surgery, the cumulative risks of recurrence (CRRs) were 3.7% in the ER + SURG group and 20.1% in the ER only group (P = .001). However, the patients with only deep submucosal invasion had a low CRR, even without surgery (2.3% in the ER + SURG group and 3.4% in the ER only groups, P = .867). In contrast, patients with indications for surgery other than deep submucosal invasion (high-risk patients) had much better outcomes when they also underwent surgery (CRRs: 5.8% in the ER + SURG group vs 58.0% in the ER only group, P < .001).

CONCLUSIONS

On the basis of a retrospective study of patients who underwent endoscopic resection for T1 CRC, those with tumors with only submucosal invasion are at low risk for cancer recurrence. However, patients with other high-risk tumor features have greater risks for cancer recurrence and benefit from subsequent surgery.

Lymphatic invasion identified with D2-40 immunostaining as a risk factor of nodal metastasis in T1 colorectal cancer

BACKGROUND

The management of T1 colorectal cancer after local resection is controversial. Regional lymph node metastasis often occurs, requiring subsequent colonic resection. The aim of this study was to reevaluate the risk factors of nodal metastasis of T1 colorectal cancer, especially to examine lymphatic vessel invasion in serially prepared hematoxylin and eosin sections and D2-40 immunostained sections to determine which is a better indicator of lymph node metastasis of T1 colorectal cancer.

METHODS

The study investigated 120 patients who underwent bowel resection and were histologically diagnosed to have T1 colorectal cancer in Kanagawa Cancer Center Hospital from 1995 to 2005. Serially prepared paraffin sections were stained with hematoxylin and eosin, or immunostained with D2-40 antibody or von Willebrand factor, and reevaluated for lymphatic vessel invasion and other risk factors, including venous invasion, histological grade, depth of submucosal invasion, and budding.

RESULTS

Lymphatic invasion diagnosed with either hematoxylin and eosin staining (p = 0.022), or D2-40 immunostaining (p = 0.001), and budding (p = 0.013) were significant risk factors for lymph node metastasis in the univariate analysis. Venous involvement, histological grade, or depth of submucosal invasion was not significant. The multivariate logistic regression analysis for the three risk factors found lymphatic invasion diagnosed with D2-40 as an independent risk factor (odds ratio 6.048, p = 0.018, CI 1.360-26.89). The sensitivity, specificity, positive predictive value, and negative predictive value were 58 %, 88 %, 35 %, and 95 %, respectively.

CONCLUSIONS

Lymphatic vessel invasion diagnosed with D2-40 was a better indicator to evaluate the risk for lymph node metastasis by T1 colorectal cancer.