Race and Ethnic Group Enrollment and Outcomes for Wilms Tumor: Analysis of the Current Era Children's Oncology Group Study, AREN03B2

BACKGROUND

To review race and ethnic group enrollment and outcomes for Wilms tumor (WT) across all 4 risk-assigned therapeutic trials from the current era Children's Oncology Group Renal Tumor Biology and Risk Stratification Protocol, AREN03B2.

STUDY DESIGN

For patients with WT enrolled in AREN03B2 (2006 to 2019), disease and biologic features, therapeutic study-specific enrollment, and event-free (EFS) and overall (OS) 4-year survival were compared between institutionally reported race and ethnic groups.

RESULTS

Among 5,146 patients with WT, no statistically significant differences were detected between race and ethnic groups regarding subsequent risk-assigned therapeutic study enrollment, disease stage, histology, biologic factors, or overall EFS or OS, except the following variables: Black children were older and had larger tumors at enrollment, whereas Hispanic children had lower rates of diffuse anaplasia WT and loss of heterozygosity at 1p. The only significant difference in EFS or OS between race and ethnic groups was observed among the few children treated for diffuse anaplasia WT with regimen UH-1 and -2 on high-risk protocol, AREN0321. On this therapeutic arm only, Black children showed worse EFS (hazard ratio = 3.18) and OS (hazard ratio = 3.42). However, this finding was not replicated for patients treated with regimen UH-1 and -2 under AREN03B2 but not on AREN0321.

CONCLUSIONS

Race and ethnic group enrollment appeared constant across AREN03B2 risk-assigned therapeutic trials. EFS and OS on these therapeutic trials when analyzed together were comparable regarding race and ethnicity. Black children may have experienced worse stage-specific survival when treated with regimen UH-1 and -2 on AREN0321, but this survival gap was not confirmed when analyzing additional high-risk AREN03B2 patients.

Combinatorial Approaches for Chemotherapies and Targeted Therapies With Radiation: United Efforts to Innovate in Patient Care

Combinatorial therapies consisting of radiation therapy (RT) with systemic therapies, particularly chemotherapy and targeted therapies, have moved the needle to augment disease control across nearly all disease sites for locally advanced disease. Evaluating these important combinations to incorporate more potent therapies with RT will aid our understanding of toxicity and efficacy for patients. This article discusses multiple disease sites and includes a compilation of contributions from expert Red Journal editors from each disease site. Leveraging improved systemic control with novel agents, we must continue efforts to study novel treatment combinations with RT.

Incidence and survival of secondary malignancies after external beam radiotherapy for prostate cancer in the SEER database

INTRODUCTION

We investigated the incidence of secondary bladder (BCa) and rectal cancers (RCa) after external beam radiotherapy (EBRT) for prostate cancer (PCa) compared to radical prostatectomy (RP) alone, and compared cancer-specific survival (CSS) of these secondary neoplasms to their primary counterparts.

METHODS

This retrospective cohort study included men in the SEER cancer registry with a diagnosis of non-metastatic, clinically node-negative PCa treated with either RP or EBRT from 1995-2011 and allowed a minimum five-year lag period for the development of secondary BCa or RCa. Patients were divided into two eras, 1995-2002 and 2003-2011, to examine differences in incidence of secondary malignancies over time. Univariable and multivariable competing risk analyses with Fine-Gray subdistribution hazard and cause-specific hazard models were used to examine the risk of developing a secondary BCa or RCa. Competing risks analyses were used to compare CSS of primary vs. secondary BCa and RCa.

RESULTS

A total of 198 184 men underwent RP and 190 536 underwent EBRT for PCa. The cumulative incidence of secondary BCa at 10 years was 1.71% for RP, and 3.7% for EBRT (p<0.001), while that of RCa was 0.52% for RP and 0.99% for EBRT (p<0.001). EBRT was associated with almost twice the risk of developing a secondary BCa and RCa compared to RP. The hazard of secondary BCa following EBRT delivered during 2003-2011 was 20% less than from 1995-2002 (p<0.09, Fine-Gray model), while that of secondary RCa was 31% less (p<0.001) (hazard ratio 0.78, p<0.001) for Fine-Gray and cause-specific hazard models. In the Fine-Gray model, the risk of death from BCa was 27% lower for secondary BCa after RP compared to primary BCa, while the risk of death was 9% lower for secondary BCa after EBRT compared to primary BCa. There was no difference in RCa-specific survival between primary or secondary RCa after RP or EBRT.

CONCLUSIONS

The risk of BCa and RCa is almost twice as high for men undergoing EBRT for localized PCa vs. RP, but that risk is declining, likely reflecting advances in radiation delivery. The development of secondary RCa or BCa does not confer elevated risk of death compared to their primary counterparts.

Late Cardiac Toxic Effects Associated With Treatment Protocols for Hodgkin Lymphoma in Children

Importance

Contemporary North American trials for children with Hodgkin lymphoma (HL) have decreased radiation therapy (RT) use and increased pharmacologic cardioprotection but also increased the cumulative doxorubicin dose, making overall treatment consequences for late cardiac toxic effects uncertain.

Objective

To estimate the risk of cardiac toxic effects associated with treatments used in modern pediatric HL clinical trials.

Design, Setting, and Participants

For this cohort study, Fine and Gray models were fitted using survivors in the Childhood Cancer Survivor Study who were diagnosed with HL between January 1, 1970, and December 31, 1999, and were followed for a median of 23.5 (range, 5.0-46.3) years. These models were applied to the exposures in the study population to estimate the 30-year cumulative incidence of cardiac disease. The study population comprised patients with intermediate-risk or high-risk HL treated in 4 consecutive Children's Oncology Group clinical trials from September 2002 to October 2022: AHOD0031, AHOD0831, AHOD1331, and S1826. Data analysis was performed from April 2020 to February 2023.

Exposures

All patients received chemotherapy including doxorubicin, and some patients received mediastinal RT, dexrazoxane, or mediastinal RT and dexrazoxane.

Main Outcomes and Measures

Estimated 30-year cumulative incidence of grade 3 to 5 cardiac disease.

Results

The study cohort comprised 2563 patients, with a median age at diagnosis of 15 (range, 1-22) years. More than half of the patients were male (1357 [52.9%]). All 2563 patients received doxorubicin, 1362 patients (53.1%) received mediastinal RT, and 307 patients (12.0%) received dexrazoxane. Radiation therapy use and the median mean heart dose among patients receiving RT decreased, whereas the planned cumulative dose of doxorubicin and use of dexrazoxane cardioprotection increased. For patients treated at age 15 years, the estimated 30-year cumulative incidence of severe or fatal cardiac disease was 9.6% (95% CI, 4.2%-16.4%) in the AHOD0031 standard treatment group (enrolled 2002-2009), 8.6% (95% CI, 3.8%-14.9%) in the AHOD0831 trial (enrolled 2009-2012), 8.2% (95% CI, 3.6%-14.3%) in the AHOD1331 trial (enrolled 2015-2019), and 6.2% (95% CI, 2.7%-10.9%) in the S1826 trial (enrolled 2019-2022), whereas the expected rate in an untreated population was 5.0% (95% CI, 2.1%-9.3%). Despite the estimated reduction in late cardiac morbidity, the frequency of recommended echocardiographic screening among survivors will increase based on current guidelines.

Conclusions and Relevance

In this cohort study of sequential HL trials, reductions in the proportion of children receiving mediastinal RT and increases in dexrazoxane use were estimated to offset the increased doxorubicin dose and produce a net reduction in late cardiac disease. Further studies on dexrazoxane are warranted to confirm whether its role in reducing cardiac toxic effects is maintained long term. These findings suggest that survivorship follow-up guidelines should be refined to align with the risks associated with treatment.

Prognostic value of chest x-ray- and CT-defined large mediastinal adenopathy in high-risk pediatric Hodgkin lymphoma: A report from the Children's Oncology Group Study AHOD0831

PURPOSE/OBJECTIVE

We compared the prognostic value of chest radiograph (CXR)- and computed tomography (CT)-derived definition of large mediastinal adenopathy (LMA) in pediatric Hodgkin lymphoma (HL).

MATERIALS/METHODS

Total 143 patients treated for stage IIIB/IVB HL on COG AHOD0831 were included in this study. Six definitions of LMA were investigated: (i) mediastinal mass ratio on CXR (MRCXR ) > 1/3; (ii) mediastinal mass ratio on CT (MRCT ) > 1/3; (iii) mediastinal mass volume on CT (MVCT ) > 200 mL; (iv) normalized mediastinal mass volume (MVCT /thoracic diameter [TD]) > 1 mL/mm; (v) mediastinal mass diameter on CT (MDCT ) > 10 cm; and (vi) normalized mediastinal mass diameter (MDCT /TD) > 1/3.

RESULTS

Median age at diagnosis was 15.8 years (range: 5.2-21.3 years). In patients with a slow early response (SER) to chemotherapy, MVCT  > 200 mL, MDCT  > 10 cm, and MDCT /TD > 1/3 were associated with worse relapse-free survival (RFS) on MVA, while MRCXR  > 1/3, MRCT  > 1/3, and MVCT /TD > 1 mL/mm trended toward worse RFS; MDCT /TD was the most strongly prognostic for inferior RFS, with a hazard ratio of 6.41 for MDCT /TD > 1/3 versus ≤1/3 on MVA (p = .02).

CONCLUSION

LMA according to MVCT  > 200 mL, MDCT  > 10 cm, and MDCT /TD > 1/3 is associated with poor prognosis in advanced-stage HL patients with SER. The normalized mediastinal diameter, MDCT /TD > 1/3 appears to be the strongest predictor of inferior RFS.

Baseline metabolic tumour burden improves risk stratification in Hodgkin lymphoma: A Children's Oncology Group study

The Children's Oncology Group AHOD0831 study used a positron emission tomography (PET) response-adapted approach in high-risk Hodgkin lymphoma, whereby slow early responders (SERs) received more intensive therapy than rapid early responders (RERs). We explored if baseline PET-based characteristics would improve risk stratification. Of 166 patients enrolled in the COG AHOD0831 study, 94 (57%) had baseline PET scans evaluable for quantitative analysis. For these patients, total body metabolic tumour volume (MTV), total lesion glycolysis (TLG), maximum standardized uptake value (SUVmax ) and peak SUV (SUVpeak ) were obtained. MTV/TLG thresholds were an SUV of 2.5 (MTV2.5 /TLG2.5 ) and 40% of the tumour SUVmax (MTV40% /TLG40% ). TLG2.5 was associated with event-free survival (EFS) in the complete cohort (p = 0.04) and in RERs (p = 0.01), but not in SERs (p = 0.8). The Youden index cut-off for TLG2.5 was 1841. Four-year EFS was 92% for RER/TLG2.5  up to 1841, 60% for RER/TLG2.5  greater than 1841, 74% for SER/TLG2.5  up to 1841 and 79% for SER/TLG2.5  greater than 1841. Second EFS for RER/TLG2.5  up to 1841 was 100%. Thus, RERs with a low baseline TLG2.5 experienced excellent EFS with less intensive therapy, whereas RERs with a high baseline TLG2.5 experienced poor EFS. These findings suggest that patients with a high upfront tumour burden may benefit from intensified therapy, even if they achieve a RER.

Focal versus craniospinal radiation for disseminated atypical teratoid/rhabdoid tumor following favorable response to systemic therapy

PURPOSE

Radiotherapy (RT) is associated with improved survival in atypical teratoid/rhabdoid tumor (ATRT); however, optimal RT delivery is unknown. A meta-analysis was conducted for disseminated (M+) ATRT receiving focal or craniospinal radiation (CSI).

METHODS

After abstract screening, 25 studies (1995-2020) contained necessary patient, disease, and radiation treatment information (N = 96). All abstract, full text, and data capture were independently double-reviewed. The corresponding author was contacted for cases of insufficient information. Response to pre-radiation chemotherapy (N = 57) was categorized as complete response (CR), partial response (PR), stable disease (SD), and progressive disease (PD). Univariate and multivariate statistics were performed to investigate survival correlation. Patients with M4 disease were excluded.

RESULTS

The 2- and 4-year overall survival (OS) was 63.8% and 45.7%, respectively, with a median follow-up of 2 years (range 0.3-13.5). The median age was 2 years (range 0.2-19.5), and 96% received chemotherapy. On univariate analysis, gross total resection (GTR, p = .0007), pre-radiation chemotherapy response (p < .001), and high-dose chemotherapy with stem cell recuse (HDSCT, p = .002) correlated with survival. On multivariate analysis, pre-radiation chemotherapy response (p = .02) and GTR (p = .012) retained survival significance as compared to a trend for HDSCT (p = .072). Comparisons of focal RT (vs. CSI) and greater than or equal to 5400 cGy primary dose were nonsignificant. Following CR or PR, a statistical trend favored focal radiation (p = .089) over CSI.

CONCLUSION

Chemotherapy response prior to RT and GTR correlated with improved survival on multivariate analysis for ATRT M+ receiving RT. No benefit was observed for CSI compared to focal RT among all patients and following favorable chemotherapy response, inviting further study of focal RT for ATRT M+.

ATRT-07. Low-grade diffusely infiltrative tumor, SMARCB1-mutant: a clinical and histopathological distinct entity showing epigenetic similarity with ATRT-MYC

Most atypical teratoid/rhabdoid tumors (ATRTs) occur in infants, but children and adolescents may also be affected. ATRTs occurring in older patients often comprise the molecular subgroup ATRT-MYC. Recently, central nervous system low-grade diffusely infiltrative tumor with INI1 deficiency (CNS LGDIT-INI1) has been described as a rare low-grade lesion (Nobusawa et al. Am J Surg Pathol 2020;44:1459-1468). Little is known on the molecular relationship of CNS LGDIT-INI1 and ATRT. We therefore further explored a series of six CNS LGDIT-INI1. The median age of the four males and two females was 16 years (range: 10-28 years). All tumors were of supratentorial location and showed low to moderate cellularity, diffuse growth of inconspicuous small SMARCB1-deficient tumor cells and reactive pleomorphic neuronal and glial cells with retained SMARCB1-staining in the background. In addition, two cases also displayed a high-grade rhabdoid component. After DNA isolation, purification and bisulfite conversion, samples were subjected to DNA methylation profiling (MethylationEPIC BeadChip array). Using DNA methylation-based classification and the Heidelberg Brain Tumor Classifier (version v11b4), all tumors were classified as ATRT-MYC (median calibrated score: 0.97). On t-SNE analysis, DNA methylation profiles grouped closely together in proximity to ATRT-MYC. Follow-up information was available for four cases (including the two cases with a high-grade component). Patients received heterogeneous treatments (including chemotherapy according to AT/RT protocols) and experienced stable disease or complete remission after an observation time of three to 56 months. In conclusion, CNS LGDIT-INI1 is a clinically and histologically distinct entity with relatively favorable outcome. Nevertheless, epigenetic similarity with ATRT-MYC and the potential of malignant progression warrants close follow-up examinations. In line with recent developments of WHO nomenclature, we propose to refer to these tumors as “low-grade diffusely infiltrative tumor, SMARCB1-mutant”.

Breast Hypoplasia and Decreased Lactation From Radiation Therapy in Survivors of Pediatric Malignancy: A PENTEC Comprehensive Review

PURPOSE

Breast hypoplasia and impaired lactation are poorly studied sequelae of chest radiation therapy (RT) in children. The Pediatric Normal Tissue Effects in the Clinic female breast task force aimed to quantitate the radiation dose-volume effects on these endpoints.

METHODS AND MATERIALS

A literature search was conducted of peer-reviewed manuscripts evaluating breast hypoplasia and lactation after chest RT in children, yielding 789 abstracts. Only 2 studies on children irradiated at <4 years of age for angioma of the breast provided dosimetric data correlated with breast hypoplasia. For patients who received brachytherapy, the dose was converted to external beam RT in equivalent 2 Gy fractions (DEBRT), although the limitations of this type of mathematical conversion need to be recognized. We calculated relative risks (RR) and 95% confidence intervals (95% CIs) based on these data. Only 1 study was relevant to the lactation endpoint, in which patients were given RT for Hodgkin lymphoma at age 14 to 40 years.

RESULTS

The 3 studies involved 206 patients in total. In patients <4 years old at the time of RT, the prevalence of patient-perceived breast hypoplasia was 38% (RR 2.5; 95% CI, 1.3-4.6) after DEBRT of <0.34 Gy, 61% (RR 4.0; 95% CI, 2.1-7.4) after DEBRT 0.34-0.97 Gy, and 97% (RR 6.3; 95% CI, 3.6-10.8) after DEBRT ≥0.97 Gy to the breast anlage. A simple linear regression model (r = 0.72; P < .001) showed that the treated breast was smaller than the untreated breast by 13% at DEBRT = 0.5 Gy, 20% at DEBRT = 1 Gy, 32% at DEBRT = 2 Gy, 51% at DEBRT = 4 Gy, 66% at DEBRT = 6 Gy, 79% at DEBRT = 8 Gy, and 90% at DEBRT = 10 Gy. The risk of unsuccessful breastfeeding was 39% after a median mediastinal dose of 41 Gy, compared with 21% in a sibling control group (P = .04). RT dose of ≥42 Gy was not associated with less breastfeeding success compared with <42 Gy, and data on lower doses were unavailable.

CONCLUSIONS

Based on extremely limited data, young adults exposed to thoracic RT as children seem to be at significant risk of breast hypoplasia and impaired lactation. Doses as low as 0.3 Gy to immature breasts can cause breast hypoplasia. Additional studies are needed to quantify dose and technique effects with modern RT indications. Prospective collection of clinical outcomes and dosimetric factors would enhance our understanding of RT-induced breast hypoplasia and impaired lactation.

Donanemab (LY3002813) Phase 1b Study in Alzheimer's Disease: Rapid and Sustained Reduction of Brain Amyloid Measured by Florbetapir F18 Imaging

BACKGROUND

Donanemab (LY3002813) is an IgG1 antibody directed at an N‑terminal pyroglutamate of amyloid beta epitope that is present only in brain amyloid plaques.

OBJECTIVES

To assess effects of donanemab on brain amyloid plaque load after single and multiple intravenous doses, as well as pharmacokinetics, safety/tolerability, and immunogenicity.

DESIGN

Phase 1b, investigator- and patient-blind, randomized, placebo-controlled study.

SETTING

Patients recruited at clinical research sites in the United States and Japan.

PARTICIPANTS

61 amyloid plaque-positive patients with mild cognitive impairment due to Alzheimer's disease and mild-to-moderate Alzheimer's disease dementia.

INTERVENTION

Six cohorts were dosed with donanemab: single dose 10-, 20- or 40- mg/kg (N = 18), multiple doses of 10-mg/kg every 2 weeks for 24 weeks (N = 10), and 10- or 20-mg/kg every 4 weeks for 72 weeks (N=18) or placebo (N = 15).

MEASUREMENTS

Brain amyloid plaque load, using florbetapir positron emission tomography, was assessed up to 72 weeks. Safety was evaluated by occurrence of adverse events, magnetic resonance imaging, electrocardiogram, vital signs, laboratory testing, neurological monitoring, and immunogenicity.

RESULTS

Treatment with donanemab resulted in rapid reduction of amyloid, even after a single dose. By 24 weeks, amyloid positron emission tomography mean changes from baseline for single donanemab doses in Centiloids were: -16.5 (standard error 11.22) 10-mg/kg intravenous; 40.0 (standard error 11.23) 20 mg/kg intravenous; and -49.6 (standard error 15.10) 40-mg/kg intravenous. Mean reduction of amyloid plaque in multiple dose cohorts by 24 weeks in Centiloids were: 55.8 (standard error 9.51) 10-mg/kg every 2 weeks; -50.2 (standard error 10.54) 10-mg/kg every 4 weeks; and -58.4 (standard error 9.66) 20-mg/kg every 4 weeks. Amyloid on average remained below baseline levels up to 72 weeks after a single dose of donanemab. Repeated dosing resulted in continued florbetapir positron emission tomography reductions over time compared to single dosing with 6 out of 28 patients attaining complete amyloid clearance within 24 weeks. Within these, 5 out of 10 patients in the 20 mg/kg every 4 weeks cohort attained complete amyloid clearance within 36 weeks. When dosing with donanemab was stopped after 24 weeks of repeat dosing in the 10 mg every 2 weeks cohort, florbetapir positron emission tomography reductions were sustained up to 72 weeks. For the single dose cohorts on day 1, dose proportional increases in donanemab pharmacokinetics were observed from 10 to 40 mg/kg. Dose proportional increases in pharmacokinetics were also observed at steady state with the multiple dose cohorts. Donanemab clearance was comparable across the dose levels. Mean donanemab elimination-half-life following 20 mg/kg single dose was 9.3 days with range of 5.6 to 16.2 days. Greater than 90% of patients had positive treatment-emergent antidrug antibodies with donanemab. However, overall, the treatment-emergent antidrug antibodies did not have a significant impact on pharmacokinetics. Donanemab was generally well tolerated. Amongst the 46 participants treated with donanemab, the following amyloid-related imaging abnormalities, common to the drug class, were observed: 12 vasogenic cerebral edema events (12 [19.7%] patients), 10 cerebral microhemorrhage events (6 [13.0%] patients), and 2 superficial siderosis events (2 [4.3%] patients).

CONCLUSIONS

Single and multiple doses of donanemab demonstrated a rapid, robust, and sustained reduction up to 72 weeks in brain amyloid plaque despite treatment-emergent antidrug antibodies detected in most patients. Amyloid-related imaging abnormalities were the most common treatment-emergent event.

Positron-emission tomography-based staging is cost-effective in early-stage follicular lymphoma

The objective was to assess the cost-effectiveness of staging PET/CT in early-stage follicular lymphoma (FL) from the Canadian health-care system perspective. Methods: The study population was FL patients staged as early-stage using conventional CT imaging and planned for curative-intent radiation therapy (RT). A decision analytic model simulated the management after adding staging PET/CT versus using staging CT alone. In the no-PET/CT strategy, all patients proceeded to curative-intent RT as planned. In the PET/CT strategy, PET/CT information could result in an increased RT volume, switching to a noncurative approach, or no change in RT treatment as planned. The subsequent disease course was described using a state-transition cohort model over a 30-y time horizon. Diagnostic characteristics, probabilities, utilities, and costs were derived from the literature. Baseline analysis was performed using quality-adjusted life years (QALYs), costs (2019 Canadian dollars), and the incremental cost-effectiveness ratio. Deterministic sensitivity analyses were conducted, evaluating net monetary benefit at a willingness-to-pay threshold of $100,000/QALY. Probabilistic sensitivity analysis using 10,000 simulations was performed. Costs and QALYs were discounted at a rate of 1.5%. Results: In the reference case scenario, staging PET/CT was the dominant strategy, resulting in an average lifetime cost saving of $3,165 and a gain of 0.32 QALYs. In deterministic sensitivity analyses, the PET/CT strategy remained the preferred strategy for all scenarios supported by available data. In probabilistic sensitivity analysis, the PET/CT strategy was strongly dominant in 77% of simulations (i.e., reduced cost and increased QALYs) and was cost-effective in 89% of simulations (i.e., either saved costs or had an incremental cost-effectiveness ratio below $100,000/QALY). Conclusion: Our analysis showed that the use of PET/CT to stage early-stage FL patients reduces cost and improves QALYs. Patients with early-stage FL should undergo PET/CT before curative-intent RT.

Pediatric classical Hodgkin lymphoma

Over the past century, classical Hodgkin lymphoma (HL) has been transformed from a uniformly fatal disease to one of the most curable cancers. Given the high cure rate, a major focus of classical HL management is reducing the use of radiation therapy (RT) and chemotherapy agents such as procarbazine and doxorubicin to minimize long-term toxicities. In both North America and Europe, an important philosophy in the management of classical HL is to guide the intensity of treatment according to the risk category of the disease. The main factors used for risk classification are tumor stage, bulk of disease, and the presence of B symptoms. Response to chemotherapy is an important factor guiding the utilization of RT in ongoing Children's Oncology Group (COG) and European Network Pediatric Hodgkin Lymphoma (EuroNet-PHL) trials. Both trial groups have transitioned to reduced RT volumes that target the highest risk sites using highly conformal techniques, along with standard or intensified chemotherapy regimens to improve outcomes in higher risk patients. However, given the potential acute toxicities of intensified chemotherapy, immunoregulatory drugs are being investigated in upcoming trials. The purpose of this review is to summarize current approaches to treating pediatric classical HL according to the COG and EuroNet-PHL.

Late effects in survivors treated for lymphoma as adolescents and young adults: a population-based analysis

PURPOSE

The study objective is to describe and quantify the incidence of treatment-induced late effects in AYA lymphoma patients.

METHODS

Consecutive patients diagnosed with Hodgkin lymphoma (HL) or non-Hodgkin lymphoma (NHL) at 15-24 years of age were identified. All patients in British Columbia who received radiation therapy (RT) from 1974 to 2014 with ≥ 5-year survival post-RT were included. Late effects' analyses included only survivors who received RT to the relevant anatomical site(s) and/or relevant chemotherapy, and were reported as cumulative incidence (CI) ± standard error.

RESULTS

Three hundred and five patients were identified (74% HL). Median age of diagnosis was 21 years. Median follow-up was 19.1 years for secondary malignancy and 7.2 years for other endpoints. Hypothyroidism was the most prevalent late effect, with a CI of 22.4 ± 2.8% and 35.1 ± 4% at 5 and 10 years, respectively. CI of in-field secondary malignancy was 0.4 ± 0.4% at 10 years and 2.8 ± 1.2% at 20 years. CI of symptomatic pulmonary toxicity was 4.6 ± 1.5% and 6.8 ± 2.0% at 5 and 10 years, respectively, and was higher in patients receiving multiple RT courses (p = 0.009). Esophageal complications occurred at a CI of 1.4 ± 0.8% at 5 years and 2.2 ± 1.1% at 10 years. CI of xerostomia/dental decay was 2.6 ± 1.3% at 5 years and 4.9 ± 2.1% at 10 years. CI of cardiac disease was at 2.3 ± 0.9% at 5 years and 4.4 ± 1.5% at 10 years. CI of infertility was 6.5 ± 1.6% at 5 years and 9.4 ± 2.1% at 10 years.

CONCLUSION

Survivors of AYA lymphoma have a high incidence and diverse presentation of late effects.

IMPLICATIONS FOR CANCER SURVIVORS

AYA lymphoma survivors should be educated about their risks of late effects and offered screening and follow-up when appropriate.

Evaluation of the discussion of late effects and screening recommendations in survivors of adolescent and young adult (AYA) lymphoma

PURPOSE

The study objective was to assess the discussion of late effects (LEs) and screening recommendations (SRs) for adolescent and young adults (AYAs) treated for lymphoma.

METHODS

A retrospective study was conducted on AYA lymphoma survivors aged 15-24 years at diagnosis who received radiation therapy (RT) ± chemotherapy between 1984 and 2010 at any of the six British Columbia (BC) Cancer treatment centers across the province. Charts were reviewed to evaluate discussion of LEs and SRs. Susceptibility to specific LEs was determined by reviewing treatment details.

RESULTS

Of 305 patients, 212 (70%) had documented discussion of at least one specific LE, 39 (13%) had non-specific documentation only, and 54 (18%) had no documented discussion of LEs. Accounting only for patients susceptible to each LEs, the most frequently discussed LEs was radiation-induced (RI) neoplasm (42%), and the least frequently discussed LEs was carotid artery stenosis (0.4%). The most common SRs discussed in susceptible patients was for RI breast cancer (43%). Of patients discharged between 1985 and 1999 vs 2000 and 2014, LEs were discussed in 63 vs 93% (P < 0.0005), and SRs were discussed in 30 vs 65%, respectively (P < 0.0005). Older age at discharge, presence of a discharge note, and occurrence of a discharge appointment were associated with increased discussion of SRs.

CONCLUSIONS

Most survivors of AYA lymphoma received some discussion of LEs and SRs, but each relevant LEs and SRs was discussed in only a minority of susceptible patients.

IMPLICATIONS FOR CANCER SURVIVORS

Survivors of AYA lymphoma and their primary care professionals may not be appropriately informed of health risks and how to screen for them.

How well do image-defined risk factors (IDRFs) predict surgical outcomes and survival in patients with neuroblastoma? A systematic review and meta-analysis

INTRODUCTION

Since their introduction to the International Neuroblastoma Risk Group (INRG) staging system in 2009, the role of Image-Defined Risk Factors (IDRFs) in predicting outcomes has been studied in heterogeneous populations with varying results. We conducted a systematic review and meta-analysis in order to determine quantitative measures of precisely how well pre-treatment IDRFs predict surgical outcomes and survival.

METHODS

A systematic review was performed for studies between January 1990 and July 2019 that compared surgical outcomes and/or survival in pediatric neuroblastoma patients with one or more IDRFs to patients without IDRFs. Summary risk ratios (RR) and hazard ratios (HR) were calculated using a random-effects model.

RESULTS

19 retrospective cohort studies were included, representing data from 1132 patients. The risk ratio (RR) of incomplete surgical resection in IDRF-positive patients compared to IDRF-negative patients was 2.45 (95% CI 1.51-3.97). The RR of surgical complications was 2.30 (95% CI 1.46-3.61). The hazard ratio (HR) for 5-year EFS was 2.08 (95% CI 2.93-4.13) while the 5-year HR for OS was 2.44 (95% CI 1.46-4.08).

CONCLUSION

IDRF-positive neuroblastoma patients have a higher risk of incomplete surgical resection, surgical complications, and 5-year mortality and/or relapse. Our results affirm that IDRFs remain a useful prognostic tool for neuroblastoma patients both for short and long-term outcomes.

LEVEL OF EVIDENCE

II.

Canadian patterns of practice for intracranial germ cell tumors in adolescents and young adults

INTRODUCTION

The study objectives were to describe patterns of practice for intracranial germ cell tumors (IGCT) in adolescents and young adults (AYA) and to determine factors associated with practice patterns.

METHODS

A survey was written containing questions on the management of two 17-year old males, one with localized pineal germinoma and the other with localized pineal non-germinomatous germ cell tumor (NGGCT). An invitation to participate anonymously in the survey was e-mailed to 119 oncologists who treat brain tumors across Canada.

RESULTS

Seventy-two (61%) of the 119 oncologists participated in the study. For the germinoma case, the most common treatment approaches were whole ventricular radiotherapy (WVRT) and chemotherapy (CH) (56%), WVRT alone (15%), and craniospinal radiotherapy (CSRT) alone (10%); for physicians recommending WVRT + CH, most frequently selected whole ventricular doses were 24 Gy (57%) and 18 Gy (20%). Chemotherapy was included in the treatment of germinoma by 96% of pediatric physicians vs. 54% of adult physicians (P = 0.001). The most common treatment approaches for NGGCT were CSRT + CH (44%), WVRT + CH (21%), and pineal gland RT + CH (15%). The selection of craniospinal vs. smaller-volume RT was not associated with the physicians' specialty, percentage of practice treating brain tumors, number of IGCTs seen, or size of institution.

CONCLUSIONS

There is wide variation in the management of IGCT in AYA across Canada. A 17-year old male with a localized pineal germinoma is highly likely to receive chemotherapy if managed by a pediatric oncologist, while the same patient is much less likely to receive chemotherapy if managed by an adult oncologist.

Characterization of anti-EBA175RIII-V in asymptomatic adults and children living in communities in the Greater Accra Region of Ghana with varying malaria transmission intensities

Background

Antibodies against Region III-V of the erythrocyte binding antigen (EBA) 175 (EBA175RIII-V) have been suggested to provide protection from malaria in a natural infection. However, the quality and quantity of naturally induced antibodies to EBA175RIII-V has not been fully characterized in different cohorts of Ghanaians. This study sought to determine the characteristics of antibodies against EBA175RIII-V in asymptomatic adults and children living in two communities of varying P. falciparum parasite prevalence in southern Ghana.

Methods

Microscopic evaluation of thick and thin blood smears was used to identify asymptomatic Plasmodium falciparum carriage and indirect enzyme linked immunosorbent (ELISA) used to assess antibody concentrations and avidity.

Results

Parasite carriage estimated by microscopy in Obom was 35.6% as opposed to 3.5% in Asutsuare. Levels of IgG, IgG1, IgG2, IgG3 and IgG4 against EBA175RIII-V in the participants from Obom were significantly higher (P < 0.05, Dunn’s Multiple Comparison test) than those in Asutsuare. However the relative avidity of IgG antibodies against EBA175RIII-V was significantly higher (P < 0.0001, Mann Whitney test) in Asutsuare than in Obom.

Conclusions

People living in communities with limited exposure to P. falciparum parasites have low quantities of high avidity antibodies against EBA175RIII-V whilst people living in communities with high exposure to the parasites have high quantities of age-dependent but low avidity antibodies against EBA175RIII-V.

Electronic supplementary material

The online version of this article (10.1186/s12865-018-0271-y) contains supplementary material, which is available to authorized users.

"Assessing the methodological quality of systematic reviews in radiation oncology: A systematic review"

OBJECTIVE

The objective of our study was to evaluate the methodological quality of systematic reviews and meta-analyses in Radiation Oncology.

METHODS

A systematic literature search was conducted for all eligible systematic reviews and meta-analyses in Radiation Oncology from 1966 to 2015. Methodological characteristics were abstracted from all works that satisfied the inclusion criteria and quality was assessed using the critical appraisal tool, AMSTAR. Regression analyses were performed to determine factors associated with a higher score of quality.

RESULTS

Following exclusion based on a priori criteria, 410 studies (157 systematic reviews and 253 meta-analyses) satisfied the inclusion criteria. Meta-analyses were found to be of fair to good quality while systematic reviews were found to be of less than fair quality. Factors associated with higher scores of quality in the multivariable analysis were including primary studies consisting of randomized control trials, performing a meta-analysis, and applying a recommended guideline related to establishing a systematic review protocol and/or reporting.

CONCLUSIONS

Systematic reviews and meta-analyses may introduce a high risk of bias if applied to inform decision-making based on AMSTAR. We recommend that decision-makers in Radiation Oncology scrutinize the methodological quality of systematic reviews and meta-analyses prior to assessing their utility to inform evidence-based medicine and researchers adhere to methodological standards outlined in validated guidelines when embarking on a systematic review.

A Cross-Sectional Cohort Study of Cerebrovascular Disease and Late Effects After Radiation Therapy for Craniopharyngioma

BACKGROUND

The study objective was to describe radiation-induced vascular abnormalities, stroke prevalence, and stroke risk factors in survivors of childhood craniopharyngioma.

PROCEDURE

Twenty survivors of childhood craniopharyngioma who received radiotherapy (RT) were included in the study. A clinical history, quality of life assessment, cognitive functioning assessment, magnetic resonance angiogram or computed tomography angiogram, fasting lipid profile, and fasting glucose or hemoglobin A1c test were obtained.

RESULTS

Median age at diagnosis was 10.3 years and median age at time of study was 29.0 years. Vascular abnormalities were detected in six (32%) of 19 patients' angiograms (vascular stenosis, decreased artery size, aneurysm, cavernoma, and small vessel disease). Five (25%) of 20 patients experienced a stroke after RT. Median time since RT was 27.8 versus 9.1 years in patients with versus without vascular abnormalities (P = 0.02). A low level of high-density lipoproteiin (HDL) was present in 100% (5/5) of patients who had a post-RT stroke as compared with 13% (2/15) of patients who did not have any post-RT stroke (P = 0.02). Previous stroke had occurred in 0% (0/5) of patients receiving growth hormone (GH) replacement at the time of study, compared to 40% (6/15) of patients who were not receiving GH replacement (P = 0.09).

CONCLUSIONS

Patients with craniopharyngioma treated with RT have a high prevalence of stroke and vascular abnormalities, particularly those with low HDL and longer duration of time since RT. There is a trend to suggest that continual GH replacement may reduce the risk of stroke. These patients should undergo careful monitoring and aggressive modification of stroke risk factors.

Population-based analysis of the impact and generalizability of the NSABP-B24 study on endocrine therapy for patients with ductal carcinoma in situ of the breast

BACKGROUND

In 1999, the National Surgical Adjuvant Breast and Bowel Project (NSABP)-B24 trial demonstrated that tamoxifen reduced relapse risk in women with ductal carcinoma in situ (DCIS) treated with breast-conserving surgery (BCS) and radiotherapy (RT). In 2002, Allred's subgroup analysis showed that tamoxifen mainly benefitted estrogen receptor (ER)-positive disease. This study evaluates the impact and generalizability of these trial findings at the population level.

PATIENTS AND METHODS

From 1989 to 2009, 2061 women with DCIS underwent BCS + RT in British Columbia. The following cohorts were analyzed: (1) pre-NSABP-B24 era (1989-1998, N = 417); (2) post-NSABP-B24 era (2000-2009, N = 1548). Cohort 2 was further divided into pre- and post-Allred eras.

RESULTS

Endocrine therapy (ET) was used in 404/2061 (20%) patients. Median age of patients treated with compared with without ET, was 53 versus 57 years, (P < 0.0005). One of 417 (0.2%) versus 399/1548 (26%) patients took ET before versus after NSABP-B24. Among the post-Allred era cohort treated with ET (N = 227), tumors were ER-positive in 65%, ER-negative in 1%, and ER-unknown in 33%; whereas of those treated without ET (N = 801), ER was positive in 43%, negative in 15%, and unknown in 42% (P < 0.0005). On multivariable analysis of the post-NSABP-B24 era, ET was associated with improved event-free survival (EFS) (hazard ratio 0.6; P = 0.02); 5-year EFS were 96.9% with ET versus 94.5% without ET.

CONCLUSIONS

ET use in DCIS patients treated with BCS + RT increased significantly after the NSABP-B24 study. ER+ disease and younger age were associated with increased ET use. ET was associated with improved EFS, confirming the generalizability of trial data at a population level.

[Profile of cytokines associated with protection against malaria episodes during pregnancy in hypo-endemic area in Senegal]

Malarial infection in non immune pregnant women is a major risk factor for pregnancy failure. However in malaria endemic areas, intermittent preventive treatment (IPTp) have been adopted to prevent malaria in pregnancy women since 2003 in Senegal. The impact of IPT on the development of immunity is not very well documented. We conducted a prospective study at the Roi-Baudouin maternity hospital of Guediawaye in Senegal to assess IL10, IL12, TNFα and IFNγ cytokines production in pregnant women under IPTp. Cytokines were analyzed in 82 sera at inclusion and delivery. P. falciparum HRP2 antigen was detected in 17% of women included by rapid diagnostic test (RDT). At inclusion the mean of IL10 response was higher in P. falciparum negative women (8 UA) compare to RDT-positive women (7 UA) p=0.069 while in delivery the opposite was found p=0.014. Low production of inflammatory cytokines IL12, IFNγ and TNFα was noted in both groups. Between inclusion and delivery, a significant increase of IL-10 production was noted while a decrease of IFNγ and TNFα cytokine was noted. Thus, IL12 and IFNγ responses may synergistically associate as malaria immune response during pregnancy.

Provincial disparities of growth hormone coverage for young adult survivors of paediatric brain tumours across Canada

BACKGROUND

Young adult survivors of paediatric brain tumours (PBTs) who have been treated with radiation therapy will likely be severely growth hormone-deficient when retested at the achievement of final height. Growth hormone replacement therapy (GHRT) is administered to treat growth hormone deficiency (GHD). Public drug coverage for GHRT falls under the responsibility of provincial governments across Canada. This study sought to determine the extent of public drug coverage and cost in each Canadian province for GHRT to treat GHD during adulthood for young adult survivors of PBTs.

METHODS

Data were collected from provincial government resources and drug formularies from 2012-2013 on the extent of coverage for GHRT based on a clinical case scenario representative of a young adult survivor of a PBT with childhood-onset radiation-induced GHD, the ingredient cost for GHRT and the applicable provincial public drug plan cost-sharing policies. A model was then created to simulate out-of-pocket costs incurred by a young adult male and a young adult female survivor of a PBT for one year of GHRT in each province with applicable cost-sharing arrangements and levels of low annual individual total income that best represent the majority of young adult survivors of PBTs. Out-of-pocket costs were expressed as a percentage of annual income. Comparisons were made between provinces descriptively, and variation among provinces was summarized statistically.

RESULTS

Alberta, Manitoba, Ontario, Quebec, New Brunswick, and Newfoundland and Labrador provide coverage for GHD during adulthood on a case-by-case basis, while British Columbia, Saskatchewan, Nova Scotia and Prince Edward Island provide no coverage. The percentage of annual income to fund GHRT across the provinces without public coverage ranged from 14.4% to 25.5% for males and 21.5% to 38.3% for females, and with public coverage was 0.0% to 4.1% for males and 0.0% to 5.0% for females.

INTERPRETATION

There are considerable out-of-pocket costs and variation in coverage provided by provincial public drug plans to fund GHRT for young adult survivors of PBTs with GHD. The implementation of a national drug formulary could potentially prevent undue financial hardship and remove disparities resulting from variations in provincial drug plans.

Perinatal hypoxia-/ischemia-induced endothelin-1 mRNA in astrocyte-like and endothelial cells

Under pathological conditions in the adult CNS, such as ischemia, subarachnoid hemorrhage and Alzheimer's disease, endothelin (ET)-1- and -3-like immunoreactivities are elevated in astrocytes of the injured adult brain. However, it is not clear whether this is due to increased synthesis or increased binding of ET-1. Further, it is not known whether ET-1 expression is altered in the perinatal brain after cerebral hypoxia/ischemia (H/I). Here, we determined the sites of ET-1 expression in perinatal mouse brain after H/I injury by in situ hybridization using a probe specific for the ET-1 gene. Astrocyte-like cells, which do not normally express ET-1 mRNA, showed high levels of ET-1 mRNA expression. Endothelial cells of the capillaries and small vessels also showed an increased level of ET-1 mRNA. Our data suggest that ET-1 mRNA levels in the astrocyte-like cells and vascular endothelial cells are dynamically regulated by ischemia and may participate in perinatal ischemia-related neural damage.

Endothelin-1 protects astrocytes from hypoxic/ischemic injury

Under pathological conditions such as ischemia (I), subarachnoid hemorrhage, and Alzheimer's disease, astrocytes show a large increase in endothelin (ET) -like immunoreactivity. However, it is not clear whether ET is protective or destructive to these cells during brain injury. Using astrocytes from ET-1-deficient mice, we determined the effect of ET-1 on these cells under normal, hypoxic (H), and hypoxic/ischemic (H/I) conditions. Under normal culture conditions, astrocytes from wild-type and ET-1-deficient mice showed no difference in their morphology and cell proliferation rates. ET-3 and ETA receptor mRNAs were up-regulated whereas ETB receptor mRNA was down-regulated in ET-1-deficient astrocytes, suggesting that ET-1 and ET-3 may complement each other's functions and that the expressions of these endothelins and their receptors are regulated by a complex feedback mechanism. Under H and H/I conditions, ET-1 peptide and mRNA were up-regulated in wild-type astrocytes, and the astrocytes without ET-1 died faster than the wild-type astrocytes, as indicated by greater efflux of lactate dehydrogenase. The present study suggests that astrocytes without ET-1 are more vulnerable to H and H/I injuries and that the up-regulation of astrocytic ET-1 is essential for the survival of astrocytes.

Genetic polymorphism of UDP-glucuronosyltransferase 2B7 (UGT2B7) at amino acid 268: ethnic diversity of alleles and potential clinical significance

UGT2B7 catalyses the glucuronidation of a diverse range of drugs, environmental chemicals and endogenous compounds. Hence, coding region polymorphisms of UGT2B7 are potentially of pharmacological, toxicological and physiological significance. Two variant UGT2B7 cDNAs encoding enzymes with either His or Tyr at residue 268 have been isolated. The variants, referred to as UGT2B7*1 and UGT2B7*2, respectively, arise from a C to T transversion at nucleotide 802 of the UGT2B7 coding region. Analysis of genomic DNA from 91 unrelated Caucasians and 84 unrelated Japanese demonstrated the presence of the variant alleles encoding UGT2B7*1 and UGT2B7*2 in both populations. However, while there was an approximately equal distribution of subjects homozygous for each allele in the Caucasian population, subjects homozygous for the UGT2B7*1 allele were over 10-fold more prevalent than UGT2B7*2 homozygotes in Japanese. The frequencies of the UGT2B7*1 and UGT2B7*2 alleles were 0.511 and 0.489, respectively, in Caucasians, and 0.732 and 0.268, respectively, in Japanese. The 95% confidence intervals for the two alleles did not overlap between Caucasians and Japanese. Rates of microsomal androsterone, menthol and morphine (3-position) glucuronidation were determined for genotyped livers from Caucasian donors. Statistically significant inter-genotypic differences were not apparent for any of the three substrates. Although the UGT2B7 polymorphism characterized here is probably not associated with altered enzyme activity, the results highlight the need to consider ethnic variability in assessing the consequences of UGT polymorphisms.

Androgen control of cyclooxygenase expression in the rat epididymis

Bradykinin and a number of peptide hormones such as angiotensin, endothelin, and vasopressin stimulate anion secretion in rat epididymis via local formation of PGE(2). These effects are mediated by cyclooxygenase (COX)-1 isozyme. The present study was undertaken to assess the androgen control of COX expression in the epididymis. Adult male Sprague-Dawley rats were bilaterally castrated through a scrotal route. Reverse transcription-polymerase chain reaction was used to measure COX-1 and COX-2 mRNAs in the epididymis in normal and castrated rats. Anion secretion in epithelia grown from the epididymides of these rats was studied by the short-circuit current technique. In normal rats, COX-1 and COX-2 mRNAs were detected in the intact epididymis. Elimination of spermatozoa by the technique of efferent duct ligation or flushing out spermatozoa did not affect the expression of either enzyme in the epididymis, indicating that the epithelium, but not spermatozoa, expressed the enzymes. Castration caused a time-dependent decrease in expression of COX-1 and COX-2 mRNAs, which were partially restored upon testosterone replacement. In epithelia cultured from castrated rats, there was a complete loss of bradykinin-induced anion secretion. This effect was reversible upon testosterone replacement. Although epithelia from castrated rats did not respond to bradykinin, they could respond to cAMP, forskolin, and PGE(2) with only 20% loss of response magnitude when compared with epithelia from normal rats. These results suggest that the expression of COX-1 and COX-2 are dependent on androgen. The loss of COX-1 expression after castration correlates with the specific loss of anion secretion induced by bradykinin and possibly other hormones.

Androgens rescue avian embryonic lumbar spinal motoneurons from injury-induced but not naturally occurring cell death

The regulation of survival of spinal motoneurons (MNs) has been shown to depend during development and after injury on a variety of neurotrophic molecules produced by skeletal muscle target tissue. Increasing evidence also suggests that other sources of trophic support prevent MNs from undergoing naturally occurring or injury-induced death. We have examined the role of endogenous and exogenous androgens on the survival of developing avian lumbar spinal MNs during their period of programmed cell death (PCD) between embryonic day (E)6 and E11 or after axotomy on E12. We found that although treatment with testosterone, dihydrotestosterone (DHT), or the androgen receptor antagonist flutamide (FL) failed to affect the number of these MNs during PCD, administration of DHT from E12 to E15 following axotomy on E12 significantly attenuated injury-induced MN death. This effect was inhibited by cotreatment with FL, whereas treatment with FL alone did not affect MN survival. Finally, we examined the spinal cord at various times during development and following axotomy on E12 for the expression of androgen receptor using the polyclonal PG-21 antibody. Our results suggest that exogenously applied androgens are capable of rescuing MNs from injury-induced cell death and that they act directly on these cells via an androgen receptor-mediated mechanism. By contrast, endogenous androgens do not appear to be involved in the regulation of normal PCD of developing avian MNs.

Generation of Alzheimer beta-amyloid protein in the trans-Golgi network in the apparent absence of vesicle formation

beta-amyloid protein (A beta) formation was reconstituted in permeabilized neuroblastoma cells expressing human Alzheimer beta-amyloid precursor protein (beta APP) harboring the Swedish double mutation associated with familial early-onset Alzheimer disease. Permeabilized cells were prepared following metabolic labeling and incubation at 20 degrees C, a temperature that allows beta APP to accumulate in the trans-Golgi network (TGN) without concomitant A beta formation. Subsequent incubation at 37 degrees C led to the generation of A beta. A beta production in the TGN persisted even under conditions in which formation of nascent post-TGN vesicles was inhibited by addition of guanosine 5'-O-(3-thiotriphosphate), a nonhydrolyzable GTP analogue, or by omission of cytosol. These and other results indicate that vesicle budding and trafficking may not be required for proteolytic metabolism of beta APP to A beta, a process that includes "gamma-secretase" cleavage within the beta APP transmembrane domain.

Trafficking of cell-surface beta-amyloid precursor protein: evidence that a sorting intermediate participates in synaptic vesicle recycling

We recently demonstrated that the Alzheimer's beta-amyloid precursor protein (APP) is internalized from the axonal cell surface. In this study, we use biochemical and cell biological methods to characterize endocytotic compartments that participate in trafficking of APP in central neurons. APP is present in presynaptic clathrin-coated vesicles purified from bovine brain, together with the recycling synaptic vesicle integral membrane proteins synaptophysin, synaptotagmin, and SV2. In contrast, APP is largely excluded from synaptic vesicles purified from rat brain. In primary cerebellar macroneurons, cell-surface APP is internalized with recycling synaptic vesicle integral membrane proteins but is subsequently sorted away from synaptic vesicles and transported retrogradely to the neuronal soma. Internalized APP partially co-localizes with rab5a-containing compartments in axons and with V-ATPase-containing compartments in both axons and neuronal soma. These results provide direct biochemical evidence that an obligate sorting compartment participates in the regeneration of synaptic vesicles during exo/endocytotic recycling at nerve terminals but do not preclude concurrent "kiss-and-run" recycling. Moreover, APP is now, to our knowledge, the first demonstrated example of an axonal cell-surface protein that is internalized with recycling synaptic vesicle membrane proteins but is subsequently sorted away from synaptic vesicles.

Regulation of spinal motoneuron survival by GDNF during development and following injury

During normal development of many vertebrate species, substantial numbers of neurons in the central and peripheral nervous system undergo naturally occurring (or programmed) cell death. For example, approximately 50% of spinal motoneurons degenerate and die at a time when these cells are establishing synaptic connections with their target muscles in the chick, mouse, rat, and human. It is generally thought that the survival of developing motoneurons depends on access to trophic molecules. Motoneurons that survive the period of programmed cell death may also die following injury in the developing or adult animal. Increasing evidence suggests that glial-cell-line-derived neurotrophic factor (GDNF) plays a physiological and/or pharmacological role in the survival of various neuronal cell types, including motoneurons. In this paper, we review the survival and growth-promoting effects of GDNF on spinal motoneurons during the period of programmed cell death and following injury.

Beta-amyloid precursor protein (APP) and APP-RNA are rapidly affected by glutamate in cultured neurons: selective increase of mRNAs encoding a Kunitz protease inhibitor domain

Alternative splicing of beta-amyloid precursor protein (APP) RNA generates APP isoforms with or without a Kunitz protease inhibitor (KPI) domain. Previously, we showed that KPI (+) APP RNA, but not KPI (-) APP RNA, is upregulated in response to experimental lesions in which neurotoxicity is dependent on NMDA receptor activation and in Alzheimer's disease hippocampus. Recent studies by Mucke et al. (1995) showed that neuronal expression of human KPI (+) APP, but not KPI (-) APP, in transgenic mice is neuroprotective against experimental lesions. In this study we examined the direct effects of the excitotoxic amino acid Glu on alternatively, spliced APP RNAs and the corresponding protein isoforms in cultured rat cortical neurons. Glu treatment rapidly induced (4.5 h) KPI (+) APP RNA but not KPI (-) APP RNA. Induction of KPI (+) RNA preceded Glu-induced neuronal cell death and was partially blocked by an NMDA-receptor antagonist. In contrast to the RNA, cellular levels of KPI (+) APP were not changed by 4.5 h of Glu treatment. Instead, the cellular full-length form of the protein KPI (-) APP was reduced by approximately 50% after 2 h of Glu treatment and remained depleted after 24 h of treatment. Cellular levels of KPI (+) forms of amyloid precursor-like protein 2 (APLP2) were not changed by Glu treatment. Our data are consistent with the hypothesis that sustained NMDA-receptor activation can regulate alternative splicing of the APP pre-mRNA in neurons.

Ciliary neurotrophic factor promotes the survival of spinal sensory neurons following axotomy but not during the period of programmed cell death

We have examined the in vivo survival effect of ciliary neurotrophic factor (CNTF) on sensory, i.e., dorsal root ganglion (DRG) neurons during the period of naturally occurring (programmed) cell death and following axotomy in the developing chick and mouse. Administration of CNTF during the period of naturally occurring cell death, from Embryonic Day (E) 6 to E10 in the chick and E14 to E18 in the mouse, had no significant effect in preventing the death of DRG neurons in either species. Axotomy on E12 in the chick or on Postnatal Day (PN) 5 in the mouse resulted in a 60% and a 33% decrease, respectively, in ipsilateral DRG neuron numbers by E16 (chick) or by PN12 (mouse), when compared to contralateral controls. CNTF treatment prevented axotomy-induced cell death of DRG neurons in both the chick and mouse. Daily administration of CNTF following axotomy in E12 chicks significantly increased (72%) DRG neurons by E16. Similarly, CNTF completely rescued mouse DRG neurons from axotomy-induced death. These results show that although CNTF has no effect on naturally occurring death of chick or mouse sensory neurons, this agent has significant ability to rescue sensory neurons following axotomy. These findings suggest that CNTF may be an effective therapeutic agent for the prevention of injury-induced death of vertebrate sensory neurons.

Apoptosis in the nervous system: morphological features, methods, pathology, and prevention

For nearly 70 years apoptosis has been known to be a form of cell death distinct from necrosis as well as an important regressive event during the normal development of the nervous system. For example, in the chick, mouse, rat and human approximately 50% of postmitotic neurons die naturally during embryonic or fetal development. It is generally accepted that neurons die during this period by apoptosis. After the period of naturally occurring cell death, the surviving neurons may undergo degeneration and death due to injury or disease later either during development or in adulthood. Recently, apoptosis has been suggested to be involved in the abnormal neuronal death that occurs following axonal injury or in neurodegenerative diseases such as amyotrophic lateral sclerosis and Alzheimer's. Although little is known about the etiology of these diseases, progress is steadily being made toward understanding their underlying mechanisms. For diseases of spinal motoneurons, during the past two years gene mutations have been identified in patients with familial amyotrophic lateral sclerosis or spinal muscular atrophy. Furthermore, a number of in vitro, in vivo, and mutant animal models have been developed in order to study the factors which control motoneuron survival and/or death. Here, we review the morphological differences between necrotic and apoptotic cell death and some of the methods used to differentiate the two pathways. We also discuss motoneuron cell death during development, following injury and in disease, and its prevention by different agents, including neurotrophic factors.

Metabolism of the amyloid precursor-like protein 2 in MDCK cells. Polarized trafficking occurs independent of the chondroitin sulfate glycosaminoglycan chain

Deposition of beta-amyloid peptide in senile plaques is a principal neuropathological hallmark of Alzheimer's disease. beta-Amyloid peptide is derived from larger amyloid precursor proteins. Amyloid precursor protein is a member of a family of integral membrane glycoproteins that includes amyloid precursor-like protein (APLP) 1 and 2. Alternatively spliced pre-mRNAs encode several APLP2 isoforms; the APLP2-751 isoform is a substrate for modifications by a chondroitin sulfate glycosaminoglycan (CS GAG) chain, whereas the APLP2-763 isoform does not undergo CS GAG modification. In this report, we have examined the sorting and metabolism of APLP2-751 and APLP2-763 in polarized epithelial Madin-Darby canine kidney (MDCK) cells. We demonstrate that, despite differences in post-translational modifications, both the APLP2-751 proteoglycan and APLP2-763 isoform were targeted and secreted to the basolateral compartment of MDCK cells. We document that the kinetics of intracellular maturation of full-length forms and secretion of soluble derivatives generated from each isoform were indistinguishable. Our results are consistent with the view that, in MDCK cells, the CS GAG chain of APLP2 has little influence on intracellular trafficking and that the principal basolateral targeting determinants are likely to reside in the APLP2 core protein.

The effects of Danshen (Salvia miltiorrhiza) on warfarin pharmacodynamics and pharmacokinetics of warfarin enantiomers in rats

The effects of Danshen (Salvia miltiorrhiza), a popular traditional Chinese medicinal herb on the pharmacokinetics and pharmacodynamics of R- and S-warfarin stereoisomers were studied in rats. After a single oral dose of racemic warfarin (2 mg kg-1), treatment with oral Danshen extract (5 g kg-1, twice daily) for 3 days significantly altered the overall pharmacokinetics of both R- and S-warfarin and increased the plasma concentrations of both enantiomers over a period of 24 h and the prothrombin time over 2 days. At steady-state levels of racemic warfarin (0.2 mg kg-1 day-1 for 5 days) the 3-day treatment of Danshen extract (5 g kg-1, twice daily) not only prolonged the prothrombin time but also increased the steady-state plasma concentrations of R- and S-warfarin. The results indicate that Danshen extracts can increase the absorption rate constant, area under plasma concentration-time curves, maximum concentrations and elimination half-lives, but decreases the clearances and apparent volume of distribution of both R- and S-warfarin. The pharmacokinetic and pharmacodynamic interactions of warfarin during co-treatment with Danshen extract observed in this study indicate an explanation for the clinically observed incidents of exaggerated warfarin adverse effects when traditional Chinese medicinal herbs or herbal products such as Danshen and Danggui (observed in a previous study) were co-administered.

Developing motor neurons rescued from programmed and axotomy-induced cell death by GDNF

During normal development of the vertebrate nervous system, large numbers of neurons in the central and peripheral nervous system undergo naturally occurring cell death. For example, about half of all spinal motor neurons die over a period of a few days in developing avian, rat and mouse embryos. Previous studies have shown that extracts from muscle and brain, secreted factors from glia, as well as several growth factors and neurotrophic agents, including muscle-derived factors, can promote the survival of developing motor neurons in vitro and in vivo. But because neurotrophins and other known trophic agents administered alone or in combination are insufficient to rescue all developing motor neurons from cell death, other neurotrophic molecules are probably essential for the survival and differentiation of motor neurons. Here we report that glial-cell-line-derived neurotrophic factor (GDNF), a potent neurotrophic factor that enhances survival of mammalian midbrain dopaminergic neurons, rescues developing avian motor neurons from natural programmed cell death in vivo and promotes the survival of enriched populations of cultured motor neurons. Furthermore, treatment with this agent in vivo also prevents the induced death and atrophy of both avian and mouse spinal motor neurons following peripheral axotomy.

Danggui (Angelica sinensis) affects the pharmacodynamics but not the pharmacokinetics of warfarin in rabbits

Danggui is a popular traditional Chinese medicinal (TCM) herb which is easily obtained by the public. The effects of Danggui on the pharmacokinetics and pharmacodynamics of warfarin were studied in rabbits. Single subcutaneous doses (2 mg/kg) of warfarin were administered to 6 rabbits with or without 3 days treatment with oral Danggui extracts (2 g/kg twice daily). Plasma warfarin concentrations were measured by high performance liquid chromatography (HPLC) for 72 h after each of the two warfarin doses. The prothrombin time (PT) was measured daily for 3 days both during the Danggui treatment period and after warfarin doses. Danggui treatment did not affect PT on its own, but significantly lowered PT values 3 days after co-treatment with single dose warfarin. No significant variations in the single dose pharmacokinetic parameters of warfarin were observed after Danggui treatment. A separate group of 6 rabbits were given daily subcutaneous doses of warfarin (0.6 mg/kg) to achieve steady state level, followed by 3 day treatment with oral Danggui extract (2 g/kg twice daily). The slight increase in PT was not significant and two rabbits died after day 7 of the treatment period. However, there was no significant difference in steady state concentrations of warfarin after the Danggui treatment. Results indicate that precautionary advice should be given to patients who self-medicate with Danggui or other TCM products while on chronic treatment with warfarin.

Metabolism of the "Swedish" amyloid precursor protein variant in Madin-Darby canine kidney cells

The 4-kDa beta-amyloid peptide (A beta), a major constituent of parenchymal amyloid deposits in Alzheimer's disease, is derived from larger amyloid precursor proteins (APP). We have examined the metabolism of APP in Madin-Darby canine kidney cells stably transfected with cDNA encoding either wild-type human APP-695 or human APP-695 that harbors the Swedish double mutation associated with familial early-onset Alzheimer's disease. Although approximately 90% of total soluble APP secreted from wild-type cells is secreted basolaterally following cleavage at the alpha-secretase site, soluble derivatives cleaved near or at the amino terminus of A beta (presumably the "beta-secretase" site) are preferentially secreted into the apical compartment of SWE cells. Concomitantly, levels of a specific A beta-containing carboxyl-terminal fragment are elevated in SWE cell lysates. Using domain-specific biotinylation and release assays, we failed to detect a beta-secretase-generated soluble derivative (APPs beta) released from the surface of SWE cells. However, APPs beta can be detected in SWE cell lysates, consistent with "beta-secretase" cleavage occurring in an intracellular compartment. Finally, we demonstrate that A beta is secreted into the basolateral compartment of SWE cells and that the majority of these A beta-related species contains an amino-terminal aspartate residue (+1).

Polymerase chain reaction: basic concepts and clinical applications in dermatology

The polymerase chain reaction (PCR) has been extensively used in basic science research, and the clinical potential of PCR is only now beginning to be realized. The PCR is based on the fundamental DNA replication process that occurs in every living cell. PCR is essentially an in vitro adaptation of the in vivo DNA copying process. Because PCR is so efficient at amplifying even picogram quantities of DNA, contamination with even trace amounts of nucleic acids can lead to the generation of unwanted DNA sequences and false-positive test results. Despite this, there has been rapid growth in the use of PCR in biomedical research and clinical diagnostics. PCR is the most sensitive test for herpes simplex virus, varicella-zoster virus, and human papillomavirus infections. Other diagnostic uses, including tests for genetic diseases, cancers, and other infectious diseases, are evolving.

Expression of a ubiquitous, cross-reactive homologue of the mouse beta-amyloid precursor protein (APP)

Alzheimer's disease is characterized by the presence of senile plaques comprised primarily of deposits of the beta-amyloid protein (A beta) derived from larger amyloid precursor proteins (APP). We have identified a cDNA that encodes a 751-amino acid APP-like protein (designated APLP2) from the mouse that, with exception of the A beta region, is highly homologous to APP. In situ hybridization and quantitative polymerase chain reaction reveal that APLP2 and APP mRNA are expressed in similar, if not identical, neuronal populations and at similar levels. APLP2 appears to mature through the same unusual secretory/cleavage pathway as APP. Furthermore, widely utilized antibodies generated against non-overlapping epitopes of APP do not discriminate between APP and APLP2. Although APLP2 cannot give rise to A beta, its near identity to APP outside the A beta domain confounds the interpretation of previous immunocytochemical and biochemical characterizations of APP biosynthesis and metabolism.

Naturally occurring and axotomy-induced motoneuron death and its prevention by neurotrophic agents: a comparison between chick and mouse

Neuronal cell death is an important regressive event during the normal development of the peripheral and central nervous systems of many vertebrate and invertebrate species. Furthermore, when neurons are deprived of their target following axonal injury (axotomy) during embryonic, fetal, or early postnatal development, they undergo massive cell death. Both naturally occurring and axotomy-induced neuronal cell death can be prevented by treatment with growth factors or neurotrophic agents. Naturally occurring cell death of spinal MNs has been extensively studied in both avians and mammals. However, compared with mammals, there is little information on the effects of axotomy in avian species and it is not known whether trophic agents can modify axotomy-induced death in avian MNs. It is also not known whether trophic/growth factors can promote the in vivo survival of mammalian MNs during the period of naturally occurring cell death. We have examined (1) the time course of axotomy-induced death of lumbar spinal MNs in chick and mouse, and (2) the survival-promoting activity of a number of previously characterized growth and trophic factors on both programmed and axotomy-induced MN death in these two species. We show that axotomy performed on, or prior to, E12 in the chick results in a rapid decrease (i.e. 50%) in MN numbers within 3-4 days postsurgery, whereas these cells were able to survive for up to 1 week following axotomy on E14. By contrast, mouse MNs remained vulnerable to axotomy for at least 5 days after birth.(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of Danshen (Salvia miltiorrhiza) on pharmacokinetics and pharmacodynamics of warfarin in rats

Danshen is a Chinese folk medicine commonly used in the Chinese population. The effects of Danshen on the pharmacokinetics and pharmacodynamics of warfarin were studied in rats. In the pharmacokinetic study, single oral doses of warfarin were administered to rats or after 3 days treatment with Danshen intraperitoneally twice daily. Plasma warfarin concentrations were measured for 48 after each of two warfarin doses by high performance liquid chromatography (HPLC). In the pharmacodynamic study, the treatments were similar to the pharmacokinetic study, the prothrombin time (PT) was measured daily both in the Danshen treatment period and after the warfarin doses for 4 days. The absorption rate (Ka), volume of distribution (Vd) and elimination half-life (T1/2) of warfarin were significantly decreased while Cmax and Tmax were significantly increased after treatment with Danshen. There was no significant change in PT during the Danshen treatment period while the PTs were increased significantly in the first two days after warfarin doses. Our results suggested that Danshen can increase the initial bioavailability of warfarin and also affect the elimination of warfarin. It can also increase the PT further after the warfarin doses. The pharmacokinetic and pharmacodynamic interactions observed in this study indicate a clinically important interaction between Danshen and warfarin if these two agents are taken together.