T4 Colon Research Articles

Outcomes of noncurative endoscopic submucosal dissection for T1 colorectal cancer: Prospective, multicenter, cohort study in Japan.

This study investigated the incidence of lymph node metastasis and long-term outcomes in patients with T1 colorectal cancer where endoscopic submucosal dissection (ESD) resulted in noncurative treatment. It is focused on those with deep submucosal invasion, a factor considered a weak predictor of lymph node metastasis in the absence of other risk factors. This nationwide, multicenter, prospective study conducted a post-hoc analysis of 141 patients with T1 colorectal cancer ≥20 mm where ESD of the lesion resulted in noncurative outcomes, characterized by poor differentiation, deep submucosal invasion (≥1000 μm), lymphovascular invasion, high-grade tumor budding, or positive vertical margins. Clinicopathologic features and patient prognoses focusing on lesion sites and additional surgery requirements were evaluated. Lymph node metastasis incidence in the low-risk T1 group, identified by deep submucosal invasion as the sole high-risk histological feature, was assessed. Lymph node metastasis occurred in 14% of patients undergoing additional surgery post-noncurative endoscopic submucosal dissection for T1 colorectal cancer. In the low-risk T1 group, in the absence of other risk factors, the frequency was 9.7%. The lymph node metastasis rates in patients with T1 colon and rectal cancers did not differ significantly (14% vs. 16%). Distant recurrence was observed in one patient (2.3%) in the ESD only group and in one (1.0%) in the additional surgery group, both of whom had had rectal cancer removed. The risk of lymph node metastasis or distant occurrence was not negligible, even in the low-risk T1 group. The findings suggest the need for considering additional surgery, particularly for rectal lesions (Clinical Trial Registration: UMIN000010136).

The Role of Tumor Location on Endoscopic and Surgical Management of Malignant Colon Polyps.

Endoscopic polypectomy could be an appropriate, definitive treatment for pathologic T1 (pT1) colon polyps without high-risk features. Prior studies suggested worse prognosis for proximal versus distal advanced-stage colon cancers following curative treatment. However, there is limited evidence on the prognostic impact of tumor location for pT1s. This was a retrospective cohort study using the Surveillance, Epidemiology, and End Results database to identify adults with T1NxMx or T1N0-3M0/x colon adenocarcinoma from 2000 to 2019. A total of 3398 patients underwent endoscopic polypectomy (17% proximal) and 28,334 had a partial colectomy (49% proximal) for pT1 adenocarcinoma. Following endoscopic polypectomy, 5-year overall and cancer-specific survival rates were 64% and 91% for proximal versus 83% and 96% for distal polyps, compared with 82% and 95% for proximal versus 88% and 97% for distal tumors after colectomy. In multivariable models, there was a greater difference in overall survival between proximal and distal polyps for those who underwent endoscopic versus surgical resection [hazard ratio (HR) 1.73, 95% confidence interval (CI) 1.49-2.02 vs. HR 1.13, 95% CI 1.08-1.18]. Patients with proximal versus distal polyps who underwent polypectomy also exhibited increased cancer-specific mortality (HR 1.94, 95% CI 1.37-2.75). However, cancer-specific survival variations based on tumor location were no longer observed in patients undergoing partial colectomy (HR 1.09, 95% CI 0.98-1.21). Proximal tumor location was independently associated with worse overall and cancer-specific survival following endoscopic polypectomy. However, after colectomy, the cancer-specific disparity based on tumor laterality was mitigated. These findings suggest that proximal location may be considered a high-risk feature in endoscopic polypectomy.

Does Colorectal Stenting as a Bridge to Surgery for Obstructive Colorectal Cancer Increase Perineural Invasion?

To clarify whether self-expandable metallic stent (SEMS) placement for obstructive colorectal cancer (CRC) increases perineural invasion (PNI), thereby worsening the prognosis. In total, 1022 patients with pathological T3 or T4 colon or rectosigmoid cancer who underwent resection were retrospectively reviewed. The study patients were divided into a no obstruction group (n=693), obstruction without stent group (n=251), and obstruction with stent group (n=78), and factors demonstrating an independent association with PNI, the difference in PNI incidence and severity between groups, and the association between PNI and the duration from SEMS placement to surgery were investigated. Survival analysis was performed for each group. On multivariate analysis, SEMS placement (hazard ratio [HR]: 2.08) was independently associated with PNI whereas SEMS placement was not. PNI occurred in 39%, 45%, and 68% of the no obstruction, obstruction without stent, and obstruction with stent group, respectively. In the obstruction with stent group, the proportion of PNI was not associated with the duration from SEMS placement to surgery. Extramural PNI, an advanced form of PNI, demonstrated no increase with increasing interval. The five-year OS was 86.3%, 76.7%, and 73.1% in no obstruction, obstruction without stent, and obstruction with stent group, respectively. On multivariate analysis, obstruction was an independent risk factor of decreased OS (HR: 1.57) whereas SEMS placement was not. The prognosis was comparable between patients with SEMS placement and those with an obstruction who did not undergo SEMS placement, thus demonstrating that SEMS is a viable, therapeutic option for BTS.

Current Management of T1 Colon Cancer in Denmark: A Nationwide Cohort Study.

To describe the management of T1 colon cancer in a retrospective study of a national cancer registry. There is increasing interest in the potential of local excision (LE) as an organ-preserving treatment for early colon cancer. However, accurate identification of patients who may have lymph node metastases (LNM) and require further surgery is a major challenge. Patients diagnosed with T1 colon cancer in Denmark from 2016 to 2020 were included and divided according to treatment: polypectomy (referred to as LE), upfront colectomy and completion colectomy. Primary outcome was the proportion of patients diagnosed by LE. Secondary outcomes included the rate of LNM, the association of histopathological risk factors with LNM, and overall survival. 1,749 patients were included, and 1,022 patients (58.4%) underwent initial LE. The rate of R1 margins after initial LE was 31.0%. Colectomy was performed in 1,160 patients (upfront in 727, completion in 433), of whom 58.3% had pT1 cancer. The rate of LNM was 11.5%. Rates of LNM were similar in patients undergoing upfront or completion colectomy (10.2% vs 12.4%, P=0.392), and in patients with any single histopathological risk factor compared to those with none (8.9% vs 10.6%, P=0.565). Although overall survival was significantly shorter in patients undergoing LE alone, no association between survival and treatment strategy was found on multivariable analysis. LE is the most common mode of diagnosis in patients with T1 colon cancer and does not negatively impact survival and postoperative outcomes. Current strategies to stratify patients to completion surgery appear insufficient, and more robust predictors are needed.

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

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. 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). 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). 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.

How to adopt endoluminal surgery in a new colorectal surgery practice and endoluminal management of T1 colon cancers

Endoluminal surgery in colorectal surgery involves the removal of polyps/lesions using advanced colonoscopic techniques such as endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD). Prior to the adoption of these techniques in a new colorectal surgery practice, a colorectal surgeon should have some mastery of basic colonoscopy skills along with colonoscopic polypectomy. There are a variety of training options to learn endoluminal surgery including industry and institutional based courses, observation of a master endoscopist, or observational experience in Japan. Adoption of these techniques in a new practice is facilitated by knowledge of what equipment is required and the availability of trained staff. Endoluminal management of T1 colon cancers is an acceptable method of treatment and an alternative to surgical resection provided that the proper parameters are met.

Construction of a diagnostic nomogram model for predicting the risk of lymph node metastasis in clinical T1 or T2 colon cancer based on the SEER database.

There are few methods related to predicting lymph node metastasis (LNM) in patients with clinically staged T1 or T2 colon cancer. In this study, we aimed to discover independent risk factors for patients with pathologic T-stage 1 (pT1) or pT2 colon cancer with LNM and to develop a nomogram for predicting the probability of LNM for patients with clinically staged T1 or T2 colon cancer. All data were drawn from the Surveillance, Epidemiology, and End Results (SEER) database. Independent risk factors for LNM were identified using univariate and multivariate logistic regression analyses, and these factors were used to construct a nomogram. The discriminatory power, accuracy, and clinical utility of the model were evaluated using receiver operating characteristic (ROC), calibration, and decision curve analysis (DCA), respectively. According to the inclusion and exclusion criteria, 32,803 patients with stage pT1 or pT2 colon cancer who had undergone surgery were selected from the SEER database. The data showed that the incidence of LNM in patients with pT1 and pT2 colon cancer was 17.11%. The age, histological grade, histological type, T classification, M classification, and tumour location were independent risk factors identified through univariate and multivariate analyses, and these factors were used to construct a nomogram. The ROC curve analysis showed that the area under the curve (AUC) of the ROC of the predictive nomogram for LNM risk was 0.6714 [95% confidence interval (CI): 0.6621-0.6806] in the training set and 0.6567 (95% CI: 0.6422-0.6712) in the validation set, indicative of good discriminatory power of the model. Calibration curve analysis demonstrated good agreement between the nomogram prediction and actual observation. DCA showed excellent clinical utility of the prediction model. The incidence of LNM was high in patients with pT1 and pT2 colon cancer. The nomogram established in this study can accurately predict the risk of LNM in patients with clinically staged T1 or T2 colon cancer before further clinical intervention, which allows clinicians to develop optimal treatment.

S2379 Brain and Adrenal Metastasis Resulting from Unexpected Recurrence After Endoscopic Resection of Low-Risk T1 Colon Cancer: A Case Report

S2379 Brain and Adrenal Metastasis Resulting from Unexpected Recurrence After Endoscopic Resection of Low-Risk T1 Colon Cancer: A Case Report

Limited wedge resection for T1 colon cancer (LIMERIC-II trial) – rationale and study protocol of a prospective multicenter clinical trial

BackgroundThe sole presence of deep submucosal invasion is shown to be associated with a limited risk of lymph node metastasis. This justifies a local excision of suspected deep submucosal invasive colon carcinomas (T1 CCs) as a first step treatment strategy. Recently Colonoscopy-Assisted Laparoscopic Wedge Resection (CAL-WR) has been shown to be able to resect pT1 CRCs with a high R0 resection rate, but the long term outcomes are lacking. The aim of this study is to evaluate the safety, effectiveness and long-term oncological outcomes of CAL-WR as primary treatment for patients with suspected superficial and also deeply-invasive T1 CCs.MethodsIn this prospective multicenter clinical trial, patients with a macroscopic and/or histologically suspected T1 CCs will receive CAL-WR as primary treatment in order to prevent unnecessary major surgery for low-risk T1 CCs. To make a CAL-WR technically feasible, the tumor may not include > 50% of the circumference and has to be localized at least 25 cm proximal from the anus. Also, there should be sufficient distance to the ileocecal valve to place a linear stapler. Before inclusion, all eligible patients will be assessed by an expert panel to confirm suspicion of T1 CC, estimate invasion depth and subsequent advise which local resection techniques are possible for removal of the lesion. The primary outcome of this study is the proportion of patients with pT1 CC that is curatively treated with CAL-WR only and in whom thus organ-preservation could be achieved. Secondary outcomes are 1) CAL-WR’s technical success and R0 resection rate for T1 CC, 2) procedure-related morbidity and mortality, 3) 5-year overall and disease free survival, 4) 3-year metastasis free survival, 5) procedure-related costs and 6) impact on quality of life. A sample size of 143 patients was calculated.DiscussionCAL-WR is a full-thickness local resection technique that could also be effective in removing pT1 colon cancer. With the lack of current endoscopic local resection techniques for > 15 mm pT1 CCs with deep submucosal invasion, CAL-WR could fill the gap between endoscopy and major oncologic surgery. The present study is the first to provide insight in the long-term oncological outcomes of CAL-WR.Trial registrationCCMO register (ToetsingOnline), NL81497.075.22, protocol version 2.3 (October 2022).

CT morphological features for predicting the risk of lymph node metastasis in T1 colorectal cancer.

The aim of this study is to evaluate the feasibility of clinicopathological characteristics and computed tomography (CT) morphological features in predicting lymph node metastasis (LNM) for patients with T1 colorectal cancer (CRC). A total of 144 patients with T1 CRC who underwent CT scans and surgical resection were retrospectively included in our study. The clinicopathological characteristics and CT morphological features were assessed by two observers. Univariate and multiple logistic regression analyses were used to identify significant LNM predictive variables. Then a model was developed using the independent predictive factors. The predictive model was subjected to bootstrapping validation (1000 bootstrap resamples) to calculate the calibration curve and relative C-index. LNM were found in 30/144 patients (20.83%). Four independent risk factors were determined in the multiple logistic regression analysis, including presence of necrosis (adjusted odds ratio [OR] = 10.32, 95% confidence interval [CI] 1.96-54.3, p = 0.004), irregular outer border (adjusted OR = 5.94, 95% CI 1.39-25.45, p = 0.035), and heterogeneity enhancement (adjusted OR = 7.35, 95% CI 3.11-17.38, p = 0.007), as well as tumor location (adjusted ORright-sided colon = 0.05 [0.01-0.60], p = 0.018; adjusted ORrectum = 0.22 [0.06-0.83], p = 0.026). In the internal validation cohort, the model showed good calibration and good discrimination with a C-index of 0.89. There are significant associations between lymphatic metastasis status and tumor location as well as CT morphologic features in T1 CRC, which could help the doctor make decisions for additional surgery after endoscopic resection. • LNM more frequently occurs in left-sided T1 colon cancer than in right-sided T1 colon and rectal cancer. • CT morphologic features are risk factors for LNM of T1 CRC, which may be related to fundamental biological behaviors. • The combination of tumor location and CT morphologic features can more effectively assist in predicting LNM in patients with T1 CRC, and decrease the rate of unnecessary extra surgeries after endoscopic resection.

ASO Visual Abstract: Colonoscopy-Assisted Laparoscopic Wedge Resection for the Treatment of Suspected T1 Colon Cancer.

ASO Visual Abstract: Colonoscopy-Assisted Laparoscopic Wedge Resection for the Treatment of Suspected T1 Colon Cancer.

Colonoscopy-Assisted Laparoscopic Wedge Resection for the Treatment of Suspected T1 Colon Cancer.

Local en bloc resection of pT1 colon cancer has been gaining acceptance during the last few years. In the absence of histological risk factors, the risk of lymph-node metastases (LNM) is negligible and does not outweigh the morbidity and mortality of an oncologic resection. Colonoscopy-assisted laparoscopic wedge resection (CAL-WR) has proved to be an effective and safe technique for removing complex benign polyps. The role of CAL-WR for the primary resection of suspected T1 colon cancer has to be established. This retrospective study aimed to determine the radicality and safety of CAL-WR as a local en bloc resection technique for a suspected T1 colon cancer. Therefore, the study identified patients in whom high-grade dysplasia or a T1 colon carcinoma was suspected based on histology and/or macroscopic assessment, requiring an en bloc resection. The study analyzed 57 patients who underwent CAL-WR for a suspected macroscopic polyp or polyps with biopsy-proven high-grade dysplasia or T1 colon carcinoma. For 27 of these 57 patients, a pT1 colon carcinoma was diagnosed at pathologic examination after CAL-WR. Histological risk factors for LNM were present in three cases, and 70% showed deep submucosal invasion (Sm2/Sm3). For patients with pT1 colon carcinoma, an overall R0-resection rate of 88.9% was achieved. A minor complication was noted in one patient (1.8%). The CAL-WR procedure is an effective and safe technique for suspected high-grade dysplasia or T1-colon carcinoma. It may fill the gap for tumors that are macroscopic suspected for deep submucosal invasion, providing more patients an organ-preserving treatment option.

ASO Author Reflections: Colonoscopic-Assisted Laparoscopic Wedge Resection Seems a Valuable Addition to the Current Local Resection Techniques in Case of Suspected Deep-Invasive T1 Colon Cancer.

ASO Author Reflections: Colonoscopic-Assisted Laparoscopic Wedge Resection Seems a Valuable Addition to the Current Local Resection Techniques in Case of Suspected Deep-Invasive T1 Colon Cancer.

Colonoscopic-Assisted Laparoscopic Wedge Resection for Colonic Lesions: A Prospective Multicenter Cohort Study (LIMERIC-Study).

The aim of this study was to evaluate the safety and efficacy of a modified CAL-WR. The use of segmental colectomy in patients with endoscopically unresectable colonic lesions results in significant morbidity and mortality. CAL-WR is an alternative procedure that may reduce morbidity. This prospective multicenter study was performed in 13 Dutch hospitals between January 2017 and December 2019. Inclusion criteria were (1) colonic lesions inaccessible using current endoscopic resection techniques (judged by an expert panel), (2) non-lifting residual/recurrent adenomatous tissue after previous polypectomy or (3) an undetermined resection margin after endoscopic removal of a low-risk pathological T1 (pT1) colon carcinoma. Thirty-day morbidity, technical success rate and radicality were evaluated. Of the 118 patients included (56% male, mean age 66 years, standard deviation ± 8 years), 66 (56%) had complex lesions unsuitable for endoscopic removal, 34 (29%) had non-lifting residual/recurrent adenoma after previous polypectomy and 18 (15%) had uncertain resection margins after polypectomy of a pT1 colon carcinoma. CAL-WR was technically successful in 93% and R0 resection was achieved in 91% of patients. Minor complications (Clavien-Dindo i-ii) were noted in 7 patients (6%) and an additional oncologic segmental resection was performed in 12 cases (11%). Residual tissue at the scar was observed in 5% of patients during endoscopic follow-up. CAL-WR is an effective, organ-preserving approach that results in minor complications and circumvents the need for major surgery. CAL-WR, therefore, deserves consideration when endoscopic excision of circumscribed lesions is impossible or incomplete.

Nomogram to Predict the Occurrence and Prognosis of Distant Metastasis in T1N0 Colon Cancer: A SEER Data-Based Study.

PurposeDistant metastasis (DM) is relatively rare in T1 colon cancer (CC) patients, especially in those with negative lymph node metastasis. The aim of this study was to explore the main clinical factors and build nomogram for predicting the occurrence and prognosis of DM in T1N0 colon cancer patients.MethodsPatients with T1N0 stage CC were collected from the Surveillance, Epidemiology, and End Result (SEER) database. All patients were divided into development and validation cohorts with the 3:1 ratio. Logistic regressions were performed to analyze the clinical risk factors for DM. Cox regression model was used to identify potential prognostic factors for patients with DM. The performance of nomogram was evaluated by concordance index (C-index), calibration curves, receiver operating characteristic (ROC) curves and decision curve analyses (DCAs). Based on cancer-specific survival (CSS), Kaplan–Meier curves were generated and analyzed using Log rank tests.ResultsA total of 6770 patients were enrolled in this study, including 428 patients (6.3%) with DM. Age, size, grade, CEA were independent risk factors associated with DM. Age, grade, CEA, surgery and chemotherapy were independent prognostic factors for CSS. Nomograms were applied and C-index, calibration curves, ROC curves and DCA curves proved good discrimination, calibration and clinical practicability of the nomogram in predicting the occurrence and prognosis of DM in T1N0 CC patients. In the DM nomogram, the AUCs for development and validation cohort were 0.901 (95% CI = 0.879–0.922) and 0.899 (95% CI=0.865–0.940), respectively. The calibration curves (development cohort: S: p = 0.712; validation cohort: S: p = 0.681) showed the relatively satisfactory prediction accuracy. Similarly, the AUCs of the nomogram at 1-, 2-, and 3-year were 0.763 (95% CI=0.744–0.782), 0.794 (95% CI=0.775–0.813), and 0.822 (95% CI=0.803–0.841) for the development cohort, and 0.785 (95% CI=0.754–0.816), 0.748 (95% CI=0.717–0.779) and 0.896 (95% CI=0.865–0.927) for the validation cohort in the CSS nomogram. The C-indices of the development and validation cohort were 0.718 (95% CI=0.639–0.737) and 0.712 (95% CI=0.681–0.743).ConclusionThe population-based nomogram could help clinicians predict the occurrence and prognosis of DM in T1N0 CC patients and provide a reference to perform appropriate metastatic screening plans and rational therapeutic options for the special population.

Association Between Chemotherapy and Survival in T1 Colon Cancer With Lymph Node Metastasis: A Propensity-Score Matched Analysis

This study aimed to comprehensively examine the efficacy of chemotherapy in T1 colon cancer patients with lymph node metastasis.MethodsThe differences in categorical variables in colon cancer patients according to lymph node status were evaluated by Pearson’s chi-square test. The Kaplan-Meier method was used to assess Cancer-specific survival (CSS) and overall survival (OS) with the log-rank test. Cox proportional hazards models were built, multivariate Cox regression analyses were performed with the hazard ratio (HR) and 95% confidence interval (CI) to identify the potential independent prognostic factors. Propensity score matching was also undertaken to adjust for treatment bias due to measured confounders.ResultsYounger age (52.2% VS. 43.0% for ≤ 65 years old, p < 0.001), female gender (50.3% VS. 46.8% for female, p < 0.001), more lymph nodes harvested (68.1% VS. 46.6% for ≥12 lymph nodes harvested, p < 0.001), Black race (13.6% VS. 12.0% for the Black race, p < 0.001), and higher tumor grade (14.2% VS. 5.6% for grade III/IV, p < 0.001) were more prone to be diagnosed with lymph node involvement. The receipt of adjuvant chemotherapy following radical surgery significantly reduced the risk of colon cancer-specific mortality by 33.9% after propensity-score matching (HR = 0.661, 95%CI = 0.476-0.917, p = 0.013).ConclusionsYounger age, female gender, more lymph nodes harvested, Black race, and higher tumor grade were more prone to be diagnosed with lymph node involvement. The receipt of adjuvant chemotherapy following radical surgery also significantly decreased the risk of colon cancer-specific mortality by 33.9% in T1 colon cancer with lymph node involvement.

Recurrence Outcomes Less Favorable in T1 Rectal Cancer than in T1 Colon Cancer.

With the implementation of screening programs worldwide, diagnosis of early-stage colorectal cancer steadily increased, including T1 cancer. Current T1 cancer treatment does not differ according to anatomic location. We therefore compared the disease-free survival of T1 cancer arising from the rectum versus the colon. The hospital-based study included subjects with T1 cancer at National Taiwan University Hospital from 2005 to 2014. Clinical, colonoscopy, and histopathology were reviewed for patients with a mean follow-up time of 7.1 (0.7-12.9) years. We conducted Kaplan-Meier analysis to compare the risk of recurrence by cancer location and Cox regression analysis to identify risk factors for T1 cancer recurrence. The final cohort included a total of 343 subjects with T1 cancer (mean age, 64.9± 11.7 years; 56.1% male), of whom 25 underwent endoscopic resection alone. Of the subjects who underwent surgery, 50 had lymph node metastasis and 268 did not. Kaplan-Meier analysis showed that the risk of recurrence was higher in T1 rectal cancer than T1 colon cancer (p=.022). Rectal location and larger neoplasm size were independent risk factors for recurrence, with hazard ratios of 4.84 (95% confidence interval, 1.18-19.92), and 1.32 (95% confidence interval, 1.06-1.65), respectively. The occurrence of advanced histology did not differ between T1 rectal and colon cancers (p=.58). T1 cancers arising from the rectum had less favorable recurrence outcomes than those arising from the colon. Further studies are needed to examine whether adjuvant radiotherapy or chemotherapy can reduce the risk of recurrence in T1 rectal cancer. Current T1 colorectal cancer treatment and surveillance do not differ according to anatomic location. Clinical, colonoscopy, and histopathology were reviewed for 343 patients with T1 cancer with a mean follow-up time of 7.1 years. Kaplan-Meier analysis showed that the risk of recurrence was higher in T1 rectal cancer than T1 colon cancer. Moreover, the rectal location was an independent risk factor for recurrence. T1 cancers from the rectum had less favorable recurrence outcomes than those arising from the colon. It is critical to clarify whether adjuvant therapy or more close surveillance can reduce recurrence risk in T1 rectal cancer.

Risk factors for lymph node metastasis in early colon cancer.

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

Suspicious T1 colon cancer with synchronous liver metastasis not detected by preoperative imaging study

Suspicious T1 colon cancer with synchronous liver metastasis not detected by preoperative imaging study

The Critical Role of Tumor Size in Predicting Prognosis for T1 Colon Cancer.

The role of horizontal growth index of tumor size in survival prediction is still underappreciated in colon cancer because of the identification of vertical infiltration index reflected by T stage. We sought to reveal the impact of T stage on the prognostic and predictive value of tumor size in colon cancer. Data of patients with stage I-III colon cancer were extracted from Surveillance, Epidemiology, and End Results Program (SEER) and Fudan University Shanghai Cancer Center (FUSCC) databases. Harrell's concordance index (c-index) and time-dependent receiver operating characteristic curve (ROC) were used to analyze the discriminative ability of prognostic factors. Stratified analyses based on T stage found that the increase of T stage significantly and negatively repressed the effect of tumor size on death and recurrence risk. In addition, tumor size showed the greatest hazard ratio of cancer-specific death and relapse in T1 colon cancer. Even more importantly, the discriminatory ability of tumor size outperformed any other widely accepted prognostic clinical features in predicting cancer-specific survival (SEER: c-index 0.637, area under the ROC [AUC] 0.649; FUSCC: c-index 0.673, AUC 0.686) and disease-free survival (FUSCC: c-index 0.645, AUC 0.656) in T1 stage colon cancer. Tumor size is a critical clinical factor with considerable prognostic and predictive value for T1 colon cancer, and it should be selectively incorporated into the current staging system to facilitate prediction of death and recurrence risk. To date, no consensus has been reached about the prognostic and predictive value of tumor size in colon cancer. Although tumor size is an independent prognostic factor for patients with colon cancer, the impact of tumor size on death or recurrence risk decreased notably with the increase of T stage. More importantly, the discriminative ability of tumor size outperformed any other clinical factors including N stage in patients with T1 colon cancer. Therefore, tumor size should be recommended to be incorporated into current staging systems to facilitate prognosis prediction for patients with T1 colon cancer.