Adjuvant Chemotherapy Versus Observation Following Resection for Patients With Nonmetastatic Poorly Differentiated Colorectal Neuroendocrine Carcinomas. Ann Surg. 2019;. [PMID: 31478977 DOI: 10.1097/sla.0000000000003562]

Evaluation of association between center colorectal neuroendocrine neoplasm volume and survival among patients with colorectal neuroendocrine carcinoma

BACKGROUND

Although correlation between center volume and survival has been reported for several complex cancers, it remains unknown if this is true for colorectal neuroendocrine carcinomas (CRNECs). We hypothesized that higher center annual volume of colorectal neuroendocrine neoplasm resections would be associated with overall survival (OS) for patients with CRNECs.

METHODS

Patients in the National Cancer Database diagnosed with stages I-III CRNEC between 2006 and 2018 and who underwent surgical resection were identified. The mean annual colorectal neuroendocrine neoplasm resection volume threshold associated with significantly worse mortality hazard was determined using restricted cubic splines. Kaplan-Meier (KM) method was used to compare OS, while Cox proportional hazards model was used for multivariable analysis.

RESULTS

There were 694 patients with CRNEC who met inclusion criteria across 1229 centers. Based on the cubic spline, centers treating fewer than one colorectal neuroendocrine neoplasm patient every 3 years on average had worse outcomes. Centers below this threshold were classified as low-volume (LV) centers corresponding with 42% of centers and about 15% of the patient cohort. In unadjusted survival analysis, LV patients had a median OS of 14 months (95% confidence interval [CI]: 10-19) while those treated at HV centers had a median OS of 33 months (95% CI: 25-49). In multivariable analysis, resection at a LV center was associated with increased risk of mortality (1.42 [95% CI: 1.01-2.00], p = 0.04).

CONCLUSION

CRNEC patients have a dire prognosis; however, treatment at an HV center may be associated with decreased risk of mortality.

Development and Validation of a Novel Machine Learning Model to Predict the Survival of Patients with Gastrointestinal Neuroendocrine Neoplasms

INTRODUCTION

Well-calibrated models for personalized prognostication of patients with gastrointestinal neuroendocrine neoplasms (GINENs) are limited. This study aimed to develop and validate a machine-learning model to predict the survival of patients with GINENs.

METHODS

Oblique random survival forest (ORSF) model, Cox proportional hazard risk model, Cox model with least absolute shrinkage and selection operator penalization, CoxBoost, Survival Gradient Boosting Machine, Extreme Gradient Boosting survival regression, DeepHit, DeepSurv, DNNSurv, logistic-hazard model, and PC-hazard model were compared. We further tuned hyperparameters and selected variables for the best-performing ORSF. Then, the final ORSF model was validated.

RESULTS

A total of 43,444 patients with GINENs were included. The median (interquartile range) survival time was 53 (19-102) months. The ORSF model performed best, in which age, histology, M stage, tumor size, primary tumor site, sex, tumor number, surgery, lymph nodes removed, N stage, race, and grade were ranked as important variables. However, chemotherapy and radiotherapy were not necessary for the ORSF model. The ORSF model had an overall C index of 0.86 (95% confidence interval, 0.85-0.87). The area under the receiver operation curves at 1, 3, 5, and 10 years were 0.91, 0.89, 0.87, and 0.80, respectively. The decision curve analysis showed superior clinical usefulness of the ORSF model than the American Joint Committee on Cancer Stage. A nomogram and an online tool were given.

CONCLUSION

The machine learning ORSF model could precisely predict the survival of patients with GINENs, with the ability to identify patients at high risk for death and probably guide clinical practice.

Epidemiology and survival outcomes of colorectal mixed neuroendocrine-non-neuroendocrine neoplasms and neuroendocrine carcinoma

BACKGROUND

Mixed neuroendocrine-non-neuroendocrine neoplasms are a rare subtype of neuroendocrine neoplasm consisting of ≥30% each of neuroendocrine and non-neuroendocrine differentiation. Neuroendocrine carcinomas are poorly differentiated neuroendocrine tumors. The epidemiology and prognosis of colorectal mixed neuroendocrine-non-neuroendocrine neoplasms and neuroendocrine carcinomas are not clearly defined in the literature. We sought to examine the presentation, patterns of care, and outcomes of patients with mixed neuroendocrine-non-neuroendocrine neoplasms and neuroendocrine carcinomas.

METHODS

We identified patients diagnosed with stage I-III colorectal (excluding appendix) mixed neuroendocrine-non-neuroendocrine neoplasms or neuroendocrine carcinomas with only one-lifetime cancer diagnosis who underwent surgical resection between 2010 and 2018 from the National Cancer Database. We performed bidirectional selection to identify variables to include in a multivariable Cox proportional hazards model.

RESULTS

We identified 189 patients with a diagnosis of stage I to III colorectal mixed neuroendocrine-non-neuroendocrine neoplasms, 66% of whom had poorly differentiated tumors and 482 with neuroendocrine carcinomas. Among patients with stage III disease, 68% of patients with mixed neuroendocrine-non-neuroendocrine neoplasms and 54% of patients with neuroendocrine carcinomas received adjuvant chemotherapy. The median survival for the overall patients with mixed neuroendocrine-non-neuroendocrine neoplasms and neuroendocrine carcinomas cohorts were 38 and 42 months, respectively (P = .22), and the median survival for patients with mixed neuroendocrine-non-neuroendocrine neoplasms and neuroendocrine carcinomas with stage III disease were 30 and 25 months, respectively (P = .27). In multivariable analysis, fewer number of positive nodes and receipt of adjuvant chemotherapy were independently associated with decreased risk of mortality for patients with mixed neuroendocrine-non-neuroendocrine neoplasms and neuroendocrine carcinomas.

CONCLUSION

Adjuvant chemotherapy is associated with improved survival in stage III mixed neuroendocrine-non-neuroendocrine neoplasms and neuroendocrine carcinomas. Future studies are warranted to identify subsets of patients benefiting most from adjuvant therapy.

Mixed adenoneuroendocrine carcinoma originating from the appendix and colorectum: a comparative analysis of a large population-based database

PURPOSE

As a rare gastrointestinal neoplasm, the demographic, clinicopathological, and prognostic characteristics of mixed adenoneuroendocrine carcinoma (MANEC) remain unclear. The purpose of this study was to evaluate its biological features, survival outcome, and prognostic factors.

METHODS

From the Surveillance, Epidemiology, and End Results (SEER) database, we retrospectively reviewed clinicopathological and survival data of 513 patients who were histopathologically diagnosed with MANEC of the appendix and colorectum bettween 2004 and 2015. The clinicopathological features and survival outcomes of MANEC located at different anatomical locations were compared, and predictive factors for cancer-specific survival (CSS) and overall survival (OS) were assessed.

RESULTS

In terms of anatomical distribution of MANEC, the appendix (64.5%, 331/513) was more frequently involved, followed by colon (28.1%, 144/513) and rectum (7.4%, 38/513). The MANEC at different anatomical locations had a distinct clinicopathological characteristic, and colorectal MANEC was significantly associated with more aggressive biological features. The survival outcomes of appendiceal MANEC were significantly better than that of colorectal MANEC (3-year CSS rate 73.8% vs 59.4%, P = 0.010; 3-year OS 69.2% vs 48.3%, P < 0.001). In addition, hemicolectomy had a better survival benefit than appendicectomy for patients with appendiceal MANEC, regardless of lymph node metastasis (P < 0.05). Tumor location, histology grade III, tumor size > 2 cm, T3-T4 stage, lymph node metastasis, and distant metastasis were independent prognostic factors for patients with MANEC.

CONCLUSIONS

Tumor location had an important prognostic significance for MANEC. As an uncommon clinical entity, colorectal MANEC had more aggressive biological features and worse prognosis than its appendiceal counterpart. The standard surgical procedure and clinical management strategy for MANEC need to be established.

Impact of surgical approach on short- and long-term outcomes in gastroenteropancreatic neuroendocrine carcinomas

BACKGROUND

Literature is lacking on the impact of advancements in minimally invasive surgery (MIS) on outcomes for patients with gastroenteropancreatic neuroendocrine carcinomas (GEP-NECs). Herein, we compared perioperative and oncologic outcomes among patients with GEP-NECs undergoing open, laparoscopic, and robotic resection.

METHODS

Patients with GEP-NECs diagnosed 2010-2019 were identified from the National Cancer Database (NCDB). We used the inverse probability of treatment weighting method to account for selection bias. Patients were stratified by surgical approach; and pairwise comparisons were conducted by analyzing short- and long-term outcomes.

RESULTS

Receipt of MIS increased from 34.2% in 2010 to 67.5 % in 2019. Altogether, 6560 patients met study criteria: 3444 (52.5%) underwent open resection, 2783 (42.4%) underwent laparoscopic resection and 333 (5.1%) underwent robotic resection. Compared with open resection, laparoscopic or robotic resection were associated with shorter post-operative length of stay, reduced 30-day and 90-day post-operative mortality, and prolonged overall survival (OS). Compared with laparoscopic resection, robotic resection was associated with reduced 90-day post-operative mortality, however, there was no significant difference in OS.

CONCLUSION

This NCDB analysis demonstrates that MIS approaches for treating GEP-NECs have become more common, with improved perioperative mortality, shorter post-operative length of stay and favorable OS, compared with open resection.

Estimated Glucose Disposal Rate Predicts Renal Progression in Type 2 Diabetes Mellitus: A Retrospective Cohort Study

Context

Insulin resistance is a feature of type 2 diabetes mellitus (T2DM). The estimated glucose disposal rate (eGDR), a validated marker for insulin resistance, is associated with complications of diabetes, but few studies have explored the relationship between eGDR and renal outcomes in T2DM.

Objective

This study investigated the value of eGDR in predicting renal progression in T2DM.

Methods

A total of 956 T2DM patients with a baseline estimated glomerular filtration rate (eGFR) ≥ 60 mL/min/1.73 m² and 5 years of follow-up were enrolled. Primary outcomes were rapid eGFR decline, eGFR <60 mL/min/1.73 m², and composite renal endpoint consisting of 50% eGFR decline, doubling of serum creatinine, or end-stage renal disease. A continuous scale with restricted cubic spline curves and a generalized linear model were applied to evaluate the associations between eGDR and primary outcomes.

Results

Rapid eGFR decline was experienced by 23.95% of patients, 21.97% with eGFR <60 mL/min/1.73 m², and 12.13% with the composite renal endpoint. The eGDR showed a relationship with follow-up eGFR and percentage change in eGFR (P < .001). An eGDR <6.34 mg/kg/min was an independent risk factor for rapid eGFR decline, eGFR < 60 mL/min/1.73 m², or the composite renal endpoint(P < .05). Compared with eGDR of 5.65∼6.91 mg/kg/min, eGDR levels >8.33 mg/kg/min decreased the risk of rapid eGFR decline by 75%, eGFR < 60 mL/min/1.73 m² by 60%, and the composite renal endpoint by 61%. Subgroup analysis was performed by sex, age, and diabetes duration, which showed that eGDR was associated with primary outcomes.

Conclusion

Lower eGDR is a predictive factor for renal deterioration in T2DM patients.

European Neuroendocrine Tumor Society (ENETS) 2023 guidance paper for digestive neuroendocrine carcinoma

This ENETS guidance paper, developed by a multidisciplinary working group, provides up-to-date and practical advice on the diagnosis and management of digestive neuroendocrine carcinoma, based on recent developments and study results. These recommendations aim to pave the road for more standardized care for our patients resulting in improved outcomes. Prognosis is generally poor for digestive NEC, most are advanced at diagnosis and median survival in metastatic disease is 11-12 months. Surgery can be of benefit for localized disease after extensive preoperative imaging. Carboplatin in combination with etoposide is recommended as first-line treatment for metastatic disease. Irinotecan with fluoropyrimidines has the best evidence as second-line treatment. Immunotherapy plays a minor role in biomarker-unselected patients. Molecular profiling if available is encouraged to identify new targets. More prospective clinical trials are highly needed to fulfil the unmet needs in this field, especially on new predictive and prognostic biomarkers and to improve survival of patients with advanced disease.

Future therapeutic strategies in the treatment of extrapulmonary neuroendocrine carcinoma: a review

Neuroendocrine neoplasms (NENs) are rare malignancies arising most commonly in the gastrointestinal and bronchopulmonary systems. Neuroendocrine carcinomas (NECs) are a subgroup of NENs characterised by aggressive tumour biology, poor differentiation and dismal prognosis. Most NEC primary lesions arise in the pulmonary system. However, a small proportion arise outside of the lung and are termed extrapulmonary (EP)-, poorly differentiated (PD)-NECs. Patients with local or locoregional disease may benefit from surgical excision; however, this is often not an option, due to late presentation. To date, treatment has mirrored that of small-cell lung cancer, with platinum-etoposide forming the basis of first-line treatment. There is a lack of consensus in relation to the most effective second-line treatment option. Low incidence, an absence of representative preclinical models and a lack of understanding of the tumour microenvironment all present challenges to drug development in this disease group. However, progress made in elucidating the mutational landscape of EP-PD-NEC and the observations made in several clinical trials are paving the way towards improving outcomes for these patients. The optimisation and strategic delivery of chemotherapeutic interventions according to tumour characteristics and the utilisation of targeted and immune therapies in clinical studies have yielded mixed results. Targeted therapies that complement specific genetic aberrations are under investigation, including AURKA inhibitors in those with MYCN amplifications, BRAF inhibitors in those with BRAFV600E mutations and EGFR suppression, and Ataxia Telangiectasia and Rad3-related inhibitors in patients with ATM mutations. Immune checkpoint inhibitors (ICIs) have conferred promising results in several clinical trials, particularly with dual ICIs and in combination with targeted therapy or chemotherapy. However, further prospective investigations are required to elucidate the impact of programmed cell death ligand 1 expression, tumour mutational burden and microsatellite instability on response. This review aims to explore the most recent developments in the treatment of EP-PD-NEC and contribute towards the requirement for clinical guidance founded on prospective evidence.

Resection of primary lesion with chemotherapy improves the survival of patients with metastatic colorectal neuroendocrine carcinoma

OBJECTIVE

To evaluate the effect of resection of primary lesion and chemotherapy on survival of patients with metastatic colorectal neuroendocrine carcinoma (CRNEC).

METHODS

Clinical data of 393 patients with metastatic CRNECs between January 2010 and December 2016 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database, including 171 patients who received resection of primary lesion and 221 patients who did not undergo surgery. With the propensity score matching method 172 non-operated patients were selected as controls. Kaplan-Meier method and Log-rank test were used to evaluate the survival differences, while the prognostic factors were analyzed by Cox proportional-hazards model. Metastatic CRNEC patients from January 2001 to December 2021 in Affiliated Jinhua Hospital, Zhejiang University School of Medicine were selected for validation.

RESULTS

Compared with non-operated patients, patients who received resection had longer cause-specific survival ( P<0.05). Patients with resected positive lymph nodes>8 had a poorer prognosis compared to those with resected positive lymph nodes≤8 ( P<0.05). Multivariate analysis showed that gender, location of primary lesion and treatments were independent risk factors for cause-specific survival in patients with metastatic CRNEC (all P<0.05). For metastatic CRNEC patients with resection of primary lesion, rectal neuroendocrine carcinoma, positive resected lymph nodes≤8 and resection of primary lesion combined with chemotherapy were associated with better cause-specific survival (all P<0.05).

CONCLUSIONS

Patients with metastatic CRNEC may benefit from resection of primary lesion, and resection of primary lesion combined with chemotherapy might be the better strategy for metastatic CRNECs. The number of positive lymph nodes resected is correlated with the prognosis of patients.

Metastatic rectal neuroendocrine carcinoma presenting with treatment-refractory immune thrombocytopenia: A case report and literature review

RATIONALE

Colorectal neuroendocrine cancer (CRNEC) accounts for < 1% of all colorectal cancers. It presents in advanced stages and carries a risk of poor survival. CRNEC may be diagnosed incidentally on imaging or routine endoscopy. When symptomatic, it may mimic colorectal adenocarcinoma. Syncope and immune thrombocytopenic purpura (ITP) have not previously been reported as clinical presentations.

PATIENT CONCERNS

A 57-year-old man with human immunodeficiency virus infection on treatment, seizure and stroke without residue presented for the evaluation of fall and syncope.

DIAGNOSIS

Physical examination revealed tachycardia, swelling, and ecchymosis of his proximal left lower extremity. Laboratory tests showed a new isolated thrombocytopenia of 26,000/mm3. Computed tomography for a trauma survey showed an incidental left posterior rectal wall mass. After hospital admission, his platelet count dropped to 14,000/mm3. A peripheral blood smear revealed low platelet count, no schistocytes or immature cells. ITP at a high risk for bleeding was diagnosed and treated with standard medical therapy but remained refractory. Bone marrow biopsy showed metastatic neuroendocrine carcinoma, likely from the rectum.

INTERVENTIONS

Patient received courses of high-dose dexamethasone and intravenous immunoglobulin. He also receive eleven units of platelet transfusion. A course of rituximab was administered. The platelet count response was suboptimal or short lived with drop to a nadir of 4000/mm3. However, after initiation of Eltrombopag, the thrombocytopenia resolved. Patient was started on etoposide, carboplatin, Atezolizumab. His hospital stay was complicated by neutropenia and sepsis, which was successfully treated.

OUTCOMES

He was discharged to subacute rehab in stable condition. About 4 months later, he was readmitted for severe thrombocytopenia, septic shock, and acute respiratory failure. Despite appropriate treatment, the patient deteriorated and expired.

CONCLUSION

CRNEC is a rare aggressive disease with dismal outcome that lacks standardized treatment. Metastasis to the bone marrow is uncommon and concomitant ITP has not been reported. We report a rare case of rectal neuroendocrine carcinoma metastatic to bone marrow associated with refractory ITP and review the relevant literature.

Resection of the Primary Tumor Improves the Survival of Patients With Stage IV Gastric Neuroendocrine Carcinoma

Background

The prognostic prolongation effect of surgical resection in the management of gastric neuroendocrine carcinoma (GNEC) with distant metastases was still uncertain. The purpose of this study was to investigate the association of primary tumor resection (PTR) with outcomes in patients with stage IV GNEC.

Methods

This retrospective study analyzed patients with distant metastatic GNEC diagnosed between 2000 and 2018 and identified using the Surveillance, Epidemiology, and End Results (SEER) database. Patients were divided into PTR and non-PTR groups. The stabilized inverse probability of treatment weighting (IPTW) method was used to reduce the selection bias. Overall survival (OS) and cancer-specific survival (CSS) were estimated using the Kaplan–Meier method and log-rank test. Cox-regression analyses (uni- and multivariate) were performed to evaluate factors potentially influencing survival.

Results

A total of 126 patients with a median follow-up of 79 months were identified. Forty-four patients underwent PTR and 82 patients did not undergo surgery. After the IPTW approach, PTR improved the OS in patients with stage IV GNEC (median OS 12 vs. 6 months, P = 0.010). The 1- and 3-year OS for patients with or without PTR were 43.8% and 34.5%, and 27.9% and 6.5%, respectively. The median CSS was 12 months for patients undergoing PTR and 6 months for those who did not. The 1 and 3-year CSS for patients with or without PTR were 45.1% and 37.0%, and 27.9% and 6.5%, respectively. In IPTW-adjusted Cox proportional hazards regression analysis, PTR was recognized as an independent factor for improved survival after the occurrence of distant metastatic disease [OS: hazard ratio (HR) = 0.305; 95% confidence interval (CI): 0.196, 0.475; and CSS: HR = 0.278; 95% CI: 0.171, 0.452].

Conclusion

PTR for stage IV GNEC contributes to a better prognosis compared with non-surgery. This study supported the resection of the primary tumor in patients with distant metastatic GNEC.

Therapeutic strategies for gastroenteropancreatic neuroendocrine neoplasms: State-of-the-art and future perspectives

Although gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) have always been considered rare tumors, their incidence has risen over the past few decades. They represent a highly heterogeneous group of neoplasms with several prognostic factors, including disease stage, proliferative index (Ki67), and tumor differentiation. Most of these neoplasms express somatostatin receptors on the cell surface, a feature that has important implications in terms of prognosis, diagnosis, and therapy. Although International Guidelines propose algorithms aimed at guiding therapeutic strategies, GEP-NEN patients are still very different from one another, and the need for personalized treatment continues to increase. Radical surgery is always the best option when feasible; however, up to 80% of cases are metastatic upon diagnosis. Regarding medical treatments, as GEP-NENs are characterized by relatively long overall survival, multiple therapy lines are adopted during the lifetime of these patients, but the optimum sequence to be followed has never been clearly defined. Furthermore, although new molecular markers aimed at predicting the response to therapy, as well as prognostic scores, are currently being studied, their application is still far from being part of daily clinical practice. As they represent a complex disease, with therapeutic protocols that are not completely standardized, GEP-NENs require a multidisciplinary approach. This review will provide an overview of the available therapeutic options for GEP-NENs and attempts to clarify the possible approaches for the management of these patients and to discuss future perspectives in this field.

Clinicopathological characteristics and prognosis of 232 patients with poorly differentiated gastric neuroendocrine neoplasms

BACKGROUND

Poorly differentiated gastric neuroendocrine neoplasms (PDGNENs) include gastric neuroendocrine carcinoma (NEC) and mixed adenoneuroendocrine carcinoma, which are highly malignant and rare tumors, and their incidence has increased over the past few decades. However, the clinicopathological features and outcomes of patients with PDGNENs have not been completely elucidated.

AIM

To investigate the clinicopathological characteristics and prognostic factors of patients with PDGNENs.

METHODS

The data from seven centers in China from March 2007 to November 2019 were analyzed retrospectively.

RESULTS

Among the 232 patients with PDGNENs, 191 (82.3%) were male, with an average age of 62.83 ± 9.11 years. One hundred and thirteen (49.34%) of 229 patients had a stage III disease and 86 (37.55%) had stage IV disease. Three (1.58%) of 190 patients had no clinical symptoms, while 187 (98.42%) patients presented clinical symptoms. The tumors were mainly (89.17%) solitary and located in the upper third of the stomach (cardia and fundus of stomach: 115/215, 53.49%). Most lesions were ulcers (157/232, 67.67%), with an average diameter of 4.66 ± 2.77 cm. In terms of tumor invasion, the majority of tumors invaded the serosa (116/198, 58.58%). The median survival time of the 232 patients was 13.50 mo (7, 31 mo), and the overall 1-year, 3-year, and 5-year survival rates were 49%, 19%, and 5%, respectively. According to univariate analysis, tumor number, tumor diameter, gastric invasion status, American Joint Committee on Cancer (AJCC) stage, and distant metastasis status were prognostic factors for patients with PDGNENs. Multivariate analysis showed that tumor number, tumor diameter, AJCC stage, and distant metastasis status were independent prognostic factors for patients with PDGNENs.

CONCLUSION

The overall prognosis of patients with PDGNENs is poor. The outcomes of patients with a tumor diameter > 5 cm, multiple tumors, and stage IV tumors are worse than those of other patients.

Neuroendocrine Carcinoma of the Anus and Rectum: Patient Characteristics and Treatment Options

INTRODUCTION

Anorectal neuroendocrine carcinomas (NECs) are uncommon malignancies with poor prognosis. Consensus guidelines exist for treating extrapulmonary NEC. However, limited data is available to guide treatment for anorectal NEC. In this study, we sought to review the clinical characteristics and outcomes of patients with NEC of the rectum and/or anus at Mayo Clinic.

PATIENTS AND METHODS

This is a retrospective study of all patients with the diagnosis of NEC of the anus and/or rectum treated across Mayo Clinic sites since 2000. Baseline patient characteristics, tumor pathology, imaging profiles, treatment strategies utilized, and survival outcomes were analyzed. Kaplan-Meier analysis was used with a significance level of P < .05.

RESULTS

The study included a total of 38 patients with primary NEC of the anus and/or rectum. The median age at diagnosis was 55.5 years. The median follow-up was 18.8 months. Fifteen patients had locoregional disease (LRD) at diagnosis. The remaining 23 had metastatic disease. Overall survival was significantly shorter in patients with LRD compared with those with metastatic disease at diagnosis (18.1 vs. 13.8 months; P = .039). The majority (n = 11) of patients with LRD were treated with concurrent chemoradiation therapy, and 10 underwent surgical resection of the primary tumor. The majority (13/15) of patients with LRD progressed, with the majority (11/15) of progressions being distant. The median progression-free survival for patients with LRD was 5.7 months (1-year progression-free survival, 26.7%).

CONCLUSION

Anorectal NEC is an aggressive malignancy with poor prognosis requiring multidisciplinary discussion. In addition, the systemic nature of anorectal NEC with distant recurrences in LRD and poor outcomes in metastatic disease emphasizes the need to further develop better systemic treatment options that can potentially improve outcomes in NEC.

Small-cell neuroendocrine carcinoma of the rectum - a rare tumor type with poor prognosis: A case report and review of literature

BACKGROUND

Small-cell neuroendocrine carcinoma (SNEC) of the rectum is a rare tumor associated with poor prognosis.

CASE SUMMARY

We report a case of a 77-year-old male who came into our hospital because of blood with his stool. An endoscopy revealed a cauliflower-like neoplasm in his rectum. Imaging examination showed that the lesion in the upper rectum was likely rectal cancer, and there was no evidence of metastasis. The patient was treated with surgery. Pathological examination confirmed SNEC of the rectum and an R0 resection was achieved. However, 1 mo after the operation, the patient developed intestinal and ureteral obstructions due to peritoneal metastases. Finally, the patient died from renal failure.

CONCLUSION

SNEC of the rectum is a high-grade carcinoma with an aggressive phenotype, and surgery should be cautiously considered.

Impact of Postoperative Chemotherapy on the Survival of Patients with High-Grade Gastroenteropancreatic Neuroendocrine Carcinoma

BACKGROUND

This study aimed to determine whether postoperative chemotherapy is associated with a survival benefit for patients with poorly differentiated neuroendocrine carcinoma (NEC) of the stomach, small bowel, or pancreas.

METHODS

Patients were identified in the National Cancer Database (NCDB) between 2004 and 2014. Inverse probability of treatment weighting (IPTW) was used to reduce selection bias. To compare the overall survival (OS) of patients in different treatment groups, IPTW-adjusted Kaplan-Meier curves and Cox proportional hazards models were used.

RESULTS

The inclusion criteria were met by 759 patients. The diagnosis was NEC of the stomach for 195 patients (25.7%), NEC of the small intestine for 278 patients (36.6%), and NEC of the pancreas for 286 patients (37.7%). Overall, 213 patients (28.1%) received postoperative chemotherapy after curative resection. For the patients who received chemotherapy, IPTW-adjusted survival showed no OS benefit. However, subgroup analysis demonstrated improved OS with observation (OB) for patients with NEC of the small intestine (hazard ratio [HR], 1.436; 95% confidence interval [CI] 1.13-1.823; P = 0.003), T3 or T4 primary tumor (HR, 1.258; 95% CI 1.08-1.465; P = 0.003), node-positive disease (HR, 1.238; 95% CI 1.040-1.475; P = 0.0165), or positive resection margin (HR, 1.4283; 95% CI 1.02-2.00; P = 0.038).

CONCLUSIONS

In this national database analysis, postoperative chemotherapy was not associated with improved survival for patients with poorly differentiated gastroenteropancreatic (GEP) NECs. These findings highlight the need for continued efforts to understand better which patients in this high-risk population will benefit from additional systemic therapy and the need for continued development of more effective therapies for these patients.