A Peptide Meets a Radionuclide to Combat a Rare Tumor.

Background: Neuroendocrine carcinomas (NECs) are rare malignancies with limited treatment options beyond surgery. Peptide receptor radionuclide therapy (PRRT) is a process by which a somatostatin analog (octreotate) is combined with a chelator (DOTA) and a radionuclide (lutetium-177 [177Lu-dotatate]). This therapy targets receptors on neuroendocrine cells, causing internalization of the radionuclide by the tumor cell, which results in cellular damage and apoptosis. Case Report: We describe the clinical and therapeutic course of a 69-year-old male with a metastatic rectal NEC in whom progressive disease was noted after multiple therapies were attempted. After PRRT with 177Lu-dotatate, the patient was asymptomatic and demonstrated a near-complete radiologic response. Conclusion: This case illustrates that treatment with PRRT may improve the outcome of patients with metastatic rectal NEC. Our case highlights the importance of further research into the use of PRRT in patients with a Ki-67 <55% and uptake on somatostatin receptor imaging.

Management of Appendiceal Neuroendocrine Tumors: Metastatic Potential of Small Tumors.

BACKGROUND: Appendiceal neuroendocrine tumors (ANETs) are rare neoplasms usually discovered incidentally during appendectomy. ANETs < 2 cm were thought to have no metastatic potential, and this dogma has driven management. Our aim is to evaluate the metastatic potential of ANETs < 2 cm. PATIENTS AND METHODS: A retrospective review was performed in a series of patients with ANETs who presented to our tertiary referral center from 1998 to 2019. Demographics, tumor characteristics, treatment, and clinical outcomes were evaluated. RESULTS: In total, 114 patients were included. Median follow-up was 3.3 years (range, 21 days-15 years). At last follow-up, 34 (30%) patients had positive regional lymph nodes and 20 (18%) patients had metastatic disease. Of the 20 patients with metastatic disease, 11 (55%) had primary ANETs < 2 cm. Patient age > 40 years at diagnosis and ANETs with serosal invasion, lymphovascular invasion, intermediate tumor grade, or positive lymph nodes were features significantly more likely to present with metastatic disease. We found no difference in the rate of lymph node positivity, metastatic disease, or overall survival when patients were stratified by tumor size or type of resection (appendectomy vs. right hemicolectomy). On multivariate analysis, patients with metastatic disease at diagnosis had worse overall survival (HR = 24.4, p = 0.008). CONCLUSIONS: In our cohort, tumor size was not a significant risk factor for metastatic disease or worse outcome as many patients with ANETs < 2 cm developed metastatic disease. Appendectomy alone was sufficient surgical management for most ANETs. Patients with risk factors for metastatic disease, regardless of primary ANET size, should be evaluated thoroughly and counseled for further management and surveillance.

Outcomes of Capecitabine and Temozolomide (CAPTEM) in Advanced Neuroendocrine Neoplasms (NENs).

Capecitabine and temozolomide (CAPTEM) have shown promising results in the treatment of neuroendocrine neoplasms (NEN). The aim of this study was to evaluate the outcome and role for CAPTEM in malignant neuroendocrine neoplasms. Data were obtained from NEN patients who received at least one cycle of CAPTEM between November 2010 and June 2018. The average number of cycles was 9.5. For analysis, 116 patients were included, of which 105 patients (91%) underwent prior treatment. Median progression free survival (PFS) and overall survival (OS) were 13 and 38 months, respectively. Overall response rate (ORR) was 21%. Disease control rate (DCR) was 73% in all patients. PFS, median OS, ORR, and DCR for pancreatic NENs (pNEN) vs. non-pNEN was 29 vs. 11 months, 35 vs. 38 months, 38% vs. 9%, and 77% vs. 71%, respectively. Patients with pNEN had a 50% lower hazard of disease progression compared to those with non-pNEN (adjusted Hazard Ratio: 0.498, p = 0.0100). A significant difference in PFS was found between Ki-67 < 3%, Ki-67 3-20%, Ki-67 > 20-54%, and Ki-67 ≥ 55% (29 vs. 12 vs. 7 vs. 5 months; p = 0.0287). Adverse events occurred in 74 patients (64%). Our results indicate that CAPTEM is associated with encouraging PFS, OS, and ORR data in patients with NENs.

Plasma Pancreastatin Predicts the Outcome of Surgical Cytoreduction in Neuroendocrine Tumors of the Small Bowel.

OBJECTIVES: Elevated pancreastatin (PST) levels have been shown to be associated with poor prognosis in small bowel neuroendocrine tumors (NETs). We hypothesized that plasma PST levels that remain elevated following surgical cytoreduction portend a poor prognosis in well-differentiated small bowel NETs. METHODS: Patients diagnosed with small bowel NETs who underwent surgical cytoreduction at our institution were identified. Demographics, histopathologic characteristics, and biochemical data were collected. Only patients who had serial preoperative PST (PreopPST) and postoperative PST (PostopPST) levels were included in this study. Patients were sorted into groups by PST level to assess their response to surgical cytoreduction (group 1, PreopPST/PostopPST normal; group 2, PreopPST elevated/PostopPST normal; group 3, PreopPST/PostopPST elevated). Survival rates were calculated from the date of surgery. RESULTS: PreopPST and PostopPST levels were collected from 300 patients. Patients in groups 1 (n = 74) and 2 (n = 81) had a significant survival advantage compared with patients in group 3 (n = 145) (P < 0.0001). Kaplan-Meier 5- and 10-year survival rates were as follows: group 1: 93% and 82%; group 2: 91% and 65%; and group 3: 58% and 34%, respectively. CONCLUSIONS: Serial monitoring of plasma PST is useful in predicting long-term survival following surgical cytoreduction and can be helpful to identify patients who have a poor prognosis.

Current Treatment Options in Gastroenteropancreatic Neuroendocrine Carcinoma.

Poorly differentiated gastroenteropancreatic neuroendocrine carcinomas (GEPNECs) are a rare neoplasm with a bleak prognosis. Currently there are little prospective data available for optimal treatment. This review discusses the current available regimens and the future direction for the treatment of GEPNECs. Treatment plans for GEPNECs are often adapted from those devised for small cell lung cancer; however, differences in these malignancies exist, and GEPNECs require their own treatment paradigms. As such, current first-line treatment for GEPNECs is platinum-based chemotherapy with etoposide. Studies show that response rate and overall survival remain comparable between cisplatin and carboplatin versus etoposide and irinotecan; however, prognosis remains poor, and more efficacious therapy is needed to treat this malignancy. Additional first-line and second-line treatment options beyond platinum-based chemotherapy have also been investigated and may offer further treatment options, but again with suboptimal outcomes. Recent U.S. Food and Drug Administration approval of peptide receptor radionuclide therapy in low- and intermediate-grade neuroendocrine tumors may open the door for further research in its usefulness in GEPNECs. Additionally, the availability of checkpoint inhibitors lends promise to the treatment of GEPNECs. This review highlights the lack of large, prospective studies that focus on the treatment of GEPNECs. There is a need for randomized control trials to elucidate optimal treatment regimens specific to this malignancy. IMPLICATIONS FOR PRACTICE: There are limited data available for the treatment of poorly differentiated gastroenteropancreatic neuroendocrine carcinomas (GEPNECs) because of the rarity of this malignancy. Much of the treatment regimens used in practice today come from research in small cell lung cancer. Given the poor prognosis of GEPNECs, it is necessary to have treatment paradigms specific to this malignancy. The aim of this literature review is to summarize the available first- and second-line GEPNEC therapy, outline future treatments, and highlight the vast gap in the literature.

Plasma Neurokinin A Levels Predict Survival in Well-Differentiated Neuroendocrine Tumors of the Small Bowel.

OBJECTIVES: Elevated neurokinin A (NKA) levels are associated with poor prognosis in patients with small bowel neuroendocrine tumors. We hypothesized that patients with NKA levels that remain elevated despite treatment with surgical cytoreduction have a poor prognosis. METHODS: Patients diagnosed with small bowel neuroendocrine tumors who underwent surgical cytoreduction at our institution were identified. Demographics, histopathologic characteristics, and biochemical data were collected. Patients were grouped by the trend of their NKA levels (group 1, continuously normal; group 2, transiently elevated but normalized after therapy; group 3, remained elevated despite therapy). Survival rates were calculated from the date of the patient's first NKA level. RESULTS: Serial NKA values after surgical cytoreduction were monitored in 267 patients. Kaplan-Meier 2-year, 5-year, and 10-year survival rates were as follows: group 1 (n = 157), 97%, 89%, and 62%; group 2 (n = 78), 99%, 90%, and 78%; and group 3 (n = 32), 88%, 69%, and 0%. Survival rates were statistically significant between groups 1 and 3 and between groups 2 and 3 (P < 0.01). CONCLUSIONS: Serial monitoring of plasma NKA levels is useful in identifying patients who have a poor prognosis. Elevated NKA levels can indicate the need for immediate therapeutic intervention.

Prognostic Factors in Typical and Atypical Pulmonary Carcinoids.

BACKGROUND: Typical and atypical carcinoids represent approximately 2% of all lung tumors. Survival of patients with typical bronchial carcinoids, unlike the survival of patients with most lung tumors, is generally long but dependent on stage. We report the findings of the Ochsner Medical Center/Louisiana State University (LSU) Health Sciences Center neuroendocrine tumor (NET) program. METHODS: A database with all patients seen at the Ochsner Medical Center/LSU NET program was queried for patients with bronchopulmonary NET. We included patients who had confirmed pathologic bronchopulmonary carcinoid and who had at least 1 clinic visit. Patients with large or small cell NETs or diffuse idiopathic pulmonary neuroendocrine cell hyperplasia were excluded. RESULTS: A total of 169 patients seen from January 1996 to March 2015 met the inclusion criteria. The mean age at diagnosis was 53 years. Of the tumors, 51% percent (86/169) were well-differentiated, 12% (21/169) were moderately differentiated, and 85% and 53% were positive on positron emission tomography and octreotide scanning, respectively. The 5- and 10-year survival rates were 88% and 81% for well-differentiated tumors and 80% and 42% for moderately differentiated tumors, respectively. The 10-year survival rates stratified by Ki-67 index ranges 0-2%, >2%-10%, and >10% were 90%, 72%, and 44%, respectively (P<0.05). CONCLUSION: Overall, patients with bronchial carcinoids have long 5- and 10-year survival rates. We found significant survival differences between nodal status, differentiation status, and carcinoid phenotype. Interestingly, the difference in survival stratified by Ki-67 indices was statistically significant despite its absence in the World Health Organization grading system. As with gastroenteropancreatic NETs, Ki-67 index could become a valuable prognostic indicator for bronchial carcinoids.

Management of pulmonary neuroendocrine tumors.

Neuroendocrine tumors (NETs) of the lung are divided into 4 major types: small cell lung cancer (SCLC), large cell neuroendocrine carcinoma (LCNEC), atypical carcinoid (AC) or typical carcinoid (TC). Each classification has distinctly different treatment paradigms, making an accurate initial diagnosis essential. The inconsistent clinical presentation of this disease, however, makes this difficult. The objective of this manuscript is to detail the diagnosis and management of the well differentiated pulmonary carcinoid (PC) tumors. A multidisciplinary approach to work up and treatment should be utilized for each patient. A multimodal radiological work-up is used for diagnosis, with contrast enhanced CT predominantly utilized and functional imaging techniques. A definitive diagnosis is based on tissue findings. Surgical management remains the mainstay of therapy and can be curative. In those with advanced disease, medical treatments consist of somatostatin analog (SSA) therapy, targeted therapy, chemotherapy or peptide receptor radionuclide therapy. SSAs are the standard of care in those with metastatic NETs, using either Octreotide long acting repeatable (LAR) or lanreotide as reasonable options, despite a scarcity of prospective data in PCs. Targeted therapies consist of everolimus which is approved for use in PCs, with various studies showing mixed results with other targeted agents. Additionally, radionuclide therapy may be used and has been shown to increase survival and to reduce symptoms in some studies. Prospective trials are needed to determine other strategies that may be beneficial in PCs as well as sequencing of therapy. Successful diagnosis and optimal treatment relies on a multidisciplinary approach in patients with lung NETs. Clinical trials should be used in appropriate patients.

Aggressive Surgical Approach to the Management of Neuroendocrine Tumors: A Report of 1,000 Surgical Cytoreductions by a Single Institution.

BACKGROUND: Neuroendocrine tumors (NETs) are rare neoplasms. Our group has treated more than 2,000 NET patients and has performed more than 1,000 surgical cytoreductive procedures. STUDY DESIGN: Records of 834 NET patients who underwent surgical cytoreduction at our institution were reviewed. Demographic information, intraoperative findings, extent of disease, complications, and survival rates were calculated. RESULTS: Eight hundred patients underwent 1,001 cytoreductive operations. Sixty-five percent had small bowel primaries. One hundred and thirty-eight patients presented with an unknown primary site, which was localized intraoperatively in 89% of these cases. The intraoperative complication rate was 9%. The incidence of intraoperative carcinoid crisis was 1%. Mean ± SD operative time was 368 ± 146 minutes. Mean ± SD hospital stay was 9 ± 10 days. Minor postoperative complications occurred after 43% of procedures and major postoperative complications were noted after 19% of procedures. The 30-day postoperative mortality rate was 2%. Median overall survival (OS) for patients with pancreatic NETs was 124 months. The 5-, 10-, and 20-year OS rates for patients with pancreatic NETs were 67%, 51%, and 36%, respectively. The life expectancy difference (between OS and actuarial survival) after surgical cytoreduction for patients with pancreatic NETs was 16.6 years. Median OS for patients with small bowel NETs was 161 months. The 5-, 10-, and 20-year OS rates for patients with small bowel NETs were 84%, 67% and 31%, respectively. The life expectancy difference after surgical cytoreduction for patients with small bowel NETs was 11.7 years. CONCLUSIONS: Surgical cytoreduction in NET patients has low morbidity and mortality rates and results in prolonged survival. We believe that surgical cytoreduction should play a major role in the care of patients with NETs.