VP-16, Cyclophosphamide, Adriamycin and Cis-platinum (V:CAP-I) in Patients with Metastatic Adenocarcinoma of the Lung

In an attempt to improve upon the 42% regression rate of the CAP-I regimen in patients with advanced adenocarcinoma of the lung, VP-16 was added to that regimen. VP-16, as a single agent, had a response rate of 12.5% (3/24) in a similar group of patients. The new regimen, V:CAP-I, had a tumor regression rate of 35% (7/20) and an estimated median survival of 171 days. Hence, we were unable to conclude that the addition of VP-16 to the CAP-I regimen statistically improved the regression rate of the CAP-I regimen.

Multimodality management of borderline resectable pancreatic neuroendocrine tumors: Sentinel report of a single-institutional experience

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Background: Pancreatic neuroendocrine tumors (PNET) constitute about 3% of pancreatic neoplasms. In borderline resectable disease, there is a lack of data to support an optimal neoadjuvant approach for curative outcomes. We describe our institutional experience with a multimodality approach. Methods: We identified all patients with borderline resectable PNET, using NCCN criteria for adenocarcinoma of the pancreas, who received neoadjuvant therapy at our institution between 2000 and 2013. The reason for borderline status was noted. Neoadjuvant regimen, radiographic response, pathologic response, surgical margins, nodal harvest, number of positive nodes, and recurrence were all documented. Results: A total of 112 patients had undergone pancreatic resections for neuroendocrine tumors during the study period. Six patients had borderline resectable disease. The mean age was 55 years (24-70). They all received at least 1 cycle of Temodar and Xeloda. Three of the six patients also received concurrent 5-FU and radiation. There was radiographic evidence of treatment response in all patients. Five of six patients (83 %) had negative margin (R0) resection. Low volume miliary metastatic disease in the liver was detected in 1 patient at the time of surgery. The median number of lymph nodes harvested was 12. Half of the patients had node positive disease. On pathologic review, 4 patients had histologic evidence of a moderate response. All patients are alive and 5/6 are free of disease. Range of follow up is 3.0-4.32 years. The patient with metastatic disease has had no progression and is the only one who is currently receiving any form of treatment. Conclusions: Neoadjuvant Temodar and Xeloda ± radiation with 5-FU sensitization can lead to R0 resection with durable response in patients with borderline resectable PNET. To our knowledge, this is the first report of the use of multimodality therapy (neoadjuvant chemotherapy ± chemoradiation and surgery) in the treatment of borderline resectable PNET.

Impact of Previous Somatostatin Analogue Use on the Activity of Everolimus in Patients with Advanced Neuroendocrine Tumors: Analysis from the Phase III RADIANT-2 Trial

BACKGROUND/AIMS

The phase III placebo-controlled RADIANT-2 trial investigated the efficacy of everolimus plus octreotide long-acting repeatable (LAR) in patients with advanced neuroendocrine tumors (NET) associated with carcinoid syndrome. Here we report a secondary analysis based on the previous somatostatin analogue (SSA) exposure status of patients enrolled in RADIANT-2.

METHODS

Patients were randomly assigned to receive oral everolimus 10 mg/day plus octreotide LAR 30 mg intramuscularly (i.m.) or to receive matching placebo plus octreotide LAR 30 mg i.m. every 28 days. SSA treatment before study enrollment was permitted. Patient characteristics and progression-free survival (PFS) were analyzed by treatment arm and previous SSA exposure status.

RESULTS

Of the 429 patients enrolled in RADIANT-2, 339 were previously exposed to SSA (95% received octreotide); 173 of 339 patients were in the everolimus plus octreotide LAR arm. All patients had a protocol-specified history of secretory symptoms, but analysis by type showed that more patients who previously received SSA therapy had a history of flushing symptoms (77%), diarrhea (86%), or both (63%) compared with SSA-naive patients (62, 62, and 24%, respectively). Patients who received everolimus plus octreotide LAR had longer median PFS regardless of previous SSA exposure (with: PFS 14.3 months, 95% confidence interval, CI, 12.0-20.1; without: 25.2 months, 95% CI, 12.0-not reached) compared with patients who received placebo plus octreotide LAR (with: 11.1 months, 95% CI, 8.4-14.6; without: 13.6 months, 95% CI, 8.2-22.7).

CONCLUSION

Everolimus in combination with octreotide improves PFS in patients with advanced NET associated with carcinoid syndrome, regardless of previous SSA exposure.

GEPNETs update: Radionuclide therapy in neuroendocrine tumors

Peptide receptor radionuclide therapy (PRRT) is a promising new treatment modality for inoperable or metastasized gastroenteropancreatic neuroendocrine tumors (GEPNETs) patients. Most studies report objective response rates in 15-35% of patients. Also, outcome in terms of progression free survival (PFS) and overall survival compares very favorably with that for somatostatin analogs, chemotherapy, or new, 'targeted' therapies. They also compare favorably to PFS data for liver-directed therapies. Two decades after the introduction of PRRT, there is a growing need for randomized controlled trials comparing PRRT to 'standard' treatment, that is treatment with agents that have proven benefit when tested in randomized trials. Combining PRRT with liver-directed therapies or with targeted therapies could improve treatment results. The question to be answered, however, is whether a combination of therapies performed within a limited time-span from one another results in a better PFS than a strategy in which other therapies are reserved until after (renewed) tumor progression. Randomized clinical trials comparing PRRT with other treatment modalities should be undertaken to determine the best treatment options and treatment sequelae for patients with GEPNETs.

Predictors of lymph node metastases and impact on survival in resected pancreatic neuroendocrine tumors: a single-center experience

BACKGROUND

Staging for pancreatic neuroendocrine tumors (PNET) considers tumor size and lymph node (LN) status; however, correlation with survival remains unclear.

METHODS

A single-institution database of patients with resected PNET was analyzed.

RESULTS

Of the 150 patients, incidentally discovered PNET was the most common presentation (42%). One hundred thirteen patients (75%) had LN data, 32 (28%) with positive LN (LN+). Procedure and tumor size did not predict LN+. Perineural invasion (P = .016) and lymphovascular (P < .001) invasion, however, were more common in LN+. Multivariate analysis showed poor/moderate differentiation predicted LN+. Median follow-up was 52 months and median overall survival was 225 months. Fifty-two patients (35%) developed recurrence and median disease-free survival (DFS) was 74 months. Only poor/moderate differentiation affected DFS.

CONCLUSIONS

PNET has an unclear prognosis based on variables factored into stage. In this study, tumor size did not predict LN+; furthermore, LN+ did not impact overall survival or DFS. Tumor differentiation appears to be more important in determining prognosis.

Peptide receptor radionuclide therapy with 177Lu-DOTATATE for patients with somatostatin receptor-expressing neuroendocrine tumors: the first US phase 2 experience

OBJECTIVE

Peptide receptor radionuclide therapy with radiolabeled somatostatin analogs is a novel method of treatment in patients with metastatic neuroendocrine tumors (NETs). For the first time in the United States, we present preliminary results of the treatment with Lutetium (177)(Lu) DOTATATE in patients with progressive NETs.

METHODS

Thirty-seven patients with grade 1 and grade 2 disseminated and progressive gastroenteropancreatic NET were enrolled in a nonrandomized, phase 2 clinical trial. Repeated cycles of 200 mCi (7.4 GBq; ±10%) were administered up to the cumulative dose of 800 mCi (29.6 GBq; ±10%).

RESULTS

Among 32 evaluable patients, partial response and minimal response to treatment were seen in 28% and 3%, respectively, and stable disease was seen in 41% of patients. A total of 28% had progressive disease. A response to treatment was significantly associated with lower burden of disease in the liver. No significant acute or delayed hematologic or kidney toxicity was observed. An impressive improvement of performance status and quality of life were seen after Lu-DOTATATE therapy.

CONCLUSIONS

Treatment with multiple cycles of (177)Lu-DOTATATE peptide receptor radionuclide therapy is well tolerated. This treatment results in control of the disease in most patients, whereas systemic toxicities are limited and reversible. Quality of life is also improved.

A multi-institutional, phase II open-label study of ganitumab (AMG 479) in advanced carcinoid and pancreatic neuroendocrine tumors

The IGF pathway has been implicated in the regulation of neuroendocrine tumor (NET) growth, and preliminary studies suggested that ganitumab (AMG 479), a human MAB against IGF1R, may have antitumor activity in this setting. We performed a two-cohort phase II study of ganitumab in patients with metastatic progressive carcinoid or pancreatic NETs (pNETs). This open-label study enrolled patients (≥18 years) with metastatic low- and intermediate-grade carcinoid or pNETs. Inclusion criteria included evidence of progressive disease (by Response Evaluation Criteria in Solid Tumors (RECIST)) within 12 months of enrollment, ECOG PS 0-2, and fasting blood sugar <160  mg/dl. Prior treatments were allowed and concurrent somatostatin analog therapy was permitted. The primary endpoint was objective response. Secondary endpoints included overall survival (OS), progression-free survival (PFS), and safety. Sixty patients (30 carcinoid and 30 pNETs) were treated with ganitumab 18  mg/kg every 3 weeks, among whom 54 patients were evaluable for survival and 53 patients for response. There were no objective responders by RECIST. The median PFS duration was 6.3 months (95% CI, 4.2-12.6) for the entire cohort; 10.5 months for carcinoid patients, and 4.2 months for pNET patients. The OS rate at 12 months was 66% (95% CI, 52-77%) for the entire cohort. The median OS has not been reached. Grade 3/4 AEs were rare and consisted of hyperglycemia (4%), neutropenia (4%), thrombocytopenia (4%), and infusion reaction (1%). Although well tolerated, treatment with single-agent ganitumab failed to result in significant tumor responses among patients with metastatic well-differentiated carcinoid or pNET.

Prognostic validity of the American Joint Committee on Cancer staging classification for midgut neuroendocrine tumors

PURPOSE

The American Joint Committee on Cancer (AJCC) staging manual has introduced a TNM staging classification for jejunal-ileal (midgut) neuroendocrine tumors (NETs). This classification has not been validated in a population consisting solely of midgut NETs. The purpose of this study was to test the prognostic validity of the classification in such a population.

METHODS

Patients with jejunal and ileocecal NETs who were treated at the Moffitt Cancer Center between 2000 and 2010 were assigned stages (I through IV). Kaplan-Meier analyses for overall survival (OS) were performed on the basis of TNM stage and pathologic grade. Multivariate modeling was performed using Cox proportional hazards regression.

RESULTS

We identified 691 patients with jejunal-ileocecal NETs. The AJCC classification in aggregate was highly prognostic for OS (P < .001). Five-year OS rates for stages I through IV were 100%, 100%, 91%, and 72%, respectively. The survival difference between stages III and IV was significant (P < .001); the difference between stages I/II versus III was not statistically significant (P = .1). Among patients with stage IIIB tumors, 5-year survival rates were 95% for resectable tumors versus 78% for unresectable mesenteric tumors (P = .02). A proliferative threshold of five mitoses per 10 high-power fields (HPF) was of greater prognostic value than a threshold of two mitoses per 10 HPF for discriminating between low- and intermediate-grade tumors.

CONCLUSION

Stage I and II midgut NETs are associated with identical survival rates. Stage IIIB tumors are heterogeneous, with significant differences in survival observed between resectable mesenteric lymph nodes versus unresectable masses in the root of the mesentery. A higher mitotic cutoff of five per 10 HPF may lead to improved prognostic differentiation between low- and intermediate-grade tumors. Revisions to the current AJCC staging and grading classification may be warranted.

Pasireotide (SOM230) shows efficacy and tolerability in the treatment of patients with advanced neuroendocrine tumors refractory or resistant to octreotide LAR: results from a phase II study

Pasireotide (SOM230) is a novel multireceptor-targeted somatostatin (sst) analog with high binding affinity for sst receptor subtype 1, 2, 3 (sst(1,2,3)) and sst(5). Because of this binding profile, pasireotide may offer symptom control in patients with neuroendocrine tumors (NETs) and carcinoid syndrome no longer responsive to octreotide LAR. This was a phase II, open-label, multicenter study of pasireotide in patients with advanced NET whose symptoms of carcinoid syndrome (diarrhea/flushing) were inadequately controlled by octreotide LAR. Patients received s.c. pasireotide 150 μg twice daily (bid), escalated to a maximum dose of 1200 μg bid until a clinical response was achieved. Forty-four patients were evaluated for efficacy and 45 for tolerability. Pasireotide 600-900 μg s.c. bid effectively controlled the symptoms of diarrhea and flushing in 27% of patients. Evaluation of tumor response in 23 patients showed 13 with stable disease and ten with progressive disease at study end. The most common drug-related adverse events were nausea (27%), abdominal pain (20%), weight loss (20%), and hyperglycemia (16%) and most were of mild or moderate severity. Pasireotide 600-900 μg s.c. bid was effective and generally well tolerated in controlling the symptoms of carcinoid syndrome in 27% of patients with advanced NET refractory or resistant to octreotide LAR therapy.

A phase II clinical trial of sunitinib following hepatic transarterial embolization for metastatic neuroendocrine tumors

BACKGROUND

The liver is the predominant site of metastases among patients with advanced neuroendocrine tumors (NETs). Prior retrospective studies have reported high response rates in patients treated with transarterial embolization (TAE). NETs are highly vascular and are known to express vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor (VEGFR). We hypothesized that administration of sunitinib, a VEGFR inhibitor, following TAE would extend progression-free survival (PFS).

PATIENTS AND METHODS

Patients with metastatic NETs to the liver underwent a series of selective TAEs followed by sunitinib (until disease progression or maximum of 12 months). Radiographic response (by RECIST), survival, and safety parameters were monitored.

RESULTS

Thirty-nine patients were enrolled. The overall response rate was 72% [95% confidence interval (CI), 0.58-0.86]. Median PFS was 15.2 months. Rates of overall survival (OS) at 1 and 4 years were 95% (95% CI, 0.88-1.00) and 59% (95% CI, 0.38-0.80), respectively. A significant 34% rise in serum VEGF was observed following the initial TAE (P = 0.03).

CONCLUSIONS

Hepatic TAE is a highly active treatment option for patients with metastatic NETs to the liver. Embolization stimulates release of VEGF into the circulation. Sunitinib, an oral VEGFR inhibitor, can be safely administered following embolization. The high rates of PFS and OS associated with this sequence of therapies are encouraging.

Palladin is a marker of liver metastasis in primary pancreatic endocrine carcinomas

BACKGROUND

Palladin is a metastasis-associated gene regulating cell motility. The expression of palladin protein in pancreatic neuroendocrine tumors (PET) and carcinomas (PECA) is not known.

MATERIALS AND METHODS

A tissue microarray (TMA) of well-differentiated (WD) PETs/PECAs (AJCC 2010) and non-neoplastic, histologically normal pancreatic tissue/islets (HNPIs) was immunostained with palladin antibody and quantified using the Allred score. The results were correlated with the presence or absence of liver metastases.

RESULTS

The retrospective study included 19 males and 19 females of age 27-79 years (mean 54). Tumor size was 0.9-11.5 cm (mean 3.8). Palladin expression was cytoplasmic and/or membranous. The tumors with high palladin expression were associated with liver metastasis (p<0.0001). All 14 primary PECA with hepatic metastases (MP-PECAs) exhibited palladin expression whereas 14 out of 24 (58%) clinically-localized primary PET (CLP-PETs) expressed palladin (p<0.01) with median Allred scores of 5 (range 3-7) and 2 (range 0-6) respectively (p<0.0001). The mean Allred score for the HNPIs in the MP-PECAs (N=6) was higher (4.2) as compared to that in the CLP-PETs (2.5,N=11) (p=0.23).

CONCLUSION

Palladin may identify primary pancreatic endocrine neoplasms with a propensity to metastasize to the liver.

Prognostic validity of a novel American Joint Committee on Cancer Staging Classification for pancreatic neuroendocrine tumors

PURPOSE

The American Joint Committee on Cancer (AJCC) staging manual (seventh edition) has introduced its first TNM staging classification for pancreatic neuroendocrine tumors (NETs) derived from the staging algorithm for exocrine pancreatic adenocarcinomas. This classification has not yet been validated.

METHODS

Patients with pancreatic NETs treated at the H. Lee Moffitt Cancer Center between 1999 and 2010 were assigned a stage (I to IV) based on the new AJCC classification. Kaplan-Meier analyses for overall survival (OS) were performed based on age, race, histologic grade, incidental diagnosis, and TNM staging (European Neuroendocrine Tumors Society [ENETS] v AJCC) using log-rank tests. Survival time was measured from time of initial diagnosis to date of last contact or date of death. Multivariate modeling was performed using Cox proportional hazards regression. Weighted Cohen's κ coefficient was computed to evaluate the agreement of ENETS and AJCC classifications.

RESULTS

We identified 425 patients with pancreatic NETs. On the basis of histopathologic grade, 5-year survival rates for low-, intermediate-, and high-grade tumors were 75%, 62%, and 7%, respectively (P < .001). When using the ENETS classification, 5-year OS rates for stages I, II, III, and IV were 100%, 88%, 85%, and 57%, respectively (P < .001). Subsequently, using the AJCC classification, 5-year OS rates for stages I, II, III, and IV were 92%, 84%, 81%, and 57%, respectively (P < .001). Both the novel AJCC classification and the ENETS classification were highly prognostic for survival.

CONCLUSION

The AJCC TNM classification for pancreatic NETs is prognostic for OS and can be adopted in clinical practice.

Recent progress in the understanding, diagnosis, and treatment of gastroenteropancreatic neuroendocrine tumors

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are relatively rare tumors that arise from the diffuse neuroendocrine system. This heterogeneous group of tumors was often considered a single entity. This belied their biological diversity, and the biggest advance in understanding these tumors over the past decades has been in understanding this diversity. Diagnosis of these tumors has been aided by advances in pathological diagnosis and classification and tumor imaging with endoscopic ultrasound and somatostatin receptor fusion imaging. Genetic and molecular advances have identified molecular targets in the treatment of these tumors. Surgery remains the mainstay of treatment, amply supported by interventional radiological techniques, including embolization. Treatment of metastatic disease has improved significantly with the addition of several new agents, including tyrosine kinase inhibitors, mammalian target of rapamycin inhibitors, and yttrium-90-DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) and lutetium-177-DOTA octreotate. Despite significant advances in the understanding and management of GEP-NETs, the survival of patients remains largely unchanged and there remains a need for the development of national and international research collaborations to spearhead future efforts.

Daily oral everolimus activity in patients with metastatic pancreatic neuroendocrine tumors after failure of cytotoxic chemotherapy: a phase II trial

PURPOSE No established treatment exists for pancreatic neuroendocrine tumor (NET) progression after failure of chemotherapy. Everolimus (RAD001), an oral inhibitor of mammalian target of rapamycin, in combination with octreotide has demonstrated encouraging antitumor activity in patients with NETs. PATIENTS AND METHODS This open-label, phase II study assessed the clinical activity of everolimus in patients with metastatic pancreatic NETs who experienced progression on or after chemotherapy. Patients were stratified by prior octreotide therapy (stratum 1: everolimus 10 mg/d, n = 115; stratum 2: everolimus 10 mg/d plus octreotide long-acting release [LAR], n = 45). Tumor assessments (using Response Evaluation Criteria in Solid Tumors) were performed every 3 months. Chromogranin A (CgA) and neuron-specific enolase (NSE) were assessed monthly if elevated at baseline. Trough concentrations of everolimus and octreotide were assessed. Results By central radiology review, in stratum 1, there were 11 partial responses (9.6%), 78 patients (67.8%) with stable disease (SD), and 16 patients (13.9%) with progressive disease; median progression-free survival (PFS) was 9.7 months. In stratum 2, there were two partial responses (4.4%), 36 patients (80%) with SD, and no patients with progressive disease; median PFS was 16.7 months. Patients with an early CgA or NSE response had a longer PFS compared with patients without an early response. Coadministration of octreotide LAR and everolimus did not impact exposure to either drug. Most adverse events were mild to moderate and were consistent with those previously seen with everolimus. CONCLUSION Daily everolimus, with or without concomitant octreotide LAR, demonstrates antitumor activity as measured by objective response rate and PFS and is well tolerated in patients with advanced pancreatic NETs after failure of prior systemic chemotherapy.

A review of the current clinical trials for gastroenteropancreatic neuroendocrine tumours

Neuroendocrine tumours of the gastroenteropancreatic axis include carcinoid tumours and islet cell tumours of the pancreas (pancreatic endocrine tumours). Standard medical therapies prescribed for these malignancies include long-acting somatostatin analogues (octreotide and lanreotide) for the palliation of hormonal syndromes; cytotoxic agents (streptozocin, dacarbazine, adriamycin and 5-fluorouracil), which are primarily for the management of advanced islet cell tumours; and hepatic artery embolisation or chemoembolisation for the treatment of liver metastases. Clinical research promises to expand this therapeutic armamentarium. Most of the experimental treatments that are being evaluated in human clinical trials fall into the following categories: angiogenesis inhibitors, novel somatostatin analogues, radiolabelled somatostatin analogues, mTOR inhibitors and novel cytotoxic agents. This review summarises the present scope of clinical research in this field.

Intermittent bowel obstruction due to a retained wireless capsule endoscope in a patient with a small bowel carcinoid tumour

A 43-year-old man with a history of metastatic carcinoid disease is presented. The patient had symptoms of chronic intermittent abdominal pain two years after undergoing a wireless capsule endoscopy procedure. Radiological examinations revealed a retained capsule endoscope, and the patient underwent exploratory laparotomy with capsule retrieval. To the authors' knowledge, this is the first case presentation of chronic, partial small bowel obstruction caused by unrecognized retention of a capsule endoscope.

Role of somatostatin analogs in the clinical management of non-neuroendocrine solid tumors

The somatostatin analogs octreotide, lanreotide and RC-160 (vapreotide) are known to have direct and indirect antitumor effects. Direct effects include the arrest of tumor growth and stimulation of apoptosis, resulting in tumor shrinkage. Indirect antiproliferative effects may occur through antiangiogenesis, immunomodulatory effects and the suppression of tumor-stimulating growth factors. With a safety profile of somatostatin analogs established over 20 years of clinical use in the treatment of neuroendocrine tumors, somatostatin analogs are attractive therapeutic options for patients with non-neuroendocrine tumors. In early clinical trials of somatostatin analogs, however, some cancer patients responded well, while others showed a lack of benefit. This variability in clinical response may reflect the selective binding affinities of octreotide, lanreotide and RC-160, which bind with high affinity to just two of the five different somatostatin receptor subtypes. Treatment response may therefore depend on the specific receptor subtype(s) present in the tumor, the relative proportion of receptor(s) expressed on the tumor cell surface and the absolute quantity of each receptor subtype. Greater understanding of the role of somatostatin receptors, their binding affinities and modes of action has led to increased research into the use of somatostatin analogs, particularly octreotide, in cancer treatment as monotherapies, in combination with hormonal treatments and cytotoxic therapies, and in both adjuvant and neoadjuvant settings. A review of the literature suggests that the antitumor potential of somatostatin analogs should be investigated further and additional studies might determine how these analogs can best be used to improve the treatment of patients with non-neuroendocrine tumors.

Survival and response after peptide receptor radionuclide therapy with [90Y-DOTA0,Tyr3]octreotide in patients with advanced gastroenteropancreatic neuroendocrine tumors

Because the role of chemotherapy, interferon, or somatostatin analogs as antiproliferative agents is uncertain, currently few treatment options exist for patients with metastatic or inoperable gastroenteropancreatic neuroendocrine tumors (GEP-NET). Fifty-eight patients with somatostatin receptor-positive GEP-NET were treated in a phase I dose-escalating study with cumulative doses of 47 mCi to 886 mCi of the radiolabeled somatostatin analog [(90)Y-DOTA(0),Tyr(3)]-octreotide. At baseline, 47 patients had progressive disease, and 36 were symptomatic. The extent of disease was: 4 patients without liver metastases and 52 patients with liver metastases, including 16 patients with very advanced disease, qualified as "end-stage," and 2 end-stage patients without liver metastases. The objective responses were 5 partial response (PR), 7 minor response (MR), 29 stable disease (SD), and 17 PD. Overall, 33 patients (57%) experienced some improvement in their disease status, including conversion from PD into SD and improvement from SD into MR. Accordingly, 21 of 36 patients (58%) had improvement in Karnofsky performance score or symptoms. The median overall survival (OS) was 36.7 months (95% confidence interval [CI] 19.4-54.1 months). The median progression-free survival in 41 patients who had at least stable disease at the end of the treatment period was 29.3 months (95% CI 19.3-39.3 months). Patients who had SD at baseline had a significantly better OS than patients who had PD at baseline. The extent of disease at baseline also was a significant predictive factor for OS. The OS after therapy with [(90)Y-DOTA(0),Tyr(3)]-octreotide was significantly better than in a historic control group of 32 comparable patients with GEP-NET who had been treated with another radiolabeled somatostatin analog, [(111)In-DTPA(0)]-octreotide (median OS 12.0 months, 95% CI 6.2-17.8 months). The difference in OS for both therapies remained highly significant in a multivariate Cox proportional hazard model including progression status and extent of disease at baseline as covariates. Although the objective response after therapy with [(90)Y-DOTA(0),Tyr(3)]-octreotide by standard criteria seems modest, the significantly longer OS compared with historic controls is most encouraging.

Selective hepatic artery embolization for treatment of patients with metastatic carcinoid and pancreatic endocrine tumors

BACKGROUND

Prognosis in patients with carcinoid and pancreatic endocrine tumors with diffuse, unresectable liver metastases is poor. Palliation is often difficult despite the use of somatostatin analogs, interferon alpha, or systemic chemotherapy. Several reviews have suggested that hepatic artery embolization, with or without intraarterial chemotherapy, can be used for control of symptoms and for cytoreduction in patients with liver dominant metastases.

METHODS

Between 2000 and 2002, 161 embolizations using polyvinyl alcohol or microspheres were performed on 84 patients with carcinoid or pancreatic endocrine tumors metastatic to the liver. A retrospective review was performed to evaluate symptomatic response, biochemical response, adverse effects, and duration of survival. Baseline and follow-up computed tomography scans were also assessed to determine radiographic response rates. Further analysis of survival was performed to assess the possible impact of various postembolization therapies.

RESULTS

Eighty-four patients underwent bland hepatic artery embolizations during the study period. Among 55 symptomatic patients, 44 patients had fewer symptoms, and among 35 patients whose tumor markers were followed, 28 had a major biochemical response. Objective radiographic responses were observed in 11 of 23 patients. No deaths occurred during therapy, and major toxicities were rare. Median overall survival was 36 months from time of initial embolization.

CONCLUSIONS

Hepatic artery embolization frequently results in clinical and radiographic responses in patients with unresectable liver metastases from carcinoid or pancreatic endocrine tumors. Morbidity is low when appropriate supportive care is provided. Hepatic artery embolization often results in regressions in patients with unresectable liver metastases from carcinoid or pancreatic endocrine tumors.

Somatostatin receptor profiling in hepatic metastases from small intestinal and pancreatic neuroendocrine neoplasms: immunohistochemical approach with potential clinical utility

BACKGROUND

The expression of somatostatin receptors (SSTRs) on endocrine tumor (ET) cells forms the basis for somatostatin analog treatment of patients with SSTR-positive, hormonally active ETs. In patients with SSTR-negative ETs, the clinical response is generally absent or suboptimal, while nonfunctioning ETs with SSTR positivity show a variable response to such therapy.

METHODS

We retrospectively studied SSTR subtype expression in hepatic metastases from 14 adult patients with primary endocrine carcinomas (ECAs) of the small intestine and pancreas and compared SSTR subtype expression among the primary and metastatic ECAs. Polyclonal antibodies against the 5 SSTR subtypes were used on formalin-fixed, paraffin sections from each primary and metastatic ECA. Both qualitative and semiquantitative evaluation of the stained ECA sections was carried out.

RESULTS

Eleven (61%) of 18 hepatic metastases from small intestinal and pancreatic ECAs were positive for SSTR-1, 15 (83%) for SSTR-2, 13 (72%) for SSTR-3, 10 (56%) for SSTR-4, and 15 (83%) for SSTR-5. Among 11 hepatic ECA metastases from small intestinal ECAs (carcinoids), 7 (63%) expressed SSTR-1, 9 (81%) expressed SSTR-2, 8 (72%) expressed SSTR-3, 6 (54%) expressed SSTR-4, and 10 (91%) expressed SSTR-5. Of 7 hepatic ECA metastases from pancreatic ECAs, 4 expressed SSTR-1, 6 expressed SSTR-2, and 5 expressed SSTR-3 and SSTR-5 each. We also observed the immunohistochemical evidence of heterogeneity of expression of various SSTR subtypes in the primary enteropancreatic ECAs and their hepatic metastases.

CONCLUSIONS

SSTR subtype expression needs to be correlated to somatostatin analog therapy. Immunohistochemical profiling of various SSTR subtypes as a part of routine surgical pathologic analysis of enteropancreatic ETs may become a useful predictor of responsiveness of ETs to various SSTR analogs.

Improved outcome with cytoreduction versus embolization for symptomatic hepatic metastases of carcinoid and neuroendocrine tumors

BACKGROUND

Few data exist regarding outcomes after resection versus embolic treatment of symptomatic metastatic carcinoid and neuroendocrine tumors. The purpose of this study was to determine whether cytoreduction provides any benefit over embolic management of diffuse neuroendocrine tumors.

METHODS

A prospective database of 734 patients treated at our institution was retrospectively queried for symptomatic metastatic tumors treated with embolization or cytoreduction. Patients were compared with regard to pretreatment performance status, relief of symptoms, and survival.

RESULTS

A total of 120 patients were identified: 59 undergoing embolization and 61 undergoing cytoreduction. Twenty-three patients had palliative cytoreduction (gross residual disease). Pretreatment performance status (Eastern Cooperative Oncology Group) was similar for both groups: .7+/-.70 (embolization) versus .8+/-.72 (cytoreduction; P=.27). Complete symptomatic relief was observed in 59% and partial relief in 32% of patients who underwent embolization, with a mean symptom-free interval of 22+/-13.6 months. A total of 69% of patients who underwent cytoreduction had complete symptomatic relief, and 23% had partial relief (P=.08 vs. embolization). The mean duration of relief was 35+/-22.0 months (P<.001 vs. embolization). The mean survival for the patients who underwent embolization was 24+/-15.8 months versus 43+/-26.1 months for those who underwent cytoreduction (P<.001). Survival in patients who underwent palliative cytoreduction was 32+/-18.9 months (P<.001 vs. embolization), whereas it was 50+/-27.6 months in patients who underwent curative resection (P<.001 vs. embolization; P<.001 vs. palliative).

CONCLUSIONS

Cytoreduction for metastatic neuroendocrine tumors resulted in improved symptomatic relief and survival when compared with embolic therapy in this nonrandomized study. Cytoreduction should be pursued whenever possible even if complete resection may not be achievable.

213Bi-[DOTA0, Tyr3]Octreotide Peptide Receptor Radionuclide Therapy of Pancreatic Tumors in a Preclinical Animal Model

PURPOSE

The somatostatin analogue [DOTA0, Tyr3]octreotide (DOTATOC) has previously been labeled with low linear energy transfer (LET) beta-emitters, such as 177Lu or 90Y, for tumor therapy. In this study, DOTATOC labeled with the high-LET alpha-emitter, 213Bi, was evaluated.

EXPERIMENTAL DESIGN

The radiolabeling, stability, biodistribution, toxicity, safety, and therapeutic efficacy of 213Bi-DOTATOC (specific activity 7.4 MBq/microg) were investigated. Biodistribution studies to determine somatostatin receptor specificity were done in Lewis rats at 1 and 3 hours postinjection. Histopathology of various organs was used to evaluated toxicity and safety. Therapeutic efficacy of 4 to 22 MBq 213Bi-DOTATOC was determined in a rat pancreatic carcinoma model.

RESULTS

Radiolabeling of the 213Bi-DOTATOC was achieved with radiochemical purity >95% and an incorporation yield > or = 99.9%. Biodistribution data showed specific binding to somatostatin receptor-expressing tissues. Administration of free 213Bi, compared with 213Bi-DOTATOC, resulted in higher radioactivity accumulation at 3 hours postinjection in the kidneys [34.47 +/- 1.40% injected dose/g (ID/g) tissue versus 11.15 +/- 0.46%, P < 0.0001] and bone marrow (0.31 +/- 0.01% ID/g versus 0.06 +/- 0.02%, P < 0.0324). A significant decrease in tumor growth rate was observed in rats treated with >11 MBq of 213Bi-DOTATOC 10 days postinjection compared with controls (P < 0.025). Treatment with >20 MBq of 213Bi-DOTATOC showed significantly greater tumor reduction when compared with animals receiving <11 MBq (P < 0.02).

CONCLUSIONS

213Bi-DOTATOC showed dose-related antitumor effects with minimal treatment-related organ toxicity. No acute or chronic hematologic toxicities were observed. Mild, acute nephrotoxicity was observed without evidence of chronic toxicity. 213Bi-DOTATOC is a promising therapeutic radiopharmaceutical for further evaluation.

Phase II study of 5-fluorouracil, doxorubicin, and mitomycin C for metastatic small bowel adenocarcinoma

BACKGROUND

Small bowel adenocarcinoma is a rare gastrointestinal malignancy that is treated primarily with surgery. Even with optimal resection, however, survival is poor and recurrences are common. Response rates to palliative combination chemotherapy are low, and the median duration of survival for metastatic disease is less than 1 year. This study aimed to document the response rate and survival time for patients with advanced small bowel adenocarcinoma who were not surgically curable and were treated with a regimen of 5-fluorouracil (5-FU), mitomycin C (Mutamycin; Bristol-Myers Squibb; Princeton, NJ), and doxorubicin (Adriamycin; Bedford Laboratories; Bedford, OH), the FAM regimen.

METHODS

This multi-institutional study was performed by the Eastern Cooperative Oncology Group (ECOG). Between November, 1983 and December, 1985, 39 patients with advanced or recurrent disease were enrolled. Chemotherapy was given as follows: 5-FU, 600 mg/m(2) on days 1, 8, 29 and 36; mitomycin C, 10 mg/m(2) on day 1; and doxorubicin, 30 mg/m(2) on days 1 and 29. Eligibility criteria included an ECOG performance status score of 0-2, measurable disease, and adequate baseline organ function. Prior chemotherapy was allowed. Response was measured by examination and imaging techniques. Survival time and time to progression were evaluated by the method of Kaplan and Meier, and these outcomes were stratified by clinical and laboratory covariates.

RESULTS

Of the 39 evaluated patients, 38 were eligible and 36 were evaluable for response. Grade 3-5 toxicities were experienced by a total of 26 patients (20 grade 3, 5 grade 4, 1 grade 5). The most common adverse events were neutropenia and vomiting. Responses were seen in a total of seven patients (2 complete responses, 5 partial responses), for a response rate of 18.4% (95% confidence interval of 7.8%-34.4%). The median survival time was 8 months.

CONCLUSIONS

The FAM regimen was active and tolerable for patients with advanced small bowel adenocarcinoma; however, the results were no better than those seen with other chemotherapy combinations.

Practical dosimetry of peptide receptor radionuclide therapy with (90)Y-labeled somatostatin analogs

The challenge for internal therapy is to deliver the highest possible dose to the tumor while sparing normal organs from damage. Currently, the potential risk of kidney and red marrow toxicity limits the amount of radioactivity that may be administered. An accurate dosimetry method that would provide reliable dose estimates to these critical organs and to tumors before therapy would allow the clinician to plan a specific therapeutic regimen and also select those patients who would benefit the most from treatment. The dosimetry for (90)Y-1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid-d-Phe(1)-Tyr(3)-octreotide is usually based on quantitative imaging at different time points that provides information on activity retention in organs over time and on stylized models representing average individuals. Because the therapeutic agent labeled with (90)Y is not suitable for quantitative imaging, the peptide surrogate labeled with the positron emitter (86)Y can be considered the most appropriate tracer for measuring distribution and retention of the radiopharmaceutical over time. Dose calculations in target organs are generally performed using the MIRDOSE program, in which S values from source to target are integrated. Significant improvement of dose estimates may be achieved by introducing patient-specific adjustments to the standard models. The use of individual kidney volumes assessed by CT instead of the use of a fixed volume for males and females may significantly improve the determination of kidney radiation doses. The use of actual CT-derived tumor volumes has also shown a dose-efficacy relationship. Additional improvements in this field include the validation and use of an (111)In surrogate to avoid the complexity of (86)Y use and the consideration of radiobiologic parameters, such as fractionation effects and the specific biologic efficacy of internally deposited radiation, which are probably underestimated using currently available methods.

Radiation sensitizers: a selective review of molecules targeting DNA and non-DNA targets

The ideal radiation sensitizer would reach the tumor in adequate concentrations and act selectively in the tumor compared with normal tissue. It would have predictable pharmacokinetics for timing with radiation treatment and could be administered with every radiation treatment. The ideal radiation sensitizer would have minimal toxicity itself and minimal or manageable enhancement of radiation toxicity. The ideal radiation sensitizer does not exist today. This review outlines the concept of combining 2 modalities of cancer treatment, radiation and drug therapy, to provide enhanced tumor cell kill in the treatment of human malignancies and discusses molecules that target DNA and non-DNA targets. Combining drugs that have unique mechanisms of action and absence of overlapping toxicities with systemically administered radiotherapy should be exploited in future clinical trials. This is an exciting time in clinical oncology research, because we have a plethora of new molecules to evaluate.

Overview of results of peptide receptor radionuclide therapy with 3 radiolabeled somatostatin analogs

A new treatment modality for inoperable or metastasized gastroenteropancreatic tumors is the use of radiolabeled somatostatin analogs. Initial studies with high doses of [(111)In-diethylenetriaminepentaacetic acid (DTPA)(0)]octreotide in patients with metastasized neuroendocrine tumors were encouraging, although partial remissions were uncommon. Another radiolabeled somatostatin analog that is used for peptide receptor radionuclide therapy (PRRT) is [(90)Y-1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid (DOTA)(0),Tyr(3)]octreotide. Various phase 1 and phase 2 PRRT trials have been performed with this compound. Despite differences in the protocols used, complete and partial remissions in most of the studies with [(90)Y-DOTA(0),Tyr(3)]octreotide were in the same ranges, 10%-30%; these ranges were higher than those obtained with [(111)In-DTPA(0)]octreotide. Treatment with the newest radiolabeled somatostatin analog, [(177)Lu-DOTA(0),Tyr(3)]octreotate, which has a higher affinity for the subtype 2 somatostatin receptor, resulted in complete or partial remissions in 30% of 76 patients. Tumor regression was positively correlated with a high level of uptake on OctreoScan imaging, a limited hepatic tumor mass, and a high Karnofsky performance score. Treatment with radiolabeled somatostatin analogs is a promising new tool in the management of patients with inoperable or metastasized neuroendocrine tumors. Symptomatic improvement may occur with all (111)In-, (90)Y-, or (177)Lu-labeled somatostatin analogs that have been used for PRRT. The results obtained with [(90)Y-DOTA(0),Tyr(3)]octreotide and [(177)Lu-DOTA(0),Tyr(3)]octreotate are very encouraging in terms of tumor regression. Also, if kidney protective agents are used, the side effects of this therapy are few and mild, and the duration of the therapy response for both radiopharmaceuticals is more than 2 y. These data compare favorably with those for the limited number of alternative treatment approaches.

Long-term follow-up of renal function after peptide receptor radiation therapy with (90)Y-DOTA(0),Tyr(3)-octreotide and (177)Lu-DOTA(0), Tyr(3)-octreotate

The kidneys are critical organs in peptide receptor radiation therapy (PRRT). Renal function loss may become apparent many years after PRRT. We analyzed the time course of decline in creatinine clearance (CLR) in patients during a follow-up of at least 18 mo after the start of PRRT with (90)Y-1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid (DOTA),Tyr(3)-octreotide ((90)Y-DOTATOC) or (177)Lu-DOTA(0),Tyr(3)-octreotate ((177)Lu-DOTATATE).

METHODS

Twenty-eight patients with metastasized neuroendocrine tumors received 1-5 cycles of (90)Y-DOTATOC, leading to renal radiation doses of 5.9-26.9 Gy per cycle and a total of 18.3-38.7 Gy. Median follow-up was 2.9 y (range, 1.5-5.4 y), with a median of 16 measurements (range, 5-53) per patient. Thirty-seven patients with metastasized neuroendocrine tumors received 3-7 cycles of (177)Lu-DOTATATE, leading to renal radiation doses of 1.8-7.8 Gy per cycle and a total of 7.3-26.7 Gy. Median follow-up was 2.4 y (range, 1.7-4.0 y), with a median of 10 (range, 6-27) measurements per patient. All renal dose estimates were calculated with the MIRDOSE3 model. All patients were infused with renoprotective amino acids during the administration of the radioactive peptides. The time trend of CLR was determined by fitting a monoexponential function through the data of individual patients, yielding the decline in CLR in terms of percentage change per year.

RESULTS

The median decline in CLR was 7.3% per y in patients treated with (90)Y-DOTATOC and 3.8% per y in patients treated with (177)Lu-DOTATATE (P = 0.06). The time trend of decline in CLR was sustained during the follow-up period. Eleven patients had a >15% per y decline in CLR. Cumulative renal radiation dose, per-cycle renal radiation dose, age, hypertension, and diabetes are probable contributing factors to the rate of decline in CLR after PRRT.

CONCLUSION

This study showed that the time course of CLR after PRRT was compatible with the pattern of sustained CLR loss in progressive chronic kidney disease.

Patient-specific dosimetry in predicting renal toxicity with (90)Y-DOTATOC: relevance of kidney volume and dose rate in finding a dose-effect relationship

Nephrotoxicity is the major limiting factor during therapy with the radiolabeled somatostatin analog (90)Y-1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid (DOTA)-d-Phe(1)-Tyr(3)-octreotide (DOTATOC). Pretherapeutic assessment of kidney absorbed dose could help to minimize the risk of renal toxicity. The aim of this study was to evaluate the contribution of patient-specific adjustments to the standard dosimetric models, such as the renal volume and dose rate, for estimating renal absorbed dose during therapy with (90)Y-DOTATOC. In particular, we investigated the correlation between dose estimates and effect on renal function after therapy.

METHODS

Eighteen patients with neuroendocrine tumors (9 men and 9 women; median age, 59 y) underwent treatment with (90)Y-DOTATOC (8.1-22.9 GBq) after pretherapeutic biodistribution study with (86)Y-DOTATOC. Kidney uptake and residence times were measured and the absorbed dose (KAD) was computed using either the MIRDOSE3.1 software assuming a standard kidney volume (KAD(StdVol)) or the MIRD Pamphlet 19 values and the actual kidney cortex volume determined by pretherapeutic CT (KAD(CTVol)). For each patient, the biologic effective dose (BED) was calculated according to the linear quadratic model to take into account the effect of dose rate and fractionation. Renal function was evaluated every 6 mo by serum creatinine and creatinine clearance (CLR) during a median follow-up of 35.5 mo (range, 18-65 mo). The individual rate of decline of renal function was expressed as CLR loss per year.

RESULTS

KAD(CTVol) ranged between 19.4 and 39.6 Gy (mean, 28.9 +/- 5.34 Gy). BED, obtained from KAD(CTVol), ranged between 27.7 and 59.3 Gy (mean, 40.4 +/- 10.6 Gy). The CLR loss per year ranged from 0% to 56.4%. In 12 of 18 patients, CLR loss per year was <20%. No correlation was observed between CLR loss per year and the KAD(StdVol) or the KAD(CTVol). In contrast, BED strongly correlated with CLR loss per year (r = 0.93; P < 0.0001). All 5 patients with CLR loss per year >20% received a BED >45 Gy. Patients who were treated with low fractionation were those with the highest rate of renal function impairment.

CONCLUSION

Radiation nephrotoxicity after (90)Y-DOTATOC therapy is dose dependent. Individual renal volume, dose rate, and fractionation play important roles in an accurate dosimetry estimation that enables prediction of risk of renal function impairment.

Metabolic effects of amino acid solutions infused for renal protection during therapy with radiolabelled somatostatin analogues

BACKGROUND

Infusion of amino acids (AAs) can reduce renal uptake of radiolabelled somatostatin analogues resulting in a lower kidney exposure during peptide radiotherapy of patients with neuroendocrine tumours. In this study, we investigated the metabolic effects related to the infusion of large amounts of amino acids in patients undergoing positron emission tomography (PET) studies with [(86)Y]DOTA(0)-D-Phe(1)-Tyr(3)-octreotide.

METHODS

Twenty-four patients, in four consecutive groups of six, received a 4 h infusion of 120 g of mixed AAs and, in addition, either a 4 h infusion of 50 g of L-lysine (n = 6), a 10 h infusion of 240 g of mixed AAs (n = 6), a 4 h infusion of 50 g of L-lysine + L-arginine (Lys-Arg; n = 6) or no infusion (control; n = 6) in randomly ordered crossover studies. A number of clinical and biochemical parameters in blood and urine were measured over 24 h, including calculation of creatinine clearance, tubular reabsorption of inorganic phosphate (TRP) and fractional urate excretion.

RESULTS

No clinical side effects occurred during the infusions except for nausea and vomiting under mixed AAs. Patients in the latter group showed an increase in serum urea, whereas patients receiving L-lysine showed an increase in serum potassium and chloride. Inorganic phosphate levels dropped at 2.5 h in all groups except controls, and a significant decrease in TRP was observed with mixed AAs but not with L-lysine or Lys-Arg.

CONCLUSION

Although infusion of AA solutions can improve the effect of therapy by allowing the administration of higher doses of radiolabelled somatostatin analogues, each preparation has specific sides effects that should be taken into account with this type of therapy.

Peptide Receptor Radionuclide Therapy

On their plasma membranes, cells express receptor proteins with high affinity for regulatory peptides, such as somatostatin. Changes in the density of these receptors during disease, for example, overexpression in many tumors, provide the basis for new imaging methods. The first peptide analogues successfully applied for visualization of receptor-positive tumors were radiolabeled somatostatin analogues. The next step was to label these analogues with therapeutic radionuclides for peptide receptor radionuclide therapy (PRRT). Results from preclinical and clinical multicenter studies already have shown an effective therapeutic response when using radiolabeled somatostatin analogues to treat receptor-positive tumors. Infusion of positively charged amino acids reduces kidney uptake, enlarging the therapeutic window. For PRRT of CCK-B receptor-positive tumors, such as medullary thyroid carcinoma, radiolabeled minigastrin analogues currently are being successfully applied. The combination of different therapy modalities holds interest as a means of improving the clinical therapeutic effects of radiolabeled peptides. The combination of different radionuclides, such as (177)Lu- and (90)Y-labeled somatostatin analogues, to reach a wider tumor region of high curability, has been described. A variety of other peptide-based radioligands, such as bombesin and NPY(Y(1)) analogues, receptors for which are expressed on common cancers such as prostate and breast cancer, are currently under development and in different phases of (pre)clinical investigation. Multireceptor tumor targeting using the combination of bombesin and NPY(Y(1)) analogues is promising for scintigraphy and PRRT of breast carcinomas and their lymph node metastases.

86Y-DOTA0)-D-Phe1-Tyr3-octreotide (SMT487)--a phase 1 clinical study: pharmacokinetics, biodistribution and renal protective effect of different regimens of amino acid co-infusion

The pharmacokinetics and dosimetry of (86)Y-DOTA(0)- d-Phe(1)-Tyr(3)-octreotide ((86)Y-SMT487) were evaluated in a phase I positron emission tomography (PET) study of 24 patients with somatostatin receptor-positive neuroendocrine tumours. The effect of amino acid (AA) co-infusion on renal and tumour uptake was assessed in a cross-over randomised setting. Five regimens were tested: no infusion, 4-h infusion of 120 g mixed AA (26.4 g l-lysine + l-arginine), 4 h l-lysine (50 g), 10 h 240 g mixed AA (52.8 g l-lysine + l-arginine) and 4 h Lys-Arg (25 g each). Comparisons were performed on an intra-patient basis. Infusions of AA started 0.5 h prior to injection of (86)Y-SMT487 and PET scans were obtained at 4, 24 and 48 h p.i. Absorbed doses to tissues were computed using the MIRD3 method. (86)Y-SMT487 displayed rapid plasma clearance and exclusive renal excretion; uptake was noted in kidneys, tumours, spleen and, to a lesser extent, liver. The 4-h mixed AA co-infusion significantly ( P<0.05) reduced (86)Y-SMT487 renal uptake by a mean of 21%. This protective effect was significant on the dosimetry data (3.3+/-1.3 vs 4.4+/-1.0 mGy/MBq; P<0.05) and was further enhanced upon prolonging the infusion to 10 h (2.1+/-0.4 vs 1.7+/-0.2 mGy/MBq; P<0.05). Infusion of Lys-Arg but not of l-lysine was more effective in reducing renal uptake than mixed AA. Infusion of AA did not result in reduced tumour uptake. The amount of (90)Y-SMT487 (maximum allowed dose: MAD) that would result in a 23-Gy cut-off dose to kidneys was calculated for each study: MAD was higher with mixed AA co-infusion by a mean of 46% (10-114%, P<0.05 vs no infusion). In comparison with 4 h mixed AA, the MAD was higher by a mean of 23% (9-37%; P<0.05) with prolonged infusion and by a mean of 16% (2-28%; P<0.05) with Lys-Arg. We conclude that infusion of large amounts of AA reduces renal exposure during peptide-based radiotherapy and allows higher absorbed doses to tumours. The prolongation of the infusion from 4 to 10 h further enhances the protective effect on the kidneys.

Somatostatin receptor-targeted radionuclide therapy of tumors: preclinical and clinical findings

In preclinical studies in rats we evaluated biodistribution and therapeutic effects of different somatostatin analogs, [(111)In-DTPA]octreotide, [(90)Y-DOTA,Tyr(3)]octreotide and [(177)Lu-DOTA,Tyr(3)]octreotate, currently also being applied in clinical radionuclide therapy studies. [Tyr(3)]octreotide and [Tyr(3)]octreotate, chelated with DTPA or DOTA, both showed high affinity binding to somatostatin receptor subtype 2 (sst(2)) in vitro. The radiolabelled compounds all showed high tumor uptake in sst(2)-positive tumors in vivo in rats, the highest uptake being reached with [(177)Lu-DOTA,Tyr(3)]octreotate. In preclinical therapy studies in vivo in rats, excellent, dose dependent, tumor size responses were found, responses appeared to be dependent on tumor size at therapy start. These preclinical data showed the great promise of radionuclide therapy with radiolabelled somatostatin analogues. They emphasised the concept that especially the combination of somatostatin analogs radiolabeled with different radionuclides, like (90)Y and (177)Lu, is most promising to reach a wider tumor size region of high curability. Furthermore, different phase I clinical studies, using [(111)In-DTPA]octreotide, [(90)Y-DOTA,Tyr(3)]octreotide or [(177)Lu-DOTA, Tyr(3)]octreotate are described. Fifty patients with somatostatin receptor-positive tumors were treated with multiple doses of [(111)In-DTPA(0)]octreotide. Forty patients were evaluable after cumulative doses of at least 20 GBq up to 160 GBq. Therapeutic effects were seen in 21 patients: partial remission in 1 patient, minor remissions in 6 patients, and stabilization of previously progressive tumors in 14 patients. The toxicity was generally mild bone marrow toxicity, but 3 of the 6 patients who received more than 100 GBq developed a myelodysplastic syndrome or leukemia. Radionuclide therapy with [(90)Y-DOTA,Tyr(3)]octreotide started in 3 different phase I trials. Overall, antimitotic effects have been observed: about 20% partial response and 60% stable disease (N = 92) along with complete symptomatic cure of several malignant insulinoma and gastrinoma patients. Maximum cumulative [(90)Y-DOTA,Tyr(3)]octreotide dose was about 26 GBq, without reaching the maximum tolerable dose. New is the use of [(177)Lu-DOTA,Tyr(3)]octreotate, which shows the highest tumor uptake of all tested octreotide analogs so far, with excellent tumor-to-kidney ratios. Radionuclide therapy with this analog in a phase 1 trial started recently in our center in 63 patients (238 administrations), Interim analysis of 18 patients with neuroendocrine tumors was performed very recently. According to the WHO, toxicity criteria no dose limiting toxicity was observed. Minor CT-assessed tumor shrinkage (25% - 50% reduction) was noticed in 6% of 18 patients and partial remission (50% - 100% reduction, SWOG criteria) in 39%. Eleven percent of patients had tumor progression and in 44% no changes were seen. These data show that radionuclide therapy with radiolabelled somatostatin analogs, like [DOTA, Tyr(3)]octreotide and [DOTA, Tyr(3)octreotate is a most promising new treatment modality for patients who have sst(2)-positive tumors.

A Phase II study of high-dose paclitaxel in patients with advanced neuroendocrine tumors

BACKGROUND

New agents with antitumor activity in patients with neuroendocrine tumors are sorely needed. A Phase II study of high-dose paclitaxel in patients with metastatic carcinoid and islet cell tumors was performed at the Mayo Clinic. Granulocyte-colony-stimulating factor (GCSF) also was administered to ameliorate neutropenia.

METHODS

Twenty-four patients (14 with carcinoid tumors, 9 with islet cell tumors, and 1 with an anaplastic tumor) were enrolled on this Phase II study of paclitaxel given as a 24-hour continuous infusion at a dose of 250 mg/m(2) every 3 weeks plus GCSF at a dose of 5 microg/kg/day subcutaneously, beginning 24 hours after the completion of the paclitaxel dose and continuing until the absolute neutrophil count was > 10,000/microL.

RESULTS

All 24 patients were evaluable for analysis. The overall response rate was 8% (95% confidence interval [95% CI], 0-0.11). At last follow-up all patients except 1 had developed disease progression, with an estimated median time to disease progression of 3.2 months (95% CI, 1.6-6.0 months). The estimated median survival was 1.5 years (95% CI, 1.0-1.8 years). Hematologic toxicity was significant with 12 of 24 patients developing Grade 4 (according to the National Cancer Institute Common Toxicity Criteria scale) neutropenia; however, there were no septic deaths reported. There were 17 episodes of Grade 4 neutropenia in these 12 patients and the duration of these events ranged from 2-5 days. More common nonhematologic toxicities included arthralgia (21 patients), anorexia (15 patients), nausea (15 patients), diarrhea (12 patients), and allergic reactions (2 patients).

CONCLUSIONS

Given the lack of antitumor activity of paclitaxel and the significant hematologic toxicity observed despite the use of GCSF support in the current study cohort of patients with neuroendocrine tumors, further studies of this combination in this particular patient population are not recommended.

Reduced uncertainty as a diagnostic benefit: an initial assessment of somatostatic receptor scintigraphy's value in detecting distant metastases of carcinoid liver tumours

This paper employs classical concepts of diminishing marginal utility to demonstrate that risk-aversion can increase the perceived value of diagnostic procedures and thus raise optimum diagnostic expenditures. The theory is applied to a model in the spirit of Phelps and Mushlin's initial technology assessments. The specific evaluation is the cost-effectiveness of somatostatin receptor scintigraphy used to detect distant metastases of carcinoid liver tumours in a patient otherwise eligible for surgical resection of the liver. Data for the model are taken from published sources and financial databases, when available, and otherwise from a senior clinician's experience (LKK). The quantitative results indicate that receptor scintigraphy may have two beneficial impacts to risk-neutral individuals. First, it may reduce the combined costs of therapy and treatment because the diagnostic procedure costs less than the expected savings generated by avoiding inappropriate surgeries. Second, it may improve the patient's expected health-status-adjusted life years (HSALY) because the information allows physicians to better match treatment to the cancer's stage. Finally the paper demonstrates that risk aversion, as embodied in classical diminishing marginal utility applied to health status, can increase the value of the diagnostic tests and can lead the patient to choose a less beneficial treatment. An illustrative risk-averse utility function changed the optimum treatment from surgery to chemotherapy and increased scintigraphy's benefit by 500%.

Increased parathyroid hormone-related peptide in patients with hypercalcemia associated with islet cell carcinoma

OBJECTIVE

To report the high prevalence of increased parathyroid hormone-related peptide (PTHrP) in patients with islet cell carcinoma and associated hypercalcemia.

DESIGN

We conducted a retrospective study of PTHrP levels in patients with hypercalcemia and eucalcemia associated with islet cell carcinoma and compared these findings with those in healthy subjects.

MATERIAL AND METHODS

Using a sensitive PTHrP immunochemiluminometric assay, we measured PTHrP levels in 17 patients with islet cell carcinoma and 110 healthy subjects. The differences between PTHrP levels in patients with normal and those with high serum calcium concentrations were analyzed statistically.

RESULTS

PTHrP levels were significantly higher (P < 0.01) in 10 patients with hypercalcemia and islet cell carcinoma (median, 14.0 pmol/L; range, undetectable to 40.1) than in 7 patients with eucalcemia and islet cell carcinoma (median, undetectable; range, undetectable to 1.3 pmol/L) or in the 110 healthy subjects (median, undetectable; range, undetectable to 4.2 pmol/L). The range of increased PTHrP levels in hypercalcemic islet cell carcinoma was 2 to 20 times the upper normal limit (2.0 pmol/L). Decreased PTHrP and serum calcium and increased parathyroid hormone levels were demonstrated in two patients after effective therapy. For all seven eucalcemic patients with islet cell carcinoma, PTHrP levels did not differ significantly from those in healthy subjects.

CONCLUSION

PTHrP levels are increased in a substantial proportion of patients with hypercalcemia and islet cell carcinoma and seem to decrease after treatment of the underlying tumor. Measurement of PTHrP levels may be useful for confirming the diagnosis of hypercalcemia associated with malignant disease and for monitoring of therapy.

Can molgramostim enhance the antitumor effects of cytotoxic drugs in patients with advanced sarcomas?

BACKGROUND

A phase I study was designed for the amalgamation of two previously studied antisarcoma regimens (ifosfamide+doxorubicin and mitomycin+doxorubicin+cisplatin) supported by molgramostim. Thus, we hoped to develop a better regimen for the treatment of advanced sarcomas.

PATIENTS AND METHODS

Fifteen adult advanced sarcoma patients and six other patients were registered and sequentially assigned to receive three progressively more myelosuppressive levels of chemotherapy: level I-ifosfamide 2500 mg/m2 + doxorubicin 40 mg/m2 + cisplatin 60 mg/m2 all given on day 0, followed by molgramostim 5 micrograms/kg every 12 hours for 14 days; level II-exactly the same chemotherapy from level I given on day 1 preceded on day 0 by ifosfamide 2500 mg/m2 and an additional four days of molgramostim given on days-6 through-3; level III-same as level II except for the addition of mitomycin 4 mg/m2 immediately prior to cisplatin on day 1. MENSA 500 mg/m2 was given five times on each day that involved ifosfamide treatment. For all levels, treatment was repeated at four-week intervals.

RESULTS

Preliminary results and toxicity were reported three years ago (J Natl Cancer Inst 86: 312-4, 1994). Mature results confirm these unexpectedly favorable results with five advanced sarcoma patients still surviving after more than three years (four more than four years).

HYPOTHESIS

Molgramostim given subcutaneously in a relatively intensive schedule might enhance the antitumor effects initiated by cytotoxic drugs in patients with advanced sarcomas. This idea should be tested formally in phase III studies.

Incidence and morbidity of cholelithiasis in patients receiving chronic octreotide for metastatic carcinoid and malignant islet cell tumors

BACKGROUND

Octreotide, a long-acting somatostatin analogue, has demonstrated clinical utility in patients with carcinoid syndrome and malignant islet cell tumors of the pancreas. Prior studies have reported a greater than expected incidence of cholelithiasis in patients treated with octreotide for acromegaly. This study attempted to determine the incidence and morbidity of cholelithiasis in a group of patients with metastatic carcinoid or malignant pancreatic islet cell tumors who were receiving chronic therapy with octreotide.

METHODS

Forty-four of 55 patients on investigational protocols with octreotide were eligible for chart review; 10 patients were excluded due to prior cholecystectomy and 1 patient due to asymptomatic cholelithiasis at presentation. Patients fell into three treatment groups. The low dose (LD) group was comprised of 17 patients receiving 150 microg of subcutaneous octreotide 3 times a day. Twenty-one patients received high dose (HD) therapy comprised of 500 microg given 3 times a day. The low dose-high dose (LD-HD) group was comprised of 6 patients who had their dose escalated from 150 microg to 225-500 microg of octreotide 3 times a day.

RESULTS

The overall incidence of cholelithiasis and/or gallbladder sludge was found to be 52.3% in all 3 treatment groups. Three of the 44 patients (6.8%) had symptomatic disease requiring emergency cholecystectomy. Five other patients underwent elective or incidental gallbladder surgery. The incidence of cholelithiasis in the LD, LD-HD, and HD groups was 35.3%, 66.6%, and 61.9%, respectively. The incidence of acute cholecystitis in the three groups was 11.8%, 0%, and 4.8%, respectively.

CONCLUSIONS

Although greater than 50% of patients receiving octreotide developed cholelithiasis, a much smaller percentage of patients had symptomatic gallbladder disease. Patients receiving chronic octreotide treatment require monitoring for the development of gallstones. However, prophylactic cholecystectomy is not indicated, unless it is performed in conjunction with bowel resection or cytoreductive hepatic surgery.

Regression of metastatic carcinoid tumor after valvular surgery for carcinoid heart disease

BACKGROUND

The carcinoid syndrome is a common sequela in patients with carcinoid tumor metastatic to the liver. Cardiac involvement occurs in 19-56% of patients with symptomatic carcinoid syndrome and, in some patients, leads to valvular surgery to relieve symptoms due to progressive right-sided heart failure. Reports of these patients have emphasized amelioration of cardiac symptoms, but postoperative tumor status rarely has been discussed.

METHODS

This report describes four patients who underwent valvular heart surgery for severe carcinoid heart disease and had regression of their metastatic carcinoid tumor postoperatively.

RESULTS

All four patients had definite clinical improvement in cardiac function and relief of symptoms related to congestive heart failure postoperatively. Unexpectedly, they also had regression of their metastatic disease, as reflected in decreased levels of urinary 5-hydroxyindoleacetic acid, and objective evidence of a reduction in the size of hepatic metastases.

CONCLUSIONS

To the authors' knowledge, these four patients represent the first reported cases of metastatic disease regression after valvular surgery for carcinoid heart disease. Further descriptions of tumor status in patients having undergone a heart operation for this disease would be valuable in determining the clinical significance of this finding.

Clinical spectrum of hyperglucagonemia associated with malignant neuroendocrine tumors

OBJECTIVE

To review the clinical features associated with hyperglucagonemia in malignant neuroendocrine tumors.

MATERIAL AND METHODS

We retrospectively reviewed the medical records of patients with hyperglucagonemia encountered at our institution from Oct. 17, 1988, through February 1993 who had a fasting serum glucagon level of at least 120 pg/mL (twice the normal value). The 71 study patients also had no evidence of a secondary cause of hyperglucagonemia and had pathologic confirmation of a neuroendocrine tumor.

RESULTS

The study group consisted of 46 men and 25 women with a median age of 57 years. Two patients had multiple endocrine neoplasia. Forty-nine patients had biochemically polyfunctional tumors, and 22 had hyperglucagonemia only. The most common initial symptoms were weight loss, abdominal pain, diarrhea, nausea, peptic ulcer disease, diabetes, and necrolytic migratory erythema (NME). Diabetes eventually developed in 25 patients and was associated with NME in 11. The highest median serum glucagon values occurred in patients with the glucagonoma syndrome or insulinomas, and the lowest median values were in those with carcinoid syndrome, Zollinger-Ellison syndrome, or diabetes without NME. Fasting glucagon and glucose measurements were not correlated. The most common hormonal syndromes were the Zollinger-Ellison syndrome and the glucagonoma syndrome. All the neuroendocrine tumors were malignant. Several methods of treatment, including surgical debulking, chemotherapy, somatostatin, and hepatic artery embolization, were used. Death occurred in 29 patients at a median of 2.79 years after diagnosis; 42 patients were alive at a median of 2.86 years after diagnosis.

CONCLUSION

A mild degree of hyperglucagonemia can commonly be associated with multifunctional neuroendocrine tumors. The glucagonoma syndrome occurs in a few patients with malignant neuroendocrine tumors and hyperglucagonemia and is associated with very high serum glucagon levels. The correlation between serum glucagon levels and the development of diabetes is limited, and other factors such as insulin may be more important than hyperglucagonemia in the development of diabetes.

The glucagonoma syndrome. Clinical and pathologic features in 21 patients

The glucagonoma syndrome is a rare disorder characterized by weight loss, necrolytic migratory erythema (NME), diabetes, stomatitis, and diarrhea. We identified 21 patients with the glucagonoma syndrome evaluated at the Mayo Clinic from 1975 to 1991. Although NME and diabetes help identify patients with glucagonomas, other manifestations of malignant disease often lead to the diagnosis. If the diagnosis is made after the tumor is metastatic, the potential for cure is limited. The most common presenting symptoms of the glucagonoma syndrome were weight loss (71%), NME (67%), diabetes mellitus (38%), cheilosis or stomatitis (29%), and diarrhea (29%). Although only 8 of the 21 patients had diabetes at presentation, diabetes eventually developed in 16 patients, 75% of whom required insulin therapy. Symptoms other than NME or diabetes mellitus led to the diagnosis of an islet cell tumor in 7 patients. The combination of NME and diabetes mellitus led to a more rapid diagnosis (7 months) than either symptom alone (4 years). Ten patients had diabetes mellitus before the onset of NME. No patients had NME clearly preceding diabetes mellitus. Increased levels of secondary hormones, such as gastrin (4 patients), vasoactive intestinal peptide (1 patient), serotonin (5 patients), insulin (6 patients, clinically significant in 1 only), human pancreatic polypeptide (2 patients), calcitonin (2 patients) and adrenocorticotropic hormone (2 patients), contributed to clinical symptoms leading to the diagnosis of an islet cell tumor before the onset of the full glucagonoma syndrome in 2 patients. All patients had metastatic disease at presentation. Surgical debulking, chemotherapy, somatostatin, and hepatic artery embolization offered palliation of NME, diabetes, weight loss, and diarrhea. Despite the malignant potential of the glucagonomas, only 9 of 21 patients had tumor-related deaths, occurring an average of 4.91 years after diagnosis. Twelve patients were still alive, with an average age follow-up of 3.67 years.

Rothmund-Thomson syndrome in siblings: evidence for acquired in vivo mosaicism

Rothmund-Thomson syndrome (RTS) is an autosomal recessive disorder characterized by skin abnormalities that appear in infancy, skeletal abnormalities, juvenile cataracts and other manifestations of premature aging, and a predisposition to malignancy. The diagnosis is made on clinical grounds as no consistent laboratory test has been identified. Chromosome studies have been reported for only three patients with RTS and in two of these three, trisomy 8 mosaicism was found. We performed a variety of cytogenetic and molecular genetic studies on two siblings with RTS and on their phenotypically normal parents. Two chromosomally abnormal clones involving either trisomy 8 or i(8q) were found in both patients with RTS. These clones were present in vivo, as they were seen in interphase buccal smears and lymphocytes from unstimulated preparations using both conventional cytogenetic studies and fluorescence in situ hybridization (FISH) with a centromere probe for chromosome 8. These results suggest that RTS is associated with in vivo clonal chromosomal rearrangements causing an acquired somatic mosaicism.