Proton Pump Inhibitor Use and Obesity-Associated Cancers in the Women's Health Initiative

PURPOSE

Proton pump inhibitors (PPIs) inhibit fatty acid synthase (FAS), a critical enzyme in lipogenesis, energy balance, and cancer cell survival. We aimed to evaluate the association of PPI use with incidence of common obesity- related cancers in women: postmenopausal breast, colorectal, and endometrial cancers.

METHODS

Our study included 124,931 postmenopausal who were enrolled in the Women's Health Initiative (WHI) observational study and clinical trials, and had responded to a year 3 follow-up assessment. We examined prescription and over the counter use of PPI and/or histamine 2 receptor antagonists (H2RA) at baseline and year 3, to isolate potential effects of FAS inhibition by PPI rather than simply acid suppression. Incident cancer cases were physician-adjudicated. Cox proportional hazard regression models were used to estimate multivariable hazard ratios (HR) and 95% confidence intervals (CI) for associations between PPI and/or H2RA use and cancer incidence after year 3.

RESULTS

There were 7956 PPI ever users (with or without H2RA use) and 9398 H2RA only users. PPI or H2RA use was not associated with risk of breast cancer (n=9186 cases), compared to women who did not use either agent (HR 1.01, 95% CI 0.93-1.10 and HR 0.95 95% CI 0.87-1.03, respectively). The incidence of colorectal cancer (n=2280) was significantly lower in PPI users (HR 0.75, 95% CI 0.61-0.92), but not in H2RA users (HR 1.13, 95% CI 0.97-1.31). This association was strengthened with increasing duration (p=0.006) and potency (p=0.005) of PPI use and held regardless of BMI or NSAID use. PPI or H2RA use was not associated with endometrial cancer (n=1231) (HR 0.81, 95% CI 0.61-1.07 and HR 1.13, 95% CI 0.91-1.40, respectively), but showed a trend in decreased risk with increasing PPI potency (P=0.048).

CONCLUSIONS

Among postmenopausal women, PPI use, but not H2RA use, demonstrated an inverse, dose-responsive association with colorectal cancer incidence. This was consistent with preclinical data that FAS inhibition prevents colon cancer progression and supports further investigation of this commonly used medication as a cancer preventive agent. PPI use was not associated with incidence of breast or endometrial cancer.

Patient Response to Receiving a Notification of Elevated Breast Cancer Risk after Regular Screening Mammogram

Background: Population-based screening for breast cancer risk can identify unaffected women at elevated risk and inform them of risk-management options. The James Cancer Hospital recently began assessing risk for women undergoing routine screening mammography. Women found to have ≥20% lifetime risk are notified – with their mammogram results via mail and electronic medical record – that they may be at elevated risk of breast cancer and should consider consulting a high-risk provider. This initial study examined findings from a subsample who participated 2–6 weeks post-notification. Purpose: We sought to determine whether women noticed and understood the notification, and to examine their reactions to the notification of elevated risk. Methods: Of 415 women recruited, 150 (36%) completed the survey, which included items to assess memory and comprehension of the notification, and whether participants had (a) seen a healthcare provider since the notification, and (b) discussed breast cancer risk and management options during that appointment. Results: Participants (aged 40–69; mean = 50.8 years) were mostly White (86%), well-educated (77%), and with above-average income (65%). Most remembered receiving the notification (73%), perceived the information not to be complex (73%), and were confident they understood the notification (93%). Somewhat fewer (64%) remembered that the notification indicated they may be at elevated risk for breast cancer, and 44% also recalled the suggestion to meet with a healthcare provider about this risk. Of the 28 participants who had already seen any healthcare provider in the few weeks since the notification, 50% discussed breast cancer risk during that appointment and 25% said they did so because of the notification. Discussions included family cancer history, actual risk of developing breast cancer, and options for additional imaging or testing. Conclusions: These findings indicate that population-based screening associated with routine mammography can motivate women at elevated breast cancer risk to discuss their risk and management options with a healthcare provider. For some proportion of women, however, complementary communication strategies may also be needed to ensure they gain awareness of their higher-risk status.

Abstract P5-10-03: Perceptions of somatic genomic testing in patients with metastatic breast cancer: Psychosocial factors, emotional well-being, and genetic comprehension

Background: Little is known regarding the effect of somatic tumor genomic testing on patient perceptions and psychological well-being. We previously demonstrated that patient perceptions of care can be negatively affected if their next cancer treatment is not supported by the genomic test. To further understand this, we investigated psychological effects of genomic testing, as well as sociodemographic and genomic comprehension factors that may attenuate these effects. Methods: In a prospective, single institution, single-arm trial, patients with metastatic breast cancer underwent next-generation sequencing (NGS) using Foundation Medicine at study entry, with sequencing results released to providers at time of next disease progression. We evaluated patient survey data before and after NGS, including questions about psychosocial characteristics, genetic comprehension, and perceived risks and expectations of the genomic testing. We evaluated psychosocial characteristics using 4 validated psychology measures: the Center for Epidemiologic Studies Depression Scale (CES-D), the Beck Anxiety Inventory (BAI), the Trust in Physician Scale (TPS), and the Communication and Attitudinal Self-Efficacy scale for Cancer (CASE-cancer). CASE-cancer measures self-efficacy, how confident patients are in their ability to navigate their cancer care. Genetic comprehension was assessed with a 7-question objective measure and a 6-question subjective measure. No formal genetic education was provided, but the informed consent process included an introduction to NGS. We included exploratory questions on perceived risks and expectations of NGS. Results: Among the 58 patients who completed the pre-NGS survey, we found high rates of depression (38%) and anxiety (47%) using validated metrics. Depression and anxiety were positively correlated (Pearson’s r=0.61; p<0.0001) but both were negatively correlated with self-efficacy (Pearson’s r=-0.43 and -0.42 for depression and anxiety, respectively; p=0.001 for both). Baseline genetic knowledge was significantly lower for non-white and lower income status patients (p=0.04 and 0.001, respectively). Genetic knowledge was not associated with any of the 4 validated psychological measures. The validated psychological measures were not associated with demographic characteristics, treatment decisions, or number of treatment options offered by the NGS test. The average time between pre-test and post-test surveys was 7.6 months. Additionally, the validated psychology measures did not significantly change from pre- to post-study (n=40 patients). However, there was a strong trend of self-efficacy decreasing from pre- to post-NGS testing (p=0.05). Subjectively, patients gained confidence in their ability to teach others about genetics from the start (33% “confident”) to the end of study (46%). Yet, objective comprehension of genetics remained modest throughout the study, with an average score of 72% in both the pre- and post-NGS surveys. The exploratory patient perception questions revealed that 33% of patients felt learning their cancer had a high chance of progressing would be too much to cope with emotionally. Conclusions: This is the first study, to our knowledge, to longitudinally evaluate multiple validated psychological metrics in MBC. NGS did not have a significant effect on depression, anxiety, or trust, but there was a trend towards decreased self-efficacy. This may be influenced by the already high rates of depression, anxiety, and trust in this population. In this study, patient genetic knowledge was limited and associated with race and income. These findings raise important questions about how to support MBC patient emotional well-being and how to improve comprehension of somatic genomic testing in future studies.

Citation Format: Elizabeth J Adams, Sarah Asad, Mahmoud Abdel-Rasoul, Raquel E Reinbolt, Robert Wesolowski, Kaitlyn Tolliver, Susan Gillespie, Katherine A Collier, Anne Noonan, Sargar Sardesai, Jeffrey VanDeusen, Nicole Williams, Charles L Shapiro, Erin R Macre, Bhuvaneswari Ramaswamy, Clara N Lee, Maryam B Lustberg, Daniel G Stover. Perceptions of somatic genomic testing in patients with metastatic breast cancer: Psychosocial factors, emotional well-being, and genetic comprehension [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-10-03.

Abstract P3-07-08: Multi-omic predictor of rapid and late relapse in primary triple negative breast cancer

Background: Triple-negative breast cancer (TNBC) is a heterogeneous disease. Clinically, we observe three distinct TNBC outcomes: 1) rapid relapse (rrTNBC) characterized by aggressive drug resistant disease; 2) late relapse (lrTNBC) characterized by indolent or treatment responsive disease; and 3) no relapse (NoRTNBC). We hypothesized that distinct clinical and genomic features of primary tumors define rapid versus late relapse in TNBC.

Approach: Using three publicly-available datasets (METABRIC, TCGA, and a prior gene expression meta-analysis), we identified 455 patients diagnosed with primary TNBC with adequate follow-up to be characterized as rrTNBC (relapse or death within 2 years of diagnosis), lrTNBC (relapse or death more than 2 years after diagnosis), or NoRTNBC (no relapse/death with at least 5 years follow-up). We compiled basic clinical (n=455 patients) and primary tumor multi-omic data, including whole transcriptome (n=455), whole genome copy number (n=317), and mutation data for 171 cancer-related genes (n=317). We evaluated intrinsic subtypes (PAM50, TNBCtype), 125 gene expression signatures, CIBERSORT immune subsets, copy number, and mutation frequency.

Results: We first evaluated patients with relapse (rrTNBC+lrTNBC) vs. NoRTNBC. There was no significant difference in age, grade, stage at diagnosis, or PAM50 or TNBC subtype proportion between relapse and NoRTNBC. Among 125 expression signatures, five immune signatures were significantly higher in NoRTNBCs (FDR p<0.05) suggesting increased immune activity in patients who do not relapse. Using CIBERSORT inferred immune subsets, anti-tumor CD8 T-cell, M1 macrophage, and gamma-delta T-cell subsets were all highly correlated to these immune signatures (all Pearson's r >= 0.3, all p<1.2e-8). Among genomic features, patients who relapsed were significantly more likely to harbor a mutation in PIK3CA (Fisher exact FDR p=0.02) but there was no significant difference in tumor mutation burden or percent genome altered (Student's t-test p=0.83 and p=0.99, respectively). We then evaluated primary TNBC genomic data in patients who ultimately developed rapid vs. late relapse. Patients with rrTNBC were more likely to be higher stage (p<0.0001) while lrTNBC were more likely to be non-basal PAM50 subtype (p=0.03). Among 11 significantly altered gene expression signatures (FDR p<0.05), 6 estrogen/luminal signatures were significantly higher in lrTNBC. Mutations in DNAH11 and PIK3CA were more common in lrTNBC (Fisher exact FDR p=0.04 and p=0.05, respectively) but there were no significant differences in tumor mutation burden or copy number burden (Student's t-test p=0.13 and p=0.45, respectively). Using 317 cases with full genomic data divided into training and validation datasets, we will report a comparison of machine learning models for predicting relapse versus no relapse and rapid versus late relapse.

Conclusions: Primary TNBC tumors destined for rapid, late, or no relapse reflect distinct genomic features. Anti-tumor immune signatures and subsets are enriched in patients who do not relapse yet no difference in mutational or copy number burden. Relative to rapid relapse TNBCs, late relapse TNBCs are enriched for non-basal tumors, estrogen/luminal expression signatures, and mutations in DNAH11 and PIK3CA.

Citation Format: Zhang Y, Nock W, Asad S, Adams E, Singh J, Damicis A, Lustberg MB, Noonan A, Reinbolt R, Sardesai S, VanDeusen J, Wesolowski R, Williams N, Ramaswamy B, Stover DG. Multi-omic predictor of rapid and late relapse in primary triple negative breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-07-08.

Abstract P1-09-01: CD8+ T-cell gene expression and signatures in breast cancer and adjacent normal breast tissue: Association with body mass index, alcohol intake, and age at diagnosis

Background: Our understanding of mediators of immune infiltration in breast cancer and normal breast tissue remains limited. We hypothesize that patient factors known to be associated with inflammation and immune subsets, including body mass index, alcohol intake, and age and diagnosis, may play an important role in the tumor-immune microenvironment. Analyses of immune gene expression and signatures facilitate interrogation of the immune microenvironment in large patient cohorts.

Methods: Participants from the Nurses' Health Study cohorts I and II diagnosed with invasive breast cancer were included. Total RNA extracted and microarray performed for 882 tumor and 695 tumor-adjacent samples, of which 623 tumors have matched tumor-adjacent data. CD8+ T-cell expression metrics were assessed: CD8A single gene expression (CD8Agene), a CD8 T-cell signature (CD8sig), and a tumor infiltrating lymphocyte signature derived from the GeparSixto clinical trial (GSAct). Standard clinicopathologic features were evaluated, as well as body mass index (BMI) one year prior to diagnosis, cumulative average alcohol intake, and age at diagnosis.

Results: Overall, tumor and adjacent normal tissue demonstrated positive correlation of CD8Agene, CD8sig, and GSAct (n=623 pairs, Pearson's r = 0.46, 0.36, 0.31, respectively; all p<0.001). Similar correlations were present in TCGA breast cancer, an independent cohort (n=112 pairs, Pearson's r = 0.34, 0.17, 0.45, respectively; all p<0.001). We evaluated paired tumor and adjacent normal samples within individual immunohistochemical (IHC) subtype or PAM50 subtype by Wilcoxon signed-rank test. There was not a consistent trend for CD8Agene, CD8sig, nor GSAct to be greater in tumor or normal within subtypes. We then evaluated patient features/exposures and tumor immune expression metrics. For tumor-adjacent normal, there was no significant association of alcohol intake, BMI, or age at diagnosis with CD8 gene/expression metrics. For tumor tissue, a multivariate model demonstrated that BMI one year before diagnosis was significantly associated with CD8Agene expression. There was no significant association of alcohol intake or age at diagnosis with CD8 gene/expression metrics. We are currently evaluating the association of these CD8 T-cell gene expression signatures with CD8 T-cell immunohistochemistry in a subset of patients, which will be reported at the time of abstract presentation.

Conclusion: In this cohort of over 600 tumor:normal pairs and a separate validation cohort, multiple distinct CD8+ T-cell expression metrics are correlated between breast cancer and tumor-adjacent normal breast tissue. This suggests that the adjacent normal breast may reflect an altered immune microenvironment in the context of breast cancer. While age at diagnosis and alcohol intake are not significantly associated with tumor CD8 expression metrics, BMI was significantly associated with tumor CD8Agene expression in a multivariate model.

Citation Format: Damicis A, Heng YJ, Kensler K, Asad S, Adams E, Singh J, Zhang Y, Nock W, Wesolowski R, Williams N, Reinbolt R, Sardesai S, VanDeusen J, Noonan A, Lustberg MB, Ramaswamy B, Eliassen AH, Hankinson SE, Tamimi R, Stover DG. CD8+ T-cell gene expression and signatures in breast cancer and adjacent normal breast tissue: Association with body mass index, alcohol intake, and age at diagnosis [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-09-01.

Abstract P4-16-03: Cardiovascular outcomes and long term survival with discontinuation of adjuvant trastuzumab

Background: Trastuzumab (T) induced cardiomyopathy remains a significant limitation to adjuvant HER2 directed therapy. Recent studies have aimed to reduce cardiotoxicity through combination with non-anthracycline (non-A) chemotherapy or shorter treatment duration. However there is limited data regarding cardiac outcomes and long-term survival with early discontinuation of adjuvant T.

Methods: An IRB-approved single-institution retrospective analysis was performed for 401 consecutive patients with non-metastatic HER2+ breast cancer treated at the Ohio State University Comprehensive Cancer Center from 2005-2015. Medical records were reviewed for clinicopathologic features, systemic treatment and survival information. Disease Free Survival (DFS) was defined as time from diagnosis to first recurrence (loco-regional or distant recurrence) including second primary breast cancer or death. Overall survival (OS) was defined as time from diagnosis to death or last known follow up. OS and DFS estimates were generated using Kaplan Meier methods and compared using Log-rank tests. Cox proportional hazard models were used to calculate univariate and multivariate hazard ratios for OS and DFS.

Results: A total of 371/401 (92.5%) patients received adjuvant T (n= 401, mean age: 59.4 years; stage 1: 120, 30%; stage II: 194, 48%; stage III: 87, 22%; ER+: 235, 58%); among whom 106/371 (28.6%) patients held adjuvant T for any reason. Median duration of therapy in patients with any interruption with T was 11.3 (0.5-16.9) months and 23/371 (6.9%) received less than 6 months of adjuvant T. Cardiomyopathy (measured as LVEF decline on 2D echocardiogram or MUGA >= 15 points) was the most common reason for withholding T (66/106, 62.3%). The majority of these patients received a cardiology referral (77/ 106, 72.6%) with a 13 day mean time to evaluation in outpatient clinic. Patients receiving non-A chemotherapy and beta blockers or ACE inhibitors during treatment were significantly less likely to experience cardiomyopathy (A vs non-A: 49/190, 25.8% vs. 16/136, 11.8% p=0.002); (Med vs no Med: 7/148, 4.73% vs 59/184, 32.1%; p<0.001). Log-rank tests indicate a significant worsening in OS and DFS for patients who discontinued T (p=0.021, 0.001 respectively). Multivariate analyses confirmed significant worsening in DFS after adjusting for age, stage, ER , node status, and cardiomyopathy (Adjusted HR: 4.0[2.02 – 7.92], p< 0.001)

Table 1- Discontinuation of adjuvant trastuzumab Number of patients (%)Initial treatment371Completed therapy with no interruption265 (71.4)Interruption of therapy for minimum of 2 weeks64 (17.2)Permanently discontinued42 (11.3)

Conclusion: Discontinuation of adjuvant trastuzumab, most often from cardiomyopathy, is an independent prognostic marker for worse DFS in non-metastatic HER2 positive breast cancer. Non-anthracycline chemotherapy and use of cardio-protective medication is associated with significantly reduced incidence of cardiotoxicity in this population. Future prospective studies should consider optimizing cardiovascular function to avoid interruption in adjuvant HER 2 directed therapy.

Citation Format: Sardesai S, Liu J, Palettas M, Stephens J, Stover D, Williams N, Reinbolt R, VanDeusen J, Wesolowski R, Lustberg M, Ramaswamy B. Cardiovascular outcomes and long term survival with discontinuation of adjuvant trastuzumab [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-16-03.

Abstract OT2-05-03: Does minocycline mitigate chemotherapy induced neuroinflammation? A phase II randomized placebo controlled study

Background: Many breast cancer (BC) patients, particularly those who receive chemotherapy (chemo), experience affective symptoms and cognitive changes that can negatively impact their quality of life. Causal links between inflammatory mediators and the development of depressive-like behavior and cognitive defects, have been established in mouse models, including studies by our group showing increased microglial activation following chemo (A.C DeVries et al). Microglia are resident immune cells of the brain, which release proinflammatory cytokines when activated. Doxorubicin (DOX) induces microglial activation in the brain. Minocycline, a second generation tetracycline, has been shown to suppress inflammation by inhibiting microglial activation in CNS disease models. We hypothesize that (1) chemo activates microglia in the brains of women being treated for BC, which can precipitate or exacerbate depression, anxiety and cognitive deficits and (2) Minocycline administration during neoadjuvant or adjuvant chemo will prevent chemo-induced microglial activation and will reduce affective and cognitive symptom burden. Trial Design: This is a single center, Phase II, double blinded randomized study of minocycline (100 mg twice a day) vs placebo twice a day in women with BC receiving DOX-based or other chemo for BC. Pts will be randomized to either oral minocycline or placebo for up to a 1 week loading period plus chemo treatment period and an optional subsequent 2 week period. Eligibility Criteria: Women diagnosed with BC stages I-III initiating first line adjuvant or neoadjuvant chemo. Aims: (1) to evaluate symptoms related to anxiety and depression and cognitive changes during and after chemo completion (2) to evaluate markers of neuro inflammation as assessed by blood based inflammatory cytokines and central markers of inflammation and microglia activation using 1 F-Fludeoxyglucose and 11C-PK11195 positron emission tomography. Primary endpoints are changes in Center for Epidemiological Studies Depression Scale (CES-D) and State Trait Anxiety Index (STAI) from baseline to end of study after minocycline vs placebo intervention. Secondary endpoints are changes in cognitive function during chemo using validated cognitive testing including N-Back Test, Behavioural Rating Inventory of Executive Function (BRIEF) and the Multifactorial Memory Questionnaire Ability Scale (MMQ). Statistical Methods: Primary analysis for efficacy will be intention-to-treat. The main objective is to preliminarily evaluate the effect of minocycline on chemo-induced depressive symptoms in terms of changes in CES-D and STAI scores. Mixed models will be used to evaluate cognitive function changes. A sample size of 23 per group, will give 80% power to detect an effect size of 0.74 standard deviation (SD) difference between the 2 groups at significance level of 0.10 based on a 2 sided two-sample t-test. From our experience, attrition of less than 20% is expected for studies in this patient population in our center, and to account for this, we plan to recruit up to 60 patients. 16 of 46 evaluable pts have been accrued to date. Accrual started in January 2016. Funded by Pelotonia grant from The OSUCCC. Contact: Study PI: Maryam.lustberg@osumc.edu

Citation Format: Boutrid H, Reinbolt R, Knopp M, Williams N, VanDeusen J, Sardesai S, Noonan A, Flora L, Gleich E, Pan X, Berger M, Vargo C, Wesolowski R, Ramaswamy B, DeVries AC, Lustberg M. Does minocycline mitigate chemotherapy induced neuroinflammation? A phase II randomized placebo controlled study [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT2-05-03.

Accuracy of pulse oximeter readings from probe placement on newborn wrist and ankle

OBJECTIVE

To compare the accuracy of pulse oximetry oxygen saturation (SpO(2)) measured on the wrist compared with the ipsilateral palm, and SpO(2) measured on the ankle compared with the ipsilateral sole.

STUDY DESIGN

In this prospective observational study, neonates admitted to the neonatal intensive care unit were enrolled. We recorded SpO(2) (Masimo Radical-7 pulse oximeter) detected at the palm and ipsilateral wrist initially, then at 30 s, and at 1 min, and we repeated the same procedure over the sole and ipsilateral ankle. We recorded the time to obtain the SpO(2) readings from all these sites. Regression analysis was performed to determine the relationship between paired SpO(2) measurements. The mean difference (bias) and standard deviation of the paired SpO(2) differences (precision) were calculated (Bland-Altman plots).

RESULT

A total of 150 patients (birth weight 2381±1020 g, gestational age 34.3±4.3 weeks, median postnatal age 3.5 days (25th-75th percentile 1-16 days)) were enrolled. There was a good correlation between SpO(2) measured at the palm versus the wrist (r=0.95, P<0.001 (right); r=0.97, P< 0.001 (left)) and between SpO(2) measured at the sole versus the ankle (r=0.92, P<0.001 (right); r=0.91, P<0.001 (left)). There was also a good agreement between paired SpO(2) measurements from these sites. The bias and precision for SpO(2) at the right palm and right wrist was 0.08±0.94% and for the left palm and left wrist 0.22±0.87%. Similarly, the bias and precision for SpO(2) at the right sole and right ankle was -0.03±0.93% and for the left sole and left ankle was -0.01±0.93%.

CONCLUSION

Our results show that the wrist and ankle can be used as alternative sites to measure SpO(2) in newborn infants in place of the routinely used palm or sole.

Lung protective ventilatory strategies in very low birth weight infants

Respiratory distress syndrome (RDS) is the most common respiratory diagnosis in preterm infants. Surfactant therapy and mechanical ventilation using conventional or high-frequency ventilation have been the standard of care in the management of RDS. Bronchopulmonary dysplasia (BPD) continues to remain as a major morbidity in very low birth weight infants despite these treatments. There is no significant difference in pulmonary outcome when an optimal lung volume strategy is used with conventional or high-frequency ventilation. Lung injury is directly related to the duration of invasive ventilation via the endotracheal tube. Studies using noninvasive ventilation, such as nasal continuous positive airway pressure and noninvasive positive pressure ventilation, have shown to decrease postextubation failures as well as a trend toward reduced risk of BPD. Lung protective ventilatory strategy may involve noninvasive ventilation as a primary therapy or following surfactant administration in very preterm infants with RDS. Initial steps in the management of preterm infants may also include sustained inflation to establish functional residual capacity, followed by noninvasive ventilation to minimize lung injury and subsequent development of BPD.

High frequency ventilation: basic concepts and clinical application

High frequency ventilation (HFV) is a mode of therapy that improves gas exchange with pressure fluctuations much lower than that required for conventional ventilation. HFV is efficacious in the "rescue" management of infants with respiratory failure. Although each HFV system has functional characteristics that are design related, it now appears that when used with similar treatment strategies and within functional limitations, similar outcomes can be achieved. Ideally, the clinician or the operator should be familiar with the basic concepts of different high frequency ventilators to achieve maximal benefits from using these devices in infants with respiratory failure.

Inhaled nitric oxide in premature neonates with severe hypoxaemic respiratory failure: a randomised controlled trial

BACKGROUND

Inhaled nitric oxide improves oxygenation and lessens the need for extracorporeal-membrane oxygenation in full-term neonates with hypoxaemic respiratory failure and persistent pulmonary hypertension, but potential adverse effects are intracranial haemorrhage and chronic lung disease. We investigated whether low-dose inhaled nitric oxide would improve survival in premature neonates with unresponsive severe hypoxaemic respiratory failure, and would not increase the frequency or severity of intracranial haemorrhage or chronic lung disease.

METHODS

We did a double-blind, randomised controlled trial in 12 perinatal centres that provide tertiary care. 80 premature neonates (gestational age < or = 34 weeks) with severe hypoxaemic respiratory failure were randomly assigned inhaled nitric oxide (n=48) or no nitric oxide (n=32, controls). Our primary outcome was survival to discharge. Analysis was by intention to treat. We studied also the rate and severity of intracranial haemorrhage, pulmonary haemorrhage, duration of ventilation, and chronic lung disease at 36 weeks' postconceptional age.

FINDINGS

The two groups did not differ for baseline characteristics or severity of disease. Inhaled nitric oxide improved oxygenation after 60 min (p=0.03). Survival at discharge was 52% in the inhaled-nitric-oxide group and 47% in controls (p=0.65). Causes of death were mainly related to extreme prematurity and were similar in the two groups. The two groups did not differ for adverse events or outcomes (intracranial haemorrhage grade 2-4, 28% inhaled nitric oxide and 33% control; pulmonary haemorrhage 13% and 9%; chronic lung disease 60% and 80%).

INTERPRETATION

Low-dose inhaled nitric oxide improved oxygenation but did not improve survival in severely hypoxaemic premature neonates. Low-dose nitric oxide in the most critically ill premature neonates does not increase the risk of intracranial haemorrhage, and may decrease risk of chronic lung injury.

Aneurysm of the ductus arteriosus: a congenital lesion

The objective of this study was to evaluate the clinical, radiological, and echocardiographic findings in 11 neonates with aneurysm of ductus arteriosus presented in our institutions between 1993 and 1996, and to postulate a new theory for the pathogenesis of this lesion. Medical records, radiographic studies, and echocardiograms were reviewed. All infants underwent follow-up echocardiograms every 2 to 3 days until the aneurysm spontaneously resolved or surgery was performed. The infants were predominantly term males; six had evidence of fetal distress, two were diagnosed prenatally by fetal echocardiogram, chest X ray evidenced mediastinal mass in six patients. The first echocardiogram showed structurally normal heart with an aneurysmal patent ductus arteriosus. In eight patients the aneurysm completely resolved by 5 to 10 days. One infant underwent surgical resection of the aneurysm after observation for 11 days with no change in size. Thrombosis of the aneurysm was noted in two patients; both underwent surgery. Increasing reports of ductal aneurysms in infants may reflect the availability of high-resolution echocardiography and more frequent use of echocardiography in the neonatal intensive care unit. Spontaneous resolution occurred in the majority of cases as in previous reports. We postulate that, at least in some cases, aneurysm of the ductus arteriosus is a congenital lesion that may represent poststenotic dilation of the ductus due to turbulent flow through a stenotic segment at its pulmonary artery end during fetal life. The presence of aneurysm of the ductus arteriosus should be excluded in selected cases of fetal distress, by fetal echocardiography.

Randomized, multicenter trial of inhaled nitric oxide and high-frequency oscillatory ventilation in severe, persistent pulmonary hypertension of the newborn

BACKGROUND

Although inhaled nitric oxide (iNO) causes selective pulmonary vasodilation and improves oxygenation in newborn infants with persistent pulmonary hypertension, its effects are variable. We hypothesized (1) that the response to iNO therapy is dependent on the primary disease associated with persistent pulmonary hypertension of the newborn (PPHN) and (2) that the combination of high-frequency oscillatory ventilation (HFOV) with iNO would be efficacious in patients for whom either therapy alone had failed.

METHODS

To determine the relative roles of iNO and HFOV in the treatment of severe PPHN, we enrolled 205 neonates in a randomized, multicenter clinical trial. Patients were stratified by predominant disease category: respiratory distress syndrome (n = 70), meconium aspiration syndrome (n = 58), idiopathic PPHN or pulmonary hypoplasia (excluding congenital diaphragmatic hernia) ("other": n = 43), and congenital diaphragmatic hernia (n = 34); they were then randomly assigned to treatment with iNO and conventional ventilation or to HFOV without iNO. Treatment failure (partial pressure of arterial oxygen [PaO2] < 60 mm Hg) resulted in crossover to the alternative treatment; treatment failure after crossover led to combination treatment with HFOV plus iNO. Treatment response with the assigned therapy was defined as sustained PaO2 of 60 mm Hg or greater.

RESULTS

Baseline oxygenation index and PaO2 were 48 +/- 2 and 41 +/- 1 mm Hg, respectively, during treatment with conventional ventilation. Ninety-eight patients were randomly assigned to initial treatment with HFOV, and 107 patients to iNO. Fifty-three patients (26%) recovered with the initially assigned therapy without crossover (30 with iNO [28%] and 23 with HFOV [23%]; p = 0.33). Within this group, survival was 100% and there were no differences in days of mechanical ventilation, air leak, or supplemental oxygen requirement at 28 days. Of patients whose initial treatment failed, crossover treatment with the alternate therapy was successful in 21% and 14% for iNO and HFOV, respectively (p = not significant). Of 125 patients in whom both treatment strategies failed, 32% responded to combination treatment with HFOV plus iNO. Overall, 123 patients (60%) responded to either treatment alone or combination therapy. By disease category, response rates for HFOV plus iNO in the group with respiratory syndrome and the group with meconium aspiration syndrome were better than for HFOV alone or iNO with conventional ventilation (p < 0.05). Marked differences in outcomes were noted among centers (percent death or treatment with extracorporeal membrane oxygenation = 29% to 75%).

CONCLUSIONS

We conclude that treatment with HFOV plus iNO is often more successful than treatment with HFOV or iNO alone in severe PPHN. Differences in responses are partly related to the specific disease associated with PPHN.

Prone positioning decreases episodes of hypoxemia in extremely low birth weight infants (1000 grams or less) with chronic lung disease

Extremely low birth weight infants with chronic lung disease (CLD) have frequent episodes of desaturation (hypoxemia). We quantified oxygenation and episodes of hypoxemia in 55 infants (birth weight < or = 1000 gm) with CLD in the supine versus prone position, for 1-hour time intervals. Oxygen saturation was measured with the Nellcor N-200 pulse oximeter and a computer program. Prone positioning increased oxygen saturation from 92.0% to 94.1% (p < 0.001) and significantly decreased episodes of hypoxemia to oxygen saturation levels of less than 90%, 85%, and 80% (p < 0.001). Our findings support prone positioning for the extremely low birth weight infant with CLD in an intensive care setting.

Pulse oximetry in newborn infants with birth weights of 620 to 4285 grams receiving dopamine and dobutamine

The reliability of pulse oximetry in neonates receiving inotropic drugs because of hypotension and microcirculatory perfusion failure has not been well documented. Signal loss of the pulse oximeter in adult patients receiving dopamine infusions has been reported. To evaluate the relationship between pulse oximeter oxygen saturation (SaO2) and co-oximeter directly measured oxygen saturation, we studied 30 infants in the first 4 days of life (birth weight 620 to 4285 gm, gestational age 26 to 43 weeks) receiving dopamine (30 patients) and dobutamine (10 infants). Infants had normal blood pressures at the time of the study. To minimize motion artifact a Nellcor N-200 (Nellcor Incorporated, Hayward, Calif.) oximeter with electrocardiographic synchronization was used. We compared pulse oximeter values with simultaneous arterial samples analyzed for oxygen saturation with an IL 282 co-oximeter (Instrumentation Laboratory, Inc., Lexington, Mass.). The values were corrected for spuriously elevated carboxyhemoglobin levels and fetal hemoglobin level was quantitatively measured. The partial pressure of oxygen at 90% hemoglobin saturation for each patient was calculated. The dosage of dopamine ranged from 4 to 28 micrograms/kg per minute and the dosage of dobutamine varied from 4 to 24 micrograms/kg per minute. Over a wide range of values for mean blood pressure (23 to 66 mm Hg), partial pressure of oxygen at 90% hemoglobin saturation (43.1 to 70.2 mm Hg), and oxygen saturation (SaO2 80% to 100%), linear regression analysis revealed a close correlation between pulse oximeter SaO2 and co-oximeter SaO2 values (r = 0.83, standard error of the estimate 2.2%, p < 0.0001). Our findings indicate that pulse oximetry can be used reliably for continuous oxygen monitoring in normotensive neonates with an SaO2 of 80% to 100% who are receiving dopamine and dobutamine.

Dexamethasone therapy in chronic lung disease

Steroids have been used in the treatment of infants with chronic lung disease (CLD) for over a decade. Some studies have reported beneficial effects from long, tapering 42-day course of dexamethasone. Short term regimens have also shown beneficial effects on ventilator dependent infants with CLD. Although steroid therapy has been successful in infants with established CLD, more recently, dexamethasone therapy is being initiated in infants with RDS considered to be at risk for developing CLD. Some of the initial studies reported higher rates of infection, but more recent prospective data have not shown an increased incidence of sepsis in patients treated with steroids. Presently, early steroid therapy appears to be beneficial to minimize lung injury in infants treated with surfactant.

Neonatal pulmonary mechanics and oxygenation after prophylactic amnioinfusion in labor: a randomized clinical trial

OBJECTIVE

Amnioinfusion has been reported to improve the perinatal outcome of pregnancies complicated by decreased amniotic fluid volume, but detailed information on its possible adverse effects on neonatal pulmonary mechanics and oxygenation is not available.

STUDY DESIGN

We evaluated 42 infants with birth weights of 2600 to 4320 g and gestational ages of 36 to 44 weeks, who were born to mothers enrolled in a prospective, randomized trial of amnioinfusion for oligohydramnios in labor. Maternal entry criteria were gestational age 36 weeks or older, estimated fetal weight more than 2500 g, oligohydramnios defined as an amniotic fluid index of 5 cm or less, and a normal fetal heart rate pattern. Evaluation of pulmonary mechanics and oxygen saturation (SaO2) was done with the infants breathing room air between birth and day 3 of life. Transpulmonary pressure, flow, and tidal volume were recorded simultaneously, and pulmonary resistance and lung compliance were calculated. SaO2 was measured for 30 minutes with the Nellcor N-200 oximeter and IBM computer oximetry software.

RESULTS

Evaluation of the data revealed no significant difference between the two groups for tidal volume, lung compliance, pulmonary resistance, or work of breathing. There were no differences between the two groups in the number of desaturation episodes or in percent of desaturations to less than 90%, 85%, or 80% SaO2.

CONCLUSION

Prior studies have shown amnioinfusion to improve perinatal outcome. Our findings demonstrate that amnioinfusion for oligohydramnios in labor does not adversely affect neonatal pulmonary mechanics or oxygenation.

Effects of early dexamethasone therapy on pulmonary mechanics and chronic lung disease in very low birth weight infants: a randomized, controlled trial

OBJECTIVE

To determine the changes in pulmonary mechanics before and during early dexamethasone therapy, and to evaluate the effect of dexamethasone on the duration of mechanical ventilation in very low birth weight (VLBW) ventilator-dependent infants at risk for chronic lung disease (CLD).

METHODS

A prospective randomized trial was conducted. Forty-three patients (birth weight 600 to 1500 g, gestational age 24 to 32 weeks) who failed to be weaned from the respirator at 7 to 14 days of age were enrolled; 23 infants received a 7-day course of dexamethasone (0.5 mg/kg/day intravenously for 3 days, 0.25 mg/kg/day for 3 days, and 0.1 mg/kg/day for 1 day), and 20 patients were in the control group. At similar mean airway pressure (MAP) and fractional inspired oxygen concentration (FiO2), respiratory system mechanics were measured before and on days 2, 5, and 7 of the study. Airway pressure, flow and tidal volume (VT) were recorded and only mechanical breaths were analyzed. Respiratory compliance (Crs) and respiratory resistance (Rrs) were calculated by two factor least mean square analysis.

RESULTS

Eighty-three percent of infants in the dexamethasone group and 90% in the control group received surfactant in the first 24 hours of life. There was a significant increase in Crs and VT in the dexamethasone group as compared with the control group (P < .001). No major changes in Rrs were observed. Dexamethasone therapy significantly decreased FiO2 and MAP P < .001) and facilitated successful weaning from mechanical ventilation. In addition to a shorter duration of mechanical ventilation (P < .01), the occurrence of CLD (FiO2 > 0.21 at 36 weeks of corrected gestational age, chest radiograph changes) was significantly decreased in the dexamethasone group (P < .01). Except for a transient increase in blood pressure and serum glucose, there were no significant differences in infection rates, intraventricular hemorrhage, or retinopathy of prematurity. Thirteen patients in the control group received dexamethasone at a later age.

CONCLUSIONS

Our findings indicate that: 1) early dexamethasone therapy in VLBW infants markedly improves respiratory compliance and tidal volume, reduces FiO2 and MAP requirements, and facilitates extubation in these infants; 2) early dexamethasone therapy reduces the duration of mechanical ventilation and decreases CLD (at 28 days and 36 weeks) in a population of VLBW infants largely treated with surfactant.

Production and characterization of a monoclonal antibody to partially purified estrogen receptor from human breast tumor

A hybridoma cell line that secretes monoclonal antibody, MAb-ER-Br-1-15-4-18 is established. The MAb is highly specific for estrogen receptor (ER) from human breast tumor cells. In order to raise the antibody, the ER was first isolated from human breast tumor. Mice were immunized with the partially purified ER and the fusion of the spleen cells from the mouse, showing the highest serum titer, with the cells of the NS-1 mouse myeloma line, produced hybrid cells which continuously secreted antibodies specific for ER. Three of the hybridoma cultures which tested strongly positive were cloned using limiting dilution method and one of the cell lines was selected for further study. The recovery of the MAb from the cell culture was done by ammonium sulfate precipitation followed by dialysis and then hydroxylapatite liquid chromatography using linear gradients. The purity of the antibody was checked by polyacrylamide gel electrophoresis. The MAb was isotyped and found to be IgG1. When checked against other antigens the MAb showed a minimal cross-reactivity to ER from rabbit uterus and none to ovalbumin or rat liver ferritin. Further experiments showed that the MAb recognized the ER bound to the hormone and ER in the nucleus of breast tumor cells.