Randomized Phase III Study of Enzalutamide Compared With Enzalutamide Plus Abiraterone for Metastatic Castration-Resistant Prostate Cancer (Alliance A031201 Trial)

PURPOSE

Enzalutamide and abiraterone both target androgen receptor signaling but via different mechanisms. The mechanism of action of one drug may counteract the resistance pathways of the other. We sought to determine whether the addition of abiraterone acetate and prednisone (AAP) to enzalutamide prolongs overall survival (OS) in patients with metastatic castration-resistant prostate cancer (mCRPC) in the first-line setting.

PATIENTS AND METHODS

Men with untreated mCRPC were randomly assigned (1:1) to receive first-line enzalutamide with or without AAP. The primary end point was OS. Toxicity, prostate-specific antigen declines, pharmacokinetics, and radiographic progression-free survival (rPFS) were also examined. Data were analyzed using an intent-to-treat approach. The Kaplan-Meier estimate and the stratified log-rank statistic were used to compare OS between treatments.

RESULTS

In total, 1,311 patients were randomly assigned: 657 to enzalutamide and 654 to enzalutamide plus AAP. OS was not statistically different between the two arms (median, 32.7 [95% CI, 30.5 to 35.4] months for enzalutamide v 34.2 [95% CI, 31.4 to 37.3] months for enzalutamide and AAP; hazard ratio [HR], 0.89; one-sided P = .03; boundary nominal significance level = .02). rPFS was longer in the combination arm (median rPFS, 21.3 [95% CI, 19.4 to 22.9] months for enzalutamide v 24.3 [95% CI, 22.3 to 26.7] months for enzalutamide and AAP; HR, 0.86; two-sided P = .02). However, pharmacokinetic clearance of abiraterone was 2.2- to 2.9-fold higher when administered with enzalutamide, compared with clearance values for abiraterone alone.

CONCLUSION

The addition of AAP to enzalutamide for first-line treatment of mCRPC was not associated with a statistically significant benefit in OS. Drug-drug interactions between the two agents resulting in increased abiraterone clearance may partly account for this result, although these interactions did not prevent the combination regimen from having more nonhematologic toxicity.

Alliance A031902 (CASPAR): A randomized phase (ph) 3 trial of enzalutamide with rucaparib/placebo in first-line metastatic castration-resistant prostate cancer (mCRPC)

TPS277

Background: Despite a growing number of treatment options for first-line mCRPC, approximately 40% of patients (pts) have radiographic progression within the first year. Co-inhibition of androgen receptor (AR) and PARP is a promising therapeutic strategy that leverages synthetic lethality induced by impaired double-strand DNA repair. Two phase III studies have shown improvement in radiographic progression-free survival (rPFS) in HRR-mutant pts with abiraterone + PARPi combinations vs abiraterone alone. However, the results in HRR-wild type pts are conflicting, with only one of the studies demonstrating a benefit with the abiraterone + PARPi combination. ENZ + RUCA has shown an acceptable safety profile & no significant drug-drug interactions (S-DDI) in a phase 1b trial. This allows its evaluation in mCRPC. Methods: CASPAR (A031902) is a phase 3 study in which 984 pts will be randomized on a 1:1 basis to ENZ plus RUCA/PBO. HRR gene aberration is not required for enrollment. All pts will undergo next-generation targeted exome sequencing from archival tumor tissue (new biopsy only required if no archival tissue is available). Treatment will be continued until disease progression and crossover is not allowed. Key eligibility criteria are age ≥ 18 years, ECOG PS 0-2, biopsy-proven prostate adenocarcinoma, progressive (PSA or radiographic) disease per Prostate Cancer Working Group 3 guidelines, measurable or non-measurable disease per RECIST 1.1, no prior treatment for mCRPC (prior docetaxel, abiraterone, darolutamide, or apalutamide in non-mCRPC setting is allowed), no significant uncontrolled comorbidity, and no medications with S-DDI with ENZ/RUCA. Hierarchical co-primary endpoints are overall survival (OS) and rPFS. The OS analysis will be undertaken as a primary endpoint if the rPFS endpoint is met. For a one-sided logrank test with a type 1 error rate equal to 0.025, the study has 90% power to detect a hazard ratio (HR) of 0.71 in rPFS (median rPFS of 15 and 21 months in control and combination arms, respectively), and 80% power to detect an HR of 0.80 in OS (median OS of 32 and 40 months, respectively). Key secondary endpoints are rPFS and OS in pts with vs without pathogenic BRCA1, BRCA2, or PALB2 alterations; and differences in adverse events and quality of life (QOL) outcomes between the treatment arms. QOL assessments include Functional Assessment of Cancer Therapy–Prostate (FACT-P), Brief Pain Inventory Short Form (BPI-SF), and EQ-5D-5L. A key correlative endpoint is the sensitivity of ctDNA testing for HRR gene alterations. Enrollment began in July 2021 & the study is available for participation to all US-NCTN sites. Clinical trial information: NCT04455750 .

Lobar or Sublobar Resection for Peripheral Stage IA Non-Small-Cell Lung Cancer

BACKGROUND

The increased detection of small-sized peripheral non-small-cell lung cancer (NSCLC) has renewed interest in sublobar resection in lieu of lobectomy.

METHODS

We conducted a multicenter, noninferiority, phase 3 trial in which patients with NSCLC clinically staged as T1aN0 (tumor size, ≤2 cm) were randomly assigned to undergo sublobar resection or lobar resection after intraoperative confirmation of node-negative disease. The primary end point was disease-free survival, defined as the time between randomization and disease recurrence or death from any cause. Secondary end points were overall survival, locoregional and systemic recurrence, and pulmonary functions.

RESULTS

From June 2007 through March 2017, a total of 697 patients were assigned to undergo sublobar resection (340 patients) or lobar resection (357 patients). After a median follow-up of 7 years, sublobar resection was noninferior to lobar resection for disease-free survival (hazard ratio for disease recurrence or death, 1.01; 90% confidence interval [CI], 0.83 to 1.24). In addition, overall survival after sublobar resection was similar to that after lobar resection (hazard ratio for death, 0.95; 95% CI, 0.72 to 1.26). The 5-year disease-free survival was 63.6% (95% CI, 57.9 to 68.8) after sublobar resection and 64.1% (95% CI, 58.5 to 69.0) after lobar resection. The 5-year overall survival was 80.3% (95% CI, 75.5 to 84.3) after sublobar resection and 78.9% (95% CI, 74.1 to 82.9) after lobar resection. No substantial difference was seen between the two groups in the incidence of locoregional or distant recurrence. At 6 months postoperatively, a between-group difference of 2 percentage points was measured in the median percentage of predicted forced expiratory volume in 1 second, favoring the sublobar-resection group.

CONCLUSIONS

In patients with peripheral NSCLC with a tumor size of 2 cm or less and pathologically confirmed node-negative disease in the hilar and mediastinal lymph nodes, sublobar resection was not inferior to lobectomy with respect to disease-free survival. Overall survival was similar with the two procedures. (Funded by the National Cancer Institute and others; CALGB 140503 ClinicalTrials.gov number, NCT00499330.).

Alliance A031902 (CASPAR): A randomized, phase (ph) 3 trial of enzalutamide with rucaparib/placebo in first-line metastatic castration-resistant prostate cancer (mCRPC)

TPS5107

Background: Despite a growing number of treatment options for first line mCRPC, approximately 40% of patients (pts) have radiographic progression within the first year. Androgen receptor (AR) signaling inhibition increases genomic instability with double-strand DNA breaks & co-inhibition of AR & PARP induces synthetic lethality in multiple preclinical models. Homologous recombination repair (HRR) gene aberrations do not appear to be necessary for this synergy as demonstrated in a ph 3 clinical trial of abiraterone & olaparib where this combination improved radiographic progression-free survival (rPFS) in HRR-wild-type pts compared with abiraterone alone. A ph 1b trial has since shown that enzalutamide plus rucaparib has acceptable safety profile & no significant drug-drug interactions (S-DDI). Methods: CASPAR/A031902 (NCT04455750) is a ph 3 study in which 984 pts will be randomized 1:1 to enzalutamide plus rucaparib or placebo. HRR gene aberration is not required for enrollment. All pts will undergo next-generation targeted-exome sequencing from archival tumor tissue (new biopsy only required if no archival tissue available). Treatment will be continued until disease progression & crossover is not allowed. Key eligibility criteria are age ≥ 18 years, ECOG PS 0-2, biopsy-proven prostate adenocarcinoma, progressive (PSA or radiographic) disease per Prostate Cancer Working Group 3 guidelines, measurable or nonmeasurable disease per RECIST 1.1, no prior treatment for mCRPC (prior docetaxel, abiraterone, darolutamide, or apalutamide in non-mCRPC setting is allowed), no significant uncontrolled comorbidity, & no medications with S-DDI with enzalutamide/rucaparib. Hierarchical co-primary endpoints are rPFS & overall survival (OS). The OS analysis will be undertaken as a primary endpoint if the rPFS endpoint is met. For a one-sided logrank test with a type 1 error rate equal to 0.025, the study has 90% power to detect a hazard ratio (HR) of 0.71 in rPFS (median rPFS of 15 & 21 months in control & combination arms, respectively) & 80% power to detect an HR of 0.80 in OS (median OS of 32 & 40 months, respectively). Key secondary endpoints are rPFS & OS in pts with vs without pathogenic BRCA1, BRCA2, or PALB2 alterations; & differences in adverse events & quality of life (QOL) outcomes between the treatment arms. QOL assessments include Functional Assessment of Cancer Therapy–Prostate (FACT-P), Brief Pain Inventory Short Form (BPI-SF) & EQ-5D-5L. A key correlative endpoint is the sensitivity of ctDNA-based testing for alterations in HRR genes. Enrollment to CASPAR began in July 2021 & the study is available for participation to all US-NCTN sites with a projected enrollment of 3 years. Support: U10CA180821, U10CA180882, U24CA196171; U10CA180888. Clinical trial information: NCT04455750.

Alliance A031902 (CASPAR): A randomized, phase (ph) 3 trial of enzalutamide with rucaparib/placebo as novel therapy in first-line metastatic castration-resistant prostate cancer (mCRPC)

TPS194

Background: Despite a growing number of treatment options for first line mCRPC, approximately 40% of patients (pts) have radiographic progression within the first year. Androgen receptor (AR) signaling inhibition increases genomic instability with double-strand DNA breaks & co-inhibition of AR & PARP induces synthetic lethality in multiple preclinical models. Homologous recombination repair (HRR) gene aberrations do not appear to be necessary for this synergy as demonstrated in a ph 2 clinical trial of abiraterone & olaparib where this combination improved radiographic progression-free survival (rPFS) in HRR-wild-type pts compared with abiraterone alone. A ph 1b trial has since shown that enzalutamide plus rucaparib has acceptable safety profile & no significant drug-drug interactions (S-DDI). Methods: CASPAR/A031902 (NCT04455750) is a ph 3 study in which 984 pts will be randomized 1:1 to enzalutamide plus rucaparib or placebo. HRR gene aberration is not required for enrollment. All pts will undergo next-generation targeted-exome sequencing from archival tumor tissue (new biopsy only required if no archival tissue available). Treatment will be continued until disease progression & crossover is not allowed. Key eligibility criteria are age ≥ 18 years, ECOG PS 0-2, biopsy-proven prostate adenocarcinoma, progressive (PSA or radiographic) disease per Prostate Cancer Working Group 3 guidelines, measurable or nonmeasurable disease per RECIST 1.1, no prior treatment for mCRPC (prior docetaxel, abiraterone, darolutamide, or apalutamide in non-mCRPC setting is allowed), no significant uncontrolled comorbidity, & no medications with S-DDI with enzalutamide/rucaparib. Hierarchical co-primary endpoints are rPFS & overall survival (OS). The OS analysis will be undertaken as a primary endpoint if the rPFS endpoint is met. For a one-sided logrank test with a type 1 error rate equal to 0.025, the study has 90% power to detect a hazard ratio (HR) of 0.71 in rPFS (median rPFS of 15 & 21 months in control & combination arms, respectively) & 80% power to detect an HR of 0.80 in OS (median OS of 32 & 40 months, respectively). Key secondary endpoints are rPFS & OS in pts with vs without pathogenic BRCA1, BRCA2, or PALB2 alterations; & differences in adverse events & quality of life (QOL) outcomes between the treatment arms. QOL assessments include Functional Assessment of Cancer Therapy–Prostate (FACT-P), Brief Pain Inventory Short Form (BPI-SF) & EQ-5D-5L. A key correlative endpoint is the sensitivity of ctDNA-based testing for alterations in HRR genes. Enrollment to CASPAR began in July 2021 & the study is available for participation to all US-NCTN sites with a projected enrollment of 3 years. Support: U10CA180821, U10CA180882, U24CA196171; U10CA180888; Clovis Oncology; http://acknowledgments.alliancefound.org Clinical trial information: NCT04455750.

CASPAR (Alliance A031902): A randomized, phase III trial of enzalutamide (ENZ) with rucaparib (RUCA)/placebo (PBO) as a novel therapy in first-line metastatic castration-resistant prostate cancer (mCRPC)

TPS181

Background: Treatment with novel antiandrogens (NAA) and androgen deprivation therapy prolongs life in men with mCRPC but approximately 40% patients (pts) have radiographic progression within the first year. Inhibition of androgen receptor signaling results in increased double-strand DNA breaks and genomic instability. NAA+PARP inhibitor (PARPi) combinations have shown induction of synthetic lethality by this mechanism in multiple preclinical studies. Homologous recombination repair (HRR) gene aberrations do not appear to be necessary for this synergy and an NAA+PARPi combination has shown improved radiographic progression-free survival (rPFS) in HRR-wild-type pts compared with NAA alone. Methods: CASPAR (A031902) is a randomized phase 3 study in which 984 pts will be randomized on a 1:1 basis to ENZ plus RUCA/PBO. A PK substudy will precede the phase 3 portion and enroll 6-18 pts to various doses of ENZ plus RUCA to establish safety and evaluate any clinically-significant drug-drug interactions (S-DDI). Treatment will be continued until disease progression and cross-over is not allowed. Co-primary endpoints are rPFS and overall survival (OS). The OS analysis will be undertaken as a primary endpoint if the rPFS endpoint is met. For a one-sided logrank test with a type 1 error rate equal to 0.025, the study has 90% power to detect a hazard ratio (HR) of 0.71 in rPFS (median rPFS of 15 and 21 months in control and combination arms, respectively), and 80% power to detect an HR of 0.80 in OS (median OS of 32 and 40 months, respectively). Key secondary endpoints are rPFS and OS in pts with vs without pathogenic BRCA1, BRCA2, or PALB2 mutations; and differences in adverse events and quality of life (QOL) outcomes between the treatment arms. QOL assessments include Functional Assessment of Cancer Therapy–Prostate (FACT-P), Brief Pain Inventory Short Form (BPI-SF), and EQ-5D-5L. A key correlative endpoint is the concordance between tissue and plasma ctDNA-based HRR testing. Key eligibility criteria are age ≥ 18 years, ECOG PS 0-2, biopsy-proven prostate adenocarcinoma, progressive (PSA or radiographic) disease per Prostate Cancer Working Group 3 guidelines, measurable or non-measurable disease per RECIST 1.1, no prior treatment for mCRPC (prior abiraterone, darolutamide, or apalutamide in non-mCRPC setting is allowed), no significant uncontrolled comorbidity, and no medications with S-DDI with ENZ/RUCA. HRR gene aberration is not required for enrollment. All pts will undergo next-generation targeted-exome sequencing from archival tumor tissue (new biopsy only required if no archival tissue available). CASPAR is available for participation to all US-NCTN sites starting in October 2020 with a projected enrollment of 3 years. Support: U10CA180821, U10CA180882; acknowledgments.alliancefound.org. Clinical trial information: NCT04455750.

PDIGREE: An adaptive phase III trial of PD-inhibitor nivolumab and ipilimumab (IPI-NIVO) with VEGF TKI cabozantinib (CABO) in metastatic untreated renal cell cancer (Alliance A031704)

TPS366

Background: First-line treatment of mRCC has rapidly changed to include IPI-NIVO or CABO, with clinical benefit of each based on the Checkmate 214 and CABOSUN (A031203) trials. Combination immunotherapy with VEGF therapies has shown benefit over sunitinib in the JAVELIN 101 and KEYNOTE 426 trials. It is yet unclear which patients (pts) benefit most from combination immunotherapy-VEGF inhibitors, and the optimal sequence of drugs. Methods: In an adaptive, randomized, multicenter phase III trial (Alliance A031704, PDIGREE), pts start treatment with induction IPI 1 mg/kg and NIVO 3 mg/kg intravenously (IV) once every 3 weeks. Key inclusion criteria include clear cell mRCC, International Metastatic RCC Database Consortium (IMDC) intermediate or poor risk, Karnofsky performance status >70, and no prior treatments for mRCC. Based on 3-month radiographic assessment (after completing IPI-NIVO combination), pts with complete responses (CR) undergo maintenance NIVO 480 mg IV every 4 weeks; pts with progression of disease (PD) switch to CABO 60 mg oral daily; pts with non-CR/non-PD are randomized to NIVO 480 mg IV every 4 weeks versus NIVO 480 mg IV every 4 weeks with CABO 40 mg oral daily. Randomization is stratified by IMDC risk criteria and presence of bone metastases. The primary endpoint of the study is overall survival (OS). We hypothesize that 3-year OS will improve to 70% for NIVO-CABO compared to 60% for NIVO alone; to achieve 85% power with a two-sided alpha of 0.05 and exponential distribution, 696 patients will be randomized. Accounting for 30% patients with either CR or PD, and 5% dropout from toxicity, up to 1046 pts will be enrolled. Key secondary endpoints include progression-free survival, 12-month CR rate, overall response rate based on RECIST 1.1 and iRECIST criteria, and toxicity profiles. Quality of life will be assessed based on the FKSI-19, PROMIS-fatigue, and EQ5D-5L questionnaires. Biomarkers associated with CR, tissue-based and plasma-based biomarkers will be assessed. Updated enrollment through January 2021 will be presented. Clinical trial information: NCT03793166 .

PDIGREE: An adaptive phase III trial of PD-inhibitor nivolumab and ipilimumab (IPI-NIVO) with VEGF TKI cabozantinib (CABO) in metastatic untreated renal cell cancer (Alliance A031704)

TPS5100

Background: First-line treatment of mRCC has rapidly changed to include IPI-NIVO or CABO, with clinical benefit of each based on the Checkmate 214 and CABOSUN (A031203) trials. Combination immunotherapy with VEGF therapies has shown benefit over sunitinib in the JAVELIN 101 and KEYNOTE 426 trials. It is yet unclear which patients (pts) benefit most from combination immunotherapy-VEGF inhibitors, and the optimal sequence of drugs. Methods: In an adaptive, randomized, multicenter phase 3 trial (Alliance A031704, PDIGREE), pts start treatment with induction IPI 1 mg/kg and NIVO 3 mg/kg intravenously (IV) once every 3 weeks. Key inclusion criteria include clear cell mRCC, International Metastatic RCC Database Consortium (IMDC) intermediate or poor risk, Karnofsky performance status > 70, and no prior treatments for mRCC. Based on 3-month radiographic assessment (after completing IPI-NIVO combination), pts with complete responses (CR) undergo maintenance NIVO 480 mg IV every 4 weeks; pts with progression of disease (PD) switch to CABO 60 mg oral daily; pts with non-CR/non-PD are randomized to NIVO 480 mg IV every 4 weeks versus NIVO 480 mg IV every 4 weeks with CABO 40 mg oral daily. Randomization is stratified by IMDC risk criteria and presence of bone metastases. The primary endpoint of the study is overall survival (OS). We hypothesize that 3-year OS will improve to 70% for NIVO-CABO compared to 60% for NIVO alone; to achieve 85% power with a two-sided alpha of 0.05 and exponential distribution, 696 patients will be randomized. Accounting for 30% patients with either CR or PD, and 5% dropout from toxicity, up to 1046 pts will be enrolled. Key secondary endpoints include progression-free survival, 12-month CR rate, overall response rate based on RECIST 1.1 and irRECIST criteria, and toxicity profiles. Quality of life will be assessed based on the FKSI-19, PROMIS-fatigue, and EQ5D-5L questionnaires. Biomarkers associated with CR, tissue-based and plasma-based biomarkers will be assessed. Updated enrollment through May 2020 will be presented. Clinical trial information: NCT03793166 .

PDIGREE: An adaptive phase III trial of PD-inhibitor nivolumab and ipilimumab (IPI-NIVO) with VEGF TKI cabozantinib (CABO) in metastatic untreated renal cell cancer (Alliance A031704)

TPS760

Background: First-line treatment of mRCC has rapidly changed to include IPI-NIVO or CABO, with clinical benefit of each based on the Checkmate 214 and CABOSUN trials. Combination immunotherapy with VEGF therapies have shown benefit in the JAVELIN 101 and KEYNOTE 426 trials over sunitinib. It is yet unclear which patients (pts) benefit most from combination immunotherapy-VEGF inhibitors, and the optimal sequence of drugs. Methods: In an adaptive, randomized, multicenter, phase 3 trial (Alliance A031704, PDIGREE), pts start treatment with induction IPI 1mg/kg and NIVO 3mg/kg intravenously (IV) once every 3 weeks. Key inclusion criteria include clear cell mRCC, IMDC intermediate or poor risk, Karnofsky performance status >70, and no prior treatments for mRCC. Based on 3-month radiographic assessment (after completing IPI-NIVO combination), pts with complete responses (CR) undergo maintenance NIVO 480mg IV every 4 weeks, pts with progression of disease (PD) switch to CABO 60mg oral daily, and pts with non-CR/non-PD are randomized to NIVO 480mg IV every 4 weeks versus NIVO 480mg IV every 4 weeks with CABO 40mg oral daily. Randomization is stratified by IMDC risk criteria and presence of bone metastases. The primary endpoint of the study is overall survival (OS). We hypothesize that 3-year OS rate will improve to 70% for NIVO-CABO compared to 60% for NIVO alone; to achieve 85% power with a two-sided alpha of 0.05 and exponential distribution, 696 patients will be randomized. Accounting for 30% patients with either CR or PD, and 5% dropout from toxicity, up to 1046 pts will be enrolled. Key secondary endpoints include PFS, 12-month CR rate, ORR based on RECIST 1.1 and irRECIST criteria, and toxicity profiles. Quality of life will be assessed based on the FKSI-19, PROMIS-fatigue, and EQ5D-5L questionnaires. Biomarkers associated with CR and association of IL-6 with treatment benefit will be assessed. Other tissue-based and plasma-based biomarkers are planned. Updated enrollment will be presented. Clinical trial information: NCT03793166.

Alliance A031201: A phase III trial of enzalutamide (ENZ) versus enzalutamide, abiraterone, and prednisone (ENZ/AAP) for metastatic castration resistant prostate cancer (mCRPC)

5008

Background: Androgen receptor (AR) signaling is an important growth mechanism in mCRPC, providing the rationale for treatment with AR axis inhibitors such as ENZ and AAP. Targeting AR with anti-androgens such as ENZ can result in compensatory autocrine and paracrine androgenic stimulation. Therefore, using ENZ with the androgen biosynthesis inhibitor AAP to dampen these resistance mechanisms could improve clinical outcomes relative to ENZ alone. Methods: Men with progressive mCRPC by Prostate Cancer Working Group 2 criteria were eligible. Prior treatment with taxanes for mCRPC and any prior treatment with ENZ or AAP was exclusionary. Patients (pts) were randomized 1:1 to ENZ or ENZ/AAP at standard FDA-approved doses. Randomization was stratified by prior chemotherapy and Halabi prognostic three risk groups. Castrating therapy was maintained. The primary endpoint was overall survival (OS) defined as the date of randomization from date of death or last follow-up. The log-rank test had 90% power to detect a hazard ratio for OS of 0.77 with a one-sided type I error rate of 0.025. Secondary endpoints included radiographic progression free survival (rPFS) and on-treatment PSA declines. Exploratory endpoints included imaging changes, and changes in serum biomarkers such as androgens, angiokines, and circulating microRNA and RNA. The primary analysis was based on the stratified log-rank test adjusting on the stratification factors. Results: Between January 2014 and August 2016, 1311 men were randomized: 657 to ENZ and 654 to ENZ/AAP. Groups were well balanced between arms, including stratification variables. 15.6% of pts were high risk, 35.3% intermediate, and 48.1% low. Median OS was 33.6 mo (95% CI 30.5-36.4) and 32.7 mo (29.9-35.4) respectively, two-sided p = 0.53. Fifty percent PSA decline rate was 80% vs. 76.5%. Grade 3-5 adverse events (AE) (all attributions) were 55.6% and 68.8% respectively. Treatment discontinuation due to AEs occurred in 5% and 12%, pt withdrawal in 5% and 13%, and progression or death in 57% and 48% of pts respectively. Conclusions: Addition of abiraterone acetate to enzalutamide did not prolong survival in men with mCRPC. The combination resulted in more AEs than enzalutamide alone. Support: U10CA180821, U10CA180882, U24CA196171; https://acknowledgments.alliancefound.org . Clinical trial information: NCT01949337.

PDIGREE: An adaptive phase 3 trial of PD-inhibitor nivolumab and ipilimumab (IPI-NIVO) with VEGF TKI cabozantinib (CABO) in metastatic untreated renal cell cancer (Alliance A031704)

TPS4596

Background: First-line treatment of mRCC has rapidly changed to include IPI-NIVO or CABO, with clinical benefit of each based on the Checkmate 214 and CABOSUN trials. Combination immunotherapy with VEGF therapies have shown benefit in the JAVELIN 101 and KEYNOTE 426 trials over sunitinib. It is yet unclear which patients (pts) benefit most from combination immunotherapy-VEGF inhibitors, and the optimal sequence of drugs. Methods: In an adaptive, randomized, multicenter, phase 3 trial (Alliance A031704, PDIGREE), pts will start treatment with induction IPI 1mg/kg and NIVO 3mg/kg intravenously (IV) once every 3 weeks. Key inclusion criteria include clear cell mRCC, IMDC intermediate or poor risk, Karnofsky performance status >70, and no prior treatments for mRCC. Based on 3-month radiographic assessment (after completing IPI-NIVO combination), pts with complete responses (CR) will undergo maintenance NIVO 480mg IV every 4 weeks, pts with progression of disease (PD) will switch to CABO 60mg oral daily, and pts with non-CR/non-PD will be randomized to NIVO 480mg IV every 4 weeks versus NIVO 480mg IV every 4 weeks with CABO 40mg oral daily. Randomization will be stratified by IMDC risk criteria and presence of bone metastases. The primary endpoint of the study is overall survival (OS). We hypothesize that 3-year OS rate will improve to 70% for NIVO-CABO compared to 60% for NIVO alone; to achieve 85% power with a two-sided alpha of 0.05 and exponential distribution, 696 patients will be randomized. Accounting for 30% patients with either CR or PD, and 5% dropout from toxicity, up to 1046 pts will be enrolled. Key secondary endpoints include PFS, 12-month CR rate, ORR based on RECIST 1.1 and irRECIST criteria, and toxicity profiles. Quality of life will be assessed based on the FKSI-19, PROMIS-fatigue, and EQ5D-5L questionnaires. Biomarkers associated with CR and association of IL-6 with treatment benefit will be assessed. Other tissue-based and plasma-based biomarkers are planned. Enrollment will begin this year. Support from UG1CA189823, U24CA196171; https://acknowledgments.alliancefound.org . Clinical trial information: NCT03793166.

CALGB 90601 (Alliance): Randomized, double-blind, placebo-controlled phase III trial comparing gemcitabine and cisplatin with bevacizumab or placebo in patients with metastatic urothelial carcinoma

4503

Background: The combination of gemcitabine (G) and cisplatin (C) is a standard therapy for metastatic urothelial carcinoma (mUC). Based on data that angiogenesis plays a role in UC growth and progression, a randomized placebo-controlled trial was performed. Methods: Patients mUC, no prior chemotherapy for metastatic disease and >12 months from prior (neo)adjuvant chemotherapy and ECOG PS 0-1 were randomized 1:1 to G 1000 mg/m2 IV days 1 and 8 and C IV 70 mg/m2 day 1 with bevacizumab (GCB) 15 mg/kg IV or placebo (GCP) day 1 every 21 days. Randomization was stratified by the presence of visceral metastases and prior chemotherapy. The primary endpoint was overall survival (OS) defined as the time from randomization to death or last follow-up (FU). Secondary endpoints included progression-free survival (PFS), objective response rate (ORR), and ≥ grade 3 toxicity. With 445 deaths, the log-rank test had an 87% power to detect a hazard ratio (HR) of 0.74 with a 2-sided α=0.05. The primary analysis was based on the stratified log-rank test adjusting on stratification factors. Alliance Data Safety and Monitoring Board approved the final OS analysis be performed at 420 events due to lower than expected event rates. Results: 506 patients were randomly assigned (252 GCB, 254 GCP) stratified by the presence of visceral disease and prior chemotherapy for UC. The median FU for patients still alive was 46.2 months. Median OS was 14.5 months for patients treated with GCB and 14.3 months for patients treated with GCP with a HR of 0.87 (95%CI 0.72-1.06; 2-sided Wald p=0.17). The HR for PFS was 0.77 (95%CI 0.63-0.93) in favor of GCB (p=0.0074). Grade 3 or greater adverse event rate was 83.5% with GCB compared to 80.7% with GCP. Conclusions: The addition of bevacizumab to GC chemotherapy did not result in improved OS (primary endpoint) in patients with mUC but there was a PFS improvement. The observed median OS of about 14 months is consistent with prior phase III trials of cisplatin-based chemotherapy. Support: U10CA180821, U10CA180882, U10CA180820, U10CA180853, U10CA180888, Genentech https://acknowledgments.alliancefound.org. Clinical trial information: NCT00942331.

Alliance A031501: Phase III randomized adjuvant study of MK-3475 (pembrolizumab) in muscle-invasive and locally advanced urothelial carcinoma (MIBC) (AMBASSADOR) versus observation

TPS504

Background: Patients with high-risk MIBC have a poor prognosis. Radical cystectomy remains the standard treatment. Yet despite substantial improvements in surgical techniques, mortality from metastatic recurrence remains high. A large number of MIBC patients are ineligible for cisplatin-based chemotherapy or have persistent muscle-invasive disease despite neoadjuvant chemotherapy (NAC). Pembrolizumab, a PD-1 inhibitor, has demonstrated significant activity and is FDA-approved for patients with advanced/chemotherapy-refractory metastatic urothelial carcinoma. We hypothesize that pembrolizumab given post-cystectomy will improve overall survival (OS) and disease-free survival (DFS) in patients with high-risk MIBC. Methods: Patients must have histologically confirmed muscle-invasive urothelial carcinoma of the bladder or upper tract, have received NAC and have ≥ pT2 and/or pN+ at surgery or be cisplatin-ineligible and have ≥ pT3 and/or pN+ at surgery or have declined adjuvant cisplatin-based therapy and have ≥ pT3 and/or pN+ at surgery. Surgery could be radical cystectomy, nephrectomy, or ureterectomy. Patients are stratified by pathologic stage, central PD-L1 status, and prior NAC. Patients are randomized to receive pembrolizumab 240 mg every 3 weeks for 1 year, or observation. The dual primary objectives are to determine DFS and OS. Secondary objectives are to determine DFS and OS in PD-L1-positive and -negative patients and assess safety. Correlative objectives are to determine whether 12 immune gene signatures, tumor molecular subtypes, diversity of T-cell receptor (TCR) clonotypes, persistence of TCR clonotypes, tumor and neoantigen burden, HLA subtypes, and plasma HGF and VEGF levels with IL-10 and IL-17 are associated with OS and DFS. Quality of Life Correlative objectives are to compare health-related quality of life as assessed by the EORTC QLQ-C30. Clinical trial information: NCT03244384.

Impact of national guidelines on family history breast cancer surveillance

The breast cancer risk of women already under family history surveillance was accurately assessed according to national guidelines in an attempt to rationalize the service. Women attending two breast units in Glasgow between November 2003 and February 2005 were included. One thousand and five women under annual surveillance were assessed and had their relatives diagnoses verified. Four hundred and ninety-seven women were at significantly increased risk and eligible for follow-up. Five hundred and eight (50%) women attending were not eligible for family history surveillance, and 498 (98%) of these women accepted discharge. In conclusion, national guidelines have helped to more clearly define women who should undergo surveillance. This avoids unnecessary and potentially harmful routine investigations, and the service has been improved.

A phase II study of sorafenib in malignant mesothelioma: results of Cancer and Leukemia Group B 30307

HYPOTHESIS

Malignant mesotheliomas (MMs) express vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor, and cKIT. Sorafenib is a potent inhibitor of the ras/raf/MEK pathway and also targets VEGFR and cKIT. We evaluated the activity of sorafenib in patients with unresectable mesothelioma.

METHODS

MM patients who had received 0 to 1 prior chemotherapy regimens were treated with sorafenib 400 mg orally twice daily continuously. The primary end point was objective response. ERK1/2 phosphorylation in archival tissues was correlated with response and survival.

RESULTS

A total of 51 patients were enrolled, 50 were evaluable and included in the analysis. Three patients had a partial response (6% [95% confidence interval = 1.3-16.6%]), and 27 (54% [95% confidence interval = 39.3-68.2%]) had stable disease. Median progression-free survival and median overall survival (OS) were 3.6 and 9.7 months, respectively. Median survival was superior in epithelioid histology versus other types (10.7 versus 3.7 months, p = 0.0179). The difference in median OS between pretreated and chemonaive patients was not statistically significant (13.2 versus 5 months, p = 0.3117). Low/negative baseline tumor phospho-ERK1/2 levels were associated with improved OS (13.9 versus 5.2 months, p = 0.0066).

CONCLUSION

Sorafenib has limited activity in advanced MM patients, similar to that seen with other VEGFR tyrosine kinase inhibitors. Additional studies of sorafenib in MM are not warranted.

Prospective surveillance of women with a family history of breast cancer: auditing the risk threshold

To evaluate current guidelines criteria for inclusion of women in special ‘breast cancer family history’ surveillance programmes, records were reviewed of women referred to Scottish breast cancer family clinics between January 1994 and December 2003 but discharged as at ‘less than ‘moderate’ familial risk’. The Scottish Cancer Registry was then interrogated to determine subsequent age-specific incidence of breast cancer in this cohort and corresponding Scottish population figures. Among 2074 women, with an average follow-up of 4.0 years, 28 invasive breast cancers were recorded up to December 2003, where 14.4 were expected, a relative risk (RR) of 1.94. Eleven further breast cancers were recorded between January 2004 and February 2006 (ascertainment incomplete for this period). The overall RR for women in the study cohort exceeded the accepted ‘cutoff’ level (RR=1.7) for provision of special counselling and surveillance. The highest RR was found for the age group 45–59 years and this group also generated the majority of breast cancers. The National Institute for Clinical Excellence (‘NICE’) guidelines appear to be more accurate than those of the Scottish Intercollegiate Guidelines Network (‘SIGN’) in defining ‘moderate’ familial risk, and longer follow-up of this cohort could generate an evidence base for further modification of familial breast cancer services.

Is it worth pursuing surgery for epilepsy in patients with normal neuroimaging?

OBJECTIVE

To determine whether it is worth pursuing surgery for the treatment of epilepsy in patients with normal neuroimaging.

METHODS

Two patient populations were studied: (1) 136 consecutive patients who were surgically treated; (2) 105 consecutive patients assessed with chronically implanted intracranial electrodes within the same period. Sixty patients belonged to both groups, and included all 21 patients who had normal neuroimaging.

RESULTS

There were no differences in the proportion of patients with favourable outcome between those with normal and those with abnormal neuroimaging, irrespective of whether intracranial recordings were required. Among the 19 operated patients with normal neuroimaging, 74% had a favourable outcome (Engel's seizure outcome grades I and II), and among the 93 patients with abnormal neuroimaging, 73% had favourable outcome (p = 0.96). In patients with temporal resections, 92% of the 13 patients with normal neuroimaging had a favourable outcome, whereas among the 70 patients with abnormal neuroimaging, 80% had a favourable outcome (p = 0.44). In patients with extratemporal resections, two of the six patients with normal neuroimaging had a favourable outcome, while 12 of the 23 patients with abnormal neuroimaging had a favourable outcome (p = 0.65). Among the 105 patients studied with intracranial electrodes, five suffered transitory deficits as a result of implantation, and two suffered permanent deficits (one hemiplegia caused by haematoma and one mild dysphasia resulting from haemorrhage).

CONCLUSIONS

It is worth pursuing surgery in patients with normal neuroimaging because it results in good seizure control and the incidence of permanent deficits associated with intracranial studies is low.

Selective innervation of lamina I projection neurones that possess the neurokinin 1 receptor by serotonin-containing axons in the rat spinal cord

Axons containing serotonin descend from brainstem to spinal cord and are thought to contribute to stimulation-produced and opioid analgesia, partly by a direct inhibitory action of serotonin on projection neurones. The density of serotoninergic innervation is highest in lamina I, which contains many nociceptive projection neurones. Two sets of anatomical criteria have been used to classify lamina I projection neurones: somatodendritic morphology and presence or absence of the neurokinin 1 receptor. To test whether the strength of serotoninergic innervation of lamina I projection neurones was related to morphology or neurokinin 1 receptor expression, we used confocal microscopy to determine the density of serotoninergic contacts on 60 cells retrogradely labelled from the caudal ventrolateral medulla. The contact density on neurones with the neurokinin 1 receptor was variable, with some cells receiving heavy input and others having few contacts. However, on average they received significantly more contacts (5.64 per 1000 microm(2) plasma membrane +/- 0.47, S.E.M.) than neurones which lacked the receptor (2.49 +/- .36). Among the neurokinin 1 neurones, serotoninergic innervation density was not related to morphology. Since the majority of serotoninergic boutons in lamina I of rat spinal cord do not appear to form synapses, we carried out electron microscopy on three heavily innervated neurokinin 1 receptor-immunoreactive projection neurones. Symmetrical synapses were found at 89% of serotoninergic contacts. These results indicate that serotoninergic innervation of lamina I projection neurones in the rat spinal cord is related to expression of neurokinin 1 receptors, but not to morphology, and that (at least on heavily innervated neurones) most serotonin-containing boutons which are in contact form synapses.

MOR-1-immunoreactive neurons in the dorsal horn of the rat spinal cord: evidence for nonsynaptic innervation by substance P-containing primary afferents and for selective activation by noxious thermal stimuli

A direct action of mu-opioid agonists on neurons in the spinal dorsal horn is thought to contribute to opiate-induced analgesia. In this study we have investigated neurons that express the mu-opioid receptor MOR-1 in rat spinal cord to provide further evidence about their role in nociceptive processing. MOR-1-immunoreactive cells were largely restricted to lamina II, where they comprised approximately 10% of the neuronal population. The cells received few contacts from nonpeptidergic unmyelinated afferents, but many from substance P-containing afferents. However, electron microscopy revealed that most of these contacts were not associated with synapses. None of the MOR-1 cells in lamina II expressed the neurokinin 1 receptor; however, the mu-selective opioid peptide endomorphin-2 was present in the majority (62-82%) of substance P axons that contacted them. Noxious thermal stimulation of the foot induced c-Fos expression in approximately 15% of MOR-1 cells in the medial third of the ipsilateral dorsal horn at mid-lumbar level. However, following pinching of the foot or intraplantar injection of formalin very few MOR-1 cells expressed c-Fos, and for intraplantar formalin injection this result was not altered significantly by pretreatment with systemic naloxone. Although these findings indicate that at least some of the neurons in lamina II with MOR-1 are activated by noxious thermal stimulation, the results do not support the hypothesis that the cells have a role in transmitting nociceptive information following acute mechanical or chemical noxious stimuli.

Should needle localization breast biopsy give way to the new technology; the advanced breast biopsy instrumentation

Between July 1995 and June 1997, 114 consecutive women underwent 118 breast biopsies for nonpalpable lesions. A limited procedure room and local anesthesia were used in 96.5 per cent of patients. Intravenous access was not established in 95 per cent of patients. Oral diazepam was given to 51 per cent of patients. Needle localization technique was used with a success rate of 97.5 per cent and average operative time of 18 minutes. Breast carcinoma was found in 29 (24.6 per cent) biopsies. A review of 99 of the 118 mammograms showed only 45 per cent of the lesions being amenable to the new technology, the advanced breast biopsy instrumentation. Advantages of the needle localization include short operative time; supine position for the patient; easy access to control bleeding; ability to choose a cosmetic site for the skin incision; minimal tissue removal before reaching the lesion; ability to maintain a sterile field; and applicability to almost any mammographic lesion identified, whether single or multiple. Disadvantages include the need for a separate procedure to place the wire and potential of missing the lesion in 2.5 per cent, requiring additional surgery.

GABAergic neurons that contain neuropeptide Y selectively target cells with the neurokinin 1 receptor in laminae III and IV of the rat spinal cord

Neuropeptide Y (NPY) is contained in a population of GABAergic interneurons in the spinal dorsal horn and, when administered intrathecally, can produce analgesia. We previously identified a strong monosynaptic link between substance P-containing primary afferents and cells in lamina III or IV with the neurokinin 1 (NK1) receptor. Because some of these cells belong to the spinothalamic tract, they are likely to have an important role in pain mechanisms. In this study, we used confocal microscopy to examine the input to lamina III/IV NK1 receptor-immunoreactive neurons from NPY-containing axons. All of the cells studied received a dense innervation from NPY-immunoreactive axons, and electron microscopy revealed that synapses were often present at points of contact. Most NPY-immunoreactive boutons were also GABAergic, which supports the suggestion that they are derived from local neurons. The association between NPY-containing axons and NK1 receptor-immunoreactive neurons was specific, because postsynaptic dorsal column neurons (which were located in laminae III-V but did not possess NK1 receptors) and lamina I neurons with the NK1 receptor received significantly fewer contacts from NPY-immunoreactive axons. In addition, the NK1 receptor-immunoreactive lamina III/IV cells received few contacts from nitric oxide synthase-containing axons (which belong to a different population of GABAergic dorsal horn neurons). The NPY-containing axons appeared to be targeted to the NK1 receptor-immunoreactive neurons themselves rather than to their associated substance P-immunoreactive inputs. The dense innervation of these cells by NPY-containing axons suggests that they may possess receptors for NPY and that activation of these receptors may contribute to NPY-mediated analgesia.

Cells in laminae III and IV of the rat spinal cord that possess the neurokinin-1 receptor and have dorsally directed dendrites receive a major synaptic input from tachykinin-containing primary afferents

Many neurons with cell bodies in laminae III or IV of the spinal dorsal horn possess the neurokinin 1 receptor and have dorsal dendrites that arborize in the superficial dorsal horn. We have performed a confocal microscopic study to determine whether these cells receive inputs from substance P-containing primary afferents. All neurons of this type received contacts from substance P-immunoreactive axons, and in most cases the contacts onto dorsal dendrites were very numerous. A great majority (90-100%) of substance P-immunoreactive varicosities in contact with these cells were also immunoreactive with antibody to calcitonin gene-related peptide, indicating that they were of primary afferent origin. The density of contacts from substance P-immunoreactive varicosities onto these cells was significantly higher than that seen on cholinergic neurons in lamina III (which do not possess the receptor). Electron microscopy revealed that synapses were present at points of contact between substance P-immunoreactive boutons and dorsal dendrites of cells with the neurokinin 1 receptor. Some cells of this type belong to the spinothalamic tract, and we therefore examined neurons with cell bodies in laminae III or IV that possessed the neurokinin 1 receptor and were labeled retrogradely after thalamic injection of cholera toxin B subunit. These cells also received contacts from substance P-immunoreactive axons on their dorsal dendrites. The results of this study indicate that neurons of this type are a major target for substance P-containing primary afferents.

An ultrastructural study of the glycine transporter GLYT2 and its association with glycine in the superficial laminae of the rat spinal dorsal horn

The glycine transporter GLYT2 is present in axonal boutons throughout the spinal cord, and its laminar distribution matches that of glycine-enriched axons, which are presumed to be glycinergic. In order to determine whether boutons which possess GLYT2 are glycine-enriched, we have carried out pre-embedding immunocytochemistry with antibody raised against GLYT2, and combined this with post-embedding detection of glycine, in the rat. GLYT2 immunoreactivity was present in boutons which formed symmetrical axodendritic, axosomatic or axoaxonic synapses, and was often seen in peripheral axons of type II synaptic glomeruli. One hundred and fifty GLYT2-immunoreactive boutons were analysed quantitatively, and in 142 (94.6%) of these the density of gold particles representing glycine-like immunoreactivity exceeded the background level (over presumed glutamatergic boutons) by at least a factor of two. Within immunoreactive boutons, the GLYT2 reaction product was associated with the plasma membrane, but often appeared as discrete clumps and was generally excluded from the region of the active sites of synapses. These results confirm that GLYT2 is associated with glycine-enriched axonal boutons in the superficial dorsal horn. They also suggest that GLYT2 is unevenly distributed on the plasma membrane of these boutons, and raise the possibility that it may be excluded from synaptic clefts.

The mu-opioid receptor (MOR1) is mainly restricted to neurons that do not contain GABA or glycine in the superficial dorsal horn of the rat spinal cord

The mu-opioid receptor MOR1 is present on primary afferent axons and a population of neurons in the superficial dorsal horn of the rat spinal cord. In order to determine which types of neuron possess the receptor we carried out pre-embedding immunocytochemistry with antibody to MOR1 and combined this with a post-embedding method to detect GABA and glycine in the rat. MOR1 immunoreactivity was seen on many small neurons in lamina II and a few in the dorsal part of lamina III. Although immunostaining was mainly restricted to the cell bodies and dendrites of these neurons, in some cases it was possible to see their axons, and a few of these entered lamina III. One hundred and thirty-nine MOR1-immunoreactive cells were tested with GABA and glycine antibodies, and the great majority of these (131 of 139; 94%) were not GABA or glycine immunoreactive, while the remainder showed GABA but not glycine immunoreactivity. These results suggest that most of the cells in the superficial dorsal horn which possess MOR1 are excitatory interneurons. They support the hypothesis that part of the action of mu-opioid agonists, such as morphine, involves the inhibition of excitatory interneurons which convey input from nociceptors to neurons in the deep dorsal horn, thus interrupting the flow of nociceptive information through polysynaptic pathways in the spinal cord.

Colocalization of GABA, glycine, and their receptors at synapses in the rat spinal cord

To determine whether GABA and glycine can act as cotransmitters at synapses in the rat spinal cord, we have compared the ultrastructural distribution of GABAA-receptor beta 3 subunit with that of the glycine receptor-associated protein gephyrin and combined this with postembedding detection of GABA and glycine. We also used a dual-immunofluorescence method to confirm that gephyrin was associated with the glycine-receptor alpha 1 subunit throughout the cord. GABAA beta 3-subunit immunoreactivity was restricted primarily to synapses, and at a majority of these synapses the presynaptic axon was GABA-immunoreactive. Many synapses showed both GABAA beta 3 and gephyrin immunoreactivity, and at most of these synapses GABA and glycine were enriched in the presynaptic axon. These results strongly support the idea that cotransmission by GABA and glycine occurs in the spinal cord.

The types of neuron in spinal dorsal horn which possess neurokinin-1 receptors

In order to provide further information about the types of spinal neuron which possess neurokinin-1 receptors, we have carried out pre-embedding immunocytochemistry on sections of rat lumbar spinal cord with an antiserum raised against a synthetic peptide corresponding to part of the sequence of the receptor, and combined this with post-embedding immunocytochemistry to detect GABA and glycine. Numerous neuronal cell bodies showing neurokinin-1 receptor-immunoreactivity were seen in lamina I, laminae III-VI, the lateral spinal nucleus and the area around the central canal. Most of the cells observed in lamina III were small and had relatively restricted dendritic trees which could often not be followed into lamina II, however some larger cells in laminae III and IV had dendrites which extended through lamina II and into lamina I. Cells of the latter type are likely to represent a major target of substance P released from small-diameter primary afferents in the superficial dorsal horn. The great majority (255 out of 283) of spinal neurons which possessed neurokinin-1 receptor-immunoreactivity, including all of those in lamina I, were not GABA- or glycine-immunoreactive, however a few cells in the deep part of the dorsal horn and the lateral spinal nucleus and several cells near the central canal were GABA-immunoreactive, and some of these were also glycine-immunoreactive. These results suggest that substance P acts through neurokinin-1 receptors mainly on excitatory neurons within the spinal cord.

Awake patient monitoring to determine the need for shunting during carotid endarterectomy

BACKGROUND

The indications for shunt placement to prevent cerebral ischemia during carotid endarterectomy have been controversial. Some investigators have recommended empiric shunting for patients presumed to be at higher risk for cerebral ischemia with a recent stroke or severe stenosis or occlusion of the contralateral internal carotid artery.

METHODS

Carotid endarterectomy was performed in 81 cases with cervical block anesthetic, monitoring the awake patient for the development of cerebral ischemia (unresponsiveness or paralysis) during carotid clamping. The need for shunting (based on awake response) was compared in patients with the arbitrarily defined empiric indications for shunting (n = 29) versus those who did not have such clinical or anatomic findings (n = 52).

RESULTS

Cerebral ischemia requiring shunting was observed in five (17.2%) of 29 cases with the defined indications for empiric shunting. This was not different than the need for shunting in the control group where cerebral ischemia was seen in eight (15.4%) of 52 cases. No intraoperative neurologic events occurred in any case, but one (1.2%) patient suffered a postoperative transient ischemia attack and another (1.2%) had a postoperative stroke.

CONCLUSIONS

Empiric clinical or anatomic indications for shunting were not reliable predictors of cerebral ischemia that developed during carotid clamping in this study. Awake patient monitoring during carotid endarterectomy with regional anesthetic allowed prompt, accurate identification of patients with cerebral ischemia who would clearly benefit from placement of a shunt.

Ultrastructural evidence of axonal shearing as a result of lateral acceleration of the head in non-human primates

The concept of shearing of axons at the time of non-impact injury to the head was first suggested in the middle of this century. However, no experimental model of diffuse axonal injury (DAI) has provided morphological confirmation of this concept. Evidence from experiments on invertebrate axons suggests that membrane resealing after axonal transection occurs between 5 and 30 min after injury. Thus, ultrastructural evidence in support of axonal shearing will probably only be obtained by examination of very short-term survival animal models. We have examined serial thin sections from the corpus callosum of non-human primates exposed to lateral acceleration of the head under conditions which induce DAI. Tearing or shearing of axons was obtained 20 and 35 min after injury, but not at 60 min. Axonal fragmentation occurred more frequently at the node/paranode but also in the internodal regions of axons. Fragmentation occurred most frequently in small axons. Axonal shearing was associated with dissolution of the cytoskeleton and the occurrence of individual, morphologically abnormal membranous organelles. There was no aggregation of membranous organelles at 20 and 35 min but small groups did occur in some axons at 60 minutes. We suggest that two different mechanisms of injury may be occurring in non-impact injury to the head. The first is shearing of axons and sealing of fragmented axonal membranes within 60 min. A second mechanism occurs in other fibres where perturbation of the axon results in axonal swelling and disconnection at a minimum of 2 h after injury.

Differences in the fatty acid composition of the grey and white matter of different regions of the brains of patients with Alzheimer's disease and control subjects

In the present study, a comparison was made of the fatty acid composition of the grey and white matter of the frontal, parietal and parahippocampal regions of post-mortem brains of patients who had died with Alzheimer's disease (n = 15) and control postmortem subjects (n = 10). Diagnosis of Alzheimer-type disease was based on the presence of senile plaques and neurofibrillary tangles in post-mortem sections. Several highly significant and specific differences were observed between the two groups. Adrenic acid (22:4 n-6) was three to four times higher in the grey matter but lower in the white matter in each of the three regions in the Alzheimer brains than in the control group. These alterations were compensated by reciprocal changes in 18:0 in the grey matter and 16:1 fatty acids in the white matter. There was no significant difference in the proportion of other fatty acids, including those of the n-6 and n-3 series, in either the grey or the white matter of any of the three regions of the two groups, except for a higher proportion of 22:6 n-3 in the parietal white matter in the Alzheimer patients. There was no significant relationship between the levels of the individual fatty acids and age at death. It is suggested that the alterations in the fatty acid composition observed in the brains of Alzheimer patients may be caused by an aberration in the system by which essential fatty acids are transported into the brain.

The cerebrovascular response to experimental lateral head acceleration

A number of microvascular changes, such as the development of astrocyte lucency, increased endothelial pit/vesicle activity, development of crater like lesions, and endothelial microvilli have been reported after injury to the brain. Lateral head acceleration in the non-human primate, however, still provides the best experimental model for human diffuse axonal injury. No attempt has yet been made to document the spatial extent or time course of the microvascular response to acceleration injury to the head. We have examined the brains of baboons 1, 4, 6, and 12 h and 7 days after acceleration injury to the head to analyse the microvascular response. In the experimental animals there was a short-term rise in intracranial pressure followed by a long-term resolution, and a reduction in both mean arterial blood pressure and cerebral perfusion pressure which, however, never dropped below 75% of baseline for more than 5 min after injury in any animal. We found evidence for extravasation of blood in a small number of blood vessels in all parts of the brain. Interendothelial tight junctions are not disrupted. Pit/vesicle activity rises in the 1st h in the occipital cortex, but not until 4 h in the frontal cortex, and remains elevated for at least 7 days. There is little change in the thalamus. Development of microvilli is most rapid in the frontal cortex with peak values at 1 h, but slower in the thalamus and occipital cortex where peak values are only obtained at 6 h. Highest numbers of microvilli occur in parasagittal regions of the brain.(ABSTRACT TRUNCATED AT 250 WORDS)

The isolation and characterization of high-density-lipoprotein subfractions containing apolipoprotein E from human plasma

1. Plasma high-density lipoprotein (HDL) was separated by heparin-Sepharose affinity chromatography into a non-bound, apolipoprotein E-poor, and a bound, apolipoprotein E-rich, fraction through the binding effect of Mn2+ in the column buffer. 2. The application of a series of elution buffers in which the concentration of Mn2+ was progressively replaced by Mg2+ resulted in the separation of the bound HDL into five subfractions. 3. Each subfraction migrated a different distance on gradient-gel electrophoresis. Three of the subfractions had RF (relative migration compared with BSA) values within the range of HDL2b. One subfraction contained largely HDL2a, with some material in the regions of HDL2b and HDL3a, and one subfraction spanned the RF regions of HDL2a, HDL3a and HDL3b. 4. The number of molecules, per HDL particle, of cholesteryl ester, non-esterified cholesterol and phospholipid increased with particle size, whereas triacylglycerol passed through a maximum and the number of amino acid residues remained approximately the same. 5. Apolipoprotein (apo) A-I was the major apoprotein in all five subfractions, but the latter differed appreciably in their contents of apo A-II and apo E. 6. The major fatty acid component of each subfraction was linoleic acid, with moderate amounts of C16:0 and C18:1 fatty acids and a smaller content of C18:0, C20:4,n-6 and C22:6,n-3, with no significant difference in composition between the subfractions. 7. This paper provides the first description of a method for the isolation of three subfractions of HDL2b together with other subfractions in quantities that are sufficient for further analytical or metabolic studies.

Changes in the choroid plexus, responses by intrinsic epiplexus cells and recruitment from monocytes after experimental head acceleration injury in the non-human primate

We have examined, by scanning and transmission electron microscopy, morphological changes in the choroid plexus of the lateral ventricles of the non-human primate brain after lateral head acceleration. We demonstrate passage of plasma and blood cells either through tears in blood vessels and the choroidal epithelium, or through the cells of the choroidal epithelium, 20 min after injury, together with morphological changes in that epithelium. At 3 and 4 h small cells with a reniform nucleus accumulate in the connective tissue core of the choroid plexus. We suggest that these are monocytes. At 6 and 12 h cells can be seen in enlarged intercellular spaces within the choroidal epithelium. These cells possess surface ruffles and we suggest that they are monocytes differentiating into macrophages and epiplexus cells. Further evidence for transepithelial migration of monocytes/macrophages is obtained at 7 days. However, at 28 days all blood has been removed from the surface of the choroid plexus and epiplexus cells possess an appearance typical of that in uninjured animals. The possible sources of epiplexus cells are discussed with reference to studies of responses after brain insult and of development. We have obtained no evidence in support of emperipolesis by monocytes through the choroidal epithelium. We suggest that monocytes/macrophages migrate, via an intercellular route, to differentiate into epiplexus cells, thus providing additional numbers of epiplexus cells after head injury.

Localisation of calcium ions and calcium-ATPase activity within myelinated nerve fibres of the adult guinea-pig optic nerve

There is no published description of the distribution of free Ca2+, nor of the distribution of Ca(2+)-ATPase activity associated with the maintenance of low axoplasmic Ca2+ concentrations, in normal central myelinated nerve fibres. We have used the oxalate-pyroantimonate technique to localise free Ca2+, together with the lead-citrate technique to localise Ca(2+)-ATPase activity within myelinated fibres from the adult guinea-pig optic nerve. Pyroantimonate precipitate occurred within the axoplasm at nodes of Ranvier and the internode, at areas of myelin disruption, within Schmidt-Lanterman incisures (SLI) and glial paranodal loops. But precipitate was absent from the axoplasm beneath SLI and at the paranode. Ca(2+)-ATPase activity was localised in axonal smooth endoplasmic reticulum (SER), the outer membrane of mitochondria, the nodal axolemma, the glial membranes of the paranodal loops, the SLI and the external aspect of the myelin sheath. We have demonstrated large domains within the axons of CNS fibres where calcium is present or absent. Moreover, we have shown that, where calcium is absent, there is localisation of Ca(2+)-ATPase activity, which would serve to remove calcium from the adjacent axoplasm. Our results are compared with information obtained from PNS fibres and some differences of distribution discussed.

The microvascular response to stretch injury in the adult guinea pig visual system

In a variety of brain injury models, both reactive axonal change and microvascular abnormalities occur. Development of a stretch injury model in the guinea pig optic nerve has allowed for the characterization of the early axonal response to injury. In this same model, we have now attempted to characterize those morphologic changes occurring in the visual system microvasculature after injury. Thirty adult guinea pigs were subjected to axonal stretch injury and killed at posttraumatic survival periods ranging from 10 minutes to 14 days. Twenty animals were examined by scanning electron microscopy (SEM) for the detection of posttraumatic changes in the surface morphology of the microvasculature, and 10 animals were processed for transmission electron microscopy (TEM) analysis. Through this approach, increased pit vesicle activity and formation of endothelial microvilli were recognized within 10 minutes of injury. Pit vesicle activity returned to control levels by 2 hours. The formation of endothelial microvilli was widespread, affecting the microvessels in both the stretched and unstretched optic nerves and in the chiasm. The greatest response developed most slowly in the stretched nerve, and it was faster but less marked in the unstretched nerve and chiasm. Microvilli were more numerous in larger vessels. Related astrocytic swelling/lucency was not apparent until 6 hours after injury. The astrocyte response was less marked than that documented after brain injury. The results of this investigation demonstrate a widespread microvascular response to stretch injury of the guinea pig optic nerve. Comparison with the documented responses to traumatic brain injury indicates different rates of response to different types of insult.

Reduced postprandial skeletal muscle blood flow contributes to glucose intolerance in human obesity

While it is well accepted that the disposal of an oral glucose load (OGL) occurs primarily in skeletal muscle, the mechanisms by which this occurs are not completely elucidated. Glucose uptake (GU) in skeletal muscle follows the Fick principal, such that GU equals the products of the arteriovenous glucose difference (AVGd) across and the blood flow (BF) into muscle. It is widely believed that in the postprandial period both insulin and glucose increase GU by increasing the AVGd; however, a role for increments in BF in the disposal and tolerance of an OGL has not been established. To investigate this issue, whole body GU (isotope dilution), leg GU (leg balance technique), leg BF, and cardiac index (CI) were measured after an overnight fast and over 180 min after an OGL (1 g/kg) in 8 lean (ln) and 8 obese (ob) subjects [mean +/- SEM age, 36 +/- 2 vs. 37 +/- 2 yr (P = NS) and 60 +/- 1 vs. 99 +/- 5 kg (P less than 0.01), respectively]. Serum glucose levels were higher in the ob than in the ln subjects between 100 and 160 min, indicating reduced glucose tolerance. Fasting and post-OGL serum insulin levels were 2- to 3-fold higher in ob vs. ln at all times, indicating insulin resistance. Peak (40-80 min) incremental whole body GU above baseline was 32% lower in ob vs. ln, (P less than 0.05). Peak femoral AVGd was not different between ob and ln (0.55 +/- 0.16 vs. 0.66 +/- 0.14 mmol/L; P = NS). Peak leg BF increased 36% over baseline in ln (0.328 +/- 0.052 to 0.449 +/- 0.073 L/min; P less than 0.05), while ob subjects displayed no change in leg BF from baseline. Consequently, peak leg GU was 44% lower in ob vs. ln (P less than 0.05). CI increased 24% from baseline at 60 min in ln (P less than 0.05), but was unchanged in ob. In summary, after an OGL 1) femoral AVGd increases in both ln and ob subjects, but skeletal muscle BF and CI increase in ln only; 2) since peak femoral AVGd values were similar in ln and ob, differences in peak leg GU and (by inference) whole body GU are largely due to reduced BF to insulin-sensitive tissues; and 3) hemodynamics play an important role in the physiological disposal of an OGL, and therefore, hemodynamic defects can potentially contribute to reduced glucose tolerance and insulin resistance.

The effect of clomipramine treatment on plasma lipoproteins and high density lipoprotein subfractions in healthy subjects

The effect of clomipramine on plasma lipoproteins, including high density lipoprotein (HDL) subfractions in five healthy males was investigated. The concentrations of total plasma cholesterol and low density lipoprotein cholesterol decreased slightly while that of total HDL-cholesterol showed a small increase, giving a decrease (p less than 0.05) in the ratio of total plasma cholesterol to HDL-cholesterol. The level of HDL2-cholesterol increased (p less than 0.01) with clomipramine treatment while there was no significant change in the concentration of HDL3-cholesterol. Gradient gel electrophoresis showed that administration of the drug was associated with an increase in the relative concentration of HDL2a as well as of HDL2b and a decrease in that of HDL3b/3c. The plasma concentration of apolipoprotein (Apo) A-I showed a small but insignificant increase. These changes in lipoprotein profile are characteristic of those associated with a decrease in coronary risk.

Calculating cardiac output from transmitral volume flow using Doppler and M-mode echocardiography

To simplify transmitral volume flow determination by Doppler echocardiography, a formula for calculating mean mitral valve orifice area using M-mode echocardiography without any 2-dimensional measurements was developed and evaluated in this study. The maximal mitral orifice area was assumed to be circular and its diameter was calculated from the maximal M-mode mitral leaflet separation. The maximal area was multiplied by the mean to maximal anterior mitral leaflet excursion ratio to correct for phasic changes in flow orifice area during ventricular filling. This measurement had a high correlation (r = 0.97, standard error of the estimate + 0.26 cm2) with mean mitral valve orifice area calculated from frame-by-frame analysis of short-axis 2-dimensional echoes in a select group of 10 normal volunteers and 10 patients with cardiomyopathy who had very high quality images of the mitral valve leaflet tips. Cardiac output calculated using the new method for orifice area estimation combined with apex view mitral valve Doppler velocities was then validated in 48 consecutive patients undergoing thermodilution cardiac output determinations with a close correlation between Doppler and thermodilution cardiac output (2.3 to 6.1 liter/min, r = 0.93, standard error of the estimate = 362 ml). The correlation improved when 12 patients with mild mitral insufficiency were excluded (r = 0.95). The M-mode echocardiogram-derived mitral valve orifice method combined with Doppler mitral valve velocities is accurate, easy to perform, has a high success rate and should increase the applicability of Doppler echocardiography for estimation of cardiac output.

The acute effect of marathon running on plasma lipoproteins in female subjects

The acute effect of running a 42.2 km marathon race on plasma lipoproteins was investigated in 12 female subjects (aged 21 to 41 years). During the race there was a significant increase (P less than 0.01) in the concentration of total plasma cholesterol. The mean post-race concentration of high density lipoprotein cholesterol (HDL-C) was 64.0 +/- 16.2 (SD) mg 100 ml-1, compared with 52.1 +/- 14.0 mg 100 ml-1 before the race, representing a significant increase (P less than 0.002). There was no significant difference in the concentration of very low density lipoprotein (VLDL) or low density lipoprotein (LDL) before and after the exercise. The mean concentration of the cholesteryl ester moiety of the HDL increased from 43.7 +/- 12.3 to 54.3 +/- 15.7 mg 100 ml-1 (P less than 0.002), while there was no significant changes in the concentration of the unesterified cholesterol, phospholipid, triacylglycerol or protein moieties of the HDL. The relative proportions of apolipoproteins A-I, A-II, C and E remained unchanged during the exercise. The changes in the concentration of each of the lipoprotein fractions observed during the marathon varied considerably between subjects. The individual increases in the concentration of HDL-C ranged from 4.1 to 28.4 mg 100 ml-1, while both increases and decreases in individual concentrations of VLDL and LDL as well as of total plasma cholesterol were observed. These observations suggest that women undergo greater changes in HDL-C concentration that men during acute exercise, while considerable variation between individuals occurs.

Drinking and creativity: objective and subjective effects

A literature characterized by considerable speculation but a paucity of empirical studies prompted this experiment on the relation between drinking and creativity. After being queried about how they believed alcohol would affect their creative performance, 40 male undergraduate social drinkers were assigned to one of four treatments in a balanced placebo design. Those actually receiving alcohol consumed a mixture containing .6 g of ethanol per kg of body weight. All subjects then completed the entire Figural portion and the Unusual Uses subtest of the Verbal portion of the Torrance Tests of Creative Thinking. Posttesting explored subjects' own evaluations of their creative products and the kinds of attributions they made about factors contributing to the outcomes. Results showed minimal effects of beverage manipulations on measured creativity even when a priori belief and concurrent mood scores were covaried. However, those individuals who thought they had received alcohol gave significantly more positive evaluations of their creative performances than did subjects who believed they were in the non-alcohol treatments. Subjects did not attribute changes in creativity to drinking. Theoretical and practical implications of these findings were discussed.

Damage to the surface of the small intestinal villus: an objective scale of assessment of the effects of single and fractionated radiation doses

Scanning electron microscopy has been used to compare damage to mouse small intestinal mucosa after irradiation with different doses of photons and neutrons. Various stages of the collapse of villous structure seen after radiation include the production of conical and rudimentary villi and a flattened mucosa. A scale is proposed to relate radiation to villous damage. Points from this scale are taken to produce comparative ratios for equivalent damage produced by different radiation conditions. RBE values are quoted for neutron. X and gamma radiation given as single or fractionated irradiation doses and as whole or partial body irradiation. The relationship between the stroma in intravillous pegs and that of the pericryptal compartment is explored.