Long-term outcomes of locally or radically resected T1 colorectal cancer

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.

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

OBJECTIVES

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).

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

KEY POINTS

• 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.

Effects of prior endoscopic resection on recurrence in patients with T1 colorectal cancer who underwent radical surgery

PURPOSE

Endoscopic resection (ER) is a reliable treatment for early colorectal cancer without lymph node metastasis. We aimed to examine the effects of ER performed prior to T1 colorectal cancer (T1 CRC) surgery by comparing long-term survival after radical surgery with prior ER to that after radical surgery alone.

METHODS

This retrospective study included patients who underwent surgical resection of T1 CRC at the National Cancer Center, Korea, between 2003 and 2017. All eligible patients (n = 543) were divided into primary and secondary surgery groups. To ensure similar characteristics between the groups, 1:1 propensity score matching was used. Baseline characteristics, gross and histological features, along with postoperative recurrence-free survival (RFS) between the two groups were compared. Cox proportional hazard model was used to identify the risk factors affecting recurrence after surgery. Cost analysis was performed to examine the cost-effectiveness of ER and radical surgeries.

RESULTS

No significant differences were observed in 5-year RFS between the two groups in matched data (96.9% vs. 95.5%, p = 0.596) and in the unadjusted model (97.2% vs. 96.8%, p = 0.930). This difference was also similar in subgroup analyses based on node status and high-risk histologic features. ER before surgery did not increase the medical costs of radical surgery.

CONCLUSION

ER prior to radical surgery did not affect the long-term oncologic outcomes of T1 CRC or significantly increased the medical costs. Attempting ER first for suspected T1 CRC would be a good strategy to avoid unnecessary surgery without concerns of worsening cancer-related prognosis.

Comparative Cost Analysis Between Endoscopic Resection and Surgery for Submucosal Colorectal Cancer

BACKGROUND

There are few studies analyzing the cost of endoscopic resection and surgical resection in the treatment of submucosal colorectal cancer.

OBJECTIVE

The objective was to perform a detailed cost analysis of endoscopic resection and surgical resection for submucosal colorectal cancer.

DESIGN

This was a retrospective observational study.

SETTING

This study was conducted at a tertiary academic center.

PATIENTS

Medical records of 484 patients with submucosal colorectal cancer who underwent endoscopic resection or surgical resection between July 2003 and July 2015 were reviewed.

MAIN OUTCOME MEASUREMENTS

The total costs during index admission and follow-up as well as clinical outcomes between the 2 groups were compared in the whole cohort and propensity score-matched cohort.

RESULTS

In the propensity score-matched analysis ( n = 155 in each group), the endoscopic resection and surgical resection groups did not show significant differences in the rates of procedure-related adverse events (6.5% vs 3.9%; p = 0.304) and recurrence (0.6% vs 1.3%; p > 0.99). Readmission was more common in the endoscopic resection group (40.6% vs 11.0%; p < 0.001) because 64 (41.3%) patients underwent additional surgery for endoscopic noncurative resection. The endoscopic resection group had a lower cost during the index admission (1335.6 vs 6698.4 USD; p < 0.001), whereas the surgical resection group had a lower cost during follow-up (2488.7 vs 5035.7 USD; p < 0.001). The total cumulative cost was lower in the endoscopic resection group (6371.3 vs 9187.1 USD; p < 0.001). The same trend was observed in the whole cohort without propensity score matching.

LIMITATIONS

A limitation of this study was the retrospective nature of analysis.

CONCLUSIONS

The total cumulative cost for treatment and follow-up for submucosal colorectal cancer was lower in the endoscopic resection group, which had comparable oncologic outcomes as the surgical resection group. Endoscopic resection can be considered a cost-effective option for initial treatment for submucosal colorectal cancer. See Video Abstract at http://links.lww.com/DCR/B881 .

ANLISIS COMPARATIVO DE COSTOS ENTRE LA RESECCIN ENDOSCPICA Y LA CIRUGA PARA EL CNCER COLORRECTAL SUBMUCOSO

ANTECEDENTES: Existen pocos estudios que analizan el costo de la resección endoscópica y la resección quirúrgica en el tratamiento del cáncer colorrectal submucoso.OBJETIVO: El objetivo fue realizar un análisis detallado de costos tanto de la resección endoscópica y la resección quirúrgica para el cáncer colorrectal submucoso.DISEÑO: Este fue un estudio observacional retrospectivo.AJUSTE: Este estudio se realizó en un centro académico terciario.PACIENTES: Se revisaron las historias clínicas de 484 pacientes con cáncer colorrectal submucoso que fueron sometidos a resección endoscópica o resección quirúrgica entre julio de 2003 y julio de 2015.PRINCIPALES MEDICIONES DE RESULTADOS: Los costos totales durante la admisión índice y el seguimiento, así como los resultados clínicos entre los dos grupos, fueron comparados en toda la cohorte y la cohorte emparejada por puntuación de propensión.RESULTADOS: En el análisis emparejado por puntuación de propensión ( n = 155 en cada grupo), los grupos de resección endoscópica y resección quirúrgica no mostraron diferencias significativas en las tasas de eventos adversos relacionados con el procedimiento (6,5% vs 3,9%, p = 0,304) y recurrencia (0,6% vs 1,3%, p > 0,99). La readmisión fue más común en el grupo de resección endoscópica (40,6% vs 11,0%, p < 0,001) porque 64 (41,3%) pacientes fueron sometidos a una cirugía adicional para lograr la resección en aquellos casos en que la resección endoscópica no fue curativa. El grupo de resección endoscópica tuvo un costo menor durante el ingreso índice (1335.6 vs 6698.4 USD, p < 0.001), mientras que el grupo de resección quirúrgica tuvo un costo menor durante el seguimiento (2488.7 vs 5035.7 USD, p < 0.001). El costo total acumulado fue menor en el grupo de resección endoscópica (6371,3 vs 9187,1 USD, p < 0,001). La misma tendencia se observó en toda la cohorte sin emparejamiento por puntuación de propensión.LIMITACIONES: La naturaleza retrospectiva del análisis.CONCLUSIONES: El costo total acumulado para el tratamiento y seguimiento del cáncer colorrectal submucoso fue menor en el grupo de resección endoscópica, que tuvo resultados oncológicos comparables a los del grupo de resección quirúrgica. La resección endoscópica puede considerarse una opción rentable para el tratamiento inicial del cáncer colorrectal submucoso. Consulte Video Resumen en http://links.lww.com/DCR/B881 . (Traducción-Dr Osvaldo Gauto ).

Long-term outcomes after endoscopic versus surgical resection of T1 colorectal carcinoma

BACKGROUND

The long-term outcomes of patients with T1 colorectal cancer (CRC) who undergo endoscopic and/or surgical treatment are not well understood. Invasive CRC confined to the colonic submucosa (T1 CRC) is challenging in terms of clinical decision-making. We compared the long-term outcomes of T1 CRC by treatment method.

METHODS

We examined 370 patients with pathological T1 CRC treated between 2000 and 2015 at Seoul St. Mary's Hospital. In total, 93 patients underwent endoscopic resection (ER) only, 82 underwent additional surgery after ER, and 175 underwent surgical resection only. Patients who did not meet the curative criteria were defined as "high-risk." High-risk patients were classified into three groups according to the treatment modalities: ER only (Group A: 35 patients), additional surgery after ER (Group B: 72 patients), and surgical resection only (Group C: 133 patients). The recurrence-free and overall survival (OS) rates, and factors associated with recurrence and mortality, were analyzed. Factors associated with lymph node metastasis (LNM) were subjected to multivariate analysis.

RESULTS

Of the 370 patients, 7 experienced recurrence and 7 died. All recurrences occurred in the high-risk group and two deaths were in the low-risk group. In high-risk groups, there was no significant group difference in recurrence-free survival (P = 0.511) or OS (P =0.657). Poor histology (P =0.042) was associated with recurrence, and vascular invasion (P =0.044) with mortality. LNMs were observed in 30 of 277 patients who underwent surgery either initially or secondarily. Lymphatic invasion was significantly associated with the incidence of LNM (P < 0.001).

CONCLUSIONS

ER prior to surgery did not affect the prognosis of high-risk T1 CRC patients, and did not worsen the clinical outcomes of patients who required additional surgery. Lymphatic invasion was the most important predictor of LNM.

Subpopulation analysis of survival in high-risk T1 colorectal cancer: surgery versus endoscopic resection only

BACKGROUND AND AIMS

This study aimed to assess the long-term survival of patients with T1 colorectal cancer (CRC) after local or surgical resection considering the type and number of risk factors for lymph node metastasis.

METHODS

This study included patients with high-risk T1 CRC who underwent therapeutic resection at the National Cancer Center, Korea between January 2001 and December 2014. Risk factors included positive resection margin, high-grade histology, deep submucosal invasion, vascular invasion, budding, and no background adenoma (BGA). We statistically divided the population into favorable or unfavorable subpopulations. The favorable subpopulation included the following 5 combinations of risk factors: positive margin only or unconditional for margin status, deep submucosal invasion only, budding only, no BGA only, and budding + no BGA. We analyzed the survival rate according to the resection type (local or surgical) in the total cohort and in each subpopulation.

RESULTS

Eighty-one and 466 patients underwent local and surgical resections, respectively. The distant recurrence-free survival (DRFS) and overall survival (OS) rates were significantly high in the surgical group (hazard ratio [HR], .20; 95% confidence interval [CI], .06-.61; P = .0045 and HR, .41; 95% CI, .25-.70; P = .0010, respectively). In the favorable subpopulation, both DRFS and OS rates were not significantly different between the surgical and local groups (HR, .26; 95% CI, .02-4.19; P = .3431 and HR, .58; 95% CI, .27-1.23; P = .1534, respectively).

CONCLUSIONS

Intensive surveillance without additional surgery may be another option in selected cases after of high-risk T1 CRC endoscopic resection.

Impact of ≥ 0.1-mm free resection margins on local intramural residual cancer after local excision of T1 colorectal cancer

Background and study aims  A free resection margin (FRM) > 1 mm after local excision of a T1 colorectal cancer (CRC) is known to be associated with a low risk of local intramural residual cancer (LIRC). The risk is unclear, however, for FRMs between 0.1 to 1 mm. This study evaluated the risk of LIRC after local excision of T1 CRC with FRMs between 0.1 and 1 mm in the absence of lymphovascular invasion (LVI), poor differentiation and high-grade tumor budding (Bd2-3). Patients and methods  Data from all consecutive patients with local excision of T1 CRC between 2014 and 2017 were collected from 11 hospitals. Patients with a FRM ≥ 0.1 mm without LVI and poor differentiation were included. The main outcome was risk of LIRC (composite of residual cancer in the local excision scar in adjuvant resection specimens or local recurrence during follow-up). Tumor budding was also assessed for cases with a FRM between 0.1 and 1mm. Results  A total of 171 patients with a FRM between 0.1 and 1 mm and 351 patients with a FRM > 1 mm were included. LIRC occurred in five patients (2.9 %; 95 % confidence interval [CI] 1.0-6.7 %) and two patients (0.6 %; 95 % CI 0.1-2.1 %), respectively. Assessment of tumor budding showed Bd2-3 in 80 % of cases with LIRC and in 16 % of control cases. Accordingly, in patients with a FRM between 0.1 and 1 mm without Bd2-3, LIRC was detected in one patient (0.8%; 95 % CI 0.1-4.4 %). Conclusions  In this study, risks of LIRC were comparable for FRMs between 0.1 and 1 mm and > 1 mm in the absence of other histological risk factors.

Full-Thickness Scar Resection After R1/Rx Excised T1 Colorectal Cancers as an Alternative to Completion Surgery

INTRODUCTION

Local full-thickness resections of the scar (FTRS) after local excision of a T1 colorectal cancer (CRC) with uncertain resection margins is proposed as an alternative strategy to completion surgery (CS), provided that no local intramural residual cancer (LIRC) is found. However, a comparison on long-term oncological outcome between both strategies is missing.

METHODS

A large cohort of patients with consecutive T1 CRC between 2000 and 2017 was used. Patients were selected if they underwent a macroscopically complete local excision of a T1 CRC but positive or unassessable (R1/Rx) resection margins at histology and without lymphovascular invasion or poor differentiation. Patients treated with CS or FTRS were compared on the presence of CRC recurrence, a 5-year overall survival, disease-free survival, and metastasis-free survival.

RESULTS

Of 3,697 patients with a T1 CRC, 434 met the inclusion criteria (mean age 66 years, 61% men). Three hundred thirty-four patients underwent CS, and 100 patients underwent FTRS. The median follow-up period was 64 months. CRC recurrence was seen in 7 patients who underwent CS (2.2%, 95% CI 0.9%-4.6%) and in 8 patients who underwent FTRS (9.0%, 95% CI 3.9%-17.7%). Disease-free survival was lower in FTRS strategy (96.8% vs 89.9%, P = 0.019), but 5 of the 8 FTRS recurrences could be treated with salvage surgery. The metastasis-free survival (CS 96.8% vs FTRS 92.1%, P = 0.10) and overall survival (CS 95.6% vs FTRS 94.4%, P = 0.55) did not differ significantly between both strategies.

DISCUSSION

FTRS after local excision of a T1 CRC with R1/Rx resection margins as a sole risk factor, followed by surveillance and salvage surgery in case of CRC recurrence, could be a valid alternative strategy to CS.

Lymphovascular Infiltration, Not Depth of Invasion, is the Critical Risk Factor of Metastases in Early Colorectal Cancer: Retrospective Population-based Cohort Study on Prospectively Collected Data, Including Validation

OBJECTIVE

To identify clinical and histopathological risk factors of LNM in T1 CRC.

SUMMARY OF BACKGROUND DATA

The requisite of additional surgery after locally resected T1 CRC is dependent on the risk of LNM. Depth of submucosal invasion is used as a key predictor of lymphatic metastases although data are conflicting on its actual impact.

METHODS

Retrospective population-based cohort study on prospectively collected data on all patients with T1 CRC undergoing surgical resection in Sweden, 2009-2017 and Denmark 2016-2018. The Danish cohort was used for validation. Potential risk factors of LNM investigated were; age, sex, tumor location, submucosal invasion, grade of differentiation, mucinous subtype, lymphovascular, and perineural invasion.

RESULTS

One hundred fifty out of the 1439 included patients (10%) had LNM. LVI (P < 0.001), perineural invasion (P < 0.001), mucinous subtype (P = 0.006), and age <60 years (P < 0.001) were identified as independent risk factors whereas deep submucosal invasion was only a dependent (P = 0.025) risk factor and not significant in multivariate analysis (P = 0.075). The incidence of LNM was 51/882 (6%) in absence of the independent risk factors. The Danish validation cohort, confirmed our findings regarding the role of submucosal invasion, LVI, and age.

CONCLUSIONS

This is a large study on LNM in T1 CRC, including validation, showing that LVI and perineural invasion, mucinous subtype, and low age constitute independent risk factors, whereas depth of submucosal invasion is not an independent risk factor of LNM. Thus, our findings provide a useful basis for management of patients after local excision of early CRC.

Impact of subdivision of pathological stage I colorectal cancer

AIM

Stage II-IV colorectal cancers are subdivided according to TNM categories. However, stage I cases are a single category, despite the inclusion of both T1 and T2 cases, which may have different outcomes. The aim of this study was to evaluate the usefulness of subdividing stage I colorectal cancers by T category.

METHODS

From 1984 to 2015, 844 patients with stage I colorectal cancer (T1: 446, T2: 398) underwent colorectal resection with lymph node dissection at three hospitals. The long-term survival and recurrence rates were compared between T1 and T2. A Cox regression analysis was used to evaluate the risk factors associated with cancer recurrence.

RESULTS

A comparison of the T1 and T2 groups revealed significant differences in 5-year overall (95.9% vs 91.4%, P = .008), recurrence-free (94.8% vs 87.1%, P = .0007), and cancer-specific survival (97.6% vs 93.6%, P = .004), and in the overall (2.5% vs 6.8%, P = .003), local (0.2% vs 1.5%, P = .04), and lymph node recurrence rates (0.2% vs 1.5%, P = .04). All local and lymph node recurrences were associated with lower rectal cancer, and this difference was significant. The Cox multivariate analysis identified male sex (P = .01, hazard ratio: 4.00, 95% confidence interval: 1.38-11.55), T2 (P = .02, hazard ratio: 2.98, 95% confidence interval: 1.17-7.60), and venous invasion (P = .03, hazard ratio: 2.38, 95% confidence interval: 1.12-5.10) as risk factors for recurrence.

CONCLUSIONS

The subdivision of stage I colorectal cancer according to T category clearly reflected the long-term outcomes.

Long-term results of a randomized study comparing open surgery and laparoscopic surgery in elderly colorectal cancer patients (Eld Lap study)

BACKGROUND

We reported favorable short-term results of laparoscopic surgery in a randomized study comparing open and laparoscopic surgery for elderly patients with colorectal cancer (CRC). The purpose of this study is to clarify the long-term outcomes of the laparoscopic surgery for elderly patients with CRC.

METHODS

The inclusion criteria were ≥ 75 years, adenocarcinoma, ≤ T4a, M0 and elective surgery. The patients were randomly allocated to open or laparoscopic surgery according to the tumor location. The survival rates, recurrence and reasons for death were compared.

RESULT

One hundred patients (right colon 43, left colon 28, rectum 29) were included in each group. Eight patients who underwent open surgery and 2 patients who underwent laparoscopic surgery were excluded from the analysis because of metastatic diseases and other malignancies found during the operations. One hundred ninety patients (98 open, 98 laparoscopic) were analyzed. There was no difference in the backgrounds excluding more patients with vascular invasion in the laparoscopic rectal cancer. There were no differences in the 5-year overall survival rate (open vs. laparoscopic; 78.9% vs. 82.1%, p = 0.638), 5-year disease-free survival rate (70.5% vs. 62.8%, p = 0.276), 5-year recurrence-free survival rate (76.1% vs. 72.1%, p = 0.419), or 5-year cancer-specific survival rate (86.1% vs. 80.5%, p = 0.208). No differences in survival were detected in the analyses of stage and tumor location. There was no significant difference in the overall recurrence rate or recurrence site. However, distant lymph node metastases and local recurrences were more common after laparoscopic surgery than after open surgery. There was no difference in the cause of death. More than half of the patients died from other diseases in both groups (57.9% vs. 52.6%, p = 0.765).

CONCLUSION

Laparoscopic surgery showed similar long-term results compared to open surgery in elderly patients with CRC. Laparoscopic surgery is an effective surgical procedure for elderly patients with CRC.

Clinical outcomes of submucosal colorectal cancer diagnosed after endoscopic resection: a focus on the need for surgery

Background/Aims

We aimed to investigate the proportion of and risk factors for residual cancer and/or lymph node metastasis after surgery was performed because of high-risk pathological features in endoscopic resection specimen of suspected superficial submucosal colorectal cancer (SSMC).

Methods

We reviewed medical records of 497 patients (58.8 ± 9.8 years, 331 males) undergoing endoscopic resection of suspected SSMC. High-risk pathological features included: deep submucosal cancer invasion ≥ 1,000 μm; positive lymphovascular and/or perineural invasion; poorly differentiated adenocarcinoma; and positive resection margin. We investigated the occurrence of additional surgery and residual cancer and/or lymph node involvement in the surgical specimen.

Results

En bloc resection was performed in 447 patients (89.9%). High-risk pathological features were detected in 372 patients (74.8%). Additional surgery was performed in 336 of 372 patients with high-risk pathological features. Of these, 47 surgical specimens (14.0%) showed residual cancer and/or lymph node metastasis. Piecemeal resection was more common in those with residual cancer and/or lymph node involvement than those without (9/47 [19.1%] vs. 24/289 [8.3%], P= 0.032). Positive resection margin was also significantly associated with positive residual cancer and/or lymph node involvement. As the number of high-risk pathological features increased, the risk of regional lymph node metastasis increased proportionally (P= 0.002).

Conclusions

High-risk pathological features were frequently detected after endoscopic resection of suspected SSMC while residual cancer and/or lymph node metastasis were not commonly present in the additional surgical specimen. Further optimized strategy for proper endoscopic management of suspected SSMC is necessary.

Executive Summary of the American Radium Society Appropriate Use Criteria for Local Excision in Rectal Cancer

The goal of treatment for early stage rectal cancer is to optimize oncologic outcome while minimizing effect of treatment on quality of life. The standard of care treatment for most early rectal cancers is radical surgery alone. Given the morbidity associated with radical surgery, local excision for early rectal cancers has been explored as an alternative approach associated with lower rates of morbidity. The American Radium Society Appropriate Use Criteria presented in this manuscript are evidence-based guidelines for the use of local excision in early stage rectal cancer that include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) used by a multidisciplinary expert panel to rate the appropriateness of imaging and treatment procedures. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment. These guidelines are intended for the use of all practitioners and patients who desire information regarding the use of local excision in rectal cancer.

Nomogram Development and External Validation for Predicting the Risk of Lymph Node Metastasis in T1 Colorectal Cancer

PURPOSE

Predicting lymph node metastasis (LNM) risk is crucial in determining further treatment strategies following endoscopic resection of T1 colorectal cancer (CRC). This study aimed to establish a new prediction model for the risk of LNM in T1 CRC patients.

MATERIALS AND METHODS

The development set included 833 patients with T1 CRC who had undergone endoscopic (n=154) or surgical (n=679) resection at the National Cancer Center. The validation set included 722 T1 CRC patients who had undergone endoscopic (n=249) or surgical (n=473) resection at Daehang Hospital. A logistic regression model was used to construct the prediction model. To assess the performance of prediction model, discrimination was evaluated using the receiver operating characteristic (ROC) curves with area under the ROC curve (AUC), and calibration was assessed using the Hosmer-Lemeshow (HL) goodness-of-fit test.

RESULTS

Five independent risk factors were determined in the multivariable model, including vascular invasion, high-grade histology, submucosal invasion, budding, and background adenoma. In final prediction model, the performance of the model was good that the AUC was 0.812 (95% confidence interval [CI], 0.770 to 0.855) and the HL chi-squared test statistic was 1.266 (p=0.737). In external validation, the performance was still good that the AUC was 0.771 (95% CI, 0.708 to 0.834) and the p-value of the HL chi-squared test was 0.040. We constructed the nomogram with the final prediction model.

CONCLUSION

We presented an externally validated new prediction model for LNM risk in T1 CRC patients, guiding decision making in determining whether additional surgery is required after endoscopic resection of T1 CRC.

Pathological risk factors for lymph node metastasis in patients with submucosal invasive colorectal carcinoma

Background

Risk grade assessment determines therapy in patients with submucosal invasive colorectal carcinoma (CRC). However, treatment decisions are often difficult due to a lack of consensus on which risk factors should be considered. We aimed to identify predictive risk factors for lymph node metastasis (LNM) in a large cohort of submucosal invasive CRC patients from China.

Patients and methods

Following collection of clinicopathological data and disease-free survival (DFS) rates from 290 patients who underwent radical intestinal resection with regional lymphadenectomy, we immunohistochemically assessed expression of DNA mismatch repair (MMR) proteins and p53. The correlation between clinicopathological parameters, MMR expression, p53 status, and LNM status was determined using chi-squared tests and logistic analysis. Receiver operator characteristic curve analysis was used to compare the predictive values. The DFS curves were plotted using the Kaplan-Meier method.

Results

LNM was detected in 15.5% of the cases (45/290 patients). Three pathological characteristics, high tumor differentiation grade, lymphovascular invasion (LVI), and tumor budding, were all positively related to LNM in univariate and multivariate analyses (P<0.05). MMR status did not correlate with either LNM or the pathological characteristics (P>0.05). Overexpression of p53 was associated with tumor budding status (P=0.036). With a negative predicative value of 0.92 and area under the curve of 0.76 (95% CI: 0.68-0.85), the combination of these three factors provided optimal predictive ability. Patients with all three risk factors had poorer DFS (P<0.001).

Conclusion

High tumor grade, LVI, and positive tumor budding serve as useful LNM predictors in submucosal invasive CRC.

Risk factors of recurrence in T1 colorectal cancers treated by endoscopic resection alone or surgical resection with lymph node dissection

PURPOSE

The recurrence of T1 colorectal cancers is relatively rare, and the prognostic factors still remain obscure. This study aimed to clarify the risk factors for recurrence in patients with T1 colorectal cancers treated by endoscopic resection (ER) alone or surgical resection (SR) with lymph node dissection, respectively.

METHODS

We reviewed 930 patients with resected T1 colorectal cancers (mean follow-up, 52.3 months). Patients were divided into two groups: those who underwent ER alone (298 cases), and those who underwent initial or additional SR with lymph node dissection (632 cases). Group differences in recurrence-free survival were evaluated using the Kaplan-Meier method and log-rank test. Associations between recurrence and clinicopathological features were evaluated in Cox regression analyses; hazard ratios (HRs) were calculated for the total population and each group.

RESULTS

Recurrence occurred in four cases (1.34%) in the ER group and six cases (0.95%) in the SR group (p = 0.32). Endoscopic resection, rectal location, and poor or mucinous (Por/Muc) differentiation were prognostic factors for recurrence in the total population. Por/Muc differentiation was prognostic factor in both groups. Female sex, depressed-type morphology, and lymphatic invasion were also prognostic factors in the ER group, but not in the SR group.

CONCLUSIONS

Endoscopic resection, rectal location, and Por/Muc differentiation are prognostic factors in the total population. For patients who undergo ER alone, female sex, depressed-type morphology, and lymphatic invasion are also risk factors for recurrence. For such patients, regional en-bloc surgery with lymph node dissection could reduce the risk of recurrence.

Long-term Recurrence-free Survival After Standard Endoscopic Resection Versus Surgical Resection of Submucosal Invasive Colorectal Cancer: A Population-based Study

BACKGROUND & AIMS

There is controversy over the optimal management for T1 colorectal cancer (T1 CRC). This study compared initial endoscopic resection with or without additional surgery, or initial surgery for T1 CRC, and assessed risk factors for lymph node metastases (LNMs) and long-term recurrence.

METHODS

We performed a registration study that included all patients diagnosed with T1 CRC from 1995 through 2011 in the southeast area of The Netherlands (n = 1315). High-risk histology (with regard to LNM) was defined as the presence of poor differentiation, lymphangio-invasion, and/or deep submucosal invasion. The primary outcome measure was the combined rate of local and distant CRC recurrence during a mean follow-up period of 6.6 years. Logistic regression and Cox proportional hazards regression analyses were performed to evaluate independent risk factors for LNM and CRC recurrence, respectively.

RESULTS

Endoscopic resection was performed in 590 patients (44.9%); of these, 220 (16.7%) underwent additional surgery. Initial surgery was performed in 725 patients (55.1%). The risk of LNM was higher in T1 CRC with histologic risk factors (15.5% vs 7.1% without histologic risk factors; odds ratio, 2.21; 95% confidence interval, 1.33-3.70). Thirty-day mortality did not differ between patients who received additional surgery (0.9%) and those who underwent only endoscopic resection (1.4%; P = .631). Rates of CRC recurrence were 6.2% (9.8/1000 patient-years) after only endoscopic resection vs 6.4% (9.4/1000 patient-years) after additional surgery (P = .912), and 3.4% (5.2/1000 patient-years) after initial surgery (P = .031). In multivariate analysis, this difference was not significant. The only independent risk factor for long-term recurrence was a positive resection margin (hazard ratio, 6.88; 95% confidence interval, 2.27-20.87).

CONCLUSIONS

Based on a population analysis of patients diagnosed with T1 CRC, additional surgery after endoscopic resection should be considered only for patients with high-risk histology or a positive resection margin.