Baseline tumor growth rate highlights the heterogeneity of well differentiated gastroenteropancreatic neuroendocrine tumors and predicts for increases in Ki67 index over time

Refined risk stratification for gastroenteropancreatic neuroendocrine tumors (GEP-NETs) has the potential to improve comparisons of study populations across clinical trials and facilitate drug development. Tumor growth rate (TGR) is a radiological metric with demonstrated prognostic value in well differentiated grade 1 and 2 (G1-2) GEP-NETs, but little is known about TGR in G3 NETs. In this retrospective study of 48 patients with advanced G1-3 GEP-NET, we calculated baseline TGR (TGR₀ ) from radiological images of metastases acquired prior to first-line therapy and evaluated its association with disease characteristics and outcomes. The median pretreatment Ki67 proliferation index for G1-3 tumors combined was 5% (range = 0.1%-52%) and median TGR₀ was 4.8%/month (m) (range = 0%-45.9%/m). TGR₀ correlated with pretreatment Ki67 across G1-3 pooled and within G3 GEP-NET. Patients with higher TGR₀ (>11.7%/m) tumors, which were primarily G3 pancreatic NETs, exhibited decreased time to first therapy (median, 2.2 vs. 5.3 months; p = .03) and shorter overall survival (median, 4.1 years vs. not reached; p = .003). Independent of therapies given, higher TGR₀ GEP-NETs experienced a greater incidence of Ki67 increase (100 vs. 50%; p = .02) and greater magnitude of Ki67 change (median, 14.0 vs. 0.1%; p = .04) upon serial biopsy. Importantly, TGR₀ , but not grade, predicted for future Ki67 increase in this series. Given the heterogeneity of well differentiated GEP-NETs, future clinical trials may benefit from stratification for TGR₀ , particularly in G1-2 tumors, in which TGR₀ does not correlate with Ki67. TGR₀ has the potential to noninvasively identify patients with previously undiagnosed grade progression and those in whom more or less frequent monitoring may be appropriate. Additional research is needed to determine the prognostic and predictive value of TGR₀ in larger and more homogeneously treated cohorts, and to ascertain if post-treatment TGR has value in previously treated patients starting a new line of therapy.

Integrated Genomic and Clinicopathologic Approach Distinguishes Pancreatic Grade 3 Neuroendocrine Tumor From Neuroendocrine Carcinoma and Identifies a Subset With Molecular Overlap

Distinguishing grade 3 pancreatic neuroendocrine tumor (G3 PanNET) from neuroendocrine carcinoma (PanNEC) is a known diagnostic challenge, and accurate classification is critical because clinical behavior and therapies differ. Although current recommendations suggest that immunohistochemistry for p53, Rb, ATRX, and DAXX can distinguish most cases, some cases remain difficult to classify using this approach. In this study, we reviewed 47 high-grade neoplasms originally diagnosed as pancreatic neuroendocrine neoplasms. In addition to the currently recommended stains, we performed capture-based sequencing of approximately 500 cancer genes and immunohistochemistry for p16 and trypsin or chymotrypsin. Using an integrated molecular and clinicopathologic approach, 42 (89%) of 47 cases had a clear final diagnosis of either G3 PanNET (n = 17), PanNEC (n = 17), or mixed acinar-NEC (n = 8). The 17 G3 PanNETs demonstrated frequent alterations in MEN1 (71%), DAXX (47%), ATRX (24%), TSC2 (35%), SETD2 (42%), and CDKN2A (41%). Contrary to prior reports, TP53 alterations were also common in G3 PanNETs (35%) but were always mutually exclusive with CDKN2A alterations in this group. The 17 PanNECs demonstrated frequent alterations in TP53 (88%), cell cycle genes RB1 (47%), CCNE1/CCND1 (12%), CDKN2A (29%), and in KRAS (53%) and SMAD4 (41%); TP53 was coaltered with a cell cycle gene in 76% of PanNECs. Diffuse strong p16 staining was observed in 69% of PanNECs in contrast to 0% of G3 PanNETs. The 8 acinar-NECs had recurrent alterations in ATM (25%), APC (25%), and STK11 (25%). Five cases remained difficult to classify, 3 of which exhibited overlapping molecular features with alterations in MEN1 with or without ATRX, and RB1 with or without TP53, making it unclear whether to classify as PanNET or PanNEC. Our data demonstrate that molecular profiling and immunohistochemistry for p16 greatly improve the diagnostic accuracy of high-grade pancreatic neuroendocrine neoplasms and identify a subset of rare cases with overlapping features of both PanNET and PanNEC.

Phase II study of pembrolizumab plus capecitabine and bevacizumab in microsatellite stable (MSS) metastatic colorectal cancer (mCRC)

3565

Background: MSS mCRC rarely responds to pembrolizumab monotherapy, but capecitabine and bevacizumab may induce immune-stimulatory effects. This study evaluates the safety, tolerability and preliminary efficacy of pembrolizumab in combination with capecitabine and bevacizumab in MSS mCRC. Methods: Single-center, phase 2 trial with safety lead-in to confirm the recommended phase 2 dose (RP2D) for capecitabine and expansion cohorts (NCT03396926). Key eligibility: MSS mCRC with stable disease (SD) or progressive disease (PD) on prior fluoropyrimidine-based therapy. Treatment: Capecitabine 1000 mg/m2 PO BID D1-14 Q21 days (confirmed RP2D) plus pembrolizumab 200 mg IV D1 Q21 days and bevacizumab 7.5 mg/kg IV D1 Q21 days. Endpoints: Primary: Objective response rate (ORR) by RECIST 1.1. Key secondary: Safety, duration of response (DOR), progression-free survival (PFS), overall survival (OS). Results: From 04/2018-10/2021, 44 patients (pts) were enrolled. Overall: Median age 53 years (range 28-79); female 50%; Caucasian 61%. Liver metastases at enrollment 80%. Prior therapies: median prior lines of therapy 2 (range 1-5); PD on fluoropyrimidine-containing regimens 91%; prior exposure to bevacizumab 86%. Complete toxicity data are available for 36 off-treatment pts. Grade ≥ 3 treatment-related (tr)AEs occurred in 10 (28%) pts, including grade 3 immune-related AEs in 4 (11%) pts. All-cause serious (s)AEs occurred in 13 (36%) pts and trSAEs in 5 (14%) pts. (tr)AEs leading to dose interruptions, reductions, or delays occurred in 21 (58%) pts, most commonly palmar-plantar erythrodysesthesia syndrome in 17 (47%) pts. Disposition: of 44 pts enrolled, 35 were removed for PD and 1 was removed for treatment noncompliance; 8 treatment ongoing. ORR in 40 evaluable pts was 5% (95% CI: 0.6,16.9). Best response by RECIST 1.1: partial response (PR) in 2 (5%); SD in 26 (65%); PD in 12 (30%). 2 responders: DOR 12 and 15 months, both with liver metastases. Median follow up was 7 months (range 1-45), with median PFS 4.3 months (95% CI: 3.9, 6.1), PFS at 6 months 31.1% (95% CI: 19.2%, 50.4%), and median OS 9.6 months (95% CI: 6.2, 13). Median time on treatment was 5 months (range 1-26). Single cell RNA sequencing on a subset of paired pre- and on-treatment biopsies demonstrated changes in the frequency of dendritic cells. Conclusions: The combination of pembrolizumab with capecitabine and bevacizumab was found to be tolerable with an expected toxicity profile in MSS mCRC pts. The ORR of 5% did not meet the prespecified target of ≥ 15%, however nearly a third of pts had PFS > 6 months. Immune profiling of tumor biopsies and peripheral blood is ongoing. Clinical trial information: NCT03396926.

Preoperative risk stratification of lymph node metastasis for non-functional pancreatic neuroendocrine neoplasm: An international dual-institutional study

BACKGROUND

/Objectives: Although the presence of lymph node metastasis (LNM) defines malignant potential, preoperative prediction of LNM has not been established for non-functional pancreatic neuroendocrine neoplasm (NF-PNEN). We sought to develop a prediction system using only preoperatively available factors that would stratify the risk of LNM for NF-PNEN.

METHODS

We retrospectively reviewed patients who underwent R0/1 resection of NF-PNEN at Kyoto University (2007-2019) and the University of California, San Francisco (2010-2019). Risk stratification of LNM was developed using preoperative factors by the logistic regression analysis. Long-term outcomes were compared across the risk groups.

RESULTS

A total of 131 patients were included in this study. Lymph nodes were pathologically examined in 116 patients, 23 (20%) of whom had LNM. Radiological tumor size [1.5-3.5 cm (odds ratio: 13.5, 95% confidence interval: 1.77-398) and >3.5 cm (72.4, 9.06-2257) against ≤1.5 cm], <50% cystic component (8.46 × 10^6, 1.68 × 10^106-), and dilatation of main pancreatic duct ≥5 mm (31.2, 3.94-702) were independently associated with LNM. When patients were classified as the low-risk (43 patients), intermediate-risk (44 patients), and high-risk groups (29 patients), proportions of LNM differed significantly across the groups (0%, 14%, and 59%, respectively). Recurrence-free survival (RFS) of the low- and intermediate-risk groups were significantly better than that of the high-risk group (5-year RFS rates of 92.2%, 85.4%, and 47.1%, respectively).

CONCLUSIONS

The prediction system using preoperative radiological factors stratifies the risk of LNM for NF-PNEN. This stratification helps to predict malignant potential and determine the surgical procedure and necessity of regional lymphadenectomy.

Temozolomide in Grade 3 Gastroenteropancreatic Neuroendocrine Neoplasms: A Multicenter Retrospective Review

BACKGROUND

Grade 3 gastroenteropancreatic neuroendocrine neoplasms (G3 GEPNENs) are often aggressive, and the optimal treatment is unclear for this subgroup of neuroendocrine neoplasms (NENs). Temozolomide (TEM)-based regimens have been increasingly used to treat grade 1-2 NENs, but their efficacy in G3 NENs remains undetermined. We aimed to assess the clinical efficacy of TEM-containing regimens in advanced grade 3 GEPNENs.

MATERIALS AND METHODS

A multicenter retrospective review (2008-2018) of patients with metastatic/unresectable G3 GEPNENs who received a TEM-containing regimen was undertaken within a North American partnership to pool data. The primary endpoint was time to treatment failure (TTF). Radiologic response was extracted from local reports.

RESULTS

One hundred and thirty patients in six high-volume NEN centers were included (median age 55, 64% male, 18% functional, 67% pancreatic NEN). Forty-nine percent were well-differentiated, 35% poorly differentiated, and 15% unknown based on local pathology reports. The regimen used was capecitabine and temozolomide (CAPTEM) in 92% and TEM alone in 8%. Radiological response by local assessment was seen in 36% of patients. Median TTF was 3.6 months and median overall survival (OS) 19.2 months. Six percent of patients required discontinuation of therapy due to adverse events. TTF was longer in first-line treatment (7.8 months vs. 2.9 months; hazard ratio, 1.62; 95% confidence interval, 1.11-2.36; p = .015) and in patients with pancreatic NENs (panNENs) compared with gastrointestinal NENs (5.8 months vs 1.8 months; p = .04). The overall response rate was higher in the first-line setting (51% vs 29%; p = .02) and in panNEN (41% vs 23%; p = .04).

CONCLUSION

This is the largest TEM treatment series in G3 NEN, involving collaboration of several major North American NEN centers as a partnership. Thirty-six percent of patients showed some degree of radiographic response, and treatment was generally well tolerated, although the median duration of response was short. Response rates and time to treatment failure were superior in the first-line setting. CAPTEM should be considered a viable treatment option in this setting. Further randomized trials are warranted.

IMPLICATIONS FOR PRACTICE

Neuroendocrine neoplasms (NENs) are heterogeneous, and optimal treatment for aggressive grade 3 (G3) NENs remains undetermined. The capecitabine and temozolomide (CAPTEM) regimen has been used in low-grade pancreas NENs but there are few data for its safety and efficacy in the G3 setting. This article reports on the efficacy of temozolomide-containing regimens, particularly CAPTEM, in management of G3 NENs. The good tolerance and response rate show that CAPTEM should be considered a viable regimen in treatment of G3 NENs pending confirmatory prospective studies.

Outcomes after high-dose radiation in the management of neuroendocrine neoplasms

BACKGROUND

Neuroendocrine neoplasms (NENs) comprise a rare and heterogenous group of cancers, for which the role of radiation therapy continues to evolve. The purpose of this study is to analyze oncologic outcomes after the use of high-dose radiation in management of NENs at a tertiary hospital.

MATERIALS AND METHODS

We performed a retrospective review of patients who received high-dose radiation with intent to cure or provide durable local control (defined as biologically effective dose (BED) ≥40, α/β = 10) for a localized or metastatic NEN from 2006 to 2019. Evaluation of disease status after radiation was performed according to Response Evaluation Criteria in Solid Tumors (RECIST) criteria when possible. Patients were grouped by differentiation (well-differentiated (WD) or poorly-differentiated (PD)) and stage (localized/locally advanced disease (L) or metastatic (M)) in analysis of probabilities of progression after radiation.

RESULTS

45 patients completed a radiation course with BED ≥40 for a NEN (median BED 72). With a median follow-up of 24 months after radiation, the 2-year actuarial rates of local relapse-free survival, new metastasis-free survival, progression-free survival, and overall survival after radiation were 98%, 45%, 41%, and 69%, respectively. 25 patients (56%) developed new metastases after completion of radiation, including 33% (n = 3) of patients with WD-L disease, 44% (n = 8) of WD-M, 77% (n = 10) of PD-L, and 80% (n = 4) of PD-M, with progressively shorter median times to progression (26, 9, 8, and 3 months, respectively; p = 0.093). Of the 25 patients evaluable by RECIST, 68% (n = 17) achieved either a complete or partial best response in the irradiated lesion.

CONCLUSIONS

These data suggest that focal, high-dose radiation has a role in the management of selected patients with NENs. Local failure is rare in patients with both well-differentiated and poorly-differentiated disease, although the predominant pattern of failure remains development of new metastases.

Phase II study of pembrolizumab plus capecitabine and bevacizumab in microsatellite stable (MSS) metastatic colorectal cancer (mCRC): Interim analysis

77

Background: MSS mCRC rarely responds to pembrolizumab monotherapy, but capecitabine and bevacizumab may induce immune-stimulatory effects. This study evaluates the safety, tolerability and preliminary efficacy of pembrolizumab in combination with capecitabine and bevacizumab in MSS mCRC. We present results at the planned interim analysis. Methods: Design:single-arm, open-label, single-site phase 2 trial with a safety lead-in to confirm the recommended phase 2 dose (RP2D) for capecitabine and expansion cohorts. Per the Simon’s 2-stage design, ≤1 response in 29 patients (pts) requires trial suspension. Key eligibility criteria: MSS mCRC with stable disease (SD) or progressive disease (PD) on prior fluoropyrimidine-based therapy. Treatment: RP2D PO capecitabine on days 1-14 plus 200 mg IV pembrolizumab and 7.5 mg/kg IV bevacizumab on day 1 in 21-day cycles. Pts are followed for toxicity and radiographic response. Results: From 04/2018-09/2020, 29 pts were enrolled, of whom 15 (52%) were female; 21 (72%) white; and median age was 55 years (range 36-77 years). Prior therapies: 2 (7%) pts had SD and 27 (93%) pts had PD on fluoropyrimidine-containing regimens; 24 (83%) pts had prior exposure to bevacizumab. The RP2D for capecitabine was 1000 mg/m2 PO BID, with no dose limiting toxicities observed. Complete toxicity data are available for 25 off-treatment pts. The most common related adverse events (AEs) were palmar-plantar erythrodysesthesia (PPE) (64%) and fatigue (68%). Grade ≥3 related AEs occurred in 9 (36%) pts, including immune-related AEs of Grade 3 dyspnea, hypophosphatemia, and pancreatitis in 1 pt each. Treatment related AEs leading to dose interruptions, reductions, or delays occurred in 15 (60%) pts, most commonly PPE in 13 (52%) pts. No pt had a related AE leading to treatment discontinuation or death. Disposition: of 29 pts enrolled, 24 were removed for PD and 1 was removed for an unrelated AE. Best response by RECIST 1.1 in 23 evaluable pts: partial response (PR) in 2 (9%); SD in 14 (61%); PD in 7 (30%). Median time on treatment was 6 months (range 2-26 months). Conclusions: Combination of pembrolizumab with capecitabine and bevacizumab was found to be tolerable with an expected toxicity profile in MSS mCRC pts. With 2 responses, the study met interim analysis criteria to continue accrual. Tissue and blood-based immune correlatives are planned. Clinical trial information: NCT03396926.

Assessment and Comparison of 18F-Fluorocholine PET and 99mTc-Sestamibi Scans in Identifying Parathyroid Adenomas: A Metaanalysis

Hyperparathyroidism is an endocrine disorder caused by one or more hyperfunctioning parathyroid glands. Current imaging consisting of ultrasound and ^99mTc-sestamibi is imprecise, making localization difficult. ¹⁸F-fluorocholine (¹⁸F-FCH) PET has recently shown promise in presurgical localization of parathyroid adenomas. The primary aim of this study was to summarize the sensitivities and specificities of studies using ¹⁸F-FCH PET to localize hyperparathyroidism. A secondary aim was to summarize a subset of studies in which ^99mTc-sestamibi scans were also used and to compare the performance of the 2 modalities. Methods: We searched the MEDLINE and EMBASE databases following the PRISMA (Preferred Reporting Items for Systematic Review and Metaanalysis) statement. Quality was assessed using the QUADAS-2 tool (Quality Assessment of Diagnostic Accuracy Studies). Twenty studies were included for quantitative assessment in our metaanalysis. A random-effects model and a hierarchic summary receiver-operating-characteristic model was used to summarize the sensitivity of ¹⁸F-FCH PET in detecting abnormal parathyroid adenomas. We used the same methodology to assess sensitivity of ^99mTc-sestamibi, as a comparison to ¹⁸F-FCH PET. Results: ¹⁸F-FCH PET had a high sensitivity, 0.97 (range, 0.96-0.98), for the detection of abnormal parathyroid adenomas. In the subpopulation for which both ¹⁸F-FCH and ^99mTc-sestamibi were reported, ¹⁸F-FCH also had a higher sensitivity, 0.96 (0.94-0.98), than the 0.54 (0.29-0.79) reported for ^99mTc-sestamibi (P < 0.001). Conclusion: ¹⁸F-FCH PET demonstrates high localization accuracy in patients with hyperparathyroidism. This metaanalysis supports the use of ¹⁸F-FCH over ^99mTc-sestamibi in patients with hyperparathyroidism.

Outcomes after high-dose radiation in management of neuroendocrine neoplasms

616

Background: In this study, we analyze outcomes after the use of high-dose radiation therapy (RT) in management of neuroendocrine neoplasms (NENs) at a high-volume center. Methods: We performed a retrospective review of patients who received high-dose RT (defined as biologically effective dose (BED) >40, α/β = 10) for their NEN. Patients with small cell lung cancer and Merkel cell carcinoma were excluded, given their unique treatment paradigms. Results: 61 patients completed a radiation course with BED >40 for their NEN (median BED 70, range 44-180). Most tumors were gastroenteropancreatic in origin (n = 20); additional primary sites included lung (n = 11), head and neck (n = 10), cervix (n = 6), other (n = 9) and unknown (n = 5). 56% (n = 34) had well-differentiated (WD) neuroendocrine tumors, and 44% (n = 27) had poorly-differentiated (PD) neuroendocrine carcinomas. Disease stage at the time of RT was localized/locally advanced (LLA, n = 27), or metastatic/recurrent (MR, n = 34). The intent of RT was definitive (n = 18), post-operative (n = 10), for oligoprogression (n = 18), or purely palliative (n = 15). 48 patients had follow-up imaging at a median follow-up of 20 months after radiation. Outcomes were grouped by differentiation and stage, with median time to progression (mTTP) in months (Table). 8% of patients had local progression, while 44% developed new metastases, including 38% of WD-LLA, 47% of PD-LLA, 37% of WD-MR, and 67% of PD-MR disease with progressively shorter median time to progression (26, 10, 8, and 3 months, respectively). Conclusions: These data suggest that focal, high-dose radiation has a role in the management of NENs. Local failure is rare in patients with both WD-LLA and PD-LLA disease. The predominant pattern of failure is development of new metastases, which appear to occur sooner and more frequently in patients with PD and MR disease. [Table: see text]

Haem iron intake and risk of lung cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort

BACKGROUND

Epidemiological studies suggest that haem iron, which is found predominantly in red meat and increases endogenous formation of carcinogenic N-nitroso compounds, may be positively associated with lung cancer. The objective was to examine the relationship between haem iron intake and lung cancer risk using detailed smoking history data and serum cotinine to control for potential confounding.

METHODS

In the European Prospective Investigation into Cancer and Nutrition (EPIC), 416,746 individuals from 10 countries completed demographic and dietary questionnaires at recruitment. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for incident lung cancer (n = 3731) risk relative to haem iron, non-haem iron, and total dietary iron intake. A corresponding analysis was conducted among a nested subset of 800 lung cancer cases and 1489 matched controls for whom serum cotinine was available.

RESULTS

Haem iron was associated with lung cancer risk, including after adjustment for details of smoking history (time since quitting, number of cigarettes per day): as a continuous variable (HR per 0.3 mg/1000 kcal 1.03, 95% CI 1.00-1.07), and in the highest versus lowest quintile (HR 1.16, 95% CI 1.02-1.32; trend across quintiles: P = 0.035). In contrast, non-haem iron intake was related inversely with lung cancer risk; however, this association attenuated after adjustment for smoking history. Additional adjustment for serum cotinine did not considerably alter the associations detected in the nested case-control subset.

CONCLUSIONS

Greater haem iron intake may be modestly associated with lung cancer risk.

Temozolomide in grade III neuroendocrine neoplasms (G3 NENs): A multicenter retrospective review

321

Background: G3 NENs are aggressive, and optimal systemic treatment is unclear. Temozolomide (TEM)-based regimens have been used to treat grade 1-2 NETs, but their efficacy in G3 NENs (Ki-67 > 20%) remains undetermined. Aims: To assess the clinical efficacy of TEM-containing regimens in advanced grade III gastroenteropancreatic NENs (GEPNENs). Methods: A multicentre retrospective review (2008-2017) of patients with metastatic/unresectable G3 GEPNENs who received a TEM-containing regimen. The primary endpoint was time to treatment failure (TTF). Radiologic response was extracted from local reports without formal RECIST criteria. Results: 118 patients in six centers were included (median age 55, 65% male, 15% functional, 75% pancreatic NEN). 57% were well-differentiated, 35% poorly-differentiated, and 18% unknown based on local pathology reports. The regimen used was CAPTEM in 93% and TEM in 7%. Best radiological responses were: complete response (1%), partial response (39%), stable disease (22%), progressive disease (31%), unknown (7%) not by RECIST. Median TTF was 150 days and median overall survival (OS) 18.0 months. Fifteen patients (14%) required dose reductions/discontinuation due to adverse events. TTF was shorter for patients on TEM alone (p = 0.02, Table 1). Well-differentiated NENs had better response rate (52% vs 26%, p = 0.02) and overall survival (30.1 vs 12.0 mo, p = 0.008) compared to poorly-differentiated NEN. Conclusions: This is the largest TEM treatment series in G3 NEN, involving collaboration of several major North American NET centers. 40% of patients showed some degree of response, and treatment was generally well-tolerated. TEM-based regimens should be considered a viable treatment option in this setting. Prospective confirmatory trials (such as EA2142) may face difficulties in accrual due to disease rarity. [Table: see text]

Emerging value of multigene panels for germline testing in patients with neuroendocrine tumors

226

Background: Neuroendocrine tumors (NETs) are known to be associated with hereditary syndromes stemming from MEN1, VHL, SDH or TSC mutations. Recent data suggest that additional germline mutations may be relevant, implying a role of germline testing with multigene panels. We examined genetic counseling (GC) referral and testing patterns, test results, and their changes over time in NET patients (pts). Methods: Retrospective chart review was conducted in 236 NET pts referred to UCSF Cancer Genetics and Prevention Program 2004-2017. Univariate logistic models were used to assess relationship between binary outcome and covariate. STATA was used for analysis and statistical significance was based on p < 0.05. Results: 139 referred pts (59%) followed up with GC. Pts with >1 family members diagnosed with cancer were more likely to attend GC [OR=2.75, p=0.010]. Among 107 pts tested, small bowel NETs were less associated with testing than pancreatic NETs [OR=0.15, p=0.001]. Single-gene tests were routine until 2015, when panels up to 130 genes became standard. Overall, 31 pts (29% of 107 tested) had a pathogenic/likely pathogenic (P/LP) result. There was no significant difference between single and multi-gene tests in identifying P/LP mutations (likely due to changes in threshold for testing over time), but greater diversity in P/LP mutations was noted with larger panels. Functional tumors showed lower rate of P/LP mutations than non-functional [OR=0.17, p=0.037]. Conclusions: Only 59% of referred pts followed up with GC, suggesting significant barriers to testing exist. Of those tested, 29% harbored a P/LP mutation. Germline mutations not traditionally associated with NETs were identified, highlighting the potential importance of larger panels to detect rare mutations. [Table: see text]

High-Temperature Cross-Linking of Carbon Nanotube Multi-Yarn Using Polyvinylpyrrolidone as a Binding Agent

Carbon nanotube (CNT) multi-yarn was cross-linked together at elevated temperatures using a poly- mer, with the intent of improving their strength and electrical conductivity. They were functionalized using an acid treatment and immersed in a bath of different concentrations (0.5%, 0.1%, and 0.2%) of polyvinylpyrrolidone (PVP). Then they were placed in an oven at various temperatures (180 °C, 200 °C, and 220 °C) in order to cause cross-linking among the carbon nanotube yarns. The phys- ical, chemical, electrical, and mechanical properties of the cross-linked yarns were investigated. The yarns cross-linked at higher temperatures and greater concentrations of PVP had a greater increase in linear mass density, indicating that the cross-linking process had worked as expected. Yarns that were cross-linked at lower temperatures had greater tensile strength and better spe- cific electrical conductivity. Those that were treated with a greater concentration of polymer had a greater ultimate tensile strength. All these results are encouraging first step, but still need further development if CNT yarn is to replace copper wire.

3-D ultrasound guidance of surgical robotics using catheter transducers: feasibility study

The goal of this study was to test the feasibility of using a real-time 3-D (RT3D) ultrasound scanner with matrix array catheter probes to guide a surgical robot. We tested the accuracy of using 3-D catheter transducers with the 3-D measurement software of the scanner to direct automatically a robot arm that touched two needle tips together within a water tank and inside a vascular graft. RMS measurement error ranged from 2.4 to 3.4 mm for two catheter designs.

A randomized clinical trial of valacyclovir in multiple sclerosis

OBJECTIVE

The human Herpesvirus type-6 (HHV-6) has been implicated in multiple sclerosis (MS). Valacyclovir is an antiviral agent with an excellent safety profile. A two-year placebo-controlled, double-blind study was conducted to (1) ascertain if high-dose, prolonged treatment with valacyclovir would be safe and (2) observe if valacyclovir would delay the progression of MS clinically or by magnetic resonance imaging (MRI).

DESIGN/METHODS

Fifty-eight patients were stratified as to severity and randomly assigned to receive valacyclovir (3000 mg/day) or placebo for a period of two years. Patients were followed clinically over the two-year period by means of the Expanded Disability Status Scale (EDSS), the Ambulation Index (AI) and brain MRI scans. Patients underwent routine lab studies every three months. Patients continued on the medication for two years unless they had a sustained progression or repeated exacerbations.

RESULTS

No patient discontinued the study due to side effects or toxicity. In Relative Ranking of Progression, time to first attack, attack rate, and time to withdrawal there were trends (but not statistically significant) toward drug effect over placebo in the Severe clinical category. MRI evaluation showed no significant drug effect.

CONCLUSIONS

Although not statistically significant, positive trends were detected for acyclovir by clinical measures, but not by MRI.

Human herpesvirus-7 (HHV-7): current status

BACKGROUND

Human herpesvirus-7 (HHV-7) is a newly discovered virus and very little is known about its prevalence, biologic, immunologic and molecular biology aspect. Besides the HHV-7 etiologic role in a few cases of exanthem subitum, its association with other diseases has not been reported.

OBJECTIVES

To review what is currently known about HHV-7.

RESULTS

HHV-7 was first isolated in 1990 from purified T-cells from a healthy individual. Following this report, an independent isolation of HHV-7 was reported from the mononuclear cells (PBMC) of a chronic fatigue syndrome patient. HHV-7 is closely related to human herpesvirus-6 (HHV-6) and human cytomegalovirus (HCMV), but is distinct from Epstein-Barr virus (EBV), herpes simplex virus and varicella zoster virus. Using polyvalent and monoclonal antibodies, several HHV-7 viral proteins were identified, ranging from 136 to 30 kDa. HHV-7 infection occurs later than HHV-6, which appears in early childhood. HHV-7 is ubiquitous, and its prevalence rate is >85% in the US population, although its rates of prevalence in Japan is lower than in the USA and Europe. HHV-7 is frequently isolated from saliva; however, HHV-7 has been consistently isolated from PBMC from young children as well. Several cases of exanthem subitum have been linked to primary infection of HHV-7, suggesting that it may also cause exanthem subitum. Primary infection with HHV-7 was also reported from a patient with features of hepatitis and exanthem subitum. This virus was also isolated from tissues from a case of hepatosplenomegaly and pancytopenia lacking either EBV or HCMV. Thus far, no other disease associated with HHV-7 has been reported. Only one continuous T-cell line (SupT1) can support the replication of HHV-7, but the virus yield is extremely low.

CONCLUSIONS

It has been about 4 years since this member of the human herpesvirus family was reported. In the coming years, more data will be available on the epidemiology, biology, immunology, molecular biology, and pathogenesis of HHV-7. The finding of reciprocal interference between HHV-7 and HIV-1, suggesting competition at the receptor level is important, needs further work and here HHV-7 may play a role as a negative cofactor in the natural history of HIV infection. Because of HHV-7 interaction with HIV-1, the possibility of its vertical transmission needs to be investigated. This review on HHV-7 is intended to provide current information on HHV-7.

Tobacco availability and point of sale marketing in demographically contrasting districts of Massachusetts

OBJECTIVE

To assess the prevalence and characteristics of tobacco sales and point-of-sale promotions and advertising in predominantly Latino business districts, and in comparison districts; and the economic importance of tobacco sales and marketing to Latino owned small businesses.

DESIGN

Observational surveys of retail establishments and interviews with store managers.

SETTING

Demographically contrasting business districts of eastern Massachusetts.

MAIN OUTCOME MEASURES

Percentage of businesses selling tobacco, numbers and characteristics of exterior and interior tobacco advertisements per store, merchant reports of promotional allowances received from tobacco distributors.

RESULTS

The proportion of businesses selling tobacco, and hence having storefront tobacco advertising, is strongly negatively correlated with per capita income in the census tracts where businesses are located (Spearman's rho = -0.794, p = 0.006). Mentholated brands are marketed disproportionately in low income, urban communities. Latino merchants are highly dependent on tobacco sales, but would require relatively modest compensation to forego tobacco promotional allowances.

CONCLUSIONS

Storefront tobacco advertising is far more prevalent in predominantly minority, low income communities than in non-minority, higher income communities, principally because of the differing mix of kinds of businesses in the two types of communities, and the greater prevalence of tobacco vendors in lower income neighbourhoods. Tobacco companies obtain this advertising at little cost.

Seroprevalence of human herpesvirus-8 (HHV-8) in countries of Southeast Asia compared to the USA, the Caribbean and Africa

Seroprevalence of HHV-8 has been studied in Malaysia, India, Sri Lanka, Thailand, Trinidad, Jamaica and the USA, in both healthy individuals and those infected with HIV. Seroprevalence was found to be low in these countries in both the healthy and the HIV-infected populations. This correlates with the fact that hardly any AIDS-related Kaposi's sarcoma has been reported in these countries. In contrast, the African countries of Ghana, Uganda and Zambia showed high seroprevalences in both healthy and HIV-infected populations. This suggests that human herpes virus-8 (HHV-8) may be either a recently introduced virus or one that has extremely low infectivity. Nasopharyngeal and oral carcinoma patients from Malaysia, Hong Kong and Sri Lanka who have very high EBV titres show that only 3/82 (3.7%) have antibody to HHV-8, demonstrating that there is little, if any, cross-reactivity between antibodies to these two gamma viruses.

Preliminary evaluation of high-frequency chest compression for secretion clearance in mechanically ventilated patients

BACKGROUND

A high-frequency chest compression (HFCC) device called the ThAIRapy System has been developed to provide secretion clearance therapy. We evaluated the safety, efficacy, and utility of the device in long-term mechanically ventilated patients. DESCRIPTION OF DEVICE: The primary components of the device are an air-pulse generator and an inflatable vest. Small gas volumes are alternately injected into and withdrawn from the vest by the air-pulse generator at a fast rate, creating an oscillatory or vibratory motion. The pulses cause the vest to inflate and deflate against the thorax of the patient.

EVALUATION METHODS

We evaluated HFCC by comparing it to percussion and postural drainage therapy (P&PD); sputum production, patient comfort (PC), pulse-oximetry saturation (SpO2), heart rate (HR), and blood pressure (BP) data were collected and compared between the 2 methods. We monitored the reliability of the device and distributed a survey questionnaire to the entire respiratory therapy staff to assess utility.

EVALUATION RESULTS

Nine patients completed the safety and efficacy portion of our evaluation. No significant difference was found between P&PD and HFCC in the wet weight of collected sputum, the mean change-in-percent of SpO2 or the mean percent change from baseline in HR, BP, or PC. All therapists believed that the ThAIRapy System was easy to learn, and 70% considered it an acceptable alternative to P&PD. Of the staff members surveyed, 80% believed that use of the HFCC device resulted in time savings in all or most cases. There were no equipment malfunctions in 225 hours of use.

CONCLUSIONS

Compared to P&PD, HFCC via the ThAIRapy System may be equally efficacious in promoting secretion clearance in long-term mechanically ventilated patients. HFCC is neither more nor less safe for patients than is P&PD using SpO2, HR, BP, and PC as outcome variables. Most of our respiratory therapists perceived HFCC as an acceptable alternative to P&PD.

Surveys of long-term ventilatory support in Minnesota: 1986 and 1992

To determine the prevalence and some characteristics of persons in Minnesota receiving long-term ventilatory support (ventilator-assisted individuals [VAIs]), we conducted a survey of this population in Minnesota in 1986 and then again in 1992 by canvassing long-term care units and home medical equipment providers. The number of VAIs in 1992 was 110 percent greater than in 1986 (216 vs 103). In 1986, 81 percent of these patients received care at home; the remaining patients were supported in long-term care facilities. By 1992, the percentage had changed to 65 percent supported in the home and 35 percent in long-term care facilities. In both surveys, the largest number of VAIs were in the diagnostic categories of poliomyelitis, cervical trauma, amyotrophic lateral sclerosis (ALS), chronic obstructive pulmonary disease (COPD), and muscular dystrophy. The primary diagnoses with the greatest increase in number of patients were cervical trauma and ALS. When VAIs were categorized by age groups, there was a large increase in the proportion of patients younger than 10 years of age and older than 60 years of age. While the number of patients is small, the total resources required for care of these patients can be substantial. These data suggest that we need to monitor the number and demographic characteristics of VAIs in the United States so that appropriate policies and programs are developed to provide effective support services.

Strategies of self-control in male young offenders who have reduced their alcohol consumption without formal intervention

Fifty-one imprisoned male young offenders who reported having stopped or reduced their alcohol consumption without formal intervention were studied to discover which self-control strategies they used to help them change their drinking behaviour. Change was precipitated by adverse consequences of drinking, particularly crime and violence. The most commonly used strategies involve social change: finding alternative activities, avoiding heavy-drinking friends, and avoiding situations where heavy drinking typically occurs. Next most frequently used strategies involve setting limits: restricting drinking time, expenditure on drink, and alcohol consumption. Finally, rate control, including beverage changes from stronger to weaker or non-alcoholic drinks, is a commonly reported strategy. The implications for the design of intervention programmes are discussed.

Anti-B-cell monoclonal antibody-purged autologous bone marrow transplantation for B-cell non-Hodgkin's lymphoma: phenotypic reconstitution and B-cell function

In the present report we have attempted to examine immunologic reconstitution following high-dose chemoradiotherapy and anti-B-cell monoclonal antibody (MoAb)-purged autologous bone marrow transplantation (ABMT). By cell-surface phenotypic analysis, the majority of patients had normal percentage of natural killer cells (NK), monocytes, and CD8+ T cells at one month post-ABMT. In contrast, the percentage of CD4+ T cells was reduced for at least 3 years, and the CD4:CD8 ratio reflected this imbalance. B-cell reconstitution was slightly prolonged, with normal percentage and absolute numbers of CD20+ B cells evident by 3 months. Although B cells returned by 3 months, in vitro assessment of B-cell function demonstrated impairment of proliferative responses to either anti-immunoglobulins bound to beads (anti-Ig), Epstein-Barr virus (EBV), or interleukin-2 (IL-2) for approximately 1 year and low molecular B-cell growth factor (BCGF) for approximately 2 or more years. Moreover, in vivo B-cell reconstitution demonstrated a more selective defect, with normal levels of immunoglobulin IgM returning at 6 months, IgG at 12 months, and IgA after 2 years. Despite normal numbers of B cells and relative normal levels of Ig early following ABMT, our in vitro data suggest an intrinsic defect in B-cell responsiveness. Moreover, these defects are similar to those observed following nonpurged autologous and allogeneic BMT, although the interval of immune impairment appears more prolonged.

Expression and regulation of CD5 on in vitro activated human B cells

The T cell-associated antigen CD5 has been shown to play an important role in the regulation of T cell activation. Monoclonal antibodies directed against CD5 upregulate helper function, and induce interleukin 2 (IL2) production by mature T cells as well as thymocytes. CD5 is also expressed on subsets of B cells associated with autoantibody production, and CD5+ B cells are present in increased numbers in patients with rheumatoid arthritis and systemic lupus erythematosis. More recently CD5 has been found to be present on human B lymphocytes following in vitro activation with phorbol myristate acetate. To date a similar functional role for CD5 has not to date been demonstrated for B cells. In this study we have shown that structurally similar CD5 molecules are present on activated B cells and T cells. In addition, CD5 on both stimulated B cells and T cells is phosphorylated, which may be important in the function of CD5 following activation. CD5 protein or mRNA was not detected on unstimulated splenic B cells depleted of any CD5+ cells. To investigate the control of CD5 expression, we examined a series of cytokines either alone or in combination for their effect on the induction of CD5. CD5 expression was specifically inhibited by IL4 but not by the other cytokines tested. This inhibition was very specific as IL4 did not inhibit the expression of other B cell activation antigens including CD25, B5, T9 and CD23 as well as the pan-B cell antigen CD20. The addition of other cytokines did not increase or reverse the inhibition of CD5 expression by IL4. This inhibition was demonstrated by immunofluorescence and flow cytometric analysis. Immunoprecipitation studies of 125I-labeled activated B cells demonstrated that there was a decrease in cell surface CD5 protein, and not simply inhibition of expression of a particular epitope. Northern blot analysis demonstrated that the expression of CD5 mRNA was markedly inhibited in the presence of IL4, whereas the induction of the protooncogene c-myb was unaffected. This suggests that IL4 inhibits CD5 protein expression on activated B cells by reducing the amount of CD5 mRNA transcription or increasing the degradation of CD5 mRNA. The role of the T cell-derived lymphokine IL4 in regulating CD5 expression may be important in the disease states characterized by increased numbers of CD5+ B cells.

Studies of in vitro activated CD5+ B cells

Human B lymphocytes undergo distinct phenotypic changes following activation with antigen and polyclonal mitogens. Increasing interest has focused on the unique subpopulation of B cells that expresses the CD5 antigen. In this study, we examined the signals that induce the expression of CD5 on normal splenic B cells. Only 12-O-tetradecanoylphorbol-13-acetate (TPA) induced CD5 expression on highly purified splenic B cells, whereas anti-immunoglobulin (anti-Ig), Epstein-Barr virus, anti-CD20, recombinant interleukin-1 (rIL-1), rIL-2, rIL-4, recombinant interferon-gamma (rINF-gamma), and B-cell growth factor all failed to induce CD5 expression. The expression of CD5 was detected on the cell surface by 48 hours and decreased by 96 hours. Dual-fluorochrome analysis demonstrated that the CD5+ B cells coexpressed the B-cell activation antigens B5, IL-2 receptor, and CD23, thereby providing phenotypic evidence that this B-cell subpopulation is activated. In vitro studies of dual-fluorochrome-sorted, TPA-stimulated splenic B cells demonstrated significantly greater tritiated thymidine incorporation and Ig secretion by the CD20+ CD5- cells than by the CD20+ CD5+ subset. These phenotypic and functional studies are consistent with the notion that TPA-induced CD5+ B cells are a subset of in vitro activated B lymphocytes.

Pre-exposure of human B cells to recombinant IL-1 enhances subsequent proliferation

The reported effects of the monocyte-derived cytokine IL-1 on human B lymphocytes are both varied and controversial. IL-1 has been reported to augment both proliferation and Ig secretion of previously activated human B cells. In the present study highly purified splenic B cells were cultured with rIL-1 before, simultaneously with, and after the addition of the polyclonal B cell mitogen, anti-Ig. rIL-1 had no significant effect on B cell proliferation when added simultaneously with or after B cell activation with anti-Ig. However, incubation of splenic B cells with rIL-1 for 24 h before stimulation with anti-Ig appeared to enhance mitogenesis. With the observation that rIL-1 exerted effects on resting B cells, the effect of rIL-1 on several events which accompany B cell activation was examined. rIL-1 failed to stimulate RNA synthesis, effect increases in cell size or intracellular Ca2+ levels, or lead to the hyperexpression of MHC class II or B cell activation Ag. These studies suggest that rIL-1 does not activate B cells but primes them to respond to subsequent activation.

Pre-exposure of human B cells to recombinant IL-1 enhances subsequent proliferation

The reported effects of the monocyte-derived cytokine IL-1 on human B lymphocytes are both varied and controversial. IL-1 has been reported to augment both proliferation and Ig secretion of previously activated human B cells. In the present study highly purified splenic B cells were cultured with rIL-1 before, simultaneously with, and after the addition of the polyclonal B cell mitogen, anti-Ig. rIL-1 had no significant effect on B cell proliferation when added simultaneously with or after B cell activation with anti-Ig. However, incubation of splenic B cells with rIL-1 for 24 h before stimulation with anti-Ig appeared to enhance mitogenesis. With the observation that rIL-1 exerted effects on resting B cells, the effect of rIL-1 on several events which accompany B cell activation was examined. rIL-1 failed to stimulate RNA synthesis, effect increases in cell size or intracellular Ca2+ levels, or lead to the hyperexpression of MHC class II or B cell activation Ag. These studies suggest that rIL-1 does not activate B cells but primes them to respond to subsequent activation.

Changes in glutamate-cycle enzyme mRNA levels in a rat model of hepatic encephalopathy

To detect possible changes in the regulation of glutamate/gamma-aminobutyric acid (GABA) enzymes at the level of gene expression in a thioacetamide-induced rat model of acute hepatic encephalopathy, we have examined changes in the mRNAs of four glutamate/GABA enzymes by quantitative RNA blot hybridization analysis. Such changes could reflect cell adaptation to excess ammonia or some other associated metabolic stress. The mRNA levels of glutamate dehydrogenase (GDH) decreased similarly in three different brain regions, whereas those of glutamine synthetase (GS) and glutaminase (GA) increased. The mRNA levels of glutamate decarboxylase (GAD) were unchanged. The results indicate that some effect of liver damage, presumably hyperammonemia, affected the expression of some, but not all, genes associated with ammonia and glutamate metabolism in the brain. This adaptation of gene expression to secondary effects of ammonia on brain amino acid neurotransmitter metabolism or brain energy metabolism could play a role in the physiological changes observed in hepatic encephalopathy.

Antigenic and cellular heterogeneity of primary uveal malignant melanomas

Monoclonal antibody (MAb) MAb8-1H, which identifies an ocular melanoma-associated antigen, and computer-assisted cytomorphometric analysis were used to investigate antigenic and cellular heterogeneity in four atypical cases of choroidal or ciliary body melanoma. The presence of one or more well-localized, morphologically distinct areas within each uveal melanoma, suggestive of multiple tumor cell populations, was observed by conventional light microscopy. In one choroidal melanoma with an unusual bilobed configuration, MAb8-1H bound only to the anterior lobe composed of spindle melanoma cells. In the other three cases, MAb8-1H bound selectively to discrete regions within the uveal melanoma corresponding to the well-localized, morphologically distinct areas seen by light microscopy. In each case, a computer was used to calculate the nuclear area of 50 tumor cells corresponding to the areas binding or not binding MAb8-1H. In three of the four cases examined, the differences in mean nuclear area between the discrete populations of tumor cells were statistically significant. Our results suggest that some uveal melanomas are composed of two or more discrete populations of tumor cells with regard to both expression of melanoma-associated antigens and cytomorphologic features.

The red eye. Why it happens, what to do, when to refer

The ability to differentiate the various causes of ocular hyperemia is important in primary care. Symptoms such as pain, photophobia, and significant blurring of vision usually signify a more serious ocular condition or even a serious systemic disease. The majority of cases can be managed by the primary care physician, but the more serious causes of a red eye deserve prompt recognition and referral to an ophthalmologist to ensure appropriate management.

Effects of dietary supplements and a tryptophan-free diet on aggressive behavior in rats

The effects of dietary excesses of tryptophan, histidine, tyrosine or choline and of a tryptophan-free diet were examined on shock-induced fighting, muricide and jump-flinch thresholds. Following the tryptophan-free diet, shock-induced fighting and pain sensitivity were specifically increased. The increased incidence of muricide was not specific to the lack of tryptophan in the diet. Groups of rats which were pair fed chow or had 0.15% L-tryptophan added to the tryptophan-free diet increased muricide as well. Brain 5-HT levels were 41% depleted following the tryptophan-free diet and reduced 13% with the 0.15% tryptophan supplement. In addition body weights were reduced in the three groups compared to control. None of the excess diets affected shock-induced fighting, muricide and jump-flinch thresholds. Body weights were decreased in the excess tryptophan, histidine, tyrosine and choline groups. These data indicate that the expression of different forms of aggression appears to be influenced by a tryptophan deficiency in the diet, but not by excesses of tryptophan, tyrosine, histidine and choline.