Dose-Volume Predictors of Radiation Pneumonitis After Thoracic Hypofractionated Radiation Therapy

PURPOSE

Hypofractionated radiation therapy (HFRT) is a common treatment for thoracic tumors, typically delivered as 60 Gy in 15 fractions. We aimed to identify dosimetric risk factors associated with radiation pneumonitis in patients receiving HFRT at 4 Gy per fraction, focusing on lung V20, mean lung dose (MLD), and lung V5 as potential predictors of grade ≥2 pneumonitis.

METHODS AND MATERIALS

All patients were treated with thoracic HFRT to 60 Gy in 15 fractions or 72 Gy in 18 fractions at a single health care system from 2013 to 2020. Tumors near critical structures (trachea, proximal tracheobronchial tree, esophagus, spinal cord, or heart) were considered central (within 2 cm), and those closer were classified as ultracentral (within 1 cm). The primary endpoint was grade ≥2 pneumonitis. Logistic regression analyses, adjusting for target size and dosimetric variables, were used to establish a dose threshold associated with <20% risk of grade ≥2 pneumonitis.

RESULTS

During a median 24.3-month follow-up, 18 patients (16.8%) developed grade ≥2 radiation pneumonitis, with no significant difference between the 2 dose regimens (17.3% vs 16.3%, P = .88). Four patients (3.7%) experienced grade ≥3 pneumonitis, including 2 grade 5 cases. Patients with grade ≥2 pneumonitis had significantly higher lung V20 (mean 23.4% vs 14.5%, P < .001), MLD (mean 13.0 Gy vs 9.5 Gy, P < .001), and lung V5 (mean 49.6% vs 40.6%, P = .01). Dose thresholds for a 20% risk of grade ≥2 pneumonitis were lung V20 <17.7%, MLD <10.6 Gy, and V5 <41.3%. Multivariable analysis revealed a significant association between lung V20 and grade ≥2 pneumonitis (adjusted odds ratio, 1.48, P = .03).

CONCLUSIONS

To minimize the risk of grade ≥2 radiation pneumonitis when delivering 4 Gy per fraction at either 60 Gy or 72 Gy, it is advisable to maintain lung V20<17.7%. MLD <10.6 Gy and V5<41.3% can also be considered as lower-priority constraints. However, additional validation is necessary before incorporating these constraints into clinical practice or trial planning guidelines.

Stereotactic ablative radiotherapy for primary renal cell carcinoma

Stereotactic ablative radiotherapy (SAbR) is an emerging non-invasive definitive treatment option for primary renal cell carcinoma (RCC), particularly when surgery is not ideal. Employing ablative doses, SAbR delivered in one to five fractions to the primary tumor has been shown to achieve high local control rates with favorable toxicity profile in multiple retrospective and prospective series, and has dispelled previous notions of RCC radio-resistance. Moreover, emerging evidence suggests possible immunomodulatory effects, leading to clinical investigations of SAbR in combination with systemic and surgical management in patients with metastatic disease. In this review, we summarize key evidence supporting SAbR delivered to the primary tumor including preclinical rationale, dose escalation studies, recent prospective trials, and outcomes from ongoing multi-institutional registries. We also discuss areas of active clinical investigation including the use of primary SAbR in combination with systemic therapies in patients with metastatic disease. The accumulated body of evidence supports SAbR as promising indication being increasingly incorporated into the multi-disciplinary management of primary RCC.

Dose-Escalated vs. Conventional Hypofractionated Radiotherapy for Lung Cancer Patients in Predominantly Central Locations

PURPOSE/OBJECTIVE(S)

Hypofractionated radiation therapy (HFRT) is an increasingly utilized treatment option for patients with lung cancers unamenable to stereotactic body radiotherapy (SBRT). Conventional HFRT (C-HFRT) is often prescribed to 60 Gy in 15 fractions, which has a lower biologically effective dose (BED10 of 84.0) than SBRT. We compared outcomes of patients treated with a dose-escalated HFRT regimen (DE-HFRT, 72 Gy in 18 fractions, BED10 of 100.8) to those treated with C-HFRT. We aimed to evaluate local control (LC), overall survival (OS), and grade 3+ toxicity between patients who received C-HFRT vs. DE-HFRT as we hypothesized DE-HFRT may be superior/equivalent to C-HFRT.

MATERIALS/METHODS

A database was created of all patients at our institution who received either thoracic C-HFRT or DE-HFRT between 2013 and 2020. Baseline variables were compared by chi-square analysis and logistic regression. We analyzed the association between treatment regimens with LC and OS (log-rank test and Cox proportional hazards regression), as well as grade 3+ toxicity.

RESULTS

A total of 107 patients were included, among whom 55 (51.4%) received C-HFRT and 52 (48.6%) received DE-HFRT. Median age was 73, 88.8% of patients had non-small cell lung cancer, 81.3% received lung-only treatment, and 52.3% had an ultra-central tumor location (within 1 cm of proximal tracheobronchial tree, esophagus, or heart). Patients with DE-HFRT were more likely to have lung-only treatment (92.3% vs. 70.9%, p = 0.005) and stage I disease (47.1% vs 24.1%, p = 0.01) than those with C-HFRT, but had a similar proportion of ultra-central tumors (57.1% vs. 54.9%, p = 0.82). Patients with DE-HFRT had a non-statistically significant trend towards higher LC (2-year 81.0% vs. 72.3%, 3-year 77.3% vs 52.3%, HR 0.53 [95% CI 0.26-1.09], p = 0.09) and OS (2-year 61.3% vs. 44.8%, 3-year 44.9% vs 33.9%, HR 0.68 [95% CI 0.41-1.11], p = 0.13) compared to those with C-HFRT. Similar findings were noted among those with lung-only treatment. Among those with ultra-central tumors, patients with DE-HFRT had statistically significantly higher LC (2-year 86.6% vs 71.2%, 3-year 86.6% vs 42.2%, HR 0.26 [95% CI 0.08-0.84] p = 0.02) and a non-statistically significant trend towards higher OS (2-year 63.8% vs 40.0%, 3-year 46.2% vs 31.1% HR 0.55 [95% CI 0.28-1.09] p = 0.09) compared to those with C-HFRT. There was no statistically significant difference in grade 3+ toxicities between DE-HFRT and C-HFRT (15.4% vs. 10.9%, OR 1.48 [95% CI 0.47-4.61], p = 0.49).

CONCLUSION

We noted promising local control and overall survival for patients treated with 72 Gy in 18 fractions compared to 60 Gy in 15 fractions, especially among those with ultra-central tumors. Grade 3+ toxicities were not significantly higher for patients undergoing dose escalation. Hence, our findings suggest that DE-HFRT to the lung is a safe and effective treatment regimen for highly selected patients who cannot undergo SBRT.

Comparing Detection Schemes for Adversarial Images against Deep Learning Models for Cancer Imaging

Deep learning (DL) models have demonstrated state-of-the-art performance in the classification of diagnostic imaging in oncology. However, DL models for medical images can be compromised by adversarial images, where pixel values of input images are manipulated to deceive the DL model. To address this limitation, our study investigates the detectability of adversarial images in oncology using multiple detection schemes. Experiments were conducted on thoracic computed tomography (CT) scans, mammography, and brain magnetic resonance imaging (MRI). For each dataset we trained a convolutional neural network to classify the presence or absence of malignancy. We trained five DL and machine learning (ML)-based detection models and tested their performance in detecting adversarial images. Adversarial images generated using projected gradient descent (PGD) with a perturbation size of 0.004 were detected by the ResNet detection model with an accuracy of 100% for CT, 100% for mammogram, and 90.0% for MRI. Overall, adversarial images were detected with high accuracy in settings where adversarial perturbation was above set thresholds. Adversarial detection should be considered alongside adversarial training as a defense technique to protect DL models for cancer imaging classification from the threat of adversarial images.

Factors associated with the use of adjuvant radiation therapy in stage III melanoma

Objective

The role of radiation therapy (RT) in melanoma has historically been limited to palliative care, with surgery as the primary treatment modality. However, adjuvant RT can be a powerful tool in certain cases and its application in melanoma has been increasingly explored in recent years. The aim of this study is to explore national patterns of care and associations surrounding the use of adjuvant RT for stage III melanoma.

Methods

The National Cancer Data Base (NCDB) was used to identify patients who were diagnosed with stage III melanoma between 2004 and 2014. Exclusion criteria included those with distant metastatic disease, in-situ histology, no confirmed positive nodes, palliative intent therapy, and dosing regimens inconsistent with National Comprehensive Cancer Network (NCCN) guidelines for adjuvant RT in melanoma. Patients treated with and without adjuvant RT were compared and factors associated with use of adjuvant RT were identified using multivariable logistic regression analyses.

Results

A total of 7,758 cases of stage III melanoma were analyzed, of which 11.7% received adjuvant RT. The mean age of the overall cohort was 58.5 years, and the majority of patients were male (64.7%), white (96.6%), on private insurance (51.3%), and presented to a non-high-volume facility (90.3%). Multivariable regression analyses revealed that patients who present to the hospital in 2009-2014 as compared to 2004-2008 (odds ratio [OR] 1.61, 95% confidence interval [CI] 1.36-1.92), had 4 or more positive nodes (OR 4.30, 95% CI 3.67-5.04), and had microscopic residual tumor (OR 2.11, 95% CI 1.46-3.04) were more likely to receive adjuvant RT. Factors that were negatively associated with receiving adjuvant RT included female gender (OR 0.72, 95% CI 0.61-0.85) and median income of at least $63,000 (OR 0.66, 95% CI 0.52-0.83).

Conclusions

This study demonstrates the rising use of RT for stage III melanoma in recent years and identifies demographic, social, clinical, and hospital-specific factors associated with patients receiving adjuvant RT. Further investigation is needed to explore disease benefits to improve guidance on the utilization of RT in melanoma.

Factors Associated With In-Hospital Mortality in Mycosis Fungoides Patients: A Multivariable Analysis

Background Mycosis fungoides (MF) is the most common form of cutaneous T-cell lymphoma (CTCL). Although it often has an indolent course, it can progress to more aggressive CTCL forms. There is sparse data in current literature describing specific clinical factors associated with in-hospital mortality in mycosis fungoides patients. An understanding of patients at greatest risk for in-hospital mortality can aid in developing recommendations for prophylaxis and empirical management. Aim We aim to characterize factors associated with in-hospital mortality in MF patients. Materials and methods The Nationwide Emergency Department Sample (NEDS) was queried for MF cases from 2006 to 2015. Baseline demographic and hospital characteristics were stratified based on survival outcomes. Multivariable logistic regression was used to identify factors associated with in-hospital mortality. Results A total of 57,665 patients with MF presenting to the ED between 2006 and 2015 were identified. Sézary syndrome, sepsis, and advanced age were associated with MF in-hospital mortality, while female sex was inversely associated. There was a downtrend in in-hospital mortality among MF patients presenting to the ED from 2006 to 2015. Conclusions Our study highlights factors crucial for risk-stratification for hospitalized MF patients.

Using Adversarial Images to Assess the Robustness of Deep Learning Models Trained on Diagnostic Images in Oncology

Deep learning (DL) models have rapidly become a popular and cost-effective tool for image classification within oncology. A major limitation of DL models is their vulnerability to adversarial images, manipulated input images designed to cause misclassifications by DL models. The purpose of the study is to investigate the robustness of DL models trained on diagnostic images using adversarial images and explore the utility of an iterative adversarial training approach to improve the robustness of DL models against adversarial images.

Exploring vulnerabilities of deep learning algorithms to adversarial images across oncologic imaging modalities.

Temporal Trends in Opioid Prescribing Patterns Among Oncologists in the Medicare Population

BACKGROUND

In the wake of the US opioid epidemic, there have been efforts to curb opioid prescribing. However, it is unknown whether these efforts have affected prescribing among oncologists, whose patients often require opioids for symptom management. We investigated temporal patterns in opioid prescribing for Medicare beneficiaries among oncologists and nononcologists.

METHODS

We queried the Centers for Medicare and Medicaid Services Part D prescriber dataset for all physicians between January 1, 2013, and December 31, 2017. We used population-averaged multivariable negative binomial regression to estimate the association between time and per-provider opioid and gabapentinoid prescribing rate, defined as the annual number of drug claims (original prescriptions and refills) per beneficiary, among oncologists and nononcologists on a national and state level.

RESULTS

From 2013 to 2017, the national opioid-prescribing rate declined by 20.7% (P < .001) among oncologists and 22.8% (P < .001) among non oncologists. During this time frame, prescribing of gabapentin increased by 5.9% (P < .001) and 23.1% (P < .001) among oncologists and nononcologists, respectively. Among palliative care providers, opioid prescribe increased by 15.3% (P < .001). During the 5-year period, 43 states experienced a decrease (P < .05) in opioid prescribing among oncologists, and in 5 states, opioid prescribing decreased more among oncologists than nononcologists (P < .05).

CONCLUSIONS

Between 2013 and 2017, the opioid-prescribing rate statistically significantly decreased nationwide among oncologists and nononcologists, respectively. Given similar declines in opioid prescribing among oncologists and nononcologists, there is concern that opioid-prescribing guidelines intended for the noncancer population are being applied inappropriately to patients with cancer and cancer survivors.

[Development of multiple organ dysfunction syndrome in patients with Coronavirus Disease 2019: clinical characteristics and risk factors]

Objective: To explore the clinical characteristics and risk factors of patients with Coronavirus Disease 2019 (COVID-19) when developing multiple organ dysfunction syndrome (MODS). Methods: Data from 458 inpatients of confirmed COVID-19 in Wuhan, Shanghai and Tongling from December 29, 2019 to March 24, 2020 were retrospectively collected. COVID-19 was confirmed by real-time RT-PCR of throat swab samples. Data of demographics, clinical presentation, laboratory tests, imaging findings, treatment and prognosis were obtained from medical record and compared between COVID-19 patients with and without MODS. Risk factors for the development of MODS were analyzed by univariate and multivariate logistic regression analysis. Results: Of the 458 COVID-19 patients (266 from Wuhan, 208 from Shanghai, and 24 from Tongling), 103 developed transient or persistent MODS in the course. More male patients were found in those with MODS (72.8% vs 54.6%, P=0.001). And MODS patients were of older age (72.8% vs 54.6%, P=0.001), more chronic comorbidities (68.0% vs 43.4%, P<0.001), and longer onset-to-admission interval (9.0 vs 7.0 d, P<0.001). In addition, patients with MODS had more expectoration (45.6% vs 29.9%, P=0.003) and shortness of breath (52.4% vs 19.4%, P<0.001), dysfunction of various systems, decreased cellular immunity and elevated IL-6 (9.6 vs 7.6 g/L, P=0.015) in laboratory tests, isolation of other pathogens (18.4% vs 5.6%, P<0.001), and infiltration of all five lobes (75.3% vs 57.6%, P=0.003). During hospitalization, patients with MODS needed a higher proportion of comprehensive treatment and reached a mortality rate of 66.0%. Independents risk factors for development of MODS in COVID-19 patients were: onset-to-admission interval>7 days (OR=2.17, 95%CI: 1.11-4.22, P=0.023), shortness of breath (OR=3.19, 95%CI: 1.60-6.37, P=0.001), lymphocyte count<1×10⁹/L (OR=2.67, 95%CI: 1.31-5.46, P=0.007), blood urea nitrogen>7mol/L (OR=6.27, 95%CI: 2.80-14.08, P<0.001), procalcitonin>0.1 ng/mL (OR=2.48, 95%CI: 1.20-5.13, P=0.014), and C-reactive protein>10 mg/L (OR=3.92, 95%CI: 1.41-10.89, P=0.009). Conclusions: COVID-19 patients with MODS were of higher severity and mortality. Early identification of high-risk groups with MODS according to risk factors may be helpful for early treatment.

Prevalence of Missing Data in the National Cancer Database and Association With Overall Survival

IMPORTANCE

Cancer registries are important real-world data sources consisting of data abstraction from the medical record; however, patients with unknown or missing data are underrepresented in studies that use such data sources.

OBJECTIVE

To assess the prevalence of missing data and its association with overall survival among patients with cancer.

DESIGN, SETTING, AND PARTICIPANTS

In this retrospective cohort study, all variables within the National Cancer Database were reviewed for missing or unknown values for patients with the 3 most common cancers in the US who received diagnoses from January 1, 2006, to December 31, 2015. The prevalence of patient records with missing data and the association with overall survival were assessed. Data analysis was performed from February to August 2020.

EXPOSURES

Any missing data field within a patient record among 63 variables of interest from more than 130 total variables in the National Cancer Database.

MAIN OUTCOMES AND MEASURES

Prevalence of missing data in the medical records of patients with cancer and associated 2-year overall survival.

RESULTS

A total of 1 198 749 patients with non-small cell lung cancer (mean [SD] age, 68.5 [10.9] years; 628 811 men [52.5%]), 2 120 775 patients with breast cancer (mean [SD] age, 61.0 [13.3] years; 2 101 758 women [99.1%]), and 1 158 635 patients with prostate cancer (mean [SD] age, 65.2 [9.0] years; 100% men) were included in the analysis. Among those with non-small cell lung cancer, 851 295 patients (71.0%) were missing data for variables of interest; 2-year overall survival was 33.2% for patients with missing data and 51.6% for patients with complete data (P < .001). Among those with breast cancer, 1 161 096 patients (54.7%) were missing data for variables of interest; 2-year overall survival was 93.2% for patients with missing data and 93.9% for patients with complete data (P < .001). Among those with prostate cancer, 460 167 patients (39.7%) were missing data for variables of interest; 2-year overall survival was 91.0% for patients with missing data and 95.6% for patients with complete data (P < .001).

CONCLUSIONS AND RELEVANCE

This study found that within a large cancer registry-based real-world data source, there was a high prevalence of missing data that were unable to be ascertained from the medical record. The prevalence of missing data among patients with cancer was associated with heterogeneous differences in overall survival. Improvements in documentation and data quality are necessary to make optimal use of real-world data for clinical advancements.

Serum metabolic markers and metabolic pathways in rats with metabolomic cecal ligation and puncture-induced sepsis

The aim of this study was to explore the dynamic changes in characteristic serum metabolic markers and pathways during early sepsis in rats. By using cecal ligation and puncture (CLP), we made rat models of sepsis, which were randomly divided into 5 groups with 10 rats in each group: group A, group B, group C, group D, and group E. We collected 2 mL of arterial blood at 0, 6, 12, 24, and 48 hours from rats in group A-E respectively and isolated serum via centrifugation. Next, adopting metabolomics analysis methods, we screened for metabolites from the animal serum with statistically and biologically significant abundance changes, and used the KEGG database to analyze the respective metabolic pathways. In all, our findings reveal that D-glucosamine 6-phosphate, D-glucosamine phosphate, α-D-glucosamine 1-phosphate, D-glucosamine 1-phosphate, and 5-hydroxy isocyanate decline continuously from 12 hours, while L-phenylalanine, (S) -α-amino-β-phenylpropionic acid, 5-methoxy indole acetic acid salt, 5-methoxy indole acetic acid, goose deoxyglycolic acid salt, goose deoxyglycolic acid, and Chen's deoxygenated sugar alcohol started to decrease from 6 hours. Additionally, 3.2,3-Bis-O-(geranyl geranyl)-sn-glycerol- 1-phosphoric acid-L-serine levels rose continuously from 12 hours. We found 13 differentially regulated ions, primarily ones involved in pathways responsible for the metabolism of sugar, amino acids, and lipids, which are related to the disorder of energy metabolism. Our findings mark serum-derived D-glucosamine and its phosphorous derivatives as characteristic metabolic markers of sepsis in rats.

Geographic-Level Association of Contemporary Changes in Localized and Metastatic Prostate Cancer Incidence in the Era of Decreasing PSA Screening

Decreased prostate-specific antigen screening since 2008 has generated much concern, including report of recent increase in metastatic prostate cancer incidence among older men. Although increased metastatic disease was temporally proceeded by decreased screening and decreased localized prostate cancer at diagnosis, it is unclear whether the 2 trends are geographically connected. We therefore used the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) database to assess geographic-specific associations between changes in localized (2008-2011) and later changes in metastatic prostate cancer incidence (2012-2015). We examined trends from 200 health-care service areas (HSAs) within SEER 18 registries. While on average for each HSA, localized incidence decreased by 27.4 and metastatic incidence increased by 2.3 per 100 000 men per year, individual HSA-level changes in localized incidence did not correlate with later changes in metastatic disease. Decreased detection of localized disease may not fully explain the recent increase in metastatic disease at diagnosis.

Emergency Department Visits for Opioid Overdoses Among Patients With Cancer

BACKGROUND

Patients with cancer may be at risk of high opioid use due to physical and psychosocial factors, although little data exist to inform providers and policymakers. Our aim is to examine overdoses from opioids leading to emergency department (ED) visits among patients with cancer in the United States.

METHODS

The Healthcare Cost and Utilization Project Nationwide Emergency Department Sample was queried for all adult cancer-related patient visits with a primary diagnosis of opioid overdose between 2006 and 2015. Temporal trends and baseline differences between patients with and without opioid-related ED visits were evaluated. Multivariable logistic regression analysis was used to identify risk factors associated with opioid overdose. All statistical tests were two-sided.

RESULTS

Between 2006 and 2015, there were a weighted total of 35 339 opioid-related ED visits among patients with cancer. During this time frame, the incidence of opioid-related ED visits for overdose increased twofold (P < .001). On multivariable regression (P < .001), comorbid diagnoses of chronic pain (odds ratio [OR] 4.51, 95% confidence interval [CI] = 4.13 to 4.93), substance use disorder (OR = 3.54, 95% CI = 3.28 to 3.82), and mood disorder (OR = 3.40, 95% CI = 3.16 to 3.65) were strongly associated with an opioid-related visit. Patients with head and neck cancer (OR = 2.04, 95% CI = 1.82 to 2.28) and multiple myeloma (OR = 1.73, 95% CI = 1.32 to 2.26) were also at risk for overdose.

CONCLUSIONS

Over the study period, the incidence of opioid-related ED visits in patients with cancer increased approximately twofold. Comorbid diagnoses and primary disease site may predict risk for opioid overdose.

National Patterns in Prescription Opioid Use and Misuse Among Cancer Survivors in the United States

IMPORTANCE

Prescription opioids are frequently prescribed to treat cancer-related pain. However, limited information exists regarding rates of prescription opioid use and misuse in populations with cancer.

OBJECTIVES

To estimate the prevalence and likelihood of prescription opioid use and misuse in adult cancer survivors compared with respondents without cancer and to identify characteristics associated with prescription opioid use and misuse in adult cancer survivors.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study is a retrospective, population-based study using data from 169 162 respondents to the National Survey on Drug Use and Health from January 2015 to December 2018. Survey data sets were queried for all respondents aged 18 years or older. Those with a reported history of cancer were termed cancer survivors and further divided into more recent (had cancer within 12 months of survey) and less recent (had cancer more than 12 months prior to survey) cohorts. Respondents with nonmelanoma skin cancer were excluded.

MAIN OUTCOMES AND MEASURES

Prescription opioid use and misuse within the past 12 months.

RESULTS

Among 169 162 respondents, 5139 (5.2%) were cancer survivors, with 1243 (1.2%) and 3896 (4.0%) reporting having more recent and less recent cancer histories, respectively. Higher rates of prescription opioid use were observed among more recent cancer survivors (54.3%; 95% CI, 50.2%-58.4%; odds ratio [OR], 1.86; 95% CI, 1.57-2.20; P < .001) and less recent cancer survivors (39.2%; 95% CI, 37.3%-41.2%; OR, 1.18; 95% CI, 1.08-1.28; P < .001) compared with respondents without cancer (30.5%, reference group). Rates of prescription opioid misuse were similar among more recent (3.5%; 95% CI, 2.4%-5.2%; OR, 1.27; 95% CI, 0.82-1.96; P = .36) and less recent (3.0%; 95% CI, 2.4%-3.6%; OR, 1.03; 95% CI, 0.83-1.28; P = .76) survivors compared with respondents without cancer (4.3%, reference group). Younger age (aged 18-34 years vs ≥65 years: OR, 7.06; 95% CI, 3.03-16.41; P < .001), alcohol use disorder (OR, 3.22; 95% CI, 1.45-7.14; P = .005), and nonopioid drug use disorder (OR, 14.76; 95% CI, 7.40-29.44; P < .001) were associated with prescription opioid misuse among cancer survivors.

CONCLUSIONS AND RELEVANCE

In this study, prescription opioid use was higher among more and less recent cancer survivors compared with the population without a history of cancer. Rates of prescription opioid misuse were low and similar among all 3 cohorts. These findings suggest that higher prescription opioid use among cancer survivors may not correspond to increased short-term or long-term misuse.

Use of prophylactic cranial irradiation in patients with extensive-stage small cell lung cancer receiving immunotherapy

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Background: Prophylactic cranial irradiation (PCI) use is controversial in extensive-stage small cell lung cancer (ES-SCLC). In addition to lack of survival benefit of PCI compared to close MRI surveillance in a 2017 published trial, the role of PCI is being further challenged in the modern immune-oncology (IO) era. The IMpower133 trial reporting a survival benefit to atezolizumab for ES-SCLC published in 2018 did not require PCI use. Contemporary practice patterns of PCI in relation to immunotherapy are unknown. Methods: We performed a retrospective cohort analysis of patients with ES-SCLC diagnosed between January 1, 2013 to September 31, 2019 from the nationwide Flatiron Health electronic health record-derived de-identified database. First-line chemotherapy (Chemo) was defined as Chemo given alone, while first-line IO therapy was IO alone or combined with chemotherapy as initial systemic therapy. Results: The cohort included 3047 ES-SCLC patients who received first-line Chemo, and 324 patients who received first-line IO. For first-line IO patients, 268 (82.7%) received first-line atezolizumab. The use of first-line IO increased from 1.2% of patients diagnosed in 2013 to 11.3% of patients diagnosed in 2018 (p < 0.001), and 54.5% of patients diagnosed in 2019 (p < 0.001). Overall documented PCI for patients receiving either first-line IO or first-line Chemo decreased from 14.7% in 2013 to 7.0% in 2018-2019 (p < 0.001). For first-line IO patients, 23 (7.1%) had documented PCI over our study period, with 5.3% of patients diagnosed in 2018-2019 having received PCI. In contrast, for first-line Chemo patients, 428 (14.0%) received PCI over our study period, and PCI use significantly decreased from 14.8% in 2013 to 7.9% in 2018-2019 (p = 0.001). In 2018-2019, use of PCI was not significantly different between patients receiving first-line IO compared to first-line Chemo (5.3% vs 7.9%, p = 0.163). Conclusions: The use of first-line IO has significantly increased in ES-SCLC. Overall PCI rates for ES-SCLC patients decreased significantly over the study period, although documented PCI use rates do not differ between patients receiving upfront IO or Chemo in 2018-2019. Further investigation is warranted regarding effectiveness of PCI in the modern IO era.

Temporal trends in opioid prescribing patterns among oncologists in the Medicare population

12022

Background: In the wake of the United States (U.S.) opioid epidemic, there have been significant governmental and societal efforts to curb opioid prescribing. However, it is unknown whether these efforts have affected prescribing among oncologists, whose patient population often requires narcotics for symptom management. We investigated temporal patterns in opioid prescribing for Medicare patients among oncologists. Methods: We queried the Centers for Medicare and Medicaid Services Part D prescriber dataset to identify independently practicing physicians between January 1, 2013 and December 31, 2017. We used population-averaged multivariable negative binomial regression to estimate the association between time and per-provider opioid prescribing rate, defined as number of opioid claims (original prescriptions and refills) per 100 patients, among oncologists and non-oncologists on both a national and statewide level. All models were adjusted for provider characteristics and annual total patient count per provider. Results: The final study sample included 20,513 oncologists and 711,636 non-oncologists. From 2013 to 2017, the national opioid prescribing rate declined by 19.3% (68.8 to 55.5 opioid prescriptions per 100 patients; P< 0.001) among oncologists and 20.4% (50.7 to 40.3 prescriptions per 100 patients; P< 0.001) among non-oncologists. During this timeframe, 40 U.S. states experienced a significant ( P< 0.05) decrease in opioid prescribing among oncologists, most notably in Vermont (-43.2%), Idaho (-34.5%), and Maine (-32.8%). In comparison, all 50 states exhibited a significant decline ( P< 0.05) in opioid prescribing among non-oncologists. In 5 states, opioid prescribing decreased more among oncologists than non-oncologists, including Oklahoma (-24.6% vs. -7.1%), Idaho (-34.5% vs. -17.8%), Utah (-31.7% vs. -18.7%), Texas (-19.9% vs. -14.7%), and New York (-24.0% vs. -19.7%) (all P< 0.05). Conclusions: Between 2013 and 2017, the opioid prescribing rate decreased by approximately 20% nationwide among both oncologists and non-oncologists. These findings raise concerns about whether opioid prescribing legislation and guidelines intended for the non-cancer population are being applied inappropriately to patients with cancer and survivors.

Utilization of next-generation sequencing and associated systemic therapy initiation in metastatic prostate cancer

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Background: There is emerging evidence for using clinical genomic classifiers for prognostication and to guide treatment choice in metastatic prostate cancer (mPC). While clinical-grade next generation sequencing (NGS) tests are increasingly available, how NGS has impacted systemic therapy selection for mPC is unclear. Methods: We performed retrospective observational study using the nationwide US Flatiron Health EHR-derived de-identified database. We identified patients with mPC diagnosed between January 1, 2013 and September 31, 2019. Receipt of NGS testing was chart-confirmed. “Short-interval” systemic therapy initiation in association with NGS testing was defined as line of therapy start within 30 days of documented NGS test result date. Results: A total 11548 mPC patients were included in our cohort, of which 1034 patients (8.9%) had documented NGS after metastatic diagnosis. There were 1210 documented NGS tests total, with 146 (14.1%) patients documented as undergoing NGS testing on more than one occasion. Median time from metastatic diagnosis to initial NGS test results was 560 days (IQR 194 to 1016 days). NGS test documentation increased from 7.1% of cases diagnosed in 2013 to 12.1% of cases diagnosed in 2017 (p < 0.001). A new line of systemic therapy was initiated within 30 days for 207 NGS test results (17.1%). Although the percent of NGS tests associated with short-interval initiation of a new line of therapy increased from 11.1% in 2013-2014 to 16.5% in 2018-2019, the difference was not statistically significant (p = 0.540). The most common systemic therapies initiated within 30 days after NGS testing were docetaxel (18.8%), cabazitaxel (16.8%), and abiraterone (15.4%). Conclusions: While there has been an increase in documented NGS tests in mPC, rates of short-interval systemic therapy initiation after NGS did not change significantly from 2013-2019. Further study is needed as to whether this will increase in years to come, as well as potential improvements in clinical outcomes due to therapy change.

Association of cytoreductive nephrectomy and survival in the immune checkpoint inhibitor era

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Background: Cytoreductive nephrectomy (CN) for patients (pts) with metastatic renal cell carcinoma (mRCC) improved overall survival (OS) in the interferon (IFN) era, but the benefit of CN in the immune checkpoint inhibitor (ICI) era is unknown. Methods: We identified pts with mRCC receiving immunotherapy (IT) from 2004-2015 in the National Cancer Database (NCDB). Pts with partial nephrectomy or ablation were excluded. The ICI era was defined as 2013-2015 based on a high-profile publication in 2012 demonstrating efficacy of ICI in mRCC and the IFN era was defined as 2004-2005 due to FDA approval of sorafenib in 12/2005. Pts receiving CN with TKI were excluded, as prior NCDB study showed an OS benefit to CN in contrast to the results of the CARMENA trial. Univariable (UVA) and multivariable (MVA) associates with OS during each era were identified using Cox regression analysis including age, sex, race, income, insurance, treatment facility type, treatment location, clinical T stage (cT), clinical N stage (cN), histology, Fuhrman grade (FG), other metastectomy, and CN. Results: There was a 65% decline in mRCC pts receiving IT from 2005 to 2006 (end of the IFN era), which remained low (11% rise from 2006-2012) until a 93% rise from 2012 to 2013 (start of the ICI era). 128 of 422 (30.3%) pts in the IFN era received CN compared to 218 of 526 (41.4%) patients in the ICI era, p<0.001. Pts in each era were balanced with respect to median age, race, income, location, cT, and histology, but the ICI era had higher proportions of pts with private insurance, treatment at an academic center, N0 disease, FG 3-4, and other metastatectomy (p<0.05). Most pts with CN in the ICI era had IT after CN (89.9%); this was not coded in the IFN era. In the IFN era, CN compared to IT alone was associated with improved OS on UVA (HR 0.59, 95% CI 0.47-0.73, p<0.001) and MVA (HR 0.62, 95% CI 0.47-0.83, p=0.001). In the ICI era, CN compared to IT alone was associated with improved OS on UVA (HR 0.63, 95% CI 0.49-0.81, p<0.001) but not on MVA (0.82, 95% CI 0.58-1.14, p=0.234). Conclusions: Despite increased utilization of CN for US pts with mRCC treated with IT during the ICI era, the lack of OS benefit in recent years suggests a need for prospective reevaluation of the value CN and its timing with ICI.

Emergency department visits for prescription and synthetic opioid overdoses among patients with cancer

6579

Background: Patients with cancer may be at high risk of opioid dependence due to physical and psychosocial factors, although little data exists to inform providers and policymakers. Our aim is to examine overdoses from prescription and synthetic opiates leading to emergency department (ED) visits among patients with cancer in the United States. Methods: The Healthcare Cost and Utilization Project Nationwide Emergency Department Sample (HCUP-NEDS) was queried for all patient visits with a primary diagnosis of prescription or synthetic opioid overdose between 2006 and 2015. Baseline differences between patients with and without cancer were assessed using chi-square and ANOVA testing. Overdose rates by primary cancer site were normalized using prevalence data from the Surveillance, Epidemiology, and End Results (SEER) Program. Weighted frequencies were used to create national estimates for all data analyses. Results: There were 682,820 weighted ED visits for synthetic opioid overdose, among which 34,547 (5.1%) visits were also associated with a diagnosis of cancer. During this timeframe, ED visits for opioid overdose among patients with cancer increased 2.5-fold, compared to 1.7-fold among those without cancer. 16.5% of patients with cancer had metastatic disease. Patients with cancer presenting for opioid overdose had higher risk of hospital admission (74.8% vs 49.6%), respiratory intubation (13.2% vs 12.2%), mortality (2.1% vs 1.1%), and cost-of-hospital-stay ($32,665 vs $31,824) compared to their non-cancer counterparts (all P < 0.05). Primary cancers with the highest normalized overdose rates (ED visits per 10,000 patients) were esophagus (134), liver & intrahepatic bile duct (124), and cervical cancer (124). Other common cancers had the following normalized overdose rates: lung (105), head and neck (70), and breast (26). Conclusions: Approximately 5% of all ED visits due to prescription and synthetic opioid overdose are among patients with cancer. The rate of increase in ED visits due to opioid overdose from cancer patients was nearly 50% higher than that from non-cancer patients over the 10-year study period. Patients with esophageal, liver, and cervical cancer may be at highest risk.

Contemporary changes in localized and metastatic prostate cancer incidence by geographic area following decreased PSA screening

1567

Background: In the setting of decreased PSA screening, the incidence of metastatic prostate cancer has been increasing in the United States. This was chronologically proceeded by decreasing localized prostate cancer incidence. While decreased detection of localized disease is hypothesized to increase likelihood of metastatic disease at diagnosis, it is unclear whether the two are geographically connected. Methods: Prostate cancer incidence was obtained from the of Surveillance, Epidemiology, and End Results (SEER) database for men 70 years or older. SEER Summary Stage 2000 was used to classify localized (local) and metastatic (distant) prostate cancers. Changes in incidence rates were calculated by health services areas (HSA), which each represents a relatively self-contained region of hospital care. We chose a priori to examine most recent years 2012-2015 for changes in metastatic disease, and proceeding years 2008-2011 for changes in localized disease. Population-weighted linear regression that was robust to outliers was performed. Results: A total of over 66,600 cases of localized and 6,400 cases of metastatic prostate cancer from 200 HSAs were included for analysis. From 2008 to 2011, localized incidence decreased from 613.6 to 534.2 per 100,000 men overall, and for each HSA on average decreased by 30.3 per 100,000 men for each year. From 2012 to 2015, metastatic incidence increased from 54.7 to 62.1 per 100,000 men overall, and for each HSA on average increased by 2.1 per 100,000 men for each year. Linear regression between HSA-level changes in localized and metastatic disease revealed a correlation coefficient of -0.023 (SE = 0.017, p = 0.16, 95% CI -0.056 to 0.009), representing lack of a statistically significant relationship between decreases in localized disease and later increases in metastatic disease within each health services region. Conclusions: Despite concerns of increasing metastatic prostate cancer incidence coinciding with decreases in PSA screening and localized cancer incidence, we do not observe a statistically significant geographic and temporal relationship between metastatic and localized disease at the HSA level. Our study is limited by short lead time and thus this trend warrants continued surveillance.

Impact of Widespread Cervical Cancer Screening: Number of Cancers Prevented and Changes in Race-specific Incidence

OBJECTIVES

With recent approval of standalone HPV testing and increasing uptake of HPV vaccination, some have postulated that we are moving toward a "post-Pap" era of cervical cancer prevention. However, the total number cases that have been prevented by Pap smear screening as well as its impact on racial disparities are unknown.

METHODS

We estimated national cervical cancer incidence from 1976 to 2009 using the Surveillance, Epidemiology, and End Result database. Screening data were obtained from the literature and National Cancer Institute Progress Reports. We examined early, late, and race-specific trends in cancer incidence, and calculated the estimated number of cancers prevented over the past 3 decades.

RESULTS

From 1976 to 2009, there was a significant decrease in the incidence of early-stage cervical cancer, from 9.8 to 4.9 cases per 100,000 women (P<0.001). Late-stage disease incidence also decreased, from 5.3 to 3.7 cases per 100,000 women (P<0.001). The incidence among black women decreased from 26.9 to 9.7 cases per 100,000 women (P<0.001), a greater decline compared with that of white women and women of other races. After adjusting for "prescreening era" rates of cervical cancer, we estimate that Pap smears were associated with a reduction of between 105,000 and 492,000 cases of cervical cancer over the past 3 decades in the United States.

CONCLUSIONS

A large number of early-stage and late-stage cervical cancers were prevented and racial disparity in cancer rates were reduced during an era of widespread Pap smear screening.

Abstract 3710: Synergy between PARP and Wee1 inhibitors suggests homologous recombination repair defect in NSCLC as a mechanistic target for combination therapy

Advanced non-small cell lung cancer (NSCLC) is the leading cause of cancer mortality. Despite progress in targeted molecular therapeutics and precision medicine, outcomes in this disease remain poor. Recent evidence suggests that impaired homologous recombination (HR) occurs in a significant subset of NSCLCs and may serve as a predictive biomarker for sensitivity to DNA damaging agents. Poly-ADP ribose polymerase (PARP) and Wee1 inhibition represent two mechanistically distinct approaches to augment the effects of DNA damage. Specifically, the PARP inhibitor olaparib impairs repair of DNA single strand breaks, which during replication lead to the formation of DNA double strand breaks (DSBs), resulting in synthetic lethality in HR deficient tumors. AZD1775 is a Wee1 inhibitor that abrogates the G2 checkpoint and thus removes a safeguard against cell cycle progression with unrepaired DNA damage. Moreover, AZD1775 has been recently reported to exhibit single-agent activity in patients harboring BRCA1/2 mutations. Therefore, we hypothesize that olaparib and AZD1775 would have synergistic effects in a subset of NSCLCs and that HR deficiency could be predictive of tumor response to combination therapy.

Utilizing Rad51 focus formation as a marker of HR deficiency, we prospectively selected representative NSCLC cell lines that either did (e.g. Calu6) or did not (e.g. A549) harbor putative defects in HR repair. We treated Calu6 and A549 and other NSCLC cells with AZD1775 and olaparib with varying drug dosing and sequencing to determine the optimal regimen for synergistic effect. Cytotoxicity was determined by CellTiter-Glo cell viability assays and synergy was quantified by calculating the combination index. Additionally, we investigated mechanistic protein markers by Western blot.

In response to combined olaparib and AZD1775 treatment, Calu6 cancer cells demonstrated markedly more pronounced synergistic sensitivity (median CI = 0.19) compared to A549 cancer cells (median CI = 0.90). Moreover, a similar trend toward a selective synergistic effect was demonstrated in a panel of 10 additional NSCLC lines. On biochemical analysis, we observed inhibition of p-Cdk1, upregulation of p-Chk1, and upregulation of p-KAP1, suggesting abrogation of the G2/M checkpoint and activation of ATM/ATR repair pathways, all consistent with the mechanistic underpinnings of our hypothesis.

Taken together, these results provide early pre-clinical evidence for the rational combination of Wee1 and PARP inhibition in the treatment of advanced NSCLC, and suggest HR deficiency as a predictive marker applicable to NSCLC. Continued mechanistic investigation and further confirmatory studies are warranted to inform the selection of patients who may maximally benefit from such combination treatment.

Citation Format: Daniel X. Yang. Synergy between PARP and Wee1 inhibitors suggests homologous recombination repair defect in NSCLC as a mechanistic target for combination therapy. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3710.

Estimating the magnitude of colorectal cancers prevented during the era of screening: 1976 to 2009

BACKGROUND

Ideally, screening detects cancer at a more curable stage and, as a result, decreases the rate of subsequent diagnosis at a late stage. Although it is suggested that some cancer screening tests have led to substantial increases in early-stage incidence with only marginal reductions in late-stage incidence (eg mammography), the association between temporal trends in colorectal cancer screening and its cumulative impact on colorectal cancer incidence is unknown.

METHODS

Colorectal cancer incidence data spanning over 3 decades (1976-2009) were collected from the Surveillance, Epidemiology, and End Results database. Data on screening use spanning the period from 1986 to 2010 were collected from the National Cancer Institute Cancer Trends Progress Report, and trends in the incidence of early-stage (in situ, local) and late-stage (regional, distant) colorectal cancer were examined among adults aged ≥50 years.

RESULTS

From 1987 to 2010--the years for which screening data were available--the percentage of adults aged ≥50 years who underwent screening rose from 34.8% to 66.1% (which included increases in colonoscopy). During that time, the incidence of late-stage colorectal cancer decreased from 118 to 74 cases per 100,000 population (P < .001). The incidence of early-stage colorectal cancer also decreased, from 77 to 67 cases per 100,000 population (P < .001). After adjusting for underlying trends in cancer incidence, colorectal screening was associated with a reduction of approximately 550,000 cases of colorectal cancer over the past 3 decades in the United States.

CONCLUSIONS

There has been a significant decline in the incidence of colorectal cancer in the United States, particularly for late-stage disease, during a time of increasing rates of screening.

Helping science and drug development to succeed through pharma-academia partnerships: Yale Healthcare Conference 2013

The theme of the 2013 Yale Healthcare Conference was "Partnerships in Healthcare: Cultivating Collaborative Solutions." The April conference brought together leaders across several sectors of health care, including academic research, pharmaceuticals, information technology, policy, and life sciences investing. In particular, the breakout session titled "Taking R&D Back to School: The Rise of Pharma-Academia Alliances" centered on the partnerships between academic institutions and pharmaceutical companies. Attendees of the session included members of the pharmaceutical industry, academic researchers, and physicians, as well as graduate and professional students. The discussion was led by Dr. Thomas Lynch of Yale University. Several topics emerged from the discussion, including resources for scientific discovery and the management of competing interests in collaborations between academia and the pharmaceutical industry.

Changes in early- and late-stage colorectal cancer incidence during the era of screening: 1976-2009

1522

Background: Ideally, screening detects cancer at a more curable stage, and as a result decreases the incidence of subsequent diagnosis at a late stage. Whereas breast cancer screening is suggested to have led to a substantial increase in the number of early-stage cancers diagnosed in the United States with only marginal reductions in the number of late stage cancers, the impact of colorectal cancer screening on cancer incidence is unknown. Methods: Colorectal cancer incidence data spanning over three decades, 1976—2009, were collected from the Surveillance, Epidemiology, and End Result (SEER) database. Screening utilization data spanning 1986—2010 were collected from the National Health Survey (NHS) progress reports. We examined trends in the incidence of early-stage (in situ, local) and late-stage (regional, distant) colorectal cancer among adults 50 years or older. Results: Over the past three decades, the incidence of late-stage colorectal cancer decreased significantly, from 118 to 74 cases per 100,000 people—a 37% decrease. The incidence of early-stage colorectal cancer also decreased, from 77 to 67 cases per 100,000 people. There was also an associated increase in the utilization rates of screening colonoscopy. From 1987 to 2010—the years for which NHS data were available—the percentage of adults 50 and older who received screening colonoscopy rose from 27% to 63%. After adjusting for trends in cancer incidence in non-screened populations, we estimated that colorectal screening was associated with a reduction of approximately 550,000 cases of colorectal cancer over the past three decades in the United States. Using the most conservative assumption of constant cancer incidence during the past three decades, 235,000 cases of colorectal cancer were prevented. Conclusions: There has been a significant decline in both early and late stage colorectal cancer diagnoses, during a time of increasing rates of increased screening.

Genotype-dependent cooperation of ionizing radiation with BRAF inhibition in BRAF V600E-mutated carcinomas

BACKGROUND

A substantial proportion of solid tumors carry the BRAF V600E mutation, which causes activation of the MEK/MAPK pathway and is a poor prognostic indicator. Patients with locally advanced human cancers are often treated with external beam radiation therapy. Given the association of Raf overactivation with radioresistance, we hypothesized that, in BRAF V600E-mutated carcinomas, there would be combinatorial activity between radiation and PLX4720, a specific BRAF V600E-inhibitor.

METHODS

Two BRAF V600E-mutated cancer cell lines and one BRAF-V600E wildtype (WT) cancer cell line were obtained. We performed cell viability assays and clonogenic assays using combinations of radiation and PLX4720. We assessed MEK and MAPK phosphorylation at different PLX4720 concentrations with western blotting, and cell cycle progression was evaluated by flow cytometry.

RESULTS

Our results show combinatorial, additive activity between radiation and PLX4720 in BRAF V600E-mutated cell lines, but not in the BRAF WT line. In BRAF V600E-mutated cells, there was a PLX4720 concentration-dependent decrease in MEK and MAPK phosphorylation. In cells with BRAF V600E mutations, PLX4720 caused cell cycle arrest at G1, and, when combined with radiation, caused a combined G1 and G2 cell cycle arrest; this pattern of cell cycle effects was not seen in the BRAF WT cell line.

CONCLUSIONS

These data suggest additive, combinatorial activity between radiation and PLX4720 in cancers carrying BRAF V600E mutations. Our data has potential for translation into the multimodality treatment of BRAF V600E-mutated cancers.

L-364,718 potentiates electroacupuncture analgesia through cck-a receptor of pain-related neurons in the nucleus parafascicularis

Electroacupuncture (EA) has been successfully used to alleviate pain produced by various noxious stimulus. Cholecystokinin-8 (CCK-8) is a neuropeptide involved in the mediation of pain. We have previously shown that CCK-8 could antagonize the analgesic effects of EA on pain-excited neurons (PENs) and pain-inhibited neurons (PINs) in the nucleus parafascicularis (nPf). However, its mechanism of action is not clear. In the present study, we applied behavioral and neuroelectrophysiological methods to determine whether the mechanisms of CCK-8 antagonism to EA analgesia are mediated through the CCK-A receptors of PENs and PINs in the nPf of rats. We found that focusing radiant heat on the tail of rats caused a simultaneous increase in the evoked discharge of PENs or a decrease in the evoked discharge of PINs in the nPf and the tail-flick reflex. This showed that radiant heat could induce pain. EA stimulation at the bilateral ST 36 acupoints in rats for 15 min resulted in an inhibition of the electrical activity of PEN, potentiation of the electrical activity of PIN, and prolongation in tail-flick latency (TFL), i.e. EA stimulation produced an analgesic effect. The analgesic effect of EA was antagonized when CCK-8 was injected into the intracerebral ventricle of rats. The antagonistic effect of CCK-8 on EA analgesia was reversed by an injection of CCK-A receptor antagonist L-364,718 (100 ng/μl) into the nPf of rats. Our results suggest that the pain-related neurons in the nPf have an important role in mediating EA analgesia. L-364,718 potentiates EA analgesia through the CCK-A receptor of PENs and PINs in the nPf.

Simultaneous measurement of axial strain, temperature, and transverse load by a superstructure fiber grating

A novel and simple fiber-optic sensor based on a superstructure fiber grating for simultaneous measurement of temperature, axial strain, and transverse load is proposed and demonstrated. By measurement of the shift and split of broadband and narrow-band loss peaks, one can determine the temperature, axial strain, and transverse load simultaneously over the ranges 0-140 degrees , 0-1200muepsilon, and 0-0.3 kg/mm, respectively.

Energy dependence of restitution in the gastric mucosa

Rapid epithelial repair (restitution) after injury is required to maintain barrier function of the gastrointestinal mucosa and skin and is thought to be a highly ATP-dependent process that would be inhibited under hypoxic conditions. However, little is known about the metabolic pathways required for restitution. Thus, this study was undertaken to evaluate, in vitro, the role of oxidative respiration and glycolysis in restitution after injury. To this end, restitution of the bullfrog gastric mucosa was evaluated under the following conditions: 1) blockade of mitochondrial respiration; 2) blockade of glycolysis; or 3) absence of glucose. The extent of mucosal repair after injury was evaluated by electrophysiology and morphology. Cell migration, repolarization, and the formation of tight junctions after injury occurred during blockade of mitochondrial respiration, whereas the recovery of mucosal barrier function did not. In contrast, glycolytic inhibition completely blocked all aspects of restitution by inhibiting the migration of surface epithelial cells. Restitution occurred in tissues incubated with glucose-free solutions, suggesting that cells contain sufficient glucose (glycogen) to drive glycolysis for many hours. Our results demonstrate that the glycolytic pathway is essential for restitution after injury in the bullfrog gastric mucosa and that all but complete repair of barrier function occurs in the absence of mitochondrial respiration.

Circulating levels of retinol, tocopherol and carotenoid in Nepali pregnant and postpartum women following long-term β-carotene and vitamin A supplementation

OBJECTIVE

To characterize circulating carotenoid and tocopherol levels in Nepali women during pregnancy and post-partum and to determine the effects of beta-carotene and vitamin A supplementation on their concentration in serum.

DESIGN

Randomized community supplementation trial.

SETTING

The study was carried out from 1994 to 1997 in the Southern, rural plains District of Sarlahi, Nepal.

SUBJECTS

A total of 1431 married women had an ascertained pregnancy, of whom 1186 (83%) provided an analyzable serum sample during pregnancy; 1098 (77%) provided an analyzable 3-4 months post-partum serum sample.

INTERVENTIONS

Women received a weekly dose of vitamin A (7000 microg RE), beta-carotene (42 mg) or placebo before, during and after pregnancy. Serum was analyzed for retinol, alpha-tocopherol, gamma-tocopherol, beta-carotene, alpha-carotene, lycopene, lutein + zeaxanthin, and beta-cryptoxanthin concentrations during mid-pregnancy and at approximately 3 months post-partum.

RESULTS

Compared to placebo, serum retinol, beta-carotene, gamma-tocopherol, beta-cryptoxanthin and lutein + zeaxanthin concentrations were higher among beta-carotene recipients during pregnancy and, except for beta-cryptoxanthin, at postpartum. In the vitamin A group, serum retinol and beta-cryptoxanthin were higher during pregnancy, and retinol and gamma-tocopherol higher at postpartum. Lutein + zeaxanthin was the dominant carotenoid, regardless of treatment group, followed by serum beta-carotene. Serum lycopene level was lowest, and very low compared to the US population. Serum retinol was higher, and carotenoid and alpha-tocopherol lower, at postpartum than during pregnancy in all groups.

CONCLUSIONS

Pregnant and lactating Nepali women have lower serum carotenoid and tocopherol levels than well-nourished populations. beta-carotene supplementation appeared to increase levels of tocopherol and other carotenoids in this population.

Influence of prenatal iron and zinc supplements on supplemental iron absorption, red blood cell iron incorporation, and iron status in pregnant Peruvian women

BACKGROUND

It is estimated that 60% of pregnant women worldwide are anemic.

OBJECTIVE

We aimed to examine the influence of iron status on iron absorption during pregnancy by measuring supplemental iron absorption, red blood cell iron incorporation, and iron status in pregnant women.

DESIGN

Subjects were 45 pregnant Peruvian women (33+/-1 wk gestation), of whom 28 received daily prenatal supplements containing 60 mg Fe and 250 microg folate without (Fe group, n = 14) or with (Fe+Zn group, n = 14) 15 mg Zn, which were were consumed from week 10 to 24 of gestation until delivery. The remaining 17 women (control) received no prenatal supplementation. Iron status indicators and isotopes were measured in maternal blood collected 2 wk postdosing with oral (57Fe) and intravenous (58Fe) stable iron isotopes.

RESULTS

Maternal serum ferritin and folate concentrations were significantly influenced by supplementation (P < 0.05). Serum iron was also significantly higher in the Fe than in the Fe+Zn (P < 0.03) or control (P < 0.001) groups. However, the supplemented groups had significantly lower serum zinc concentrations than the control group (8.4+/-2.3 and 10.9+/-1.8 micromol/L, respectively, P < 0.01). Although percentage iron absorption was inversely related to maternal serum ferritin concentrations (P = 0.036), this effect was limited and percentage iron absorption did not differ significantly between groups.

CONCLUSIONS

Because absorption of nonheme iron was not substantially greater in pregnant women with depleted iron reserves, prenatal iron supplementation is important for meeting iron requirements during pregnancy.

Antagonistic effect of CCK-8 on morphine-inhibited electrical and contractile activities of rat jejunum in vitro

In the present investigation, antagonistic action of cholecystokinin octapeptide (CCK-8) against morphine on the electrical and contractile activity of rat jejunum in vitro was studied. The results showed that the potentiation of acetylcholine (ACh) on both the burst of spike and the contractility were inhibited by morphine, which could be completely antagonized by CCK-8. The CCK-8 effect, again, could be suppressed by CCK-A receptor antagonist devazepide (10 nmol/L), but partially by CCK-B receptor antagonist L-365, 260 at 10 nmol/L or completely at concentration of 30 nmol/L. The above results demonstrated that the antagonism of CCK-8 on morphine was mediated by both CCK-A and CCK-B receptors.

[Effect of tremulacin on actions of SRS-A and histamine]

The effect of tremulacin (TRC) extracted from Mao Bai Yang (Folia Populus tomentosa Carr) on actions of SRS-A and histamine were investigated by using isolated guinea pig ileum and spectrofluorometric assay. TRC was found to inhibit the contraction of isolated guinea pig ileum induced by histamine and SRS-A, in a dose-dependent manner with IC50 of 1.78 x 10(-4) mol.L-1 and 2.51 x 10(-4) mol.L-1, respectively. TRC at the dose of 10(-4) mol.L-1 inhibited SRS-A release from sensitized isolated guinea pig lung. While at the dose of 10(-5) mol.L-1 inhibited histamine release from the peritoneal mast cells in sensitized rats. These results indicate that inhibition of the release of histamine and SRS-A may play an important role in the mechanism of antiinflammatory actions of TRC.

Antiinflammatory effects of Tremulacin, a Salicin-related substance isolated from Populus tomentosa Carr. leaves

Tremulacin was shown to inhibit carrageenan-induced paw edema in rats and croton oil-induced ear edema in mice. It was also found to inhibit peritoneal leucocyte migration in rats and acetic acid-induced writhing responses in mice. Experiments with isolated longitudinal muscle strips of sensitized guinea pig ileum showed that tremulacin decreased the biosynthesis of Slow Reaction Substance of Anaphylaxis. Tremulacin exerted inhibitory effects on leukotriene B4 biosynthesis in intrapleural leucocytes. These results suggest that the mechanism of antiinflammatory actions of tremulacin is relevant to inhibition of 5-lipoxygenase activity. This is quite different from non-steroid antiinflammatory drugs, such as aspirin, which inhibits prostaglandin synthesis and being a cyclooxygenase inhibitor.