Additional Surgical Resection After Endoscopic Resection for Patients With High-risk T1 Colorectal Cancer

Approaches and considerations in the endoscopic treatment of T1 colorectal cancer

The detection of early colorectal cancer (CRC) is increasing through the implementation of screening programs. This increased detection enhances the likelihood of minimally invasive surgery and significantly lowers the risk of recurrence, thereby improving patient survival and reducing mortality rates. T1 CRC, the earliest stage, is treated endoscopically in cases with a low risk of lymph node metastasis (LNM). The advantages of endoscopic treatment compared with surgery include minimal invasiveness and limited tissue disruption, which reduce morbidity and mortality, preserve bowel function to avoid colectomy, accelerate recovery, and improve cost-effectiveness. However, T1 CRC has a risk of LNM. Thus, selection of the appropriate treatment between endoscopic treatment and surgery, while avoiding overtreatment, is challenging considering the potential for complete resection, LNM, and recurrence risk.

Current treatment of pT1 rectal cancers in Denmark: A retrospective national cohort study

AIM

Organ preservation strategies for patients with rectal cancer are increasingly common. In appropriately selected patients, local excision (LE) of pT1 cancers can reduce morbidity without compromising cancer-related outcomes. However, determining the need for completion surgery after LE can be challenging, and it is unknown if prior LE compromises subsequent total mesorectal excision (TME). The aim of this study is to describe the current management of patients with pT1 rectal cancers.

METHOD

This is a retrospective national cohort study of the Danish Colorectal Cancer Group database, including patients with newly diagnosed pT1 cancers between 2016 and 2020. Patients were stratified according to treatment into LE alone, completion TME after LE or upfront TME. The treatment and outcomes of these groups were compared.

RESULTS

A total of 1056 patients were included. Initial LE was performed in 715 patients (67.7%), of whom 194 underwent completion TME (27.1%). The remaining 341 patients underwent upfront TME (32.3%). Patients undergoing LE alone were more likely to be male with low rectal cancers and greater comorbidity. No differences in specimen quality or perioperative outcomes were noted between patients undergoing completion or upfront TME. Eighty-five patients (15.9%) had lymph node metastases (LNM). Pathological risk factors poorly discriminated between patients with and without LNM, with similar rates seen in patients with zero (14.1%), one (12.0%) or two (14.4%) risk factors.

CONCLUSION

LE is a key component of the treatment of pT1 rectal cancer and does not appear to affect the outcomes of completion TME. Patient selection for completion TME remains a major challenge, with current stratification methods appearing to be inadequate.

Risk of recurrence in high-risk T1 colon cancer following endoscopic and surgical resection: registry-based cohort study

BACKGROUND

Endoscopic resection of T1 colon cancer (CC) is currently limited by guidelines related to risk of lymph node metastases. However, clinical outcome following endoscopic and surgical resection is poorly investigated.

METHOD

A retrospective multicentre national cohort study was conducted on prospectively collected data from the Swedish colorectal cancer registry on all non-pedunculated T1 CC patients undergoing surgical and endoscopic resection between 2009 and 2021. Patients were categorized on the basis of deep submucosal invasion (Sm2-3), lymphovascular invasion (LVI), poor tumour differentiation, and R1/Rx into low- and high-risk cases. The primary outcomes of interest were recurrence rates and disease-free interval (DFI, defined as time from treatment to date of recurrence) according to resection methods and risk factors (sex, age at diagnosis, histologic grade, LVI, perineural invasion, mucinous subtype, submucosal invasion, tumour location, resection margin and nodal positivity in the surgical group).

RESULTS

In total, 1805 patients undergoing endoscopic (488) and surgical (1317) resection with 60.0 months median follow-up were included. Recurrence occurred in 18 (3.7%) endoscopically and 48 (3.6%) surgically resected patients. Adjuvant treatment was administered in 7.4% and 0.2% of the cases respectively in the surgical and endoscopically treated patients. Five-year DFI was 95.6% after endoscopic and 96.2% after surgical resection, with no significant difference when adjusting for confounding factors (HR 1.03, 95% c.i. 0.56 to 1.91, P = 0.920). There were no statistically significant differences in recurrence comparing endoscopic (1.7%) versus surgical (3.6%) low-risk and endoscopic (5.4%) versus surgical (3.8%) high-risk cases. LVI was the only significant risk factor for recurrence in multivariate Cox regression (HR 3.73, 95% c.i. 1.76 to 7.92, P < 0.001).

CONCLUSIONS

This study shows no difference in recurrence after endoscopic and surgical resection in high-risk T1 CC. Although it was not possible to match groups according to treatment, the multivariate analysis showed that lymphovascular invasion was the only independent risk factor for recurrence.

Right hemicolectomy combined with duodenum-jejunum Roux-en-Y anastomosis for hepatic colon carcinoma invading the duodenum: A single-center case series

BACKGROUND

Hepatic colon carcinoma invading the duodenum is not common in clinical practice. Surgical treatment of colonic hepatic cancer that invades the duodenum is difficult, and the surgical risk is high.

AIM

To discuss the efficacy and safety of duodenum-jejunum Roux-en-Y anastomosis for the treatment of hepatic colon carcinoma invading the duodenum.

METHODS

From 2016 to 2020, 11 patients from Panzhihua Central Hospital diagnosed with hepatic colon carcinoma were enrolled in this study. Clinical and therapeutic effects and prognostic indicators were retrospectively analyzed to determine the efficacy and safety of our surgical procedures. All patients underwent radical resection of right colon cancer combined with duodenum-jejunum Roux-en-Y anastomosis.

RESULTS

The median tumor size was 65 mm (r50-90). Major complications (Clavien-DindoI-II) occurred in 3 patients (27.3%); the average length of hospital stay was 18.09 ± 4.21 d; and only 1 patient (9.1%) was readmitted during the 1^st mo after the surgery. The 30-d mortality rate was 0%. After a median follow-up of 41 m (r7-58), the disease-free survival at 1, 2, and 3 years was 90.9%, 90.9% and 75.8%, respectively; the overall survival at 1, 2, and 3 years was 90.9%.

CONCLUSION

In selected patients, radical resection of right colon cancer combined with duodenum-jejunum Roux-en-Y anastomosis is clinically effective, and the complications are manageable. The surgical procedure also has an acceptable morbidity rate and mid-term survival.

Prognostic Factors for Lymph Node Metastases in pT1 Colorectal Cancer Differ According to Tumor Morphology: A Nationwide Cohort Study

OBJECTIVE

To investigate whether there is a differential impact of histopathological risk factors for lymph node metastases (LNM) in pedunculated and nonpedunculated pT1 colorectal cancers (CRC).

BACKGROUND

Tumor budding, lymphovascular invasion (LVI), and venous invasion (VI) are recognized risk factors for LNM in pT1 CRC. Whether the importance of these factors varies according to tumor morphology is unknown.

METHODS

Patients undergoing resection with lymphadenectomy for pT1 CRC in Denmark from January 2016 to January 2019 were identified in the Danish Colorectal Cancer Database and clinicopathological data was reviewed. Prognostic factors for LNM were investigated using multivariable analyses on the cohort as a whole as well as when stratifying according to tumor morphology (pedunculated vs. nonpedunculated).

RESULTS

A total of 1167 eligible patients were identified, of whom 170 had LNM (14.6%). Independent prognostic factors for LNM included LVI [odds ratio (OR)=4.26, P <0.001], VI (OR=3.42, P <0.001), tumor budding (OR=2.12, P =0.002), high tumor grade (OR=2.76, P =0.020), and age per additional year (OR=0.96, P <0.001). On subgroup analyses, LVI and VI remained independently prognostic for LNM regardless of tumor morphology. However, tumor budding was only prognostic for LNM in pedunculated tumors (OR=4.19, P <0.001), whereas age was only prognostic in nonpedunculated tumors (OR=0.61, P =0.003).

CONCLUSIONS

While LVI and LI were found to be prognostic of LNM in all pT1 CRC, the prognostic value of tumor budding differs between pedunculated and nonpedunculated tumors. Thus, tumor morphology should be taken into account when considering completion surgery in patients undergoing local excision.

Risk of recurrence after local resection of T1 rectal cancer: a meta-analysis with meta-regression

BACKGROUND

T1 rectal cancer (RC) patients are increasingly being treated by local resection alone but uniform surveillance strategies thereafter are lacking. To determine whether different local resection techniques influence the risk of recurrence and cancer-related mortality, a meta-analysis was performed.

METHODS

A systematic search was conducted for T1RC patients treated with local surgical resection. The primary outcome was the risk of RC recurrence and RC-related mortality. Pooled estimates were calculated using mixed-effect logistic regression. We also systematically searched and evaluated endoscopically treated T1RC patients in a similar manner.

RESULTS

In 2585 unique T1RC patients (86 studies) undergoing local surgical resection, the overall pooled cumulative incidence of recurrence was 9.1% (302 events, 95% CI 7.3-11.4%; I2 = 68.3%). In meta-regression, the recurrence risk was associated with histological risk status (p < 0.005; low-risk 6.6%, 95% CI 4.4-9.7% vs. high-risk 28.2%, 95% CI 19-39.7%) and local surgical resection technique (p < 0.005; TEM/TAMIS 7.7%, 95% CI 5.3-11.0% vs. other local surgical excisions 10.8%, 95% CI 6.7-16.8%). In 641 unique T1RC patients treated with flexible endoscopic excision (16 studies), the risk of recurrence (7.7%, 95% CI 5.2-11.2%), cancer-related mortality (2.3%, 95% CI 1.1-4.9), and cancer-related mortality among patients with recurrence (30.0%, 95% CI 14.7-49.4%) were comparable to outcomes after TEM/TAMIS (risk of recurrence 7.7%, 95% CI 5.3-11.0%, cancer-related mortality 2.8%, 95% CI 1.2-6.2% and among patients with recurrence 35.6%, 95% CI 21.9-51.2%).

CONCLUSIONS

Patients with T1 rectal cancer may have a significantly lower recurrence risk after TEM/TAMIS compared to other local surgical resection techniques. After TEM/TAMIS and endoscopic resection the recurrence risk, cancer-related mortality and cancer-related mortality among patients with recurrence were comparable. Recurrence was mainly dependent on histological risk status.

Risk of recurrence after endoscopic resection of nonpedunculated T1 colorectal cancer

BACKGROUND

The long-term outcome after local excision of T1 colorectal cancer (CRC) remains unknown. The aim of this study was to examine clinical and histopathological risk factors for recurrence in patients with T1 CRC undergoing endoscopic resection.

METHODS

This was a retrospective registry-based population study on prospectively collected data of all patients with nonpedunculated T1 CRC undergoing only local excision (no salvage surgery) in Sweden between 2009 and 2018. Potential risk factors for recurrence, including age, sex, tumor location, resection margins, lymphovascular, perineural, and submucosal invasion, grade of differentiation, and mucinous subtype, were analyzed using univariate and multivariate cox regression.

RESULTS

Median follow-up time was 60 months, and 28 /602 patients (4.7 %) had a recurrence (13 local and 18 distant). Recurrence rate stratified by submucosal invasion was: Sm1 3.5 % (14 /397), Sm2 6.0 % (8 /133), and Sm3 8.3 % (6 /72), with no significant differences. Resection margins, lymphovascular and perineural invasion, grade of differentiation, mucinous subtype, and age were not significant risk factors for recurrence. In contrast, rectal location was found to be a significant risk factor for tumor recurrence in multivariate analysis (hazard ratio 3.08, P = 0.006). The 3- and 5-year disease-free survival was 96.2 % and 91.1 %, respectively, in T1 CRC patients undergoing endoscopic resection.

CONCLUSION

Tumor recurrence was rare (4.7 %) in this large population-based study on recurrence after local excision of nonpedunculated T1 CRC. Rectal location was an independent risk factor for recurrence, suggesting the need for strict surveillance after endoscopic resection of early rectal cancer.

Clinical outcome of local treatment and radical resection for pT1 rectal cancer

BACKGROUND

Rectal cancer is mainly cured by radical resection with neoadjuvant chemoradiation or adjuvant chemotherapy. Pathological T1 lesions can be managed by local treatment and radiotherapy thereafter. Lower morbidity is the key benefit of these local treatments. Since nodal metastasis is important for staging, radical resection (RR) is suggested. Rectal cancer has higher surgical morbidity than colon cancer; local treatment has been the preferred choice by patients.

METHODS

We retrospectively enrolled data of 244 patients with pT1 rectal adenocarcinoma. A total of 202 patients (82.8%) underwent RR, including low anterior resection (LAR) and abdomino-perineal resection (APR), and 42 patients (17.2%) underwent LT, including transanal excision and colonoscopic polypectomy.

RESULTS

In our study, seven patients (16.7%) had loco-regional recurrence and distant metastasis from the LT group while eight patients (4.0%) had distant metastasis without loco-regional recurrence from the RR group. The lymph node metastasis rate in RR group was 8.4%. Forty-seven patients (24.2%) underwent LAR with temporary stoma, and its reversal rate was 100%. In the RR group, postoperative complication rate was 10.4% with a mortality rate of 0.5%. Recurrence-free survival (RFS) was 95.7% for RR and 80.2% for LT (P = 0.001), and overall survival (OS) was 93.7% for RR and 70.0% for LT (P = 0.001).

CONCLUSION

This study found that RFS and OS in patients of pT1 rectal adenocarcinoma that had received RR were better than receiving LT. Further adjuvant chemotherapy was possible for some RR patients. A higher recurrence rate after LT must be balanced against the morbidity and mortality associated with RR.

Targeted Nursing Combined with Endoscopic Submucosal Injection of Carbon Nanoparticles in the Treatment of Colorectal Cancer

Aim

To evaluate the effectiveness of targeted nursing in an endoscopic submucosal injection of carbon nanoparticles to locate colorectal cancer.

Methods

From September 2017 to September 2019, 82 patients with colorectal cancer who underwent endoscopic submucosal injection of carbon nanoparticles for locating the tumor were recruited and assigned via the random number table method (1 : 1) to receive either conventional nursing (control group) or targeted nursing (observation group). Outcome measures included psychological status, compliance, nursing satisfaction, quality of life, and daily living ability.

Results

After intervention, the self-rating anxiety scale (SAS) scores and self-rating depression scale (SDS) scores were decreased in both groups, with lower results in the observation group (P < 0.001). Patients given target nursing were associated with higher compliance and nursing satisfaction of patients versus conventional nursing (P < 0.05). Patients receiving targeted nursing had a better quality of life versus those receiving conventional nursing (P < 0.001). Targeted nursing resulted in a higher Barthel index (BI) in patients versus conventional nursing 1 d, 7 d, and 14 d after nursing (P < 0.05).

Conclusion

Targeted nursing alleviates the negative emotions of patients with colorectal cancer and improves their compliance, nursing satisfaction, daily living ability, and quality of life.

Prediction of lymph node metastasis in early colorectal cancer based on histologic images by artificial intelligence

Risk evaluation of lymph node metastasis (LNM) for endoscopically resected submucosal invasive (T1) colorectal cancers (CRC) is critical for determining therapeutic strategies, but interobserver variability for histologic evaluation remains a major problem. To address this issue, we developed a machine-learning model for predicting LNM of T1 CRC without histologic assessment. A total of 783 consecutive T1 CRC cases were randomly split into 548 training and 235 validation cases. First, we trained convolutional neural networks (CNN) to extract cancer tile images from whole-slide images, then re-labeled these cancer tiles with LNM status for re-training. Statistical parameters of the tile images based on the probability of primary endpoints were assembled to predict LNM in cases with a random forest algorithm, and defined its predictive value as random forest score. We evaluated the performance of case-based prediction models for both training and validation datasets with area under the receiver operating characteristic curves (AUC). The accuracy for classifying cancer tiles was 0.980. Among cancer tiles, the accuracy for classifying tiles that were LNM-positive or LNM-negative was 0.740. The AUCs of the prediction models in the training and validation sets were 0.971 and 0.760, respectively. CNN judged the LNM probability by considering histologic tumor grade.

Histopathological risk factors for lymph node metastases in T1 colorectal cancer: meta-analysis

BACKGROUND

National screening programmes increase the proportion of T1 colorectal cancers. Local excision may be possible, but the risk of lymph node metastases (LNMs) could jeopardize long-term outcomes. The aim of the present study was to review the association between histopathological findings and LNMs in T1 colorectal cancer.

METHODS

A systematic literature search was conducted using PubMed,Embase, and Cochrane online databases. Studies investigating the association between one or more histopathological factors and LNMs in patients who underwent resection for T1 colorectal cancer were included.

RESULTS

Sixteen observational studies were included in the meta-analysis, including a total of 10 181 patients, of whom 1 307 had LNMs. Lymphovascular invasion (odds ratio (OR) 7.42; P < 0.001), tumour budding (OR 4.00; P < 0.001), depth of submucosal invasion, whether measured as at least 1000 µm (OR 3.53; P < 0.001) or Sm2-3 (OR 2.12; P = 0.020), high tumour grade (OR 3.75; P < 0.001), polypoid growth pattern (OR 1.59; P = 0.040), and rectal location of tumour (OR 1.36; P = 0.003) were associated with LNMs.

CONCLUSION

Distinct histopathological factors associated with nodal metastases in T1 colorectal cancer can aid selection of patients for local excision or major excisional surgery.

En bloc right hemicolectomy with pancreatoduodenectomy for right-sided colon cancer invading duodenum

Background

En bloc right hemicolectomy with pancreatoduodenectomy (RHCPD) is the optimum treatment to achieve the adequate margin of resection (R0) for locally advanced right-sided colon cancer with duodenal invasion. Information regarding the indications and outcomes of this procedure is limited.

Method

In this retrospective study, 2269 patients with right colon cancer underwent radical right colectomy between October 2010 and May 2019, in which 19 patients underwent RHCPD for LARCC were identified. The overall survival (OS), disease-free survival (DFS), operative mortality, postsurgical complications, gene mutational analysis, and prognostic factors were evaluated. Survival was estimated using Kaplan–Meir method.

Results

Of these 19 patients who underwent LARCC, the OS was 88%, 66%, and 58% at 1, 3, and 5 years. The DFS was 72%, 56%, and 56% at 1, 3, and 5 years. The median operative time was 320 min (range: 222–410 min), and the median operative blood loss was 268 mL (range: 100–600 mL). The OS was significantly better among patients with well-differentiated tumor, N0 stage, and high microsatellite instability (MSI) and in patients who received adjuvant chemotherapy. The major postoperative complications occurred in 8 patients (42%), with pancreatic fistula (PF) being the most common. On the basis of the univariate analysis, poorly differentiated tumor, regional lymph node dissemination, MSI status, and no perioperative chemotherapy were the significant predictors of poor survival (P < 0.05).

Conclusions

This study suggests that RHCPD is feasible and can achieve complete tumor clearance with favorable outcome, particularly in patients with lymph node-negative status.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-021-01286-0.

Does Additional Laparoscopic-Assisted Surgery after Endoscopic Submucosal Dissection Affect Short Outcomes in Patients with Stage T1 Colorectal Cancer? A Propensity Score-Based Analysis

BACKGROUND

Additional surgery is necessary in cases with non-curative endoscopic submucosal dissection. It is still unknown whether preceding endoscopic submucosal dissection (ESD) for T1 colorectal carcinoma affects the short outcomes of patients who underwent additional surgery or not as compared with surgery alone without ESD.

METHODS

Patients (101 pairs) with T1 colorectal cancer who underwent additional laparoscopic-assisted surgery after endoscopic submucosal dissection (additional surgery group, n = 101) or laparoscopic-assisted surgery alone (surgery alone group, n = 101) were matched (1:1). Short-term morbidity, operation outcomes, and lymph node metastasis of the resected specimen were compared.

RESULTS

There were no significant differences between the additional laparoscopic-assisted surgery and laparoscopic-assisted surgery alone groups in lymph node metastasis (9.9 vs. 5.9%, respectively, p = 0.297), operative time (147.76 ± 52.00 min vs. 156.50 ± 54.28 min, p = 0.205), first flatus time (3.56 ± 1.10 days vs. 3.63 ± 1.05 days, p = 0.282), first stool time (4.30 ± 1.04 days vs. 4.39 ± 1.22 days, p = 0.293), time to intake (5.00 ± 1.18 days vs. 5.25 ± 1.39 days, p = 0.079), blood loss (44.75 ± 45.40 mL vs. 60.40 ± 78.98 mL, p = 0.603), harvest lymph nodes (18.74 ± 7.22 vs. 20.32 ± 9.69, p = 0.438), postoperative surgical complications (p = 0.733), and postoperative length of hospital stay (8.68 ± 4.00 days vs. 8.39 ± 1.94 days, p = 0.401).

CONCLUSION

ESD did not increase the difficulty of additional laparoscopic-assisted surgery, hospital stay, or the incidence of postoperative complications. Additional laparoscopic-assisted surgery is safe and recommended for patients with T1 cancer at high risk of lymph node metastasis and residual cancer after non-curative ESD.

Surgical resection after endoscopic resection in patients with T1 colorectal cancer: a meta-analysis

PURPOSE

Additional surgical resection (ASR) after endoscopic resection (ER) in patients with colorectal cancer (CRC) allows a complete staging and may decrease the recurrence rate, but no meta-analysis is available. This study aimed to compare the effectiveness of ER vs. ER + ASR as a treatment for patients with T1 (stage 1) CRC.

METHODS

We performed a systematic search from databases (PubMed, Embase, and Cochrane library) for cohort studies published up to November 2019. The outcomes were overall survival (OS), local recurrence, recurrence, disease-specific survival, recurrence-free survival, and metastasis.

RESULTS

Seven studies were included. There were 1205 patients in the ASR group and 993 patients in the ER group. Compared with ER, ASR was associated with better OS (OR = 0.31, 95% CI: 0.18-0.53, P < 0.001) and a borderline significant difference in lower local recurrence rates (OR = 0.29, 95% CI: 0.08-1.01, P = 0.052), but no differences were observed in recurrences, disease-specific survival, recurrence-free survival, and distant metastasis. A sensitivity analysis was performed; excluding each study sequentially from the pooled analysis did not affect the overall conclusion of the study.

CONCLUSION

Compared with ER, ASR after ER could improve the overall survival for patients with T1 CRC.

Long-Term Outcomes of T1 Colorectal Cancer after Endoscopic Resection

Background and Aims: Endoscopic resection (ER) for submucosal invasive colorectal cancer (T1 CRC) can be grouped as curative ER (C-ER) and non-curative ER (NC-ER). Little is known about the long-term outcomes of patients in these two groups. Therefore, we have evaluated the long-term outcomes in endoscopically resected T1 CRC patients in C-ER and NC-ER groups. Methods: We conducted a retrospective study on 220 patients with T1 CRC treated with ER from January 2007 to December 2017. First, we investigated the long-term outcomes (5-year overall survival [OS] and recurrence-free survival [RFS]) in the C-ER group (n = 49). In the NC-ER group (n = 171), we compared long-term outcomes between patients who underwent additional surgical resection (ASR) (n = 117) and those who did not (surveillance-only, n = 54). Results: T1 CRC patients in the C-ER and NC-ER groups had a median follow-up of 44 (interquartile range 32–69) months. There was no risk of tumor recurrence and cancer-related deaths in patients with C-ER. In the NC-ER group, the 5-year OS rates were 75.3% and 92.6% in the surveillance-only and ASR subgroups, respectively. The hazard ratio (HR) for ASR in NC-ER vs. surveillance-only in NC-ER was statistically insignificant. However, RFS rates were significantly different between the ASR (97.2%) and surveillance-only (84.0%) subgroups. Multivariate analysis indicated a submucosal invasion depth (SID) of >2500 µm and margin positivity to be associated with recurrence. Conclusions: The surveillance-only approach can be considered as an alternative surgical option for T1 CRCs in selected patients undergoing NC-ER.

Additional surgery after endoscopic submucosal dissection for colorectal cancer: a review of 53 cases

BACKGROUND

Endoscopic submucosal dissection (ESD) allows the en bloc resection of tumors and is particularly indicated for T1 colorectal cancer. The number of patients undergoing additional surgery after colorectal ESD is increasing. This study aimed to retrospectively evaluate the efficacy and long-term outcomes in patients with additional surgery.

METHODS

Of 1018 patients who underwent colorectal ESD in our hospital between February 2010 and July 2018, 53 patients who underwent additional surgery in our hospital were retrospectively analyzed and investigated for their clinicopathological characteristics. The need for additional surgery was determined by a pathological examination according to the guideline [1].

RESULTS

In total, 53 patients (24 men, 29 women; mean age, 68.2 years; mean tumor diameter, 30.5 mm) were included. Laparoscopic surgery was performed in 47 (88.7%) patients. Liver metastases were preoperatively observed in one patient, for whom hepatectomy was simultaneously performed. All procedures included pathological R0 resection. Postoperative complications occurred in 9 (17.0%) patients. There were no complications requiring reoperation. Fifteen (28.3%) patients had a positive vertical margin; of these patients, residual tumor was observed in the resected specimens of two (13.3%) patients. Eight patients (15.1%) had lymph node metastasis (LNM): four (25.0%) and four (10.8%) of 16 and 37 patients with and without vascular invasion, respectively. Eleven patients (20.8%) had grade 2 or 3 tumor budding, and four (36.4%) of these had LNM. Postoperative recurrence was observed in two (3.8%) patients.

CONCLUSION

Additional surgery after ESD for T1 colorectal cancer was effective and had good long-term outcomes.