Pathologic research update of colorectal neuroendocrine tumors

A Rare Case of Metastatic Poorly Differentiated Neuroendocrine Tumor Arising From the Sigmoid Colon in an Active Duty Service Member

Neuroendocrine tumors (NET) are rare malignancies that contain neural and endocrine cells with a median age of diagnosis of 63 years. NETs are typically located in the gastrointestinal (GI) tract, the pancreas, or the lungs. Within the GI tract, the most common locations for NETs are the small bowel, appendix, or rectum. They are often asymptomatic and found incidentally on imaging or during procedures. NETs arising from the left side of the colon are very uncommon. While most NETs are well-differentiated by histology and are slow growing, 7% are poorly differentiated and usually progress rapidly. While rare, it is vital to be vigilant for this reason We present such a case of poorly differentiated metastatic NET of the sigmoid colon in a young active duty service member.

Localized Colonic Small-Cell Carcinoma with Pathological Complete Response after Neoadjuvant Cisplatin and Etoposide: A Case Report

Extrapulmonary small-cell carcinoma (SCC) is a rare neoplasm that shares certain features with its pulmonary counterpart and occurs predominantly in the gastrointestinal tract (GIT). It is a high-grade and poorly differentiated neuroendocrine tumor, usually diagnosed in advanced stages, with a poor prognosis and few therapeutic options in that setting. This is a case report of a 77-year-old Spanish male patient with localized SCC of the colon, who presented a pathological complete response in the surgical specimen after neoadjuvant chemotherapy with cisplatin and etoposide. To date, 5 years after surgery, the patient remains without evidence of tumor recurrence. As clinical guidelines for the management of this entity are lacking, and therefore its management has not been standardized, an attempt to summarize the current evidence in the literature was made.

External Validity of Somatostatin Analogs Trials in Advanced Neuroendocrine Neoplasms: The GETNE-TRASGU Study

INTRODUCTION

Somatostatin analogs (SSA) prolong progression-free survival (PFS) in patients with well-differentiated gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs). However, the eligibility criteria in randomized clinical trials (RCTs) have been restricted, which contrasts with the vast heterogeneity found in NENs.

METHODS

We identified patients with well-differentiated (Ki-67% ≤20%), metastatic GEP-NENs treated in first line with SSA monotherapy from the Spanish R-GETNE registry. The therapeutic effect was evaluated using a Bayesian Cox model. The objective was to compare survival-based outcomes from real-world clinical practice versus RCTs.

RESULTS

The dataset contained 535 patients with a median age of 62 years (range: 26-89). The median Ki-67% was 4 (range: 0-20). The most common primary tumor sites were as follows: midgut, 46%; pancreas, 34%; unknown primary, 10%; and colorectal, 10%. Half of the patients received octreotide LAR (n = 266) and half, lanreotide autogel (n = 269). The median PFS was 28.0 months (95% CI: 22.1-32.0) for octreotide versus 30.1 months (95% CI: 23.1-38.0) for lanreotide. The overall hazard ratio for lanreotide versus octreotide was 0.90 (95% credible interval: 0.71-1.12). The probability of effect sizes >30% with lanreotide versus octreotide was 2 and 6% for midgut and foregut NENs, respectively.

CONCLUSION

Our study evaluated the external validity of RCTs examining SSAs in the real world, as well as the main effect-modifying factors (progression status, symptoms, tumor site, specific metastases, and analytical data). Our results indicate that both octreotide LAR and lanreotide autogel had a similar effect on PFS. Consequently, both represent valid alternatives in patients with well-differentiated, metastatic GEP-NENs.

Endoscopic and surgical treatment of T1N0M0 colorectal neuroendocrine tumors: a population-based comparative study

BACKGROUND

With the rapid advances in endoscopic technology, endoscopic therapy (ET) is increasingly applied to the treatment of small (≤ 20 mm) colorectal neuroendocrine tumors (NETs). However, long-term data comparing ET and surgery for management of T1N0M0 colorectal NETs are lacking. The purpose of this work was to compare overall survival (OS) and cancer-specific survival (CSS) of such patients with ET or surgery.

METHODS

Patients with T1N0M0 colorectal NETs were identified within the Surveillance Epidemiology and End Results (SEER) database (2004-2016). Demographics, tumor characteristics, therapeutic methods, and survival were compared. Propensity score matching (PSM) was used 1:3 and among this cohort, Cox proportional hazards regression models were performed to evaluate correlation between treatment and outcomes.

RESULTS

Of 4487 patients with T1N0M0 colorectal NETs, 1125 were identified in the matched cohort, among whom 819 (72.8%) underwent ET and 306 (27.2%) underwent surgery. There was no difference in the 5-year and 10-year OS and CSS rates between the 2 treatment modalities. Likewise, analyses stratified by tumor size and site showed that patients did not benefit more from surgery compared with ET. Moreover, multivariate analyses found no significant differences in OS [Hazard Ratio (HR) = 0.857, 95% Confidence Interval (CI): 0.513-1.431, P = 0.555] and CSS (HR = 0.925, 95% CI: 0.282-3.040, P = 0.898) between the 2 groups. Similar results were observed when comparisons were limited to patients with different tumor size and site.

CONCLUSIONS

In this population-based study, patients with lesions < 10 mm treated endoscopically had comparable long-term survival compared with those treated surgically, which demonstrates ET as an alternative to surgery in T1N0M0 colorectal NETs of < 10 mm. Further high-quality prospective studies are warranted to comprehensively evaluate the role of ET in patients with tumors 10 to 20 mm.

Prognostic role of neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio in patients with midgut neuroendocrine tumors undergoing resective surgery

AIM

Several studies demonstrated the prognostic value of the neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR) and platelet-to-white blood cells ratio (PWR) in different types of tumors. However, there is no information about a possible role of NLR, PLR and PWR as predictor of presence of metastasis or multifocal disease in patients undergoing surgery with curative intent for midgut NET. The aim of our study was to test the role of preoperative NLR, PLR and PWR as predictors of patients undergoing surgery with curative intent for midgut NET.

METHODS

We retrospectively enrolled seven foregut, 35 midgut and six hindgut NET patients with gastrointestinal neuroendocrine tumors operated in our Units from January 2005 to June 2016. Details about preoperative laboratory data, surgical operation, histology and follow-up were retrieved. Non-parametric statistics, ROC curve analysis and survival analysis were used.

RESULTS

NLR was significantly higher in patients with distant metastasis (p = 0.04). The ROC curve analysis indicated that a threshold value of NLR of 2.6 predicted the presence of peritoneal metastasis with a specificity of 100% and a sensitivity of 71% and an overall accuracy of AUC = 0.81 (95%CI: 0.59-0.94), p = 0.05. PLR and PWR was not be associated to metastasis but tended to be associated to multifocal disease.

CONCLUSION

In patients with midgut NET, an impaired adaptive immune response, as suggested by a high NLR ratio, was associated to the presence of distant metastasis and in particular of peritoneal metastasis. This information may be helpful when planning the treatment of a patient with a midgut NET.

A well differentiated neuroendocrine tumor of the jejunum with peritoneal carcinomatosis: A case report

Neuroendocrine tumors (NETs), belong to a group of neoplasms that arise from neuroendocrine cells and express markers such as synaptophysin and chromogranin A. The digestive system (DS) is the most common site of NET development. The World Health Organization classification divides NETs into low grade (G1-G2) tumors (NETs) and high grade carcinomas [neuroendocrine carcinomas (NECs)], based on mitotic index and histological criteria. NET prognosis depends on tumor stage and grade. Low grade G1 NETs are characterized by a low proliferative rate and an indolent clinical course with a 5-year survival rate ranging between 38% (pancreas) and 88% (rectum). The present study reports a case of a low grade (G1) multifocal jejunal tumor with histologically confirmed features of aggressiveness, namely peritoneal carcinomatosis, lymph node metastasis and vascular carcinomatous emboli. Prediction of clinical behavior and survival in such a case is challenging. Although multiplicity and nodal metastases is not unusual for low grade NETs in this part of the gastrointestinal tract, peritoneal carcinomatosis is an extremely rare finding. Surgeons and histopathologists should be familiar with such eventualities and tumor boards are required in order to conclude whether aggressive therapeutic interventions may have any impact on patients' long term survival.

Colon and Rectal Neuroendocrine Tumors: Are They Really One Disease? A Single-Institution Experience over 15 Years

Colon and rectal neuroendocrine tumors (NETs) are often studied as one entity. Recent evidence suggests that worse outcomes are associated with colon compared with rectal NETs; direct comparisons are lacking. Our aim was to assess clinicopathologic, treatment, and survival differences between these diseases. All patients who underwent resection of colorectal NETs at one institution from 2000 to 2014 were included and analyzed. Of 29 patients, 12(41%) had colon and 17 (59%) had rectal NETs. Baseline demographics were similar between groups, although colon patients tended to be symptomatic at presentation (67% vs 44%, P = 0.41). Eighty-three per cent of colon patients underwent surgical resection, whereas 77 per cent of rectal patients underwent endoscopic or transanal resection ( P = 0.003). Colon patients had larger (3.4 cm vs 0.7 cm, P = 0.03), higher T-stage (T3/T4: 91% vs 14%, P = 0.003), higher grade tumors (42% vs 12%, P = 0.09) with more lymph nodes (58% vs 24%, P = 0.12) and lymphovascular invasion positivity (58% vs 24%, P = 0.32). Five-year disease-specific survival was 53% versus 80 per cent for colon and rectal patients, respectively ( P = 0.22). After excluding high-grade tumors, colon NETs were associated with lymphovascular invasion positivity (100% vs 17%, P = 0.05) and advanced T-stage (80% vs 8%, P = 0.01). Colon and rectal 5-year disease-specific survival was 67 versus 80 per cent ( P = 0.86). Colon and rectal NETs clinically seem to be distinct entities. Colon tumors have more aggressive clinicopathologic features, which may translate to worse outcomes. These differences in tumor biology may demand distinct management and should be further studied in a multi-institutional setting.

Concurrent Occurrence of Tumor in Colon and Small Bowel following Intestinal Obstruction: A Case Report and Review of the Literature

An intestinal obstruction occurs when either the small or large intestine is partly or completely blocked so it prevents passing the food or fluid through the small/large bowel. This blockage is due to the existence of a mechanical obstruction such as foreign material, mass, hernia, or volvulus. Common symptoms include cramping pain, nausea and vomiting, changes in bowel habits, inability to pass stool, and lack of gas. We present a case of an 83-year-old man who had been referred to Taleghani Hospital with symptoms of bowel obstruction. He underwent the surgery. The findings of exploration of the entire abdomen showed two types of mass separately in two different organs. In postoperative workup, pathology reported two types of tumors (adenocarcinoma and neuroendocrine tumors).

The Prognostic Significance of Neuroendocrine Differentiation in Colorectal Carcinomas: Our Experience

INTRODUCTION

Neuroendocrine differentiation in colorectal carcinomas, detected using immunohistochemistry and ultrastructural techniques, has been studied as a prognostic marker for invention of targeted therapy. There are a few studies done on this aspect which have shown conflicting results ranging from poor prognosis to no prognostic significance.

AIM

The aim of the study was to determine the clinical significance of neuroendocrine differentiation in colorectal carcinomas using immunohistochemical stains such as chromogranin A & synaptophysin in relation to its prognostic significance.

MATERIALS AND METHODS

A retrospective study was conducted wherein all the colorectal carcinomas, received in the Department of Pathology, over a period of 3 years, were reviewed. Neuroendocrine markers were done on 53 cases of moderately, poorly and undifferentiated adenocarcinomas. Based on the degree of immunoreactivity for these markers, tumours were divided into group 0, group 1, group 2, group 3 & group 4. Group 0 & 1 were categorized as neuroendocrine differentiation absent & group 2, 3 & 4 as present. Neuroendocrine differentiation was correlated with age, sex, grade, stage, diagnosis & survival. Follow up data of the cases was recorded.

RESULTS

Neuroendocrine differentiation was present in 18 cases (33.9%). The degree of immunoreactivity for neuroendocrine markers in present study were; group 0- 58%, 1- 7.5%, 2- 9%, 3- 13% & 4- 11%. The mean age of patients was 54 years with a slight male preponderance {M:F::1.6:1}. Most of the carcinomas with neuroendocrine differentiation belonged to Grade II (61%) & Stage II & III (83%). Neuroendocrine differentiation did not show any significant association with age, sex, location, histological type, grade, stage & survival.

CONCLUSION

The above results indicate that the presence of neuroendocrine differentiation cannot be recommended as a prognostic marker in colorectal carcinomas.

Diagnostic accuracy of endoscopic ultrasonography for rectal neuroendocrine neoplasms

AIM: To investigate the diagnostic accuracy of endoscopic ultrasonography (EUS) for rectal neuroendocrine neoplasms (NENs) and the differential diagnosis of rectal NENs from other subepithelial lesions (SELs).

METHODS: The study group consisted of 36 consecutive patients with rectal NENs histopathologically diagnosed using biopsy and/or resected specimens. The control group consisted of 31 patients with homochronous rectal non-NEN SELs confirmed by pathology. Epithelial lesions such as cancer and adenoma were excluded from this study. One EUS expert blinded to the histological results reviewed the ultrasonic images. The size, original layer, echoic intensity and homogeneity of the lesions and the perifocal structures were investigated. The single EUS diagnosis recorded by the EUS expert was compared with the histological results.

RESULTS: All NENs were located at the rectum 2-10 cm from the anus and appeared as nodular (n = 12), round (n = 19) or egg-shaped (n = 5) lesions with a hypoechoic (n = 7) or intermediate (n = 29) echo pattern and a distinct border. Tumors ranged in size from 2.3 to 13.7 mm, with an average size of 6.8 mm. Homogeneous echogenicity was seen in all tumors except three. Apart from three patients (stage T2 in two and stage T3 in one), the tumors were located in the second and/or third wall layer without involvement of the fourth and fifth layers. In the patients with stage T1 disease, the tumors were located in the second wall layer only in seven cases, the third wall layer only in two cases, and both the second and third wall layers in 27 cases. Approximately 94.4% (34/36) of rectal NENs were diagnosed correctly by EUS, and 74.2% (23/31) of other rectal SELs were classified correctly as non-NENs. Eight cases of other SELs were misdiagnosed as NENs, including two cases of inflammatory lesions and one case each of gastrointestinal tumor, endometriosis, metastatic tumor, lymphoma, neurilemmoma, and hemangioma. The positive predictive value of EUS for rectal NENs was 80.9% (34/42), the negative predictive value was 92.0% (23/25), and the diagnostic accuracy was 85.1%.

CONCLUSION: EUS has satisfactory diagnostic accuracy for rectal NENs with good sensitivity, but unfavorable specificity, making the differential diagnosis of NENs from other SELs challenging.

Advanced small-cell colon carcinoma: a case report

Introduction

Small-cell colon carcinoma is a very rare disease among colon neoplasms; it is difficult to achieve long-term survival due to its aggressive tumor behavior. Here we report the long-term survival of a patient with advanced small-cell colon carcinoma achieved by a combination of surgery and continuous chemotherapy.

Case presentation

A 67-year-old Japanese man underwent abdominal computed tomography in our institution for follow up after gastrectomy, and abnormal thickness of the sigmoid colon wall was revealed. An endoscopy demonstrated a 20mm Bormann 2 lesion with central ulceration located 20cm from the anal verge. A sigmoidectomy was performed. Histologically, the tumor deeply invaded the tissue and extended beyond the serosa, and was diagnosed as small-cell carcinoma. Cisplatin plus irinotecan was administered for adjuvant chemotherapy. Nine months after surgery, a follow-up computed tomography showed an enlarged lymph node behind the inferior vena cava and a 15×8mm nodule located at the ventral side of the cecum. Under consideration of progressive disease, cisplatin plus irinotecan therapy was performed again using the same regimen. After nine cycles of cisplatin plus irinotecan therapy, a follow-up gastric endoscopy demonstrated external tumor invasion to the duodenum wall. Carboplatin plus etoposide therapy was selected as a third-line regimen. After six cycles of carboplatin plus etoposide therapy, the recurrence sites were maintained in a stable condition, and the survival time reached approximately 30 months after the initial surgery.

Conclusions

We report the long-term survival of a patient with advanced small-cell colon carcinoma. In the future, the accumulation and analysis of rare cases that obtain a better survival time will contribute to clarifying neuroendocrine carcinoma biology, and help to improve the prognosis.

Distribution, incidence, and prognosis in neuroendocrine tumors: a population based study from a cancer registry

Neuroendocrine tumors are considered rare tumors: recently an increased incidence and an improvement in survival were described. We explore distribution, incidence and survival of neuroendocrine tumors using population based registry data. We extracted from the Tuscan Cancer Registry neuroendocrine tumors from 1985-2005, and we evaluated distribution, incidence ad survival according to sex, site of tumor, age and stage at diagnosis. 455 cases of neuroendocrine tumors were identified. The overall incidence increased over the study period from 0.7 per 100,000 per year to 1.6 among men (APC +3.6) and from 0.3 to 2.1 among women (APC +4.8). The anatomic distribution of tumors was lung 25.7%, small intestine 23.5%, appendix 10.9%, colon 10.3%, pancreas 9.4%, stomach 7.4%, and rectum 5.2%. Neuroendocrine tumors were more frequent among males and incidence rate increased with age. We observed increased incidence of neuroendocrine tumors, while survival did not change over time. Prognosis varied with age, stage and localization; females had better survival than males. The increase number of neuroendocrine tumors may be due, at least in part, to better registration and to improvement of diagnosis.