Long-term outcomes of 1-2 cm rectal neuroendocrine tumors after local excision or radical resection: A population-based multicenter study

Objectives

Studies on rectal neuroendocrine tumors (R-NETs) that are 1-2 cm in size are limited, and the optimal treatment for these tumors is not well established.

Methods

Data from patients with primary localized R-NETs 1-2 cm in size were retrospectively collected from 17 large-scale referral medical centers in China. Long-term prognosis, quality of life (QOL), and fecal incontinence were evaluated, and the effects of local excision (LE) or radical resection (RR) were elucidated using propensity score matching (PSM).

Results

A total of 272 patients were included in this study; 233 underwent LE, and the remaining 39 underwent RR. Patients in the LE group showed lower tumor location, fewer postoperative Clavien-Dindo III-V complications, more G1 tumors, and lower tumor stage. There were no significant differences in the relapse-free survival or overall survival (OS) between the LE and RR groups after PSM. Patients in the LE group reported superior physical, role, emotional, social, and cognitive functions, global QOL, and Wexner fecal incontinence scores compared with those in the RR group (all P < 0.050). Eighteen (6.6%) patients had lymph node metastases. Multivariable analysis revealed that tumor location (odds ratio [OR] = 3.19, 95% confidence interval [CI] 1.04-10.07, P = 0.010), neutrophil-to-lymphocyte ratio (NLR) > 1.80 (OR = 4.50, 1.46-15.89, P = 0.012), and T3-T4 (OR = 36.31, 95% CI 7.85-208.62, P < 0.001) were independent risk factor for lymph node metastasis.

Conclusions

R-NETs measuring 1-2 cm generally have a favorable prognosis, and there is no difference in postoperative survival between LE and RR. For patients without lymph node metastasis, LE should be the preferred choice; however, for patients with a higher tumor location, preoperative NLR >1.8 or T3/T4 tumors, RR should be considered.

Size Criteria Is Not Sufficient in Selecting Patients for Local Excision Versus Radical Excision for Rectal Neuroendocrine Tumors >2 cm: A National Cancer Database Analysis

BACKGROUND

Patients with rectal neuroendocrine tumors >2 cm often undergo radical surgery, despite limited data supporting this practice. Five- and 10-year survival rates for these patients have been reported previously as 74.8% and 58.6%.

OBJECTIVE

Overall survival was compared between local excision and radical surgery and pN0 and pN1 within the radical surgery subgroup for rectal neuroendocrine tumors >2 cm. Factors independently associated with survival were identified.

DESIGN

A retrospective, nationwide, multivariate regression analysis was performed.

SETTINGS

Data are from the National Cancer Database (2004-2013).

PATIENTS

Patients with rectal neuroendocrine tumors >2 cm, excluding stages T4 and M1, were included.

MAIN OUTCOME MEASURES

Outcome measures were overall survival and independent risk factors for overall survival based on multivariate regression analysis.

RESULTS

Each group had 178 patients. After local excision, 5- and 10-year overall survival rates were 88% and 72% vs 51% and 42% after radical surgery (p < 0.001). A multivariate Cox proportional hazards model showed similar survival (p = 0.96). Tumor factors independently associated with survival were nodal metastasis (HR = 2.01 (95% CI, 1.01-3.97)), poorly differentiated tumors (HR = 4.82 (95% CI, 1.65-14.01)), and undifferentiated tumors (HR = 9.91 (95% CI, 2.77-35.49)). After radical surgery, patients with and without nodal metastasis had 5-year survival rates of 44% vs 59% (unadjusted p = 0.09; adjusted p = 0.11), with insufficient 10-year survival data.

LIMITATIONS

The study is a retrospective analysis and includes only Commission on Cancer-accredited hospitals. Long-term follow-up was limited. Lymphovascular invasion was missing for a majority of patients analyzed.

CONCLUSIONS

Local excision for select patients with rectal neuroendocrine tumors >2 cm is a viable alternative to radical surgery. Nodal status and tumor grade independently predict survival and should be factored into surgical intervention selection. In higher-risk patients selected for radical surgery, survival was similar between the pN0 and pN1 groups, possibly indicating a benefit of radical surgery for these patients. See Video Abstract at http://links.lww.com/DCR/B455.

EL CRITERIO DE TAMAO NO ES SUFICIENTE PARA SELECCIONAR PACIENTES PARA LA ESCISIN LOCAL VERSUS ESCISIN RADICAL PARA TUMORES NEUROENDOCRINOS RECTALES CM ANLISIS DE UNA BASE DE DATOS NACIONAL DE CANCER

ANTECEDENTES:Los pacientes con tumores neuroendocrinos rectales >2 cm a menudo se someten a cirugía radical, a pesar de los datos limitados que respaldan esta práctica. La supervivencia a cinco y diez años para estos pacientes se había informado anteriormente como 74,8% y 58,6%, respectivamente.OBJETIVO:Se comparó la supervivencia global entre escisión local y cirugía radical, y pN0 y pN1 dentro del subgrupo de cirugía radical para tumores neuroendocrinos rectales >2 cm. Se identificaron factores asociados de forma independiente con la supervivencia.DISEÑO:Se realizó un análisis retrospectivo de regresión multivariante a nivel nacional.AJUSTE:Los datos provienen de la Base de Datos Nacional sobre el cáncer (2004-2013).PACIENTES:Pacientes con tumores neuroendocrinos rectales > 2 cm, excluyendo los estadios T4 y M1.PRINCIPALES MEDIDAS DE RESULTADO:Las medidas de resultado fueron la supervivencia general y los factores de riesgo independientes para la supervivencia general según el análisis de regresión multivariante.RESULTADOS:Cada grupo tuvo 178 pacientes. Después de la escisión local, la supervivencia global a cinco y diez años fue del 88% y 72% frente al 51% y el 42% después de la cirugía radical (p <0,001). Un modelo multivariado de riesgos proporcionales de Cox mostró una supervivencia similar (p = 0,96). Los factores tumorales asociados de forma independiente con la supervivencia fueron metástasis ganglionares (HR = 2,01; IC, 1,01-3,97), tumores pobremente diferenciados (HR = 4,82, IC, 1,65-14,01) y tumores indiferenciados (HR = 9,91, IC, 2,77-35,49). Después de la cirugía radical, los pacientes con y sin metástasis ganglionar tuvieron una supervivencia a cinco años del 44% frente al 59%, respectivamente (p no ajustado = 0,09; p ajustado = 0,11), con datos insuficientes de supervivencia a diez años.LIMITACIONES:El estudio es un análisis retrospectivo e incluye solo hospitales acreditados por la Comisión de Cáncer. El seguimiento a largo plazo fue limitado. La mayoría de los pacientes analizados no tenían invasión linfovascular.CONCLUSIONES:La escisión local para pacientes seleccionados con tumores neuroendocrinos rectales >2 cm es una alternativa viable a la cirugía radical. El estado ganglionar y el grado del tumor predicen de forma independiente la supervivencia y deben tenerse en cuenta en la selección de la intervención quirúrgica. En los pacientes de mayor riesgo seleccionados para cirugía radical, la supervivencia fue similar entre los grupos pN0 vs. pN1, lo que posiblemente indica un beneficio de la cirugía radical para estos pacientes. Consulte Video Resumen en http://links.lww.com/DCR/B455.

Local Excision Versus Radical Resection for 1- to 2-cm Neuroendocrine Tumors of the Rectum: A National Cancer Database Analysis

BACKGROUND

The optimal surgical management for 1- to 2-cm, nonmetastatic rectal neuroendocrine tumors remains unknown.

OBJECTIVE

We sought to determine overall survival and operative outcomes in patients who underwent local excision versus radical resection of rectal neuroendocrine tumors.

DESIGN

The National Cancer Database (2004-2013) was queried to identify patients with nonmetastatic rectal neuroendocrine tumors who underwent local excision or radical resection.

SETTING

The study included national data.

PATIENTS

There were 274 patients in the local excision group and 47 patients in the radical resection group.

MAIN OUTCOME MEASURES

The primary outcome was overall survival. Secondary outcomes included 30-day mortality, hospital length of stay, and procedural outcomes.

RESULTS

There were no differences in demographics between the 2 groups. Patients who underwent radical resection had slightly larger tumors with higher stage and grade. Patients undergoing local excision had higher rates of positive margins (8.23% vs 0%; p = 0.04). There were no deaths within 30 days in either group, but patients who had radical resection had longer median hospital length of stay (0 vs 3 d; p < 0.01). After adjusting with a Cox proportional hazards model, no difference was seen in survival between the 2 patient groups (HR = 2.39 (95% CI, 0.85-6.70); p = 0.10).

LIMITATIONS

There are several limitations, which include that this work is a retrospective review; the data set does not include variables such as depth of tumor invasion, which may influence surgical treatment or local recurrence rates; and patients were not randomly assigned to treatment groups.

CONCLUSIONS

There is no survival benefit to radical resection of 1- to 2-cm, nonmetastatic rectal neuroendocrine tumors. This suggests that local excision may be a feasible and less morbid option for intermediate-sized rectal neuroendocrine tumors. See Video Abstract at http://links.lww.com/DCR/A744.

Risk factors associated with the progression and metastases of hindgut neuroendocrine tumors: a retrospective study

BACKGROUND

The worldwide incidence of neuroendocrine tumors (NETs) has increased remarkably, with the hindgut being the second most common site for such tumors. However, the mechanisms underlying progression and metastasis of hindgut NETs are unclear. A retrospective study was conducted to elucidate these mechanisms.

METHODS

Clinicopathological data of cases of hindgut NET between April 1996 and September 2015 were analyzed, retrospectively. Patients with neuroendocrine carcinoma were excluded. Formalin-fixed paraffin-embedded tissues of hindgut NET cases were subjected to detailed morphometric and immunohistochemical analyses. Statistical analyses were performed using the non-parametric Mann-Whitney U test, Spearman's correlation coefficient, and chi-squared test. Multivariate logistic regression analysis was conducted as appropriate for the data set.

RESULTS

Fifty-six hindgut NET cases were considered. Microvessel density and lymphatic microvessel density were identified as significant risk factors for venous and lymphatic invasion. There was a positive correlation between microvessel density and the maximum tumor diameter. Multivariate logistic regression analysis revealed that the maximum tumor diameter alone was an independent predictor of lymph node metastasis, whereas lymphovascular invasion and MVD was not the predictor of lymph node metastasis. There were no significant correlations between the Ki-67 labeling index and any of the parameters evaluated including age, sex, the maximum tumor diameter, venous invasion, lymphatic invasion, microvessel density, lymphatic microvessel density, and lymph node metastasis.

CONCLUSIONS

Angiogenic mechanisms may play important roles in the progression of hindgut NET. Otherwise, the maximum tumor diameter alone was an independent predictor of lymph node metastasis in hindgut NETs. Moreover, our study raises the question of whether the presence of lymphovascular invasion, in endoscopically obtained hindgut NET tissues, is an absolute indication for additional surgery or not.

Short- and Long-term Outcomes of Laparoscopic Total Mesenteric Excision for Neuroendocrine Tumors of the Rectum

BACKGROUND

To our knowledge, no studies to date have assessed the short- and long-term outcomes of laparoscopic total mesenteric excision in patients with neuroendocrine tumors of the rectum.

OBJECTIVE

The purpose of this study was to investigate the short- and long-term outcomes of patients who underwent laparoscopic rectal resection plus total mesenteric excision for rectal neuroendocrine tumors at our institution.

DESIGN

This was a single center, retrospective study.

SETTINGS

The study was conducted at a tertiary care facility.

PATIENTS

Eight-two patients with neuroendocrine tumors who underwent rectal resection with total mesenteric excision, 77 laparoscopically, between June 2005 and August 2015 were included.

INTERVENTIONS

Laparoscopic rectal resection and total mesenteric excision were the study interventions.

MAIN OUTCOME MEASURES

Demographic characteristics and surgical and postoperative outcomes were measured.

RESULTS

Median tumor size was 8.8 mm (range, 3.0-35.0 mm); 63.6% of tumors were located in the lower rectum, with the median distance from the tumor to the anal verge being 50.0 mm (range, 20.0-130.0 mm). Anal preservation was achieved in all of the patients. Anastomotic leakage occurred in 5 patients (6.5%), but there were no deaths. Seventy-one patients (92.2%) had tumor invasion confined to the submucosa. Lymph node metastasis was present in 29 patients (37.7%), including 26 (33.8%) with perirectal and 5 (6.5%) with lateral lymph node metastasis. The median follow-up period in 59 patients was 42 months (range, 11-113 months), and the 3-year overall survival rate was 97.8%.

LIMITATIONS

The study was limited by its single-center, retrospective analysis.

CONCLUSIONS

Laparoscopic rectal resection with total mesenteric excision is safe in patients with rectal neuroendocrine tumors, with good short- and long-term outcomes. Because rectal neuroendocrine tumors are smaller and show superficial invasion, the rate of anal preservation may be high.

[Rectal neuroendocrine tumors: surgical therapy]

The incidence of rectal neuroendocrine tumors (NET) has increased in recent years. Most of these neoplasms are asymptomatic and are diagnosed by colonoscopy screening, which could be one of the reasons for the increasing occurrence. As less than 1 % of rectal NET produce serotonin they are practically never discovered due to a carcinoid syndrome. The current guidelines of the European (ENETS) and North American (NANETS) Neuroendocrine Tumor Societies support clinicians with useful diagnostic and treatment algorithms. The most important criteria for therapy are tumor size and histopathological risk factors for metastases. For well-differentiated rectal neuroendocrine neoplasms < 1 cm, local endoscopic or surgical excision is recommended. Due to the lack of evidence tumors sized 1-2 cm represent a grey area for prognosis and treatment. All NET > 1.5 cm must be excised by radical surgery as low anterior rectal resection or abdominoperineal extirpation with total mesorectal excision (TME). Resectable liver and lung metastases of well-differentiated NETs should be surgically treated with curative intent.