Emerging therapies for advanced gastroenteropancreatic neuroendocrine tumors

Metastatic rectal neuroendocrine tumor presenting as an inguinal mass: A case report and review of literature

•

Neuroendocrine tumors (NETs) are a heterogeneous and relatively rare group of neoplasms that often develop along the gastrointestinal tract.

•

Rectal NETs are usually incidental findings on colonoscopy or present with metastatic disease.

•

Treatment regimens for advanced metastatic rectal NETs are currently being developed.

Introduction

Neuroendocrine tumors (NET) are a heterogeneous group of rare carcinomas that most often manifest along the gastrointestinal tract. Some of these tumors have the ability to secrete vasoactive peptides and hormones.

Presentation of case

The present report describes the case of a previously healthy 52-year old man who presented with a painful right inguinal mass. Upon surgical exploration, a lymph node metastasis of a high-grade NET was found. Further investigations revealed a rectal NET with pulmonary, pelvic and penile metastases.

The patient was treated with 6 cycles of carboplatin and etoposide. Although initial follow-up imaging after 3 cycles of chemotherapy revealed stable disease, there was progression of the metastases after completion of systemic treatment. Second and third-line chemotherapy regimens were instituted along with pelvic and whole-brain radiation therapy extending the patient’s survival to 18 months after the initial diagnosis.

Discussion

This case highlights the aggressive nature high-grade NETs as described in the current literature. Treatment modalities of colorectal NETs include local excision for non-metastatic disease and systemic palliative chemotherapy for advanced disease. However, there are no controlled trials in favor of palliative chemotherapy.

Conclusion

Rectal NETs are rare tumors which often have an atypical presentation or present in advanced stages. Currently, surgical options exist for local disease while treatment modalities for more advanced disease is still under investigation.

Radiation therapy improves survival in rectal small cell cancer - Analysis of Surveillance Epidemiology and End Results (SEER) data

Background

Small cell carcinoma of the rectum is a rare neoplasm with scant literature to guide treatment. We used the Surveillance Epidemiology and End Results (SEER) database to investigate the role of radiation therapy in the treatment of this cancer.

Methods

The SEER database (National Cancer Institute) was queried for locoregional cases of small cell rectal cancer. Years of diagnosis were limited to 1988–2010 (most recent available) to reduce variability in staging criteria or longitudinal changes in surgery and radiation techniques. Two month conditional survival was applied to minimize bias by excluding patients who did not survive long enough to receive cancer-directed therapy. Patient demographics between the RT and No_RT groups were compared using Pearson Chi-Square tests. Overall survival was compared between patients who received radiotherapy (RT, n = 43) and those who did not (No_RT, n = 28) using the Kaplan-Meier method. Multivariate Cox proportional hazards model was used to evaluate important covariates.

Results

Median survival was significantly longer for patients who received radiation compared to those who were not treated with radiation; 26 mo vs. 8 mo, respectively (log-rank P = 0.009). We also noted a higher 1-year overall survival rate for those who received radiation (71.1% vs. 37.8%). Unadjusted hazard ratio for death (HR) was 0.495 with the use of radiation (95% CI 0.286-0.858). Among surgery, radiotherapy, sex and age at diagnosis, radiation therapy was the only significant factor for overall survival with a multivariate HR for death of 0.393 (95% CI 0.206-0.750, P = 0.005).

Conclusions

Using SEER data, we have identified a significant survival advantage with the use of radiation therapy in the setting of rectal small cell carcinoma. Limitations of the SEER data apply to this study, particularly the lack of information on chemotherapy usage. Our findings strongly support the use of radiation therapy for patients with locoregional small cell rectal cancer.

Liver transplantation for metastatic liver malignancies

PURPOSE OF REVIEW

Liver transplantation is a validated treatment of primary hepatobiliary tumours. Over the last decade, a renewed interest for liver transplantation as a curative treatment of colorectal liver metastasis (CR-LM) and neuro-endocrine metastasis (NET-LM) has developed.

RECENT FINDINGS

The ELTR and UNOS analyses showed that liver transplantation may offer excellent disease-free survival (ranging from 30 to 77%) in case of NET-LM, on the condition that stringent selection criteria are implemented. The interest for liver transplantation in the treatment of CR-LM has been fostered by the Norwegian SECA study. Five-year A 5-year survival rate of 60% could be reached. Despite the high recurrence rate (90%), one-third of patients were disease free following pulmonary surgery for metastases.

SUMMARY

Liver transplantation will take a more prominent place in the therapeutic algorithm of CR-LM and NET-LM. Larger experiences are necessary to improve knowledge about tumour biology and to refine selection criteria. A multimodal approach adding neo and adjuvant medical treatment to the transplant procedure will be key to bring this oncologic transplant project into the clinical arena. The preserved liver function in these patients will allow a more deliberate access to split liver and living donation for these indications.

Neuroendocrine tumor disease: an evolving landscape

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) represent a heterogenous group of tumors arising from a variety of neuroendocrine cell types. The incidence and prevalence of GEP-NENs have markedly increased over the last three decades. Symptoms are often absent in early disease, or vague and nonspecific even in advanced disease. Delayed diagnosis is thus common. Chromogranin A is the most commonly used biomarker but has limitations as does the proliferative marker Ki-67%, which is often used for tumor grading and determination of therapy. The development of a multidimensional prognostic nomogram may be valuable in predicting tumor behavior and guiding therapy but requires validation. Identification of NENs that express somatostatin receptors (SSTR) allows for SSTR scintigraphy and positron emission tomography imaging using novel radiolabeled compounds. Complete surgical resection of limited disease or endoscopic ablation of small lesions localized in stomach or rectum can provide cure; however, the majority of GEP-NENs are metastatic (most frequently the liver and/or mesenteric lymph nodes) at diagnosis. Selected patients with metastatic disease may benefit from advanced surgical techniques including hepatic resection or liver transplantation. Somatostatin analogs are effective for symptomatic treatment and exhibit some degree of antiproliferative activity in small intestinal NENs. There is a place for streptozotocin, temozolomide, and capecitabine in the management of pancreatic NENs, while new agents targeting either mTOR (everolimus) or angiogenic (sunitinib) pathways have shown efficacy in these lesions.