Meike Körner

TNM staging of foregut (neuro)endocrine tumors: a consensus proposal including a grading system

The need for standards in the management of patients with endocrine tumors of the digestive system prompted the European Neuroendocrine Tumor Society (ENETS) to organize a first Consensus Conference, which was held in Frascati (Rome) and was based on the recently published ENETS guidelines on the diagnosis and treatment of digestive neuroendocrine tumors (NET). Here, we report the tumor–node–metastasis proposal for foregut NETs of the stomach, duodenum, and pancreas that was designed, discussed, and consensually approved at this conference. In addition, we report the proposal for a working formulation for the grading of digestive NETs based on mitotic count and Ki-67 index. This proposal, which needs to be validated, is meant to help clinicians in the stratification, treatment, and follow-up of patients.

TNM staging of midgut and hindgut (neuro) endocrine tumors: a consensus proposal including a grading system

Criteria for the staging and grading of neuroendocrine tumors (NETs) of midgut and hindgut origin were established at the second Consensus Conference in Frascati (Rome) organized by the European Neuroendocrine Tumor Society (ENETS). The proposed tumor–node–metastasis (TNM) classifications are based on the recently published ENETS Guidelines for the Diagnosis and Treatment of gastroenteropancreatic NETs and follow our previous proposal for foregut tumors. The new TNM classifications for NETs of the ileum, appendix, colon, and rectum, and the grading system were designed, discussed, and consensually approved by all conference participants. These proposals need to be validated and are meant to help clinicians in the stratification, treatment and follow-up of patients.

GLP-1 Receptor Expression in Human Tumors and Human Normal Tissues: Potential for In Vivo Targeting

Peptide hormone receptors overexpressed in human tumors, such as somatostatin receptors, can be used for in vivo targeting for diagnostic and therapeutic purposes. A novel promising candidate in this field is the GLP-1 receptor, which was recently shown to be massively overexpressed in gut and lung neuroendocrine tumors—in particular, in insulinomas. Anticipating a major development of GLP-1 receptor targeting in nuclear medicine, our aim was to evaluate in vitro the GLP-1 receptor expression in a large variety of other tumors and to compare it with that in nonneoplastic tissues. Methods: The GLP-1 receptor protein expression was qualitatively and quantitatively investigated in a broad spectrum of human tumors (n = 419) and nonneoplastic human tissues (n = 209) with receptor autoradiography using 125I-GLP-1(7–36)amide. Pharmacologic competition experiments were performed to provide proof of specificity of the procedure. Results: GLP-1 receptors were expressed in various endocrine tumors, with particularly high amounts in pheochromocytomas, as well as in brain tumors and embryonic tumors but not in carcinomas or lymphomas. In nonneoplastic tissues, GLP-1 receptors were present in generally low amounts in specific tissue compartments of several organs—namely, pancreas, intestine, lung, kidney, breast, and brain; no receptors were identified in lymph nodes, spleen, liver, or the adrenal gland. The rank order of potencies for receptor binding—namely, GLP-1(7–36)amide = exendin-4 ≫ GLP-2 = glucagon(1–29)—provided proof of specific GLP-1 receptor identification. Conclusion: The GLP-1 receptors may represent a novel molecular target for in vivo scintigraphy and targeted radiotherapy for a variety of GLP-1 receptor-expressing tumors. For GLP-1 receptor scintigraphy, a low-background signal can be expected, on the basis of the low receptor expression in the normal tissues surrounding tumors.

Consensus guidelines for the management of patients with liver metastases from digestive (neuro)endocrine tumors: Foregut, midgut, hindgut, and unknown primary

a DRK Kliniken Westend, Berlin , Germany; b UFR Bichat-Beaujon-Louis Mourier, Service de Chirurgie Digestive, Hopital Louis Mourier, Colombes , France; c Medicine and Surgery, General Surgery Section, MED/18 – General Surgery and d Department of Pathology, University of Verona, Verona , Italy; e Netherlands Cancer Centre, Amsterdam , and f Department of Nuclear Medicine, Erasmus University Medical Center, Rotterdam , The Netherlands;

Consensus guidelines for the management of patients with digestive neuroendocrine tumors - Well-differentiated jejunal-ileal tumor/carcinoma

Consensus guidelines for the management of patients with digestive neuroendocrine tumors : well-differentiated jejunal-ileal tumor/carcinoma

High expression of peptide receptors as a novel target in gastrointestinal stromal tumours

Recent significant advances in understanding the biology of gastrointestinal stromal tumours (GIST) have led to the introduction of a new targeted therapy (imatinib mesylate, Glivec). Hopes of a new era of a specific cancer therapy, however, have been tempered by the recognition that a significant proportion of patients who initially respond to the drug eventually become resistant to it. Given the successful development of peptide receptor scintigraphy and radiotherapy for neuroendocrine tumours, we postulated that a similar approach could offer a valid alternative in the diagnosis and therapy of GIST. Using in vitro receptor autoradiography to measure peptide receptors, we found that 16/19 GIST expressed bombesin subtype 2 receptors, 16/19 expressed vasoactive intestinal peptide subtype 2 receptors (VPAC2) and 12/19 expressed cholecystokinin subtype 2 receptors, in most cases in extremely high densities. All GIST metastases were shown to express two or more of these peptide receptors in very high density. Receptors were also expressed in non-responders to Glivec or after chemo-embolisation. Conversely, somatostatin subtype 2, cholecystokinin subtype 1, bombesin subtype 1 and 3, and neuropeptide Y subtype Y1 and Y2 receptors were not or only rarely expressed. These data represent a strong molecular basis for the use of radiolabelled bombesin, vasoactive intestinal peptide and/or cholecystokinin analogues as targeting agents to localise GIST tumours in patients by in vivo scintigraphy and/or to perform targeted radiotherapy to destroy GIST primaries, metastases and recurrences, including those resistant to Glivec.

Consensus guidelines for the management of patients with digestive neuroendocrine tumours: Well-differentiated colon and rectum tumour/carcinoma

a Department of Gastroenterology, North Hampshire Hospital, Basingstoke , UK; b Stadtisches Klinikum Neuss, Lukaskrankenhaus, Chirurgische Klinik I, Neuss , Germany; c Istituto di Radiologia, Policlinco GB Rossi, Verona , Italy; d Institute for Pathology, Kantonsspital, Baden , Switzerland; e Departments of Internal Medicine and Endocrinological and Metabolic Sciences, University of Genoa, Genoa , Italy; f II. Internal Medical Department, University Hospital Martin, Martin , Slovakia; g G. Genimatas Hospital, Athens , Greece; h Erciyes University Medical School, Department of Endocrinology and Metabolism, Kayseri , Turkey; i H. Lee Moffitt Cancer Center/ University of South Florida, Tampa, Fla. , USA; j Anatomie Pathologique, Hopital Edouard Herriot, Lyon , France;

Somatostatin receptor subtype 2A immunohistochemistry using a new monoclonal antibody selects tumors suitable for in vivo somatostatin receptor targeting.

High overexpression of somatostatin receptors in neuroendocrine tumors allows imaging and radiotherapy with radiolabeled somatostatin analogues. To ascertain whether a tumor is suitable for in vivo somatostatin receptor targeting, its somatostatin receptor expression has to be determined. There are specific indications for use of immunohistochemistry for the somatostatin receptor subtype 2A, but this has up to now been limited by the lack of an adequate reliable antibody. The aim of this study was to correlate immunohistochemistry using the new monoclonal anti-somatostatin receptor subtype 2A antibody UMB-1 with the gold standard in vitro method quantifying somatostatin receptor levels in tumor tissues. A UMB-1 immunohistochemistry protocol was developed, and tumoral UMB-1 staining levels were compared with somatostatin receptor binding site levels quantified with in vitro 125I-[Tyr3]-octreotide autoradiography in 89 tumors. This allowed defining an immunohistochemical staining threshold permitting to distinguish tumors with somatostatin receptor levels high enough for clinical applications from those with low receptor expression. The presence of >10% positive tumor cells correctly predicted high receptor levels in 95% of cases. In contrast, absence of UMB-1 staining truly reflected low or undetectable somatostatin receptor expression in 96% of tumors. If 1% to 10% of tumor cells were stained, a weak staining intensity was suggestive of low somatostatin receptor levels. This study allows for the first time a reliable recommendation for eligibility of an individual patient for in vivo somatostatin receptor targeting based on somatostatin receptor immunohistochemistry. Under optimal methodological conditions, UMB-1 immunohistochemistry may be equivalent to in vitro receptor autoradiography.

NPY receptors in human cancer: a review of current knowledge.

Many peptide hormone receptors are over-expressed in human cancer, permitting an in vivo targeting of tumors for diagnostic and therapeutic purposes. NPY receptors are novel and promising candidates in this field. Using in vitro receptor autoradiography, Y1 and Y2 receptors have been found to be expressed in breast carcinomas, adrenal gland and related tumors, renal cell carcinomas, and ovarian cancers in both tumor cells and tumor-associated blood vessels. Pathophysiologically, tumoral NPY receptors may be activated by endogenous NPY released from intratumoral nerve fibers or tumor cells themselves, and mediate NPY effects on tumor cell proliferation and tumoral blood supply. Clinically, tumoral NPY receptors may be targeted with NPY analogs coupled with adequate radionuclides or cytotoxic agents for a scintigraphic tumor imaging and/or tumor therapy.

Evaluation of Histologic, Serologic, and Clinical Changes in Response to Abatacept Treatment of Primary Sjögren's Syndrome: A Pilot Study

To prospectively evaluate histopathologic, blood cellular, serologic, and clinical changes in response to abatacept treatment in patients with primary Sjögrens syndrome (SS).