Propensity adjusted appraisal of the surgical strategy for appendiceal carcinoids

Risk of lymph node metastases and conditional survival in appendiceal neuroendocrine neoplasms

BACKGROUND

National Comprehensive Cancer Network guidelines recommend segmental colectomy for appendiceal neuroendocrine neoplasms >2.0 cm given the risk for lymph node involvement. However, additional clinicopathologic factors are associated with nodal metastases, and thus survival. Given dynamic changes of prognosis over time, conditional overall survival, the probability of surviving after a specific interval, has emerged as a novel oncologic outcome, but is scarcely available for appendiceal neuroendocrine neoplasms.

METHODS

Adults with stage I-III appendiceal neuroendocrine neoplasms who underwent colectomy from 2010-2017 were identified in the National Cancer Database. Tumor histologies included neuroendocrine tumor grade 1, neuroendocrine tumor grades 2 and 3, neuroendocrine carcinoma, mixed neuroendocrine non-neuroendocrine neoplasm, and goblet cell carcinoma.

RESULTS

Of 3,541 patients (median age 51 years, 43% male, 88% White), 16% had positive lymph nodes. Overall, 40% had neuroendocrine tumor grade 1, 4% neuroendocrine tumor grades 2 and 3, 10% neuroendocrine carcinoma, 12% mixed neuroendocrine non-neuroendocrine neoplasm, and 30% goblet cell carcinoma. Increasing depth of invasion, lymphovascular invasion, and increasing size were associated with lymph node metastases. Eighty-seven percent were alive at 2 years. Mortality after 2 years was associated with older age, mixed neuroendocrine non-neuroendocrine neoplasm and goblet cell carcinoma histology, penetration through serosa, nodal involvement, and tumor size.

CONCLUSIONS

In a national cohort, 1 in 6 patients had positive lymph nodes, which was associated with depth of invasion, lymphovascular invasion, and size. These findings indicate additional factors should be considered when determining the extent of surgical resection and surveillance to improve survival outcomes. Additionally, patients with penetration through serosa, and mixed neuroendocrine non-neuroendocrine neoplasm or goblet cell carcinoma histology had worse conditional overall survival, potentially reflecting more aggressive tumor biology that warrants closer follow-up.

An Update on Appendiceal Neuroendocrine Tumors

The mainstay of appendiceal neuroendocrine neoplasm (aNEN) treatment is surgery, based on simple appendectomy or right-sided hemicolectomy with lymphadenectomy (RHC). The majority of aNENs are adequately treated with appendectomy, but current guidelines have poor accuracy in terms of selecting patients requiring RHC, especially in aNENs 1-2 cm in size. Simple appendectomy is curative for appendiceal NETs (G1-G2) < 1 cm (if the resection status is R0), whereas RHC with lymph node dissection is recommended in tumors ≥ 2 cm in diameter, based on the high risk of nodal metastases in these cases. The clinical management of aNENs 1-2 cm in size is more controversial because lymph node or distant metastases are uncommon but possible. In our opinion, patients with tumor size > 15 mm or with grading G2 (according to WHO 2010) and/or lympho-vascular invasion should be referred for radicalization with RHC. However, decision-making in these cases should include discussion within a multidisciplinary tumor board at referral centers with the aim of offering each patient a tailored treatment, also considering that relatively young patients with long-life expectancy represent the majority of cases.

An unusual case of appendicitis due to appendiceal neuroendocrine tumor in a patient: A case report

Appendiceal neuroendocrine tumor (NET) is the most common type of appendiceal cancer and is rare in the pediatric population. The clinical characteristics of this cancer are not specific and are highly similar to those of acute appendicitis. By contrast, acute appendicitis is a common surgical indication that is caused by obstruction of the appendix lumen. With a detection rate of 0.5-1% in all appendectomy specimens, appendiceal NET is rare histopathologically and can easily be missed. However, detecting an appendiceal NET in a patient with appendicitis is highly difficult. Therefore, clinicians must be aware of this much under-reported and rare tumor in children. In the present report, a case was reported, of a 13-year-old female child who initially presented with clinical presentation of acute appendicitis, but was subsequently diagnosed with appendiceal NET by histopathological examination after an emergency appendectomy. Follow-up examination including abdominal enhanced CT and enteroscopy 2 years after surgery revealed normal results.

Diseño y validación de un nomograma pronóstico de supervivencia en pacientes con tumores neuroendocrinos primarios del apéndice cecal

Introducción. Los tumores neuroendocrinos apendiculares (TNE-A) corresponden a la neoplasia apendicular más común. Aunque habitualmente tienen un comportamiento benigno, su potencial de extensión regional y metástasis, hacen necesario determinar de manera precisa el pronóstico de cada paciente. El objetivo del presente estudio fue diseñar y validar un nomograma pronóstico para predecir la supervivencia de los pacientes con TNE-A. Métodos. Estudio de cohorte retrospectiva, de acuerdo a la información de la base de datos de vigilancia, epidemiología y desenlaces del Instituto Nacional de Cáncer de los Estados Unidos de América. Se incluyeron los pacientes con diagnóstico de TNE-A entre 1978 y 2016. El análisis de supervivencia se realizó mediante un modelo de regresión de Cox. Con estos resultados se construyeron los nomogramas para la supervivencia general y específica de cáncer a uno, dos, tres y cinco años. Los análisis fueron realizados en el software estadístico R (v. 3.5.3). Resultados. Se incluyeron 3585 pacientes con diagnóstico de TNE-A, el 55,8 % fueron mujeres, y la mediana de edad fue de 49 años. El subtipo histológico más frecuente fue el Tumor de Histología Mixta (THM). La edad, el subtipo histológico, el tamaño y la extensión tumoral, fueron las únicas variables asociadas independientemente con la supervivencia después del análisis multivariado. El nomograma validado presentó una capacidad de discriminación sobresaliente para predecir tanto supervivencia general 0,81 (IC95%: 0,76-0,86), como específica a cáncer 0,88 (IC95%: 0,83 a 0,92). Discusión. El presente estudio propone un nomograma pronóstico de supervivencia para pacientes con TNE-A, teniendo en cuenta el subtipo histológico, y alcanza una capacidad de discriminación sobresaliente para la predicción de estos desenlaces. Destacamos el peor pronóstico de los pacientes con THM, además de la supervivencia similar entre los pacientes llevados a hemicolectomía y aquellos sometidos a apendicectomía o resección del ciego, luego del análisis multivariado. Se requiere evaluar el rol de modalidades terapéuticas adyuvantes en la supervivencia de estos pacientes.

The effect of prophylactic surgery in survival and HRQoL in appendiceal NEN

BACKGROUND/AIMS

Long-term outcomes are understudied in patients with well-differentiated appendiceal neuroendocrine neoplasms (WD-ANENs). We aimed to evaluate the validity of currently applied criteria for completion prophylactic right hemicolectomy (pRHC) and determine its association with patient outcomes, including health-related quality of life (HRQoL).

METHODS

Eligible patients from five European referral centers were divided between those who underwent appendectomy alone and those who underwent completion pRHC. HRQoL EORTC-QLC-C30 questionnaires and cross-sectional imaging data were prospectively collected. Age- and sex-matched healthy controls were recruited for HRQoL analysis' validation.

RESULTS

We included 166 patients (119 women [71.2%]: mean age at baseline: 31 ± 16 years). Mean follow-up was 50.9 ± 54 months. Most patients (152 [92%]) had tumors ≤20 mm in size. Fifty-eight patients (34.9%) underwent pRHC that in final analysis was regarded as an overtreatment in 38/58 (65.5%). In multivariable analysis, tumor size >20 mm was the only independent predictor for lymph node (LN) involvement (p = 0.002). No mortality was reported, whereas 2-, 5- and 10-year recurrence-free survival in patients subjected to postoperative cross-sectional imaging (n = 136) was 98.5%, 97.8%, and 97.8%, respectively. Global HRQoL was not significantly impaired in patients with WD-ANEN compared with age- and sex-matched healthy individuals (median scores 0.83[0.08-1] vs 0.83[0.4-1], respectively; p = 0.929). Among patients with WD-ANEN impaired social functioning (p = 0.016), diarrhea (p = 0.003) and financial difficulties (0.024) were more frequently reported in the pRHC group.

CONCLUSIONS

WD-ANEN is a low-malignant neoplasm with unconfirmed associated mortality, low recurrence rate, and overall preserved HRQoL. pRHC comes at a price of excessive surgery, functional HRQoL issues, and diarrhea. The value per se of a prophylactic surgical approach to patients with WD-ANENs <20 mm is challenged.

TNM: a simple classification system for complicated intra-abdominal sepsis after acute appendicitis

BACKGROUND

Delayed diagnosis in case of acute appendicitis (AA) could lead to complicated intra-abdominal sepsis (IAS). Grading systems are not commonly employed in the clinical practice, because they are too complicated or too specific. Therefore, we suggest grading the severity of complicated IAS after AA with a simple system: TNM, an acronym borrowed by cancer staging where T indicates temperature, N neutrophils, and M multiple organ failure (MOF). This prospective observational study evaluates the predictive value of the TNM score on mortality of patients with complicated IAS after AA.

METHODS

Sixty-eight patients with complicated IAS after AA were treated. Three classes of attributes were chosen: temperature (T), neutrophils count (N), and MOF (M). After defining the categories T (T0-T4), N (N0-N3) and M (M0-M2), these were grouped in stages (0-IV). Variables analyzed for their possible relation to death were age, sex, temperature, neutrophils count, preoperative organ failure, immunocompromised status, stage (0-IV). Odds ratios were calculated in a univariate and multivariate analysis.

RESULTS

TNM staging was: one patient stage 0; 16 patients at stage I; 26 patients at stage II; 16 patients at stage III; nine patients at stage IV. Death occurred in 15 patients (22%). Neutrophil count, preoperative organ failure, immunocompromised status, stages III-IV were potential predictors of postoperative death in univariate analysis; only stage IV was significant independent predictor of postoperative mortality in multivariate analysis.

CONCLUSIONS

TNM classification is very easy to use; it helps to define the mortality risk and is useful to objectively compare patients with sepsis.

Appendiceal Carcinoid Tumors: Is There a Survival Advantage to Colectomy over Appendectomy?

BACKGROUND

Guidelines recommend colectomy for appendiceal carcinoid tumors larger than 2 cm, but physicians debate whether colectomy would be beneficial in treating smaller tumors. We sought to determine when colectomy confers a survival advantage over appendectomy.

METHODS

Appendiceal carcinoid patients in the US Surveillance, Epidemiology, and End Results (SEER) database (1988-2011) were stratified by age group, gender, TNM stage, tumor grade, and race. Kaplan-Meier and logistic regression analyses relating grade, stage, and receipt of colectomy to overall and cancer-specific survival were performed.

RESULTS

Of 817 patients who underwent surgical extirpation of an appendiceal carcinoid, 338 (41%) had appendectomy alone and 479 (59%) had additional colectomy. Surprisingly, patients who underwent colectomy had worse cancer-specific survival (HR 1.98, 95% CI 1.32-2.98, p = 0.001) than those who underwent appendectomy, and colectomy did not confer a survival advantage over appendectomy in any subset analysis including low-grade or high-grade tumors, smaller or larger than 2 cm, or node-positive, non-metastatic tumors. Even when accounting for stage and grade, colectomy was not associated with significantly better survival rates. Furthermore, as colectomy frequency has increased over the last decade, the 5-year survival rate has trended down. The main predictors of cancer-specific mortality in carcinoid patients were high-grade (grades 3-4) and high-stage (node positive or metastatic) tumors.

CONCLUSIONS

Survival in patients with carcinoid tumor of the appendix is primarily determined by tumor grade and stage. Our study found no survival advantage to colectomy over appendectomy in a large cohort of patients with the disease. Further investigation is necessary prior to recommending change of practice for patients with appendiceal carcinoid tumors.

Practice Patterns and Guideline Non-Adherence in Surgical Management of Appendiceal Carcinoid Tumors

BACKGROUND

Surgical management of appendiceal carcinoid tumors is heavily debated, despite National Comprehensive Cancer Network guidelines recommending aggressive resection of tumors >2 cm. We investigated national practice patterns and the predictors and impact of guideline non-adherence.

STUDY DESIGN

The National Cancer Database was queried for cases of appendiceal carcinoids diagnosed from 2004 to 2015 treated with either appendectomy or hemicolectomy. Multivariable logistic regression, adjusted for demographic and clinical factors, identified associations with the procedure type among patients stratified by tumor size ≤2 cm and >2 cm. Cox Proportional Hazards then identified associations with overall survival among stratified patient groups.

RESULTS

Of 3,198 cases of appendiceal carcinoids, 1,893 appendectomies and 1,305 hemicolectomies were identified. Contrary to National Comprehensive Cancer Network guidelines, 32.4% of tumors ≤2 cm were treated with hemicolectomy and 31.3% of tumors >2 cm were treated with definitive appendectomy. Hemicolectomy for small tumors was associated with age 65 years and older (odds ratio [OR] 2.4; 95% CI 1.7 to 3.3; reference group age 18 to 39 years), history of malignancy (OR 2.0; 95% CI 1.6 to 2.6), tumor size 1.1 to 2 cm (OR 2.8; 95% CI 2.3 to 3.4; reference group size ≤1 cm), and lymphovascular invasion (OR 2.2; 95% CI 1.6 to 3.2); appendectomy for large tumors was associated with age 65 years and older only (OR 2.2; 95% CI 1.1 to 4.2). Procedure type was not associated with survival for small or large tumors (hazard ratio 1.0; 95% CI 0.7 to 1.4 and hazard ratio 1.1; 95% CI 0.6 to 2.0, respectively).

CONCLUSIONS

Despite well-known size-based treatment guidelines for appendiceal carcinoids, one-third of patients in the US undergo hemicolectomy for small tumors and appendectomy for large tumors. Guideline non-adherence, however, is not associated with overall survival. Reasons for these practice patterns should be explored, and guidelines revisited.

Survival after resection of appendiceal carcinoma by hemicolectomy and less radical than hemicolectomy: a population-based propensity score matched analysis

AIM

The operative treatment for non-metastatic appendiceal carcinoma is controversial despite the recommendation of right hemicolectomy (RH) by many researchers. The aim of this population-based study was to compare outcomes after RH and less radical resection than right hemicolectomy (LRH).

METHOD

A total of 1144 patients who underwent resection with additional lymphadenectomy of Stages I-III appendiceal carcinoma from 2004 to 2012 were identified in the Surveillance, Epidemiology and End Results database. Overall survival (OS) and cancer-specific survival (CSS) after RH and LRH were assessed by unadjusted and risk-adjusted Cox regression analysis and by propensity score matched analysis.

RESULTS

A total of 855 (74.7%) patients underwent RH and 289 (25.3%) underwent LRH. In an unadjusted analysis, survival after LRH and RH did not differ in OS [hazard ratio (HR) 0.95, 95% CI 0.71-1.26, P = 0.707] and CSS (HR 0.95, 95% CI 0.69-1.32, P = 0.762). The 5-year OS and CSS in patients who underwent RH were 71.6% (95% CI 67.8-75.6%) and 76.4% (95% CI 72.8-80.3) compared with 73.8% (95% CI 67.9-80.2) and 78.7% (95% CI 73.2-84.7) in patients with LRH, respectively. No relevant difference in survival between LRH and RH could be observed in a multivariable analysis (OS, HR 0.90, 95% CI 0.65-1.25, P = 0.493; CSS, HR 0.87, 95% CI 0.60-1.26, P = 0.420) and after propensity score adjusted analysis (OS, HR 0.87, 95% CI 0.62-1.22, P = 0.442; CSS, HR 0.97, 95% CI 0.67-1.40, P = 0.883).

CONCLUSIONS

In this retrospective analysis, survival after RH for non-metastatic appendiceal carcinoma was not statistically significantly superior to LRH. Hence, LRH with lymphadenectomy might be sufficient for treatment of non-metastatic appendiceal carcinoma.

Regional lymph node involvement and outcomes in appendiceal neuroendocrine tumors: a SEER database analysis

Background

Appendiceal neuroendocrine neoplasms are most often diagnosed incidentally during appendectomy. The need for subsequent right hemicolectomy (RHC) is determined based on the risk of regional lymph node (LN) involvement. Tumor size has historically been used as an indicator of this risk, but controversy remains regarding its cut off. Furthermore, the impact of RHC on survival is unclear.

Methods

We used the SEER database to identify patients diagnosed with appendiceal neuroendocrine tumors.

Results

Of 1731 patients, 38.0% had well-differentiated neuroendocrine tumors (WDNETs), 60.8% had mixed histology tumors (MHTs), and 1.2% had poorly differentiated neuroendocrine carcinomas (PDNECs). In patients with WDNETs and MHTs who had adequate lymphadenectomy, higher rates of LN involvement were noted for tumors size 11-20 mm than ≤10 mm (56.8% vs. 11.6%, p <0.001; 32.9% vs. 10.4%, p=0.004, respectively). The type of surgery did not affect OS in cases with MHTs with LN involvement (HR 1.00; 95% CI, 0.53-1.89; p =0.99). Patients with regionally advanced WDNET showed excellent survival and only 3 patients (out of 118) died from cancer within 10 years.

Conclusions

10 mm appears to be a more appropriate cutoff than 20 mm for predicting LN metastasis in appendiceal NETs. Cases with WDNETs and nodal involvement demonstrate overall excellent prognosis irrespective of type of surgery (i.e. RHC may not improve outcome). In MHTs with LN metastases, survival is markedly worse in spite of RHC. The role of adjuvant therapy should be evaluated in this subset.

Novel nomogram combining depth of invasion and size can accurately predict the risk for regional nodal metastases for appendiceal neuroendocrine tumors (A-NET)

INTRODUCTION

The need for regional lymphadenectomy for treating appendiceal neuroendocrine tumors (A-NET) is determined by the risk of nodal metastasis. Current guidelines for A-NET are solely based on tumor size. Methods Patients with A-NET from 1988 to 2012 were identified from the SEER registry. The depth of invasion was defined as limited to the lamina propria (LP), invading the muscularis propria (MP), and through the serosa (TS).

RESULTS

A total of 418 patients were included; the majority were female, white, and node-negative. On univariate and multivariable, the risk of nodal metastasis was associated with age, size, depth of invasion, and extent of surgery. The model predicted the likelihood of nodal metastasis, with an area under the curve of 0.89. On survival analysis, age and tumor size predicted the survival in A-NET. In a Cox regression model, they continued to predict survival. These data were utilized to create a nomogram to predict the risk of nodal metastases.

CONCLUSION

This nomogram, accurately predicts the risk of regional nodal metastases in A-NET. In addition to providing valuable information on risk for regional nodal metastases, the depth of invasion is also predictive of survival for A-NET.

Neuroendocrine, goblet cell and mixed adeno-neuroendocrine tumours of the appendix: updates, clinical applications and the future

Appendiceal neuroendocrine neoplasms are rare, clinically challenging tumours that are typically incidentally diagnosed, have a poorly understood biology and have controversy surrounding their management. Most are adequately treated with appendectomy, and although distant metastases are rare, the threat of disease dissemination remains and current guidelines possess poor accuracy in terms of selecting patients requiring more extensive surgery, i.e. oncological right-hemicolectomy. Areas covered: In this article, we discuss the presentation and diagnostic work-up of patients with appendiceal neuroendocrine neoplasms, and also examine the evidence base for existing management strategies. We highlight controversies within the management of these tumours, and anticipate avenues for further progress. Although no longer classified as neuroendocrine neoplasms, we also discuss two related forms of tumours with neuroendocrine features - goblet cell cancers and mixed adeno-neuroendocrine carcinomas. Expert commentary: Existing guidelines for the treatment of appendiceal neuroendocrine neoplasms are derived from a limited evidence base and are unable to accurately predict which patients require extensive attempts at surgical disease control. Future advances in the field of improved patient selection for more extensive surgery may be possible with multi-factorial tumour assessment integrating morphological and molecular analyses.

Clinical Significance of Metastatic Lymph Nodes in the Gut of Patients with Pure and Mixed Primary Appendiceal Carcinoids

BACKGROUND

Right hemicolectomy is indicated for primary appendiceal carcinoids with diameters greater than 2 cm because of an increased risk of metastasis to the lymph nodes of the gut. However, the natural history of positive nodes remains unknown.

OBJECTIVE

The aim of this study was to investigate the impact of metastatic lymph nodes on survival among patients with pure or mixed primary appendiceal carcinoids, while controlling for potential confounders such as age, sex, tumor size, surgical intervention, and lymph node rate (number of positive lymph nodes/lymph node yield).

DESIGN

This is a retrospective comparative study..

SETTINGS

Data were retrieved from the Surveillance, Epidemiology and End Results database.

PATIENTS

Patients undergoing colectomy for appendiceal carcinoids between 1998 and 2009 were selected.

MAIN OUTCOME MEASURES

The survival curves for the 2 groups were compared to evaluate differences in prognosis. Univariate and multivariate analyses were performed.

RESULTS

Lymph node rates did not significantly differ between the pure and mixed carcinoid groups (p = 0.768), although overall survival was poorer among patients with mixed carcinoids (p = 0.004; HR, 0.498; 95% CI, 0.310-0.800). For pure carcinoids, surgical intervention (p = 0.029; HR, 0.241; 95% CI, 0.067-0.867), age (p < 0.001; HR, 1.083; 95% CI, 1.051-1.116), and lymph node rate (p = 0.039; HR, 5.295; 95% CI, 1.089-25.754) were independent predictors of overall survival. For mixed carcinoids, surgical intervention (p = 0.019; HR, 1.675; 95% CI, 1.088-2.578), tumor size (p < 0.001; HR, 0.442; 95% CI, 0.286-0.683), age (p < 0.001; HR, 1.041; 95% CI, 1.026-1.056), and lymph node rate (p < 0.001; HR, 17.471; 95% CI, 10.047-0.382) were significant prognostic factors.

LIMITATIONS

The study is limited by its retrospective nature and by the shortcomings of the Surveillance, Epidemiology and End Results database related to the availability and quality of data.

CONCLUSION

Based on the data retrieved from the Surveillance, Epidemiology and End Results database and adjusted for potential confounding factors, the lymph node rate of metastasis strongly impacts overall survival among patients with pure or mixed carcinoids. Nodal metastasis thus appears to be a reliable clinical hallmark of tumor aggressiveness.

Features Associated With Metastases Among Well-Differentiated Neuroendocrine (Carcinoid) Tumors of the Appendix: The Significance of Small Vessel Invasion in Addition to Size

BACKGROUND

The risk of metastatic disease among carcinoid tumors of the appendix increases with tumor size. However, it is unclear if any features other than size are also associated with an increased risk of metastatic disease.

OBJECTIVE

The aim of this study was to review the characteristics of appendiceal carcinoid tumors and determine if other histologic features besides size should guide surgical decision making.

DESIGN

This study involved a retrospective case series.

SETTINGS

This study was conducted at a single tertiary acute care hospital.

PATIENTS

Patients diagnosed with an appendiceal carcinoid tumor between 2000 and 2014 were identified. Goblet cell carcinoids, adenocarcinomas with neuroendocrine features, and tumors from other primary locations were excluded.

INTERVENTIONS

Simple appendectomy or segmental/total colectomy with lymphadenectomy was performed.

MAIN OUTCOME MEASURES

The primary outcomes measured were metastases, recurrence, and overall survival.

RESULTS

Seventy-nine patients were included. The overall incidence of metastatic disease was 10%. Patients with metastatic disease were more likely to be male (75% vs 28%, p = 0.008), have small-vessel invasion (43% vs 5%, p = 0.001), and have larger tumors (median 2.0 cm vs 0.5 cm, p < 0.001). Among tumors <2 cm, the incidence of metastases among tumors with small-vessel invasion was 60% compared with 0% among those without small-vessel invasion (p < 0.001). Among tumors ≥2 cm, the incidence of metastases was 50% irrespective of small-vessel invasion. If small-vessel invasion was used as a second indication for performing a right hemicolectomy along with size ≥2 cm, both the sensitivity and negative predictive value would have been 100% compared with 63% and 96% if size was used alone. Patients with metastatic disease had a higher incidence of recurrence (13% vs 0%, p = 0.003), but overall survival was 100% in both groups.

LIMITATIONS

Small sample size, retrospective design, and limited long-term follow-up were the limitations of this study.

CONCLUSIONS

Carcinoid tumors of the appendix <2 cm with small-vessel invasion have similar metastatic potential as tumors ≥2 cm. Therefore, a recommendation for a right hemicolectomy should be considered for tumors <2 cm with small-vessel invasion. Additional prospective multicenter studies are warranted.