Risk Factors for Lymph Node Metastasis and Oncologic Outcomes in Small Rectal Neuroendocrine Tumors with Lymphovascular Invasion

Treatment indicators and prognostic factors in colorectal neuroendocrine neoplasms and adenocarcinoma with neuroendocrine differentiation: a single center retrospective study

PURPOSE

This study compared survival and metastasis occurrence between colorectal neuroendocrine neoplasms (cNEN) and colorectal adenocarcinoma with neuroendocrine differentiation (cNED) and further explored their prognostic factors and treatment indicators.

METHODS

Patients diagnosed as cNEN and cNED in West China Hospital from January 2009 to December 2020 were enrolled. The diagnosis and metastasis rates were calculated. Univariate and multivariate Cox analyses were conducted for progression-free survival (PFS) in cNEN surgical patients, and generalized linear regression was used for metastatic disease.

RESULT

The study enrolled 435 patients, including 257 neuroendocrine tumors (NET), 52 neuroendocrine carcinomas (NEC), 29 mixed neuroendocrine-non-neuroendocrine neoplasms (MiNEN), and 97 NED patients, of whom 202 received local resection, and 233 received radical resection. Metastasis rates were higher in MiNEN and NEC groups compared to other groups (NED: 28.9%, MiNEN: 58.6%, NEC: 65.4%, NET: 8.6%, p < 0.001). The liver is the main metastatic site in cNEN, whereas cNED metastasized to various sites. For NEC and MiNEN patients, colon location (p = 0.002) and T stage > 2 (p = 0.040) were associated with disease progression separately. Independent risk factors for metastatic NET included tumor grade G2/G3 (p < 0.001), colon location (p = 0.001), size ≥ 1 cm (p = 0.005), and CK20 partial positive (p < 0.001).

CONCLUSION

cNEN show high metastatic capacity and are challenging to diagnose. More aggressive treatment and follow-up strategies are necessary for those patients. NET tumor grade higher than G2, size larger than 1 cm, or located in the colon should be managed with radical surgery.

Predictors of lymph node metastasis and survival in radically resected rectal neuroendocrine tumors: A Surveillance, Epidemiology, and End Results (SEER) database analysis

BACKGROUND

Rectal neuroendocrine tumors are uncommon tumor types. Lymph node metastases may occur in up to 40%, potentially impacting decision-making. We aimed to assess risk factors for lymph node metastases of rectal neuroendocrine tumors and their association with overall and cancer-specific survival.

METHODS

This retrospective case-control study involved patients with stage I to III rectal neuroendocrine tumors who underwent radical resection. Data were derived from the Surveillance, Epidemiology, and End Results database (2000-2020). Patients with pathologic evidence of lymph node metastases were compared to those without lymph node metastases for baseline patient and tumor characteristics. The main outcomes were lymph node metastases, overall survival, and cancer-specific survival.

RESULTS

In total, 580 patients (50.9% male; mean age: 58.9 years) were included. The lymph node metastases rate was 37.1%. Independent predictors of lymph node metastases were Grade 2 neuroendocrine tumors (odds ratio: 8.06; P = .001), neuroendocrine carcinoma (odds ratio: 2.59, P = .006), large-cell neuroendocrine carcinoma (odds ratio: 4.89; P = .017), T2 tumors (odds ratio: 6.44; P < .001), T3 tumors (odds ratio: 27.5; P < .001), and T4 tumors (odds ratio: 17.3; P < .001). Lymph node metastases were associated with shorter restricted mean overall survival (40.8 vs 52.7 months; P < .001) and cancer-specific survival (41.3 vs 54.8 months; P < .001). When adjusted for other confounders, the nodal status of rectal neuroendocrine tumors was not independently associated with overall (hazard ratio = 1.56; P = .165) or cancer-specific survival (hazard ratio = 1.69; P = .158). Significant factors associated with worse overall survival and cancer-specific survival were age, tumor size, neuroendocrine carcinomas, large-cell neuroendocrine carcinomas, and the number of positive lymph nodes.

CONCLUSIONS

Lymph node metastases of rectal neuroendocrine tumors were more likely associated with high-grade, large-sized, and T2 to T4 tumors. The number of involved lymph nodes was an independent predictor of overall and cancer-specific survival. Other independent survival predictors were tumor grade, size, and T stage.

Laparoscopic versus open surgery for rectal neuroendocrine tumors: a multicenter real-world study

BACKGROUND

Owing to the lack of evidence-based medical studies with large sample sizes, the surgical approach for the radical resection of rectal neuroendocrine tumors remains controversial.

METHODS

We retrospectively collected the medical records of patients with rectal neuroendocrine tumors who underwent radical resection at 17 large tertiary care hospitals in China between January 1, 2010, and April 30, 2022. All patients were divided into laparoscopic and open surgery groups. After propensity score matching to reduce confounders, the postoperative and oncologic outcomes were compared between the groups.

RESULTS

We enrolled 174 patients with rectal neuroendocrine tumors who underwent radical surgery. After random matching, 124 patients were included in the comparison (62, laparoscopic surgery group; 62, open surgery group). The laparoscopic surgery group had fewer complications (14.5% vs. 35.5%, P = 0.007) and superior relapse-free survival (P = 0.048). Subgroup analysis revealed that the laparoscopic surgery group had fewer complications (10.9% vs. 34.7%, P = 0.004), shorter postoperative hospital stays (9.56 ± 5.21 days vs. 12.31 ± 8.61 days, P = 0.049) and superior relapse-free survival (P = 0.025) in the rectal neuroendocrine tumors ≤ 4 cm subgroup.

CONCLUSIONS

Laparoscopic surgery was associated with improved postoperative outcomes and oncologic prognosis for patients with rectal neuroendocrine tumors ≤ 4 cm; it can serve as a safe and feasible option for radical surgery of rectal neuroendocrine tumors.

Clinical and pathological features of advanced rectal cancer with submesenteric root lymph node metastasis: Meta-analysis

BACKGROUND

Advanced rectal cancer with submesenteric lymph node metastasis is a common complication of advanced rectal cancer, which has an important impact on the treatment and prognosis of patients.

AIM

To investigate the clinical and pathological characteristics of inferior mesenteric artery (IMA) root lymph node metastases in patients with rectal cancer. The findings of this study provided us with fresh medical information that assisted us in determining the appropriate treatment for these patients.

METHODS

Our study searched PubMed, Google Scholar, and other databases and searched the relevant studies and reports on the risk factors of IMA root lymph node metastasis of rectal cancer published in the self-built database until December 31, 2023. After data extraction, the Newcastle-Ottawa scale was used to evaluate the quality of the included literature, and RevMan5.3 software was used for meta-analysis and heterogeneity testing. The fixed effect modules without heterogeneity were selected to combine the effect size, and the random effect modules with heterogeneity were selected to combine the effect size. The cause of heterogeneity was found through sensitivity analysis, and the data of various risk factors were combined to obtain the final effect size, odds ratio (OR) value, and 95% confidence interval (CI). Publication bias was tested by drawing funnel plots.

RESULTS

A total of seven literature were included in this study. By combining the OR value of logistic multivariate regression and the 95%CI of various risk factors, we concluded that the risk factors for lymph node metastasis in the IMA region of rectal cancer were as follows: Preoperative carcinoembryonic antigen (CEA) > 5 ng/mL (OR = 0.32, 95%CI: 0.18-0.55, P < 0.05), tumor located above peritoneal reflexive (OR = 3.10, 95%CI: 1.78-5.42, P < 0.05), tumor size ≥ 5 cm (OR = 0.36, 95%CI: 0.22-0.57, P < 0.05), pathological type (mucinous adenocarcinoma/sig-ring cell carcinoma) (OR = 0.23, 95%CI: 0.13-0.41, P < 0.05), degree of tumor differentiation (low differentiation) (OR = 0.17, 95%CI: 0.10-0.31, P < 0.05), tumor stage (T3-4 stage) (OR = 0.11, 95%CI: 0.04-0.26, P < 0.05), gender and age were not risk factors for IMA root lymph node metastasis in rectal cancer (P > 0.05).

CONCLUSION

Preoperative CEA level, tumor location, tumor size, tumor pathologic type, tumor differentiation, and T stage were correlated with IMA root lymph node metastasis.

Incidence and patterns of lymph node metastases in head and neck rhabdomyosarcoma: One-institution study

INTRODUCTION

Head and neck rhabdomyosarcoma (HNRMS) is an aggressive malignant soft tissue tumor that easily develops lymph node metastasis (LNM) and distant metastasis. No literature investigates the pattern of LNM in HNRMS.

METHODS

Ninety-five consecutive patients with HNRMS newly diagnosed at one institution between November 2011 and July 2023 were retrospectively reviewed. All the patients underwent head and neck contrast-enhanced MRI and/or CT, PET-CT if necessary. The associations between LNMs and clinical characteristics and histopathological parameters were discovered.

RESULTS

44.2% of patients had evidence of LNM at diagnosis, and the most common LNM occurred in the ipsilateral retropharyngeal space. The primary tumor metastasizes to the retropharyngeal space, and then next to level II is the most common LN drainage basin. In multivariate analysis, only distant metastasis determines the prognosis, other than LN status.

CONCLUSIONS

LNM has a high incidence in HNRMS and rarely causes contralateral metastasis for localized lesions or skip metastasis.

Local Excision Versus Radical Resection for Grade 2 Rectal Neuroendocrine Tumors: A Multicenter Propensity Score-Matched Analysis

BACKGROUND

Studies on grade 2 rectal neuroendocrine tumors are limited, and the optimal treatment for these tumors is not well established.

OBJECTIVE

We aimed to compare the oncologic results of local excision versus radical resection for the treatment of grade 2 rectal neuroendocrine tumors.

DESIGN

Retrospective multicenter propensity score-matched study to minimize heterogeneity between groups and focus on the differences between surgery strategies.

SETTINGS

Seventeen large-scale Chinese medical centers participated in this study.

PATIENTS

A total of 144 patients with pathologically confirmed grade 2 rectal neuroendocrine tumors were retrospectively analyzed.

MAIN OUTCOME MEASURES

Cancer-specific survival and relapse-free survival were assessed to compare surgery strategies.

RESULTS

A total of 144 patients with grade 2 rectal neuroendocrine tumors were enrolled in this study. Twenty-seven patients underwent endoscopic resection, 55 underwent transanal excision, 50 underwent radical resection, and 12 underwent palliative surgery or biopsy for distant metastasis. Of the 50 patients who underwent radical resection, 30 (60.0%) had clinically positive lymph nodes on the basis of the histopathology results. The optimal cutoff value for tumor size to predict cancer-specific survival was 1.5 cm. In patients with grade 2 rectal neuroendocrine tumors of ≤1.5-cm size, there were no significant differences in cancer-specific survival and relapse-free survival between local excision and radical resection groups ( p > 0.05). In patients with grade 2 rectal neuroendocrine tumors of >1.5-cm size, relapse-free survival was significantly lower in the local excision group than in the radical resection group ( p = 0.04).

LIMITATIONS

The nature of retrospective reviews and a relatively short follow-up period are limitations of this study.

CONCLUSIONS

Grade 2 rectal neuroendocrine tumors have a nonnegligible rate of lymph node metastasis. Local excision is a feasible choice for tumors of ≤1.5 cm size without metastasis, whereas radical resection is more beneficial in those of >1.5 cm size. See Video Abstract .

ESCISIN LOCAL VERSUS RESECCIN RADICAL PARA TUMORES NEUROENDOCRINOS RECTALES GRADO ANLISIS MULTICNTRICO CON PUNTUACIN DE PROPENSIN COINCIDENTE

ANTECEDENTES:Los estudios sobre los tumores neuroendocrinos rectales de grado 2 son limitados y el tratamiento óptimo para estos tumores no está bien establecido.OBJETIVO:Comparar los resultados oncológicos de la escisión local versus la resección radical para el tratamiento de tumores neuroendocrinos rectales grado 2.DISEÑO:Estudio multicéntrico retrospectivo emparejado por puntuación de propensión para minimizar la heterogeneidad entre grupos y centrarse en la diferencia entre estrategias quirúrgicas.ESCENARIO:Diecisiete centros médicos chinos de gran tamaño participaron en este estudio.PACIENTES:Se analizaron retrospectivamente un total de 144 pacientes con tumores neuroendocrinos rectales grado 2 patológicamente confirmados.PRINCIPALES MEDIDAS DE RESULTADO:Se evaluaron la supervivencia específica del cáncer y la supervivencia libre de recaída para comparar las estrategias quirúrgicas.RESULTADOS:En este estudio se inscribieron un total de 144 pacientes con tumores neuroendocrinos rectales grado 2. Veintisiete pacientes se sometieron a resección endoscópica, 55 a escisión transanal, 50 a resección radical y 12 a cirugía paliativa o biopsia por metástasis a distancia. De los 50 pacientes que se sometieron a resección radical, 30 (60,0%) tenían ganglios linfáticos clínicamente positivos según los resultados histopatológicos. El valor de corte óptimo para el tamaño del tumor para predecir la supervivencia específica del cáncer fue de 1,5 cm. En pacientes con tumores neuroendocrinos rectales grado 2 ≤ 1,5 cm, no hubo diferencias significativas en la supervivencia específica del cáncer y la supervivencia libre de recaída entre los grupos de escisión local y resección radical ( p >0,05). En pacientes con tumores neuroendocrinos rectales grado 2 > 1,5 cm, la supervivencia libre de recaída fue significativamente menor en el grupo de escisión local que en el grupo de resección radical ( p = 0,04).LIMITACIONES:La naturaleza de la revisión retrospectiva y el período de seguimiento relativamente corto son limitaciones de este estudio.CONCLUSIONES:Los tumores neuroendocrinos rectales grado 2 tienen una tasa no despreciable de metástasis en los ganglios linfáticos. La escisión local es una opción factible para tumores ≤ 1,5 cm sin metástasis, mientras que la resección radical es más beneficiosa en aquellos > 1,5 cm. (Traducción-Dr. Felipe Bellolio ).

Assessing risk stratification in long-term outcomes of rectal neuroendocrine tumors following endoscopic resection: a multicenter retrospective study

OBJECTIVES

While endoscopic resection of rectal neuroendocrine tumors (NETs) has significantly increased, long-term data on risk factors for recurrence are still lacking. Our aim is to analyze the long-term outcomes of patients with rectal NETs after endoscopic resection through risk stratification.

METHODS

In this multicenter retrospective study, we included patients who underwent endoscopic resection of rectal NETs from 2009 to 2018 and were followed for ≥12 months at five university hospitals. We classified the patients into three risk groups according to the clinicopathological status of the rectal neuroendocrine tumors: low, indeterminate, and high. The high-risk group was defined if the tumors have any of the followings: size ≥ 10 mm, lymphovascular invasion, muscularis propria or deeper invasion, positive resection margins, or mitotic count ≥2/10.

RESULTS

A total of 346 patients were included, with 144 (41.6%), 121 (35.0%), and 81 (23.4%) classified into the low-, indeterminate-, and high-risk groups, respectively. Among the high-risk group, seven patients (8.6%) received salvage treatment 28 (27-67) days after the initial endoscopic resection, with no reported extracolonic recurrence. Throughout the follow-up period, 1.1% (4/346) of patients experienced extracolonic recurrences at 56.5 (54-73) months after the initial endoscopic resection. Three of these patients (75%) were in the high-risk group and did not undergo salvage treatment. The risk of extracolonic recurrence was significantly higher in the high-risk group compared to the other groups (p = 0.039).

CONCLUSION

Physicians should be concerned about the possibility of metastasis during long-term follow-up of high-risk patients and consider salvage treatment.

Preoperative prediction of lymphovascular invasion of colorectal cancer by radiomics based on 18F-FDG PET-CT and clinical factors

Purpose

The purpose of this study was to investigate the value of a clinical radiomics model based on Positron emission tomography-computed tomography (PET-CT) radiomics features combined with clinical predictors of Lymphovascular invasion (LVI) in predicting preoperative LVI in patients with colorectal cancer (CRC).

Methods

A total of 95 CRC patients who underwent preoperative 18F-fluorodeoxyglucose (FDG) PET-CT examination were retrospectively enrolled. Univariate and multivariate logistic regression analyses were used to analyse clinical factors and PET metabolic data in the LVI-positive and LVI-negative groups to identify independent predictors of LVI. We constructed four prediction models based on radiomics features and clinical data to predict LVI status. The predictive efficacy of different models was evaluated according to the receiver operating characteristic curve. Then, the nomogram of the best model was constructed, and its performance was evaluated using calibration and clinical decision curves.

Results

Mean standardized uptake value (SUVmean), maximum tumour diameter and lymph node metastasis were independent predictors of LVI in CRC patients (P < 0.05). The clinical radiomics model obtained the best prediction performance, with an Area Under Curve (AUC) of 0.922 (95%CI 0.820-0.977) and 0.918 (95%CI 0.782-0.982) in the training and validation cohorts, respectively. A nomogram based on the clinical radiomics model was constructed, and the calibration curve fitted well (P > 0.05).

Conclusion

The clinical radiomics prediction model constructed in this study has high value in the preoperative individualized prediction of LVI in CRC patients.

Risk Factors for Lymph Node Metastasis of Rectal Neuroendocrine Tumor and Its Prognostic Impact: A Single-Center Retrospective Analysis of 195 Cases with Radical Resection

PURPOSE

The incidence of rectal neuroendocrine tumors (NETs) has been steadily increasing. The risk factors for and prognostic impact of lymph node (LN) metastasis were analyzed in 195 patients with stage I-III rectal NET who underwent radical surgery.

METHODS

This retrospective, single-center study analyzed risk factors for LN metastasis focusing on previously identified factors and a novel risk factor: multiple rectal NETs. The association between LN metastasis and the prognosis was also analyzed.

RESULTS

Pathologically, the LN metastasis rate (also the rate of stage III disease) was 39%, which was higher than the clinical LN metastasis rate of 14%. Tumor size > 10 mm, presence of central depression, tumor grade G2, depth of invasion, LN swelling on preoperative imaging (cN1), venous invasion and multiple NETs were identified as risk factors for LN metastasis. As the tumor size and risk factors increased, the rate of LN metastasis increased. Among these 7 factors, venous invasion, cN1, and multiple NETs were identified as independent predictors of LN metastasis. LN metastasis of rectal NETs was associated with significantly poor disease-free and disease-specific survival.

CONCLUSIONS

As risk factors increase, the potential for rectal NETs to metastasize to the LNs increases and LN metastasis is associated with a poor prognosis. This is the first study to report multiple NETs as a risk factor for LN metastasis. A future study examining the survival benefit of radical surgery accompanying LN dissection compared with local resection is warranted.

Optimising Outcomes and Surveillance Strategies of Rectal Neuroendocrine Neoplasms

Rectal neuroendocrine neoplasms are increasing in incidence, in part due to increased endoscopic procedures being performed for bowel cancer screening. Whilst most of these lesions are low-grade well-differentiated neuroendocrine tumours, they can have a varied clinical behaviour. Frequently, these lesions are incorrectly characterised at endoscopy and, therefore, incompletely excised using standard polypectomy techniques. Furthermore, some cases are not fully staged prior to or post resection. In this article we discuss the endoscopic and surgical options available to improve the likelihood of achieving an R0 resection and the staging procedures that should be used in these NETs. We also review factors that may suggest a higher risk of nodal involvement or recurrence. This information may help determine whether endoscopic or surgical resection techniques should be considered. In cases of R1 resection we discuss the management options available and the long-term surveillance options and when these should be offered to patients.

Development of novel prediction models for nodal and distant metastasis in G1 and G2 colorectal neuroendocrine tumors

PURPOSE

We aimed to construct novel nomograms for nodal and distant metastasis for patients with G1 and G2 colorectal neuroendocrine tumors (NETs).

METHODS

A training set and validation set were obtained by including G1 and G2 colorectal NET patients from the Surveillance, Epidemiology, and End Results database and the Cancer Hospital Chinese Academy of Medical Science, respectively. The area under curve (AUC) values under receiver operating characteristic (ROC) curves, calibration plots, and the Hosmer‒Lemeshow tests were used to evaluate the discriminability and calibration of nomograms.

RESULTS

In total, 3690 and 172 patients were included in the training set and validation set, respectively. Tumor size, location, and T stage were included in the nomogram predicting nodal metastasis. The AUC values of the nomogram were 0.972 (95% confidence interval (CI): 0.964-0.980) and 0.897 (95% CI: 0.846-0.948) in the training set and validation set, respectively. The calibration plots and Hosmer‒Lemeshow test for the training set (P = 0.999) and validation set (P = 0.537) showed good model calibration. Tumor size, T stage, and N stage were incorporated into the nomogram predicting distant metastasis. The ROC curves demonstrated desirable discrimination both in the training set (AUC = 0.938 (95% CI: 0.921-0.954)) and validation set (AUC = 0.938 (95% CI: 0.890-0.988)). The calibration curves and Hosmer‒Lemeshow test indicated acceptable model calibration both in the training set (P = 0.908) and validation set (P = 0.722).

CONCLUSION

The proposed nomograms may be used as a reliable tool to predict the nodal and distant metastasis in G1 and G2 colorectal NETs.

Assessment of the Risk of Nodal Involvement in Rectal Neuroendocrine Neoplasms: The NOVARA Score, a Multicentre Retrospective Study

Rectal neuroendocrine tumors (r-NETs) are rare tumors with overall good prognosis after complete resection. However, there is no consensus on the extension of lymphadenectomy or regarding contraindications to extensive resection. In this study, we aim to identify predictive factors that correlate with nodal metastasis in patients affected by G1–G2 r-NETs. A retrospective analysis of G1–G2 r-NETs patients from eight tertiary Italian centers was performed. From January 1990 to January 2020, 210 patients were considered and 199 were included in the analysis. The data for nodal status were available for 159 cases. The nodal involvement rate was 9%. A receiver operating characteristic (ROC) curve analysis was performed to identify the diameter (>11.5 mm) and Ki-67 (3.5%), respectively, as cutoff values to predict nodal involvement. In a multivariate analysis, diameter > 11.5 mm and vascular infiltration were independently correlated with nodal involvement. A risk scoring system was constructed using these two predictive factors. Tumor size and vascular invasion are predictors of nodal involvement. In addition, tumor size > 11.5 mm is used as a driving parameter of better-tailored treatment during pre-operative assessment. Data from prospective studies are needed to validate these results and to guide decision-making in r-NETs patients in clinical practice.

Risk Factors Associated with the Development of Metastases in Patients with Gastroenteropancreatic Neuroendocrine Tumors: A Retrospective Analysis

Neuroendocrine tumors develop from systemic endocrine and nerve cells, and their occurrence has increased recently. Since these tumors are heterogeneous, pathological classification has been based on the affected organ. In 2019, the World Health Organization introduced a change expected to influence neuroendocrine tumor research, as gastroenteropancreatic neuroendocrine tumors are now included within a unified classification. This retrospective study aimed to investigate the characteristics (e.g., lymph node metastases and all other metastases) of gastroenteropancreatic neuroendocrine tumors using this new classification in 50 cases. Tumor size, depth, MIB-1 index, lymphatic invasion, venous invasion, and neuroendocrine tumor grade were significantly correlated with lymph node metastasis and other metastases. The venous invasion was more strongly correlated with lymph node metastasis and all other types of metastases than with lymphatic invasion. Identification rates for lymphatic invasion were considered lower because of structural problems such as lymphatic vessels being much thinner than veins. However, venous invasion was considered effective in compensating for the low identification rate in cases of lymphatic invasion. In future research, a unified classification and standardized framework for assessment will be important when analyzing the characteristics of neuroendocrine tumors, and large-scale studies are required.