Oncology clinical trial disruption during the COVID-19 pandemic: a COVID-19 and cancer outcomes study

Background

COVID-19 disproportionately impacted patients with cancer as a result of direct infection, and delays in diagnosis and therapy. Oncological clinical trials are resource-intensive endeavors that could be particularly susceptible to disruption by the pandemic, but few studies have evaluated the impact of the pandemic on clinical trial conduct.

Patients and methods

This prospective, multicenter study assesses the impact of the pandemic on therapeutic clinical trials at two large academic centers in the Northeastern United States between December 2019 and June 2021. The primary objective was to assess the enrollment on, accrual to, and activation of oncology therapeutic clinical trials during the pandemic using an institution-wide cohort of (i) new patient accruals to oncological trials, (ii) a manually curated cohort of patients with cancer, and (ii) a dataset of new trial activations.

Results

The institution-wide cohort included 4756 new patients enrolled to clinical trials from December 2019 to June 2021. A major decrease in the numbers of new patient accruals (−46%) was seen early in the pandemic, followed by a progressive recovery and return to higher-than-normal levels (+2.6%). A similar pattern (from −23.6% to +30.4%) was observed among 467 newly activated trials from June 2019 to June 2021. A more pronounced decline in new accruals was seen among academically sponsored trials (versus industry sponsored trials) (P < 0.05). In the manually curated cohort, which included 2361 patients with cancer, non-white patients tended to be more likely taken off trial in the early pandemic period (adjusted odds ratio: 2.60; 95% confidence interval 1.00-6.63), and substantial pandemic-related deviations were recorded.

Conclusions

Substantial disruptions in clinical trial activities were observed early during the pandemic, with a gradual recovery during ensuing time periods, both from an enrollment and an activation standpoint. The observed decline was more prominent among academically sponsored trials, and racial disparities were seen among people taken off trial.

Real-world progression-free survival (rwPFS) and time to next line of therapy (TTNT) as intermediate endpoints for survival in metastatic breast cancer: A real-world experience

6520

Background: Real-world progression-free survival (rwPFS) and time to next line of therapy (TTNT) are two endpoints of clinical interest in patients with metastatic breast cancer (MBC). Their validation as intermediate endpoints for overall survival (OS), in a real-world setting, remains not fully established. Methods: We conducted a retrospective cohort study using the nationwide US Electronic Health Record-derived de-identified Flatiron Health database. The study population included pts diagnosed with MBC from Jan 1, 2011 to Feb 30, 2021. rwPFS was defined as the time from start of first-line systemic therapy for MBC to disease progression or death. TTNT was defined as the time from start of first-line systemic therapy until start of next line of therapy. The nonparametric Kendall tau correlation between each surrogate endpoint (rwPFS and TTNT) and OS was evaluated using the Hougaard copula model in the Weibull margin distribution. Kendall’s tau (τ) with its 95%CI was calculated across the entire dataset, and within each disease subgroup defined by receptor (ER and/or PR status defined as hormone receptor [HR], and HER2) status. This work was conducted on behalf of the imCORE network and the Dana-Farber Cancer Institute. Results: Overall, 9,770 patients with MBC were included. Median age was 63 years (IQR: 54-72 years). HR+/HER2- disease represented the most frequent MBC subtype (n=6,287; 64.4%), followed by HER2+ (n=2,096; 21.5%) and triple negative (n=1,387; 14.2%) disease. Median f/u was 41.5 months (95%CI: 40.4 to 42.8). Median OS in the overall population was 32.4 months (95%CI: 31.2 to 33.3). Median rwPFS was 11.5 months (95%CI: 11.1 to 11.9), and median TTNT was 11.1 months (95%CI: 10.7 to 11.5). Across the entire population, the correlation of rwPFS with OS was 0.54 (95%CI: 0.53-0.56), while the correlation of TTNT with OS was 0.47 (95%CI: 0.46-0.48) (Table). Conclusions: rwPFS and TTNT may represent meaningful intermediate endpoints for OS in patients with MBC overall, and within the different disease subgroups. [Table: see text]

An update on the overall epidemiology, clinical characteristics, and outcomes from the COVID-19 and Cancer Consortium (CCC19)

10565

Background: Despite mitigation and treatment strategies, COVID-19 continues to negatively impact patients (pts) with cancer. Identifying factors that remain consistently associated with morbidity and mortality is critical for risk identification and care delivery. Methods: Using CCC19 registry data through 12/31/2021 we report clinical outcomes (30-day case fatality rate [CFR], mechanical ventilation use (MV), intensive care unit admission (ICU), and hospitalization) in adult pts with cancer and laboratory confirmed SARS-CoV-2, stratified by patient, cancer, and treatment-related factors. Results: In this cohort of 11,417 pts (with 4% reported vaccination prior to COVID-19), 55% required hospitalization, 15% ICU, 9% MV, and 12% died. Overall outcome rates remained similar for 2020 and 2021 (Table). Hydroxychloroquine was utilized in 11% and other anti-COVID-19 drugs (remdesivir, tocilizumab, convalescent plasma, and/or steroids) in 30%. Higher CFRs were observed in older age, males, Black race, smoking (14%), comorbidities (pulmonary [17%], diabetes mellitus [16%], cardiovascular [19%], renal [21%]), ECOG performance status 2+ (31%), co-infection (25%), especially fungal (35%), and initial presentation with severe COVID-19 (48%). Pts with hematologic malignancy, active/progressing cancer status, or receiving systemic anti-cancer therapy within 1-3 months prior to COVID-19 also had worse CFRs. CFRs were similar across anti-cancer modalities. Other outcomes (ICU, MV, hospitalization) followed similar distributions by pt characteristics. Conclusions: Unfavorable outcome rates continue to remain high over 2 years, despite fewer case reports in 2021 owing to multiple factors (e.g., pandemic dynamics, respondent fatigue, overwhelmed healthcare systems). Pts with specific socio-demographics, performance status, comorbidities, type and status of cancer, immunosuppressive therapies, and COVID-19 severity at presentation experienced worse COVID-19 severity; and these factors should be further examined through multivariable modeling. Understanding epidemiological features, patient and cancer-related factors, and impact of anti-COVID-19 interventions can help inform risk stratification and interpretation of results from clinical trials. [Table: see text]

Fumarate hydratase-deficient renal cell carcinoma: The real-world experience at Dana-Farber Cancer Institute and Moores Cancer Center

e16522

Background: Fumarate hydratase (FH)-deficient renal cell carcinoma (RCC) is a rare and aggressive tumor with limited clinical trials dedicated to therapeutics for this disease. This retrospective study aimed to report a multi-center experience in the systemic treatment of FH-deficient RCC. Methods: The medical records of patients undergoing systemic therapy for advanced or metastatic FH-deficient RCC at Dana-Farber Cancer Institute and Moores Cancer Center were reviewed from 2012 to 2021. Demographic, histologic, molecular, and survival parameters were collected. Response was assessed using RECIST 1.1 criteria. A confirmative initial diagnosis of FH-RCC was made utilizing FH/2SC immunohistochemistry (n = 12) and/or the presence of an FH mutation (n = 6). The primary endpoint of this study was to characterize patients with FH-deficient RCC in the modern era. Results: 18 patients were included; median age at diagnosis was 45 (interquartile range [IQR]: 40-55) years. All patients had a Karnofsky Performance Status (KPS) ≥ 80. Among 14 patients with evaluable IMDC criteria, 1 (7.4%) had favorable-risk disease, while 10 (71.4%) and 3 (21.4%) had intermediate- and poor-risk disease, respectively. Tumors at diagnosis were stage III (n = 6, 33.3%), and IV (n = 12, 66.7%). Median time from diagnosis to the start of systemic therapy was 2.8 months. Six types of regimens were given as first-line therapy (Table). Fourteen patients (78%) developed disease progression on frontline therapy and received subsequent therapy; two patients, initially treated with an mTOR inhibitor and combined vascular endothelial growth factor (VEGF) inhibitor and immune checkpoint inhibitor (ICI), are off therapy and still under surveillance with no recurrence to date; one patient passed away while on frontline therapy; and one patient has limited follow-up. For a median follow-up of 22 months (IQR:6.4-49), the 18-month-overall survival estimate was 81% (95% confidence interval [CI]: 53%-94%) and median progression-free survival (PFS) was 6.7 months (95%CI: 5.0-17.0). Conclusions: This study shows considerable heterogeneity in the treatment for FH deficient-RCC, with disparate clinical outcomes. Dedicated trials and guidelines on the management of FH-deficient RCC are needed.[Table: see text]

COVID-19 vaccination and breakthrough infections in patients with cancer

BACKGROUND

Vaccination is an important preventive health measure to protect against symptomatic and severe COVID-19. Impaired immunity secondary to an underlying malignancy or recent receipt of antineoplastic systemic therapies can result in less robust antibody titers following vaccination and possible risk of breakthrough infection. As clinical trials evaluating COVID-19 vaccines largely excluded patients with a history of cancer and those on active immunosuppression (including chemotherapy), limited evidence is available to inform the clinical efficacy of COVID-19 vaccination across the spectrum of patients with cancer.

PATIENTS AND METHODS

We describe the clinical features of patients with cancer who developed symptomatic COVID-19 following vaccination and compare weighted outcomes with those of contemporary unvaccinated patients, after adjustment for confounders, using data from the multi-institutional COVID-19 and Cancer Consortium (CCC19).

RESULTS

Patients with cancer who develop COVID-19 following vaccination have substantial comorbidities and can present with severe and even lethal infection. Patients harboring hematologic malignancies are over-represented among vaccinated patients with cancer who develop symptomatic COVID-19.

CONCLUSIONS

Vaccination against COVID-19 remains an essential strategy in protecting vulnerable populations, including patients with cancer. Patients with cancer who develop breakthrough infection despite full vaccination, however, remain at risk of severe outcomes. A multilayered public health mitigation approach that includes vaccination of close contacts, boosters, social distancing, and mask-wearing should be continued for the foreseeable future.

Predictors of objective response to first-line immuno-oncology combination therapies in metastatic renal cell carcinoma: Results from the international metastatic renal cell database consortium (IMDC)

310

Background: Predictors of objective response to first-line (1L) immuno-oncology (IO) combination therapies remain elusive. We sought to characterise clinical variables and their association with investigator assessed best overall response. Methods: Using the IMDC, we retrospectively identified patients treated with 1L ipilimumab nivolumab (IPI-NIVO) or approved IO/vascular endothelial growth factor (VEGF) inhibitor combinations (IOVE). Patients were classified, per RECIST v1.1, as responders (complete or partial response (CR or PR)) or non-responders (stable or progressive disease (SD or PD)). Logistic regression was used to adjust for IMDC criteria. Results: Out of 1084 patients, 794 (73%) received IPI-NIVO and 290 (27%) received IOVE (axitinib+pembrolizumab, cabozantinib+nivolumab, axitinib+avelumab, lenvatinib+pembrolizumab). Favourable, intermediate and poor IMDC risk comprised 147 (16%), 517 (55%) and 272 (29%) respectively. Of the 898 patients with evaluable responses, 37 (4%) achieved a best response of CR, 343 (38%) PR, 315 (35%) SD and 203 (23%) PD. Corresponding median overall survival from time of 1L initiation was: not reached, 55.9, 48.1, and 13 months respectively (logrank p < 0.0001). In a multivariable model, lung metastases and cytoreductive nephrectomy (CN) (performed after diagnosis of metastatic disease and before 1L therapy) retained independent association with response, after adjustment for IMDC criteria. Factors not associated with response included (with univariable p values): gender (p = 0.58), age (p = 0.06), sarcomatoid histology (p = 0.99), smoking status (p = 0.39), liver (p = 0.63) and brain (p = 0.12) metastases. As in the VEGF monotherapy era, improved IMDC prognostic risk was associated with response. Results were similar when restricted to the IPI-NIVO cohort. Conclusions: Presence of lung metastases, CN and better IMDC risk group are associated with a higher probability of response to 1L immunotherapy combination regimens. Further work to identify reliable predictors of response to guide treatment selection and patient counselling is warranted.[Table: see text]

Temporal changes in the screening, diagnosis and surgical treatment of genitourinary (GU) malignancies during the COVID-19 pandemic

281

Background: The COVID-19 pandemic has been associated with a significant disruption in healthcare services including cancer screening and diagnosis. Delays in cancer screening and treatment may lead to increased mortality. We aimed to analyze changes in screening, diagnosis and surgical treatment of common GU malignancies in relation to the COVID-19 pandemic. Methods: We evaluated screening, novel diagnoses, and surgical management modalities of prostate cancer (PCa), urothelial carcinoma (UC) and renal cell carcinoma (RCC) within Massachusetts General Brigham, the largest healthcare system in the Northeastern United States, over four 3-month time periods during the pandemic (March 2020- March 2021). The percentage change in screening, diagnoses and management modalities during pandemic periods as compared to the immediate pre-pandemic period (December 2019-March 2020) was calculated as (Nperiod – Ncontrol)/Ncontrol. The difference in “predicted” versus “observed” diagnoses in each pandemic period was compared to the average of the four preceding 3-month periods (March 2019-March 2020) to account for seasonal variation. Results: The first pandemic peak (March-June 2020) was associated with a significant decline across screening, diagnosis and treatment, ranging from -15.7 to -64.8%, followed by a progressive recovery, ranging from -5.9 to +25.1% in the latest period (December 2020-March 2021) (Table). Although 725 diagnoses were “missed“ between March and June 2020 as compared to the previous 12 months, 971 diagnoses were “recovered” between June 2020 and March 2021. Conclusions: A substantial disruption in the screening, diagnosis and treatment of GU malignancies was observed early in the pandemic, followed by a progressive rebound and recovery. The highest declines were observed for PSA screening, and the lowest for cystectomy procedures, reflecting triaging of care based on severity during the pandemic.[Table: see text]

First-line therapy for metastatic renal cell carcinoma with pancreatic metastases: Results from the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC)

317

Background: Metastatic renal cell carcinoma (mRCC) with pancreatic metastases (PM) is characterised by heightened angiogenesis, which is associated with improved outcomes with vascular endothelial growth factor (VEGF) inhibitors. We aimed to compare the efficacy of first-line (1L) ipilimumab/nivolumab (IOIO) vs. anti-PD(L)1/anti-VEGF (IOVE) vs. VEGF monotherapy (VE) in mRCC patients with and without PM. Methods: We performed a retrospective analysis of patients with and without PM, using the IMDC. Sites of metastases were captured at initiation of 1L. Patients with PM could also have metastases at other sites. We studied overall survival (OS) from start of 1L therapy using Cox regression, adjusted for IMDC risk groups. Kaplan Meier survival curves were generated. Results: 543/7,634 (7%) patients had PM. Patients with PM in the overall population had improved OS compared to those without, 56 vs 25.6 months respectively (HR 0.63, 95% CI 0.55-0.73, p<0.0001). When examining the effect of PM within 1L options, those treated with IOVE exhibited a longer OS if PM were present vs absent, median not reached vs 45 months respectively (HR 0.41, 95% CI 0.18-0.93 p=0.03). This association was also seen in patients with treated with 1L VE, in those with PM vs absent, median 53.1 vs 25.1 months respectively (HR 0.65, 95% CI 0.55-0.76, p <0.0001). Contrastingly there was no difference in median OS of patients with or without PM in patients receiving IOIO, 41.4 vs 44.4 months respectively (HR 0.86, 95% CI 0.48-1.56, p=0.62). Comparing the outcomes between 1L therapies in patients with PM the median OS of IOVE vs VE was not reached vs 53.1 months respectively (HR 0.37, 95% CI 0.16-0.83 p=0.02). Conversely, upfront VE and IOIO had a similar median OS of 53.1 vs 41.4 months respectively (HR 0.81, 95% CI 0.45-1.47 p=0.49). We were unable to find any difference in OS between those treated with IOVE vs IOIO, median not reached vs 41.4 months respectively (HR 0.52 95%, CI 0.19-1.45, p=0.21), but the low event rate limited this interpretation. Conclusions: We found that the presence of PM leads to an indolent biological behavior and was associated with improved outcomes when 1L therapy included a VE component. PM patients had comparable OS outcomes on 1L VE and 1L IOIO therapy, but improved OS when treated with 1L IOVE. Anti-angiogenic therapy may be necessary to optimize outcomes in PM and this warrants prospective evaluation. [Table: see text]

CABOSEQ: The efficacy of cabozantinib post up-front immuno-oncology combinations in patients with advanced renal cell carcinoma: Results from the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC)

318

Background: There are limited data to understand the activity of cabozantinib (CABO) as second line (2L) therapy post standard of care ipilimumab-nivolumab (IPI-NIVO) or immuno-oncology(IO)/vascular endothelial growth factor (VEGF) inhibitor combinations (IOVE). The activity of subsequent 3L approved therapies post CABO has not been established. Methods: Using the IMDC dataset, we examined all patients who received 2L CABO. We sought to identify the overall response rate (ORR), time to treatment failure (TTF) and overall survival (OS) of 2L CABO after IPI-NIVO, approved IOVE combinations and other 1L approaches. Additionally, we examined these outcomes for patients that received an approved 3L treatment post 2L CABO. Hazard ratios were adjusted for IMDC risk groups. Results: 346 patients were identified who had all received 2L CABO (78 post 1L IPI NIVO, 46 post 1L IOVE, 222 post 1L other). Of the entire cohort, 12.6%, 62.6% and 24.8% were IMDC favourable, intermediate and poor risk, respectively. 84% had clear cell histology, 18.5% had a sarcomatoid component and 38.3% had bone metastases at diagnosis. Outcomes for patients that received 2L CABO, stratified by 1L therapy are outlined in the table, followed by outcomes for patients that received subsequent 3L therapy post 2L CABO. After adjustment for IMDC criteria, the HR for 2L CABO OS and TTF for IOVE vs IPI-NIVO were 1.73 (95% CI 0.83-3.62 p = 0.14) and 1.62 (0.89-2.95 p = 0.11), respectively. Conclusions: There is clinically meaningful activity of CABO post IPI-NIVO, IOVE and other standard 1L approved therapies. Broadly, time to event endpoints and response rates are similar irrespective of 1L therapy. Approved systemic therapies post CABO, mainly single agent VEGF inhibitors also have activity, though as expected this is diminished compared to earlier lines of therapy. These are real world benchmarks with which to counsel our patients when using single agent CABO.[Table: see text]

Association of clinical factors and recent anticancer therapy with COVID-19 severity among patients with cancer: a report from the COVID-19 and Cancer Consortium

BACKGROUND

Patients with cancer may be at high risk of adverse outcomes from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We analyzed a cohort of patients with cancer and coronavirus 2019 (COVID-19) reported to the COVID-19 and Cancer Consortium (CCC19) to identify prognostic clinical factors, including laboratory measurements and anticancer therapies.

PATIENTS AND METHODS

Patients with active or historical cancer and a laboratory-confirmed SARS-CoV-2 diagnosis recorded between 17 March and 18 November 2020 were included. The primary outcome was COVID-19 severity measured on an ordinal scale (uncomplicated, hospitalized, admitted to intensive care unit, mechanically ventilated, died within 30 days). Multivariable regression models included demographics, cancer status, anticancer therapy and timing, COVID-19-directed therapies, and laboratory measurements (among hospitalized patients).

RESULTS

A total of 4966 patients were included (median age 66 years, 51% female, 50% non-Hispanic white); 2872 (58%) were hospitalized and 695 (14%) died; 61% had cancer that was present, diagnosed, or treated within the year prior to COVID-19 diagnosis. Older age, male sex, obesity, cardiovascular and pulmonary comorbidities, renal disease, diabetes mellitus, non-Hispanic black race, Hispanic ethnicity, worse Eastern Cooperative Oncology Group performance status, recent cytotoxic chemotherapy, and hematologic malignancy were associated with higher COVID-19 severity. Among hospitalized patients, low or high absolute lymphocyte count; high absolute neutrophil count; low platelet count; abnormal creatinine; troponin; lactate dehydrogenase; and C-reactive protein were associated with higher COVID-19 severity. Patients diagnosed early in the COVID-19 pandemic (January-April 2020) had worse outcomes than those diagnosed later. Specific anticancer therapies (e.g. R-CHOP, platinum combined with etoposide, and DNA methyltransferase inhibitors) were associated with high 30-day all-cause mortality.

CONCLUSIONS

Clinical factors (e.g. older age, hematological malignancy, recent chemotherapy) and laboratory measurements were associated with poor outcomes among patients with cancer and COVID-19. Although further studies are needed, caution may be required in utilizing particular anticancer therapies.

CLINICAL TRIAL IDENTIFIER

NCT04354701.

The impact of antibiotic (Ab) exposure on clinical outcomes in patients with metastatic renal cell carcinoma (mRCC) treated with immune checkpoint inhibitors (ICI) or VEGF targeted therapy (VEGF-TT)

4552

Background: Retrospective studies have shown an association between Ab exposure and inferior clinical outcomes in patients receiving ICI across various tumor types, including mRCC. However, it is unclear whether Ab exposure has a unique interaction with ICI or is an independent prognostic marker, regardless of treatment. We sought to examine Ab exposure and its association with clinical outcomes in patients with mRCC treated with ICI compared to VEGF-TT. Methods: We identified patients treated with ICI (anti-PD-L1 alone or in combination with VEGF or CTLA4 inhibitor) or VEGF-TT alone in first to fourth line settings from 2009-2020 across 3 academic centers in North America. Ab exposure was defined as administration of Ab within 60 days prior to initiation of systemic therapy. Outcomes of interest were response rate (RR), time to treatment failure (TTF) and overall survival (OS). Multivariable Cox regression was performed to control for imbalances in International mRCC Database Consortium (IMDC) risk factors, histology, and treatment line. Results: We identified 748 patients. Among the ICI (n=427) and VEGF-TT (n=321) cohorts, 13% vs 15% (p=0.47) had Ab exposure and 57% vs 48% (p=0.046) were treated in the first line setting. The proportion of favorable, intermediate, and poor risk disease by IMDC criteria differed between Ab exposed and unexposed patients in the ICI (14% vs 18%, 47% vs 62%, 39% vs 21% p=0.03) and VEGF-TT (7% vs 13%, 43% vs 60%, 50% vs 27%, p=0.01) cohorts. RR, TTF and OS results are displayed in Table 1. Multivariable analysis did not show a significant independent association between Ab exposure and OS in both the ICI (HR 1.13, p=0.62) and VEGF-TT (HR 1.32, p=0.16) cohorts. Treatment modality (ICI vs VEGF-TT) did not modify the effect of Ab exposure on OS (p=0.84). Conclusions: Ab exposure was associated with higher IMDC risk scores in both the ICI and VEGF-TT cohorts as well as inferior OS on univariable analysis. After adjusting for IMDC risk factors, histology and treatment line, we were unable to find an independent association between Ab exposure and OS in multivariable analysis for either cohort.[Table: see text]

Outcomes of first-line (1L) ipilimumab and nivolumab (IPI-NIVO) and subsequent therapy in metastatic renal cell carcinoma (mRCC): Results from the International mRCC Database Consortium (IMDC)

4554

Background: IPI NIVO is approved for 1L treatment of IMDC intermediate/poor risk mRCC based on the CHECKMATE 214 trial. Herein, we report the clinical effectiveness of 1L IPI NIVO and second line (2L) therapy in the real-world setting. Methods: Using the IMDC dataset, patients (pts) treated with 1L IPI NIVO were identified. The outcomes of interest were 1L and 2L overall response rate (ORR), treatment duration (TD), time to next treatment (TTNT), and overall survival (OS). Results: 706 pts were included: 9% (57/614), 58% (354/614), and 33% (203/614) were IMDC favorable (fav), intermediate (int), and poor risk, respectively. Median age was 61 years. The majority of pts were males (71%), had clear cell histology (85%), and underwent nephrectomy (61%). 36%, 19%, and 8% of patients had bone, liver, and brain metastases, respectively. The 12-month OS for pts with IMDC fav, int, and poor risk disease was 92%, 79%, and 56%, respectively (p<0.01). The corresponding estimates for 24 months were 80%, 69%, and 38% (p<0.01). Pts who responded (39%) were more likely to have better IMDC risk category (p=0.02), received nephrectomy (p=0.04), normal neutrophil count (p<0.01), and clear cell histology (p=0.01). Pts with progressive disease as best response (27%) were more likely to have not received nephrectomy (p<0.01), worse IMDC risk category (p=0.02), bone metastases (p=0.01), liver metastases (p=0.04), and non-clear cell histology (p=0.01). Of the 66% (466/706) of pts who discontinued 1L IPI NIVO, 51% (236/466) received 2L therapy: sunitinib (40%), cabozantinib (25%), pazopanib (18%), axitinib (8%), and others (9%). The ORR, median TD, and median OS for those who received either sunitinib, cabozantinib, pazopanib or axitinib was 16%, 4.5 months (mo) (95% CI 3.7-5.6), and 14.5 mo (95% CI 10.9-25.9), respectively. 33% (129/386) of pts discontinued IPI NIVO due to irAEs. Conclusions: Our study benchmarks the real-world experience of 1L IPI NIVO in mRCC. IMDC criteria is prognostic for clinical outcome. Tyrosine kinase inhibitors have clinical activity post IPI NIVO.[Table: see text]

Racial and ethnic disparities among patients with breast cancer and COVID-19

6500

Background: Racial/ethnic minorities have disproportionately increased risk of contracting COVID-19 and experiencing severe illness; they also have worse breast cancer (BC) outcomes. COVID-19 outcomes among racial/ethnic minorities with BC are currently unknown. We sought to compare clinicopathologic characteristics and COVID-19 outcomes stratified by race/ethnicity. Methods: The COVID-19 and Cancer Consortium registry (NCT04354701) was used to identify patients with invasive BC and laboratory-confirmed SARS-CoV-2 diagnosed in the U.S. between 2020-03-06 and 2021-02-04. The primary analysis was restricted to women who self-identified as non-Hispanic White (NHW), non-Hispanic Black (NHB), or Hispanic (H). Demographic, cancer characteristics, and COVID-19 outcomes were evaluated. COVID-19 outcomes included: hospital admission, intensive care unit (ICU) admission, mechanical ventilation, death within 30 days of COVID-19 diagnosis and death from any cause during follow-up. Descriptive statistics were used to compare clinicopathologic characteristics and Fisher exact tests were used to compare COVID-19 outcomes across the 3 racial/ethnic groups. Results: A total of 1133 patients were identified of which 1111 (98%) were women; of which 575 (52%) NHW, 243 (22%) NHB, 183 (16%) H, and 110 (10%) other/unknown. Baseline characteristics differed among racial/ethnic groups. H were younger (median age: NHW 63y; NHB 62y; H 54y) and more likely to be never smokers (NHW 62%; NHB 62%; H 78%). NHB had higher rates of obesity (NHW 40%; NHB 54%; H 46%), diabetes (NHW 16 %; NHB 32%; H 20%) and combined moderate and severe baseline COVID-19 at presentation (NHW 28%; NHB 42%; H 28%). Cancer characteristics are as shown (Table). Significant differences were observed in outcomes across racial/ethnic groups including higher rates of hospital admission (NHW 34%; NHB 49%; H 34%; P <0.001), mechanical ventilation (NHW 3%; NHB 9%; H 5%; P=0.002), 30-day mortality (NHW 6%; NHB 9%; H 4%; P=0.043) and total mortality (NHW 8%; NHB 12%; H 5%; P=0.05) among NHB compared to NHW and H. Conclusions: This is the largest study to show significant differences in COVID-19 outcomes by racial/ethnic groups of women with BC. The adverse outcomes in NHB could be due to higher moderate to severe COVID-19 at presentation and preexisting co-morbidities. H did not have worse outcomes despite having more active disease and recent anti-cancer therapy, including with cytotoxic chemotherapy – potentially due to younger age and nonsmoking status.[Table: see text]

Effect of high-dose corticosteroid use on efficacy of immune checkpoint inhibitors in patients with renal cell carcinoma (RCC)

4583

Background: The use of High-Dose Corticosteroids (HDC) has been linked to poor outcomes in patients with lung cancer treated with immune checkpoint inhibitors (ICIs) (Ricciuti B, JCO, 2019). There is no data on the effect of HDC on renal cell carcinoma patients (RCC) treated with immunotherapy. We hypothesized that HDC use would be associated with worse outcomes in RCC patients receiving ICIs. Methods: This study evaluated a retrospective cohort of patients with RCC at Dana-Farber Cancer Institute in Boston, MA. Clinical information including demographics, IMDC risk score, RCC histology, steroid administration, ICI regimen, line of therapy, time to treatment failure (TTF) and overall survival (OS) were collected. Patients were divided into those receiving HDC (prednisone ≥10 mg or equivalent for ≥ 1 week, HDC group) or not receiving HDC (No-HDC group). HDC administration was evaluated in relation to TTF and OS in a univariate analysis (Log-rank test) and a multivariate analysis (Cox regression). Results: 190 patients with RCC receiving ICIs were included, with a median age of 59 years. HDC were administered to 56 patients and 134 patients received no (N= 116) or only low-dose (N=18) steroids. In the HDC group, 40 patients received steroids for immune-related adverse events, 8 for other cancer-related indications, and 8 for non-oncological indications. There was no difference in TTF between the HDC and No-HDC groups (12-mo TTF rate: 34.8 vs. 32.3%, respectively; log-rank p=0.65). Similarly, there was no difference in OS between the HDC and No-HDC groups (36-mo OS rate: 56.7 vs. 62.4%, respectively; log-rank p=0.97). After adjusting for IMDC risk group, RCC histology, ICI regimen type, and line of therapy, TTF and OS did not differ in the HDC group as compared to No-HDC group (HR=1.14 [95%CI: 0.80-1.62], p=0.44 and HR=1.17 [95%CI: 0.65-2.11], p=0.59, respectively). Conclusions: In this retrospective study of patients with RCC treated with ICIs, administration of high-dose corticosteroids was not associated with worse outcomes.[Table: see text]

Effect of Bacillus Calmette-Guerin (BCG) exposure on severity of COVID-19 infection: A COVID-19 and Cancer Consortium (CCC19) study

4529

Background: Oncology patients experience more severe disease outcomes from COVID-19 infection than the general population. BCG is a live bovine tuberculosis bacillus with immunotherapeutic effects in urothelial cancers; it is also used as vaccination against Mycobacterium tuberculosis in parts of the world. As BCG vaccination has been associated with broad protection against viral pathogens, BCG exposure through vaccination or intravesical therapy may modulate host immunity and reduce the severity of COVID-19 infection. We report the effect of BCG exposure on COVID-19 severity in oncology patients from the CCC19 registry. Methods: The CCC19 registry (NCT04354701) was used to identify patients with prior BCG exposure. Cohort A received intravesical treatment for bladder carcinoma, and cohort B received prior BCG vaccination. Each cohort was matched 3:1 to non-BCG-exposed controls by age, sex, race, primary cancer type, cancer status, ECOG performance status (PS) and calendar time of COVID-19 infection. The primary endpoint was COVID-19 severity reported on an ordinal scale (uncomplicated, hospitalized, admitted to ICU +/- ventilated, died within 30 days) of patients exposed to prior BCG compared to matched non-exposed controls. 2-sided Wilcoxon rank-sum tests were used. Results: As of 6-Feb-2021 we included 124 patients with BCG exposure, 68 patients with bladder carcinoma who had received intravesical BCG (Cohort A), and 64 cancer patients with prior BCG vaccination (Cohort B). Median age was 76 years, IQR 69-83 (Cohort A) and 67 years, IQR 62-74 (Cohort B). Bladder cancer pts were predominately male (78%) vs 55% for Cohort B. Patients with PS 2+ were uncommon, 18% in Cohort A and 16% in Cohort B. COVID-19 illness severity was no different in patients exposed to prior intravesicular BCG (p=0.87). COVID-19 illness severity was no different in patients exposed to prior intradermal BCG vaccination (p=0.60). Conclusions: Despite this being the largest such cohort reported to date, we failed to demonstrate an association of prior BCG exposure with modulation of severity of COVID-19 illness. Prospective trials evaluating the protective effect of BCG vaccination are ongoing and will add further insight into the effect of BCG on COVID-19 illness.[Table: see text]

Lower respiratory tract disease (LRTD) in patients with cancer and COVID-19: A COVID-19 and Cancer Consortium (CCC19) study

6563

Background: Immunodeficiency in patients (pts) with cancer can lead to the progression of common respiratory viral infections to lower respiratory tract disease (LRTD) with potentially high mortality. Understanding risk factors of SARS-CoV-2 related LRTD in pts with cancer is imperative for the development of preventive measures. Methods: We examined all patients aged 18 years or older with cancer and laboratory-confirmed SARS-CoV-2 infection reported between March 16, 2020 and February 6, 2021 in the international CCC19 registry. We examined frequency of LRTD (pneumonia, pneumonitis, acute respiratory distress syndrome, or respiratory failure), demographic and clinicopathologic factors associated with LRTD, and 30-day and overall mortality in pts with and without LRTD. Results: Of 7,289 pts with a median follow-up time of 42 (21-90) days, 2187 (30%) developed LRTD. Pts of older age (65 yrs or older), male sex, pre-existing comorbidities, baseline immunosuppressants, baseline corticosteroids, and ECOG performance status of 2 or more had substantially higher rates of LRTD compared to those without these risk factors (Table). We did not observe differences in LRTD rates between pts of different racial/ethnic groups, smoking history, hypertension, obesity, cancer status, timing or type of anti-cancer therapy. LRTD was more likely in pts with thoracic malignancy (39%), hematological malignancy (39%) compared to those with other solid tumors (27%). The majority of pts (86%) had symptomatic presentation; however, 8% of pts with asymptomatic presentation developed LRTD. 30-day and overall mortality rates were significantly higher in pts with LRTD than those without LRTD (31% vs. 4% and 38% vs. 6%, P < 0.05). Conclusions: COVID-19 related LRTD rate is high and associated with worse mortality rates in pts with cancer. The majority of risk factors associated with LRTD demonstrate underlying immunodeficiency or lung structural damage as a driving force in this population. Identifying pts at high-risk for developing LRTD can help guide clinical management, improve pt outcomes, increase the cost-effectiveness of antiviral therapy, and direct future clinical trial designs for vaccine or antiviral agents.[Table: see text]

Outcomes of first-line (1L) immuno-oncology (IO) combination therapies in metastatic renal cell carcinoma (mRCC): Results from the International mRCC Database Consortium (IMDC)

276

Background: Ipilimumab and nivolumab (IPI-NIVO) and IO/vascular endothelial growth factor (VEGF) inhibitor combinations (IOVE) are now standard of care 1L treatment options for mRCC. However, there is limited head-to-head comparative evidence between these strategies. Methods: Using the IMDC dataset, patients treated with a 1L IOVE combination (pembrolizumab axitinib, avelumab axitinib and nivolumab cabozantinib) were compared with those treated with IPI-NIVO. The outcomes of interest were overall response rate (ORR), treatment duration (TD), time to next treatment (TTNT), and overall survival (OS). A preplanned subgroup analysis of the IMDC intermediate/poor risk population was conducted. Hazard ratios were adjusted for IMDC risk factors. Results: 723 patients were included for analysis (N=571 for IPI-NIVO and N=152 for IOVE). The median age was 60 in both groups. The proportion of patients with IMDC favorable, intermediate and poor risk disease in IPI-NIVO vs. IOVE groups were 9% vs. 33%, 58% vs. 53%, 33% vs. 14%, respectively. In the intermediate/poor risk groups (Table), ORR and median TD were lower and shorter in IPI-NIVO vs IOVE while no difference in median TTNT and OS was detected. The HR for death adjusting for IMDC criteria for IPI-NIVO vs. IOVE was 0.92 (95% CI 0.61-1.40, p=0.71). IMDC risk groups and the presence or absence of sarcomatoid histology, brain, liver or bone metastases were not associated with differences in OS between these treatments (all p>0.2). Patients that had dose delays or steroid use (defined as >40mg of prednisone equivalent/day) for immune related adverse events (irAEs) were associated with longer median TTNT (21.6 vs. 9.5 mons, p=0.02) and OS (NR vs. 44.4 mons, p=0.01) despite similar treatment durations (7.6 vs. 8.9 mons, p=0.77) compared to those without dose delays or steroid use. Conclusions: We were unable to detect any differences in OS between IPI-NIVO and IOVE regimens in the IMDC intermediate/poor risk groups and amongst various subgroups. Patients who experienced irAEs requiring dose delay or steroids had longer overall survival. [Table: see text]

The very favorable metastatic renal cell carcinoma (mRCC) risk group: Data from the International Metastatic RCC Database Consortium (IMDC)

339

Background: The IMDC criteria have been used as a prognostic tool for patients with mRCC receiving single agent VEGF-targeted drugs, and more recently combination immuno-oncology (IO) +/- VEGF-targeted agents, which improve outcomes over VEGF TKI monotherapy. We sought to identify a subset of patients with very favorable outcomes, for which less intensive therapy might be considered. Methods: Utilizing the IMDC dataset, 1638 patients with IMDC favorable risk disease received first-line systemic therapy. Patients were randomly selected in a 2:1 ratio to the training and testing sets, stratified by year of systemic therapy initiation. Multivariable Cox regression estimated prognostic factors for overall survival (OS). Results: Median age was 63 (range 21-95) years and 98% had received prior nephrectomy. First-line systemic therapy consisted of targeted therapy (91%), IO-combination regimens (8%), or other (1%). From the training data, three variables (primary diagnosis to systemic therapy <3 vs ≥3yr; Karnofsky Performance Status 80 vs >80; presence of brain, liver, or bone metastasis) significantly predicted for OS in the multivariable model (hazard ratio 1.4~1.5, p-values<0.05). The model had similar performance in the test dataset (C-index=0.64). Using the 3 included risk factors, patients were classified to very favorable risk (0 risk factors, 29% of patients) or favorable risk disease (≥1 risk factors, 71% of patients). Clinical outcomes for the two risk groups are presented in the table below. Conclusions: We identified a very favorable risk group in the IMDC criteria in RCC patients treated with first-line therapy. External validation including populations receiving IO containing therapies is ongoing. [Table: see text]

Severe-COVID-19 and mortality among patients (pts) with prostate cancer (PCa) receiving androgen deprivation therapy (ADT)

39

Background: The presence of progressing cancer, male sex and advanced age have been shown to increase the severity of coronavirus disease 2019 (COVID-19). Given that the androgen regulated gene TMPRSS2 has been implicated in SARS-CoV-2 viral entry, we hypothesized that ADT may improve COVID-19 outcomes. This analysis evaluated clinical outcomes of pts with PCa with concurrent SARS-CoV-2 infection and investigated the impact of ADT on occurrence of severe-COVID-19 and mortality. Methods: Data was obtained via the COVID-19 and Cancer Consortium (CCC19), a multicenter registry including >120 cancer centers with de-identified data from pts with COVID-19 and cancer. Men with confirmed SARS-CoV-2 infection and a primary diagnosis of prostate cancer were included: data cutoff of July 31, 2020. The primary endpoint was the development of severe-COVID-19 (death, ICU admission, or mechanical ventilation) among pts on ADT vs. those not on ADT at time of COVID-19 infection. Secondary endpoints included 30-day mortality based on ADT use. Mortality and development of severe-COVID-19 were assessed in Pts grouped by therapy: 1st generation androgen receptor inhibitor (ARI-1), 2nd generation ARI (darolutamide, enzalutamide, apalutamide, ARI-2), abiraterone/prednisone, and chemotherapy. Propensity score matching was utilized. Logistic regression was utilized to adjust for age, ECOG PS, comorbidities, and race. Results: 589 pts were included; median follow-up was 42 days (IQR 25-90) and 62% (363/589) were hospitalized. Severe-COVID-19 developed in 28% of pts and the all-cause 30-day mortality rate was 19%. There was no significant difference in the development of severe-COVID-19 or 30-day mortality between Pts on ADT vs not on ADT, whether using descriptive statistics with the entire population or using the propensity score matched population (Table). Among the descriptive population, the numerical rates of severe-COVID-19 and mortality were lowest in Pts receiving ARI-2, but sample size was low. Conclusions: The overall 30-day mortality rate and percentage developing severe-COVID-19 were high. There was no statistical difference in the development of severe-COVID-19 or mortality based on receipt of ADT; however, this analysis is limited by the retrospective nature and small N after propensity-matching. [Table: see text]

Administration of immune checkpoint inhibitors using teleoncology model of care in Far North Queensland: A multicenter review of safety outcomes

2084

Background: The Teleoncology model of care, as developed and implemented across health services in Far North Queensland (Australia), improves access to specialist oncology services, including telehealth supervised administration of Oncology drugs for patients in rural/remote towns. There is limited published data regarding the safety of checkpoint inhibitor immunotherapy when it is administered via Teleoncology. Aim: Evaluate safety of immunotherapy administration via Teleoncology, including immune-related adverse events (irAE), treatment delays, hospital admissions and interhospital transfers, in comparison to a retrospective control population. Methods: Retrospective review of all patients treated with immunotherapy via Teleoncology as part of Cairns and Hinterland Hospital and Health Service (CHHHS) and the Townsville Teleoncology Network (TTN) between January 2015 and April 2019. A retrospective cohort treated at Townsville Cancer Centre over the same time period was used as a control group. Results: Fifty-one patients received a total of 624 cycles of immunotherapy (all single agent anti-PD-1/L-1) via Teleoncology. The control population included 142 patients who received 1697 cycles of immunotherapy. Baseline characteristics were well matched between groups. Compared to the control population, patients treated via telehealth did not have statistically significant differences in the rate of Grade 3+ irAE (13.7% v 8%), hospital admissions (13.7% v 7.4%) or protocol suspensions due to immune toxicity (16% v 10%). One patient with Grade 3+ irAE required interhospital transfer for investigation and management, which occurred within 24 hours of presentation to hospital. There were no treatment-related mortalities in either group. Conclusions: Checkpoint inhibitor immunotherapy can safely be delivered using the Teleoncology model of care in rural and remote centres. The incidence of toxicity for single agent immunotherapy was predictably low and not significantly different between groups, however the numbers in this retrospective study were small. The time to recognition and management of immune mediated toxicity in rural and remote centres is an important factor that was not assessed in this study and will be considered in future work.

Treatment outcomes for metastatic castrate-resistant prostate cancer (mCRPC) patients (pts) following docetaxel (D) for hormone sensitive disease

78

Background: There is no prospective data to guide optimal selection of treatment for first line (1L) mCRPC after D and androgen deprivation therapy (ADT) is given in the hormone sensitive setting. We explored efficacy of 1L treatment in this group. Methods: Pts with mCRPC treated with D for hormone sensitive disease were identified from a prospectively maintained multi-site mCRPC database (ePAD) of patients treated in a community and academic setting in Australia. 1L treatment, clinicopathologic and outcome data were extracted. Results: We identified 93 pts, median age 65y (range 43–85), who received median 6 cycles of D-ADT and developed mCRPC between May 2013 and Jun 2019. 58% had Gleason ≥ 8, median PSA at diagnosis was 53 ng/mL (range 0.67–7086), 65% had de-novo metastatic disease. Median time to mCRPC was 14.8mo (range 1.3 to 56.9) with median time to 1L 16.3mo (range 2.1–57.2). Eighty-five patients (91%) received at least one further active treatment for mCRPC with outcomes below. Conclusions: Abiraterone, enzalutamide, and cabazitaxel all demonstrate activity for 1L mCRPC following progression on D-ADT. Compared to historical controls, PSA responses appear less than pre-docetaxel, but greater than the post-docetaxel setting.[Table: see text]

Linking eutrophication indicators in eelgrass habitats to nitrogen loading and mitigating site characteristics in eastern New Brunswick, Canada

Nitrogen loading has been linked to eutrophication and seagrass bed declines worldwide, yet early warning signs and potential mitigating factors are often less clear. Our objective was to use published nitrogen loading model results together with eelgrass habitat surveys from 7 bays in Atlantic Canada to assess linkages between nitrogen loading, tidal flushing and bivalve aquaculture on observed eutrophication indicators in eelgrass habitats. Field surveys revealed significant differences in primary indicators (annual algae, tissue nitrogen) and secondary changes in eelgrass bed structure, yet no large loss of eelgrass cover or biomass. Multivariate analyses found positive correlations between nitrogen loading and eutrophication indicators, with distinct clusters of high- and low-impact sites, and the mitigating effects of flushing time and aquaculture. Our results highlight that combining measures of nitrogen loading, eutrophication indicators and mitigating factors can help detect early warning signs and assess eutrophication risk to inform management and conservation of coastal ecosystems before significant losses of seagrass occurs.

Recent therapeutic advances for treating medulloblastoma: focus on new molecular targets

Medulloblastoma is the most common malignant brain tumor in children. This malignant tumor of the cerebellum commonly affects children and is believed to arise from the precursor cells of the external granule layer or neuroepithelial cells from the cerebellar ventricular zone of the developing cerebellum. The standard treatment, consisting of surgery, craniospinal radiotherapy and chemotherapy, still provides a poor overall survival for infants and young children. Furthermore, the dose of radiation that can be safely given without causing extensive neurocognitive and endocrinologic sequelae is limited. Therefore, understanding the oncogenic pathways that lead to medulloblastoma, as well as the identification of specific molecular targets with significant therapeutic implications in order to develop new strategies for therapy, is crucial to improve patient survival without substantially increasing toxicity. In this review, we discuss recent therapeutics for treating medulloblastoma, focusing on new molecular targets, as well as advances in translational studies for the treatment of this malignancy.

PINP: a serum biomarker of bone formation in the rat

Serum PINP has emerged as a reliable marker of bone turnover in humans and is routinely used to monitor bone formation. However, the effects of PTH (1-34) on bone turnover have not been evaluated following short-term treatment. We present data demonstrating that PINP is an early serum biomarker in the rat for assessing bone anabolic activity in response to treatment with PTH (1-38). Rat serum PINP levels were found to increase following as few as 6 days of treatment with PTH (1-38) and these increases paralleled expression of genes associated with bone formation, as well as, later increases in BMD. Additionally, PINP levels were unaffected by treatment with an antiresorptive bisphosphonate. PINP may be used to detect PTH-induced early bone formation in the rat and may be more generally applicable for preclinical testing of potential bone anabolic drugs.

Plasma steroids and steroid-binding capacity in male semelparous dasyurid marsupials (Phascogale tapoatafa) that survive beyond the breeding season in captivity

The semelparous dasyurids display a unique life history, in that all males die within a few weeks of the completion of the breeding season. Studies of several semelparous species have revealed that the male die-off is stress-related, and accompanied by increased plasma androgen and cortisol levels and decreased corticosteroid binding capacity, resulting in suppression of immune and inflammatory responses. This study examines the endocrine profile of male brush-tailed phascogales (Phascogale tapoatafa) that survive beyond the breeding season in captivity. Plasma cortisol, corticosteroid binding globulin and albumin levels were monitored in both males and females and steroid partitioning calculated. Captive males surviving beyond the breeding season did not show the elevation in plasma cortisol and decrease in corticosteroid binding capacity reported in wild males. Plasma albumin concentrations also remained constant during the sampling period. These data indicate that captive males do not undergo the same stress response described in wild populations.

Meiotic competence in horse oocytes: interactions among chromatin configuration, follicle size, cumulus morphology, and season

Horse oocytes were collected from an abattoir over a 15-mo period. After classification of follicle size and cumulus morphology, oocytes were either fixed immediately (0 h) or matured in vitro (24 h). There was no effect of season on the number of antral follicles present on the ovaries, or on oocyte maturation rate for any class of oocyte. The proportion of oocytes having condensed chromatin at 0 h increased with increasing follicle size. The oocyte maturation rate also increased with follicle size, and for follicles </= 20-mm diameter, was higher for oocytes initially having expanded cumuli than for those having compact cumuli. The maturation rate was strongly correlated (r(2) = 0.92) with the proportion of oocytes having condensed chromatin at 0 h. Oocytes with diffuse chromatin were found essentially only in follicles </= 20-mm diameter that yielded compact granulosa, indicating follicle viability. Presence of diffuse chromatin was inversely related to maturation rate. We conclude that the major signal for chromatin condensation, and thus acquisition of meiotic competence, occurs in viable follicles after 20-mm diameter in the horse. Condensation of chromatin in oocytes in smaller apparently viable follicles, while associated with acquisition of meiotic competence, may represent a pre-atretic change.

Ascariasis in the subdistrict of Cavacos, municipality of alterosa (MG), Brazil: effect of mass treatment with albendazole on the intensity of infection

The clinical and epidemiologic aspects of infection with Ascaris lumbricoides were studied in a random stratified sample of the population of the subdistrict of Cavacos, municipality of Alterosa (Minas Gerais, Brazil). The effect of mass treatment with a single dose of albendazole on the prevalence and intensity of infection was also studied six months later in the same population. During the first phase of the study, a questionnaire was applied to 248 individuals to obtain information about the socioeconomic, sanitary and clinical conditions of the population surveyed. A total of 230 fecal samples were also examined by the Kato-Katz technique in order to determine the intensity of A. lumbricoides infection. Two hundred and two individuals were simultaneously submitted to blood counts and 70 children aged 12 years or less were evaluated for nutritional status. The presence of A. lumbricoides and other helminth eggs was also determined in 22 soil samples collected in the urban zone of Cavacos. Infection with enteroparasitic helminths was detected in 29.1% of the sample, with a predominance of A. lumbricoides (23.9%). Parasitism and/or intensity of A. lumbricoides infection were significantly correlated with age range (15 years or less), social class, sanitary and living conditions (water, sewage and domiciliary area per person), and presence of abdominal pain. However, these parameters were not correlated with nutritional status or hematocrit levels. During the second phase of the study, a slight but not statistically significant decrease in the prevalence of A. lumbricoides infection was detected after treatment with albendazole. However, an important and significant reduction in the amount of A. lumbricoides eggs eliminated through the feces was detected, indicating that the intensity of A. lumbricoides infection was lower in all the age ranges of the Cavacos population, especially among younger individuals, even six months after administration of the anthelminthic agent.

Effect of follicular components on meiotic arrest and resumption in horse oocytes

Two experiments were conducted to evaluate the effect of follicular components on the maintenance of meiotic arrest in horse oocytes. In Expt 1, oocytes were incubated for 24 h with follicular fluid, or with granulosa cells suspended either in medium or in follicular fluid at 25 x 10(6) cells ml-1. None of the treatments resulted in significant maintenance of the germinal vesicle stage over that of non-suppressive control. Culture with follicular fluid plus granulosa cells resulted in a significantly higher proportion of oocytes at metaphase I compared with controls. In Expt 2, oocytes were divided into those originally having compact or expanded cumuli. Oocytes were cultured with sheets of mural granulosa or sections of follicle wall, or after injection into intact dissected follicles. After incubation, half of the oocytes from each suppressive treatment were matured for 24 h. All three suppressive treatments were effective in maintaining oocytes at the germinal vesicle stage (no significant difference from control oocytes fixed directly after removal from the follicle). However, no treatment maintained normal viability of oocytes, as significantly fewer oocytes were at metaphase II after all the suppression-maturation treatments compared with the maturation control. The highest rate of post-suppression maturation was found in the mural granulosa treatment. Within this treatment, the proportion of oocytes in metaphase II was significantly higher for oocytes with expanded than for oocytes with compact cumuli (31% versus 11%, respectively; P < 0.05). Suppression by injection into an intact follicle was associated with a lack of progression to metaphase II during subsequent maturation.(ABSTRACT TRUNCATED AT 250 WORDS)

Reversal of the red beet tonoplast H(+)-ATPase by a pyrophosphate-generated proton electrochemical gradient

The reversal of the tonoplast H(+)-ATPase to mediate ATP synthesis was investigated in tonoplast vesicles isolated from red beet (Beta vulgaris L.) storage tissue. Our approach involved use of the H(+)-PP(i)ase to establish a proton electrochemical gradient (delta muH+) across the tonoplast vesicle membrane to drive the H(+)-ATPase in reverse. However, an initial problem with this approach was the presence of an adenylate kinase activity in the tonoplast fraction that interfered with measurement of ATP synthesis as a coupling between the H(+)-ATPase and H(+)-PP(i)ase. Inclusion of the adenylate kinase inhibitor p1p5-di(adenosine)pentaphosphate (Ap5A) in assays at 50 microM led to a complete inhibition of this activity and allowed measurement of ATP synthesis coupled to PPi hydrolysis. When measured in the presence of Ap5A, PPi-dependent ATP synthesis was blocked by Triton X-100 and inhibited by gramicidin D, imidodiphosphate, nitrate, and bafilomycin A. These results are consistent with PPi-dependent ATP synthesis occurring as a coupled process involving a delta muH+ established across the membrane. Furthermore, the observation that ATP synthesis is inhibited by inhibitors of the tonoplast H(+)-ATPase (nitrate and bafilomycin A) would suggest that this enzyme is involved in the synthetic reaction and can operate in reverse to synthesize ATP from ADP and Pi. A thermodynamic analysis of coupling between the H(+)-PP(i)ase and H(+)-ATPase suggests that PPi-driven ATP synthesis could only occur under these reaction conditions if the H+/substrate stoichiometries for the H(+)-PP(i)ase and H(+)-ATPase were 1 and 2, respectively. These values are consistent with transport stoichiometries previously determined for these enzymes in red beet tonoplast vesicles using kinetic methods.

Energy transduction in tonoplast vesicles from red beet (Beta vulgaris L.) storage tissue: H+/substrate stoichiometries for the H(+)-ATPase and H(+)-PPase

The H+/substrate stoichiometries of the tonoplast H(+)-ATPase and H(+)-PPase were determined by a kinetic approach. Using red beet (Beta vulgaris L.) tonoplast vesicles, rates of substrate-dependent H+ transport were estimated by (I) a mathematical model describing the time course of delta pH formation, (II) the rate of H+ leakage following H+ pump inhibition at a steady state delta pH, and (III) the initial rate of alkalinization of the external medium. When compared with rates of substrate hydrolysis measured under identical conditions, all three methods yielded an H+/ATP stoichiometry of 2 while the H+/PPi stoichiometry was determined to be 1 using methods I and II. Experimental limitations did not permit an analysis of the H+/PPi stoichiometry by method III. From these results and the estimated level of substrate and product typically found in the cytoplasm of plant cells, it is suggested that the H(+)-ATPase and H(+)-PPase as primary H(+)-pumps are poised toward net substrate hydrolysis under in vivo conditions thereby operating in parallel to generate a proton electrochemical gradient across the tonoplast.

In vitro maturation of horse oocytes: characterization of chromatin configuration using fluorescence microscopy

The chromatin configuration of resting horse oocytes and the time course of in vitro oocyte maturation was characterized using a fluorescent, DNA-specific label. Oocytes were classified as having either compact (CP) or expanded (EX) cumuli at the time of collection. Centrifugation of oocytes was effective in allowing visualization of the germinal vesicle. Two main chromatin configurations were found in oocytes known to have a germinal vesicle: condensed chromatin (CC), in which the chromatin formed a dense mass surrounding the nucleolus; and fluorescing nucleus (FN), in which the entire nucleus, containing diffuse or spotty chromatin, was visible. The proportion of CC to FN was higher for oocytes with EX cumuli. At time 0, 78% of CP oocytes and 73% of EX oocytes were in the germinal vesicle stage. Significantly more EX than CP oocytes were in metaphase I or II at time 0. In both CP and EX groups, maturation had not begun after 8 h of incubation. Maximal maturation occurred after 24 h for oocytes in the EX group, whereas CP oocytes continued to mature between 24 and 32 h. The percentage of EX oocytes in metaphase I did not change between 24 and 32 h, indicating a possible arrest of some EX oocytes at metaphase I. There was no difference in the percentage of oocytes at metaphase II between the CP and EX groups after 32 h of incubation.

Culture of 5-day horse embryos in microdroplets for 10 to 20 days

Embryos were recovered from the uteri of mares 5 d after ovulation. Six embryos, all morulae, were placed singly in 200-ul droplets of Ham's F-12 with 10% fetal calf serum and cultured at 37 degrees C in a 5% CO(2) atmosphere. The embryos expanded to form blastocysts by the third day of culture. The blastocysts hatched from their zona pellucida, rather than the zona thinning and flaking off, as occurs in vivo. Hatching from the zona pellucida began on the third day of culture and was complete in five of six embryos by the sixth day. The embryonic capsule, normally present in equine embryos after Day 6, was not seen in the cultured embryos. The blastocysts continued to expand until 15 to 17 d of age (10 to 12 d in culture), reaching an average diameter (+/- SD) of 2052 +/- 290 um, after which time they either collapsed or contracted. These results demonstrate that equine embryos can be maintained in long-term culture in vitro, exhibiting continued growth and expansion in the absence of the embryonic capsule.

Larval development test for detection of anthelmintic resistant nematodes

The growth, using freshly cultured Escherichia coli with ampicillin or heat-treated lyophilised E coli as a food source, of the larvae of the mouse nematode Nematospiroides dubius and the infectivity of resulting third stage larvae were determined. Concentrations of E coli between 0.5 and 1 mg dry weight ml-1 permitted optimal larval development for both N dubius and Trichostrongylus colubriformis. Development of larvae of susceptible and cambendazole-resistant strains of Haemonchus contortus in thiabendazole solutions showed clear differences between the strains and the larval development test was more sensitive than the egg hatch test. The test also detected a levamisole resistant strain of H contortus, although the degree of resistance could not be adequately measured. It is concluded that the test can be run with any anthelmintic to which resistance is suspected.

Language processing in men at risk for alcoholism: an event-related potential study

Event-related potentials (ERPs) were recorded from a group of men with (FH+) and without (FH-) a family history of alcoholism. ERPs were recorded over the left and right cerebral hemispheres and over midline locations while subjects performed a letter rhyming task. The ERPs to the letters displayed major group differences in a negative component with a latency of 430 msec (N430). The amplitude of N430 was significantly smaller in the FH+ as compared to the FH- subjects. These group differences were more pronounced in ERPs recorded from over the right than the left hemisphere. In addition, in the FH+ group only the latency of N430 was linearly related to personal drinking habits. These results suggest that (1) certain brain functions associated with the language processing required in this task are different in men at high and low risk for the development of alcoholism and (2) moderate social use of ethanol may have more pronounced effects on language-relevant brain functions in FH+ than in FH- individuals.

Germicidal persistence of teat dips by modified excised teat procedure

An excised teat protocol was modified to evaluate persistence of germicidal activity of teat dips over 8 h. Five teat dip formulations, iodophor (1%), chlorhexidine gluconate (.55%), linear dodecyl benzene sulfonic acid (1.94%), sodium chlorite-lactic acid in a water base, and sodium chlorite-lactic acid in a gel base were tested against Escherichia coli and Klebsiella oxytoca. Iodophor and chlorhexidine had high germicidal activity throughout 8 h, whereas dodecyl benzene sulfonic acid had little activity. Germicidal activity of both sodium chlorite-lactic acid teat dips was high initially but declined with time. The gel base dip, however, remained more germicidal than the water base dip. Results were similar for either organism for most teat dips. However, chlorhexidine was less effective and the gel base dip more effective against Klebsiella oxytoca than Escherichia coli. Standard errors often appeared higher for Klebsiella oxytoca than for Escherichia coli. These assays may prove useful for laboratory screening of teat dips to determine germicidal persistence over time.

Evaluation of experimental teat dip containing sodium chlorite and lactic acid by excised teat assay

An experimental teat dip containing sodium chlorite and lactic acid, diluted in water, was evaluated by excised teat protocol. The teat dip was tested against 21 microorganisms. Included were: Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus uberis, Escherichia coli, Klebsiella oxytoca, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Numerous strains were tested for strain differences. Environmental bacteria were included because of their increasing importance as a cause of bovine mastitis. All excised teats were dipped in a bacterial suspension containing about 1 X 10(8) cfu/ml. Negative control teats were not dipped in a germicidal compound. Positive controls were dipped in 1% iodophor. Effectiveness of the experimental teat dip was expressed as the percent reduction in mean log of bacteria recovered from dipped teats as compared to numbers recovered from control teats. The sodium chlorite - lactic acid dip caused a greater percent log reduction than iodophor for 14 of 21 strains tested. However, differences were generally slight. The experimental teat dip appeared effective against Gram-negative bacteria. Some differences in percent log reduction were observed between strains of the same species. Lowest effectiveness and greatest strain variation were observed with Staphylococcus aureus for both dips tested.

Cerebral activation patterns in an arithmetic and a visuospatial processing task

Evoked potentials (EPs) to a probe tone stimulus were recorded simultaneously at the temporal and parietal areas of the left and right hemisphere of dextral adults engaged in either an arithmetic or a visuospatial task. The probe EP amplitude was attenuated in the left temporal area during the arithmetic task and in the left temporal and both parietal areas, but significantly more in the right, during the visuospatial task, indicating distinct patterns of regional cerebral engagement for the two types of cognitive activity.

Determination of acetaminophen in pharmaceutical preparations and body fluids by high-performance liquid chromatography with electrochemical detection

A sensitive and very rapid assay for acetaminophen was developed based on the combination of high-performance chromatographic columns with a thin-layer electrochemical detector. Application to liquid and solid dosage forms and body fluids has been demonstrated. Great advantage derives from the detector selectivity, which permits discrimination against many potentially interfering substances without need for extensive separations or formation of derivatives. As little as 0.005% of the hydrolysis product, p-aminophenol, can be detected in the presence of the intact drug following cation-exchange chromatography. Acetaminophen can be quantitatively determined in serum on the 50-ng/ml level by liquid chromatography using a pellicular polyamide packing.