Abstract P1-20-06: Association of circulating tumor DNA with clinical outcomes in metastatic breast cancer patients

Background: Circulating tumor DNA (ctDNA) can be used as a non-invasive method to detect and quantify genomic alterations (GA) in blood. We evaluated the relationship between ctDNA features, radiographic disease progression (RDP) and progression-free survival (PFS) in patients (pts) with metastatic breast cancer (MBC).

Methods: A retrospective analysis of 32 female MBC pts with plasma ctDNA tested prior to a radiology scan was performed. Plasma ctDNA tests were run by Inivata using a 36-gene panel for detecting point mutations, short insertions/deletions, and copy number variations. ctDNA features were tabulated for each pt and included number of genomic alterations (numGA), maximum mutant allele frequency (maxMAF), and sum of mutant allele frequency (sumMAF). Univariate and multivariable logistic regression (LR) models were used to explore ctDNA features associated with RDP. Univariate and multivariable Cox proportional hazards models were used to identify ctDNA features that were associated with PFS. All models included ctDNA features as continuous variables.

Results: Frequency of subtypes were 38% HR+HER2-, 28% HR+HER2+, 28% triple-negative, and 6% HR-HER2+. 97% had prior chemotherapy; 92% of HR+HER2-negative pts had prior endocrine therapy. 20 of 32 samples (69%) had GAs. The most common GAs were TP53 (50%), ESR1 (25%), PIK3CA (19%), and GATA3 (9.4%). Median numGA was 1 (0-12); median maxMAF was 1.9 (0-65.5); median sumMAF was 2.2 (0-157.2). Univariate LR analysis identified numGA (p=0.025), maxMAF (p=0.034), and sumMAF (p=0.049) to be significantly associated with RDP; numGA (p=0.056) and maxMAF (p=0.109) were retained in the final multivariable LR model. Univariate Cox regression analysis showed that numGA (HR=1.32, p<0.001), maxMAF (HR=1.03, p=0.011), and sumMAF (HR=1.02, p=0.002) were significantly associated with PFS; numGA (HR= 1.30, p=0.001) and maxMAF (HR= 1.02, p=0.045) were retained in the final multivariable Cox model.

Conclusions: Blood ctDNA profiling contributes to the prediction of RDP and PFS in MBC pts. High number of alterations and high allele fraction of these alterations were associated with worse clinical outcomes. These data provide an overview of the ctDNA dynamics in treated MBC pts.

Citation Format: Tan AR, Symanowski J, Kim EN, Hosking M, Morris CD, Plagnol V, Farhangfar CJ, Ersek JL. Association of circulating tumor DNA with clinical outcomes in metastatic breast cancer patients [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 P1-20-06.

Acute rheumatic fever and poststreptococcal reactive arthritis: diagnostic and treatment practices of pediatric subspecialists in Canada

OBJECTIVE

We conducted a survey of pediatric specialists in rheumatology, cardiology, and infectious diseases to ascertain present Canadian clinical practice with respect to diagnosis and treatment of acute rheumatic fever (ARF) and poststreptococcal reactive arthritis (PSReA), and to determine what variables influence the decision for or against prophylaxis in these cases.

METHODS

A questionnaire comprising 6 clinical case scenarios of acute arthritis occurring after recent streptococcal pharyngitis was sent to members of the Canadian Pediatric Rheumatology Association, and to heads of divisions of pediatric cardiology and pediatric infectious diseases at the 16 university affiliated centers across Canada.

RESULTS

There is considerable variability with respect to diagnosis in cases of ReA following group A streptococcal (GAS) infection both within and across specialties. There is extensive variability regarding the decision to provide prophylaxis in cases designated as ARF or PSReA. Findings indicated that physicians are most comfortable prescribing antibiotic prophylaxis in the presence of clear cardiac risk and are less inclined to such intervention for patients diagnosed with PSReA. When prophylaxis was recommended for cases of PSReA, the majority of respondents prescribed longer term courses of antibiotics.

CONCLUSION

The lack of observed consistency in diagnosis and treatment in cases of reactive arthritis post-GAS infection likely reflects the lack of universally accepted criteria for diagnosis of PSReA and insufficient longterm data regarding carditis risk within this population. There is a need for clear definitions and treatment guidelines to allow greater consistency in clinical practice across pediatric specialties.

A multicentre international study of sedation for uncontrolled symptoms in terminally ill patients

The issue of symptom management at the end of life and the need to use sedation has become a controversial topic. This debate has been intensified by the suggestion that sedation may correlate with 'slow euthanasia'. The need to have more facts and less anecdote was a motivating factor in this multicentre study. Four palliative care programmes in Israel, South Africa, and Spain agreed to participate. The target population was palliative care patients in an inpatient setting. Information was collected on demographics, major symptom distress, and intent and need to use sedatives in the last week of life. Further data on level of consciousness, adequacy of symptom control, and opioids and psychotropic agents used during the final week of life was recorded. As the final week of life can be difficult to predict, treating physicians were asked to complete the data at the time of death. The data available for analysis included 100 patients each from Israel and Madrid, 94 patients from Durban, and 93 patients from Cape Town. More than 90% of patients required medical management for pain, dyspnoea, delirium and/or nausea in the final week of life. The intent to sedate varied from 15% to 36%, with delirium being the most common problem requiring sedation. There were variations in the need to sedate patients for dyspnoea, and existential and family distress. Midazolam was the most common medication prescribed to achieve sedation. The diversity in symptom distress, intent to sedate and use of sedatives, provides further knowledge in characterizing and describing the use of deliberate pharmacological sedation for problematic symptoms at the end of life. The international nature of the patient population studied enhances our understanding of potential differences in definition of symptom issues, variation of clinical practice, and cultural and psychosocial influences.

Natural history and surgical outcomes for isolated discrete subaortic stenosis in children

OBJECTIVE

To document the natural history and surgical outcomes for discrete subaortic stenosis in children.

DESIGN

Retrospective review.

SETTING

Tertiary care paediatric cardiology centres.

PATIENTS

92 children diagnosed between 1985 and 1998.

MAIN OUTCOME MEASURES

Echocardiographic left ventricular outflow gradient (echograd), and aortic insufficiency (AI).

RESULTS

The mean (SEM) age at diagnosis was 5.3 (0.4) years; the mean echograd was 30 (2) mm Hg, with AI in 22% (19/87) of patients. The echograd and incidence of AI increased to 35 (3) mm Hg and 53% (36/68) (p < 0.05) 3.6 (0.3) years later. The echograd at diagnosis predicted echograd progression and appearance of AI. 42 patients underwent surgery 2.2 (0.4) years after diagnosis. Preoperatively echograd and AI incidence increased to 58 (6) mm Hg and 76% (19/25) (p < 0.05). The echograd was 26 (4) mm Hg 3.7 (0.4) years postoperatively, with AI in 82% (31/38) of patients. Surgical morbidities included complete heart block, need for prosthetic valves, and iatrogenic ventricular septal defects. Eight patients underwent reoperation for recurrent subaortic stenosis. The age at diagnosis of 44 patients followed medically and 42 patients operated on did not differ (5.5 (0.6) v 5. 0 (0.6) years, p < 0.05). However, the echograd at diagnosis in the former was less (21 (2) v 40 (5) mm Hg, p < 0.05) and did not increase (23 (2) mm Hg) despite longer follow up (4.1 (0.4) v 2.2 (0. 4) years, p < 0.05). The incidence of AI at diagnosis and at last medical follow up was also less (14% (6/44) v 34% (13/38); 40% (17/43) v 76% (19/25), p < 0.05).

CONCLUSIONS

Many children with mild subaortic stenosis exhibit little progression of obstruction or AI and need not undergo immediate surgery. Others with more severe subaortic stenosis may progress precipitously and will benefit from early resection despite risks of surgical morbidity and recurrence.

Role of the toxic neutrophil count in the early diagnosis of Kawasaki disease

OBJECTIVE

To determine whether the toxic neutrophil count (TNC), defined as the sum of the number of peripheral blood neutrophils with vacuoles plus the number with toxic granulations per 100 neutrophils examined, can be used as an aid to early diagnosis of Kawasaki disease (KD).

METHODS

Prospective evaluation at a tertiary care pediatric hospital of 56 acutely febrile children with at least one other clinical criterion for KD. Clinical characteristics and TNC were compared for 3 groups of patients: those with (1) definite KD, (2) probable KD, and (3) unlikely KD. The sensitivity and specificity of the TNC at various cutoff points was determined.

RESULTS

We evaluated 56 patients (Group 1, N=27; Group 2, N=4; Group 3, N=25). Mean TNC (TNC/mm3) were higher in the patients with definite KD compared to patients with unlikely KD (38 vs 24; p=0.037). At a TNC cutoff of > or =70, the test had a specificity of 100%, but a sensitivity of only 18%. The likelihood ratio (the number of times more likely this TNC result is to be found in KD versus non-KD subjects) was 8.89. At a cutoff of > or =10, the test had a high sensitivity of 92% and specificity of 38%.

CONCLUSION

No laboratory test replaced the need for careful clinical evaluation in cases of suspected KD. The TNC may be a useful adjunct to the clinical assessment of children with KD, particularly at the extremes of measurement.

Atrial and venous thrombosis secondary to septic arthritis of the sacroiliac joint in a child with hereditary protein C deficiency

Septic arthritis and osteomyelitis in children is seldom accompanied by calf vein thrombosis and rarely by atrial thrombosis. We report the case of an 11-year, 5-month-old boy with septic arthritis and osteomyelitis of the sacroiliac region who developed deep venous thrombosis, in addition to life-threatening right atrial thrombosis. After an intensive hematologic investigation, a hereditary protein C deficiency was revealed. The association of venous thrombosis with septic arthritis or osteomyelitis should raise the possibility of the presence of protein C deficiency.

Aortic cusp prolapse in ventricular septal defect and its association with aortic regurgitation--appropriate timing of surgical repair and outcomes

OBJECTIVES

To determine the appropriate indications and timing for surgery in children with either a perimembranous or a subarterial type of ventricular septal defect (VSD) associated with aortic cusp prolapse.

DESIGN

Retrospective review of children with VSD and associated aortic cusp prolapse with or without aortic regurgitation. This review was based on data obtained from clinical findings, two-dimensional echocardiography, cardiac catheterization and angiocardiography.

SETTING

Tertiary health care facility with two-dimensional and colour Doppler echocardiographic and cardiac surgery facilities, and a catheterization laboratory.

PATIENTS

Forty-eight patients were found to have perimembranous or subarterial VSDs in association with aortic cusp prolapse with or without aortic regurgitation.

INTERVENTIONS

All 48 patients had high resolution two-dimensional and colour Doppler echocardiography. Of the 19 patients who underwent surgical closure of their VSD, five also had an aortic valvuloplasty and one had an aortic valve replacement. Cardiac catheterization was performed in 16 of the 19 surgical patients and 12 of the 29 nonsurgical patients.

MEASUREMENTS AND MAIN RESULTS

Annual clinical and echocardiographic assessments in the nonsurgical group did not demonstrate increasing aortic insufficiency. Two children in the nonsurgical group showed spontaneous resolution of aortic insufficiency. In the surgical group, four children with VSD and clinical aortic insufficiency had surgery at less than five years of age; two were found to be regurgitant-free, one had trivial clinical aortic insufficiency and the other had echocardiography-only insufficiency. Of the seven surgical patients older than five years with VSD and clinical aortic insufficiency, four were found to be regurgitant-free, one had echocardiography-only regurgitation and two were unchanged. Two children undergoing surgery with VSD and no aortic insufficiency had postoperative echocardiography-only regurgitation, presumably related to cusp deformity from presurgical prolapse. Children with large VSDs with or without aortic cusp prolapse required surgery for indications of shunt size and pulmonary resistance.

CONCLUSIONS

For children with small perimembranous VSDs and cusp prolapse, surgery is indicated only if there is clinical evidence of aortic regurgitation and progressive left ventricular enlargement.

Transoesophageal echocardiographic assessment of obstruction to the pulmonary venous pathway in children with Mustard or Senning repair

The morphology and mechanism of obstruction to the pulmonary venous pathway in patients following either Mustard or Senning repair of complete transposition was assessed using transoesophageal echocardiography. Seven patients underwent catheterization and complete transoesophageal study in both transverse and longitudinal planes, followed by balloon dilation of the obstructed venous pathway in five of seven under transoesophageal echocardiography guidance. A complete scan of both systemic and venous pathway was obtained in all patients. Four patients with a Mustard repair were found to have a 'tubular' baffle, with stenosis resulting from a discrete wedge of tissue arising from the atrial free wall in association with fibrous adhesions to the baffle. In the three patients with a Senning repair the intra-atrial baffle showed a characteristic 'peaked' appearance, with stenosis of the venous pathway stenosis related directly to contracture of the patch used to augment the atrial free wall. The mechanism of obstruction appears to be inherent to the different surgical techniques. Indwelling transoesophageal echocardiography provided immediate haemodynamic and morphologic assessment of the efficacy of dilation of the obstructed venous pathway.

An approach to the neonate with sudden dysrhythmia: diagnosis, mechanisms, and management

The clinical course of a newborn can be rendered more complex by the sudden development of a disturbance in heart rhythm and conduction. The caregiver's ability to recognize a particular dysrhythmia and its most probable mechanism is crucial for optimal management. During the past 15 years, there has been significant progress in the understanding of the electrophysiologic basis of rhythm disturbances in the newborn period. This understanding has led to more precise diagnosis and effective treatment regimens for infants with dysrhythmias. Using recent case studies from one intensive care nursery as illustrations, this article discusses the clinical presentation and electrophysiologic mechanisms of three common forms of rhythm and conduction disturbance. The discussion pertains to disturbances of rhythm in association with tachycardia only. Emphasis is placed on the electrocardiographic diagnosis and clinical management of these infants.

Responses of systemic and pulmonary veins to the presence of an intravascular stent in a swine model

The outcome of stent implantation for children with pulmonary venous obstruction has been characterized by late reocclusion associated with a marked vessel neointimal proliferation. The purpose of this study was to compare the responses of the systemic vein and pulmonary vein to the presence of an intravascular stent, using a Yorkshire swine (N = 10) model. Under cardiopulmonary bypass, a single Palmaz stent was placed in the inferior vena cava (IVC) and right lower pulmonary vein (PV) with sacrifice at 4.9-6.1 months. Angiography and hemodynamic data were determined at 1 and 3 months post-stent implant and prior to euthanasia. All stents were found to be patent, with no difference in degree of thrombosis or neointimal formation. No statistical difference was found in the initial and final stent diameter for both inferior vena cava and pulmonary vein stents (PV initial 6.8 +/- 0.9; final 7.1 +/- 0.6) (IVC initial 10.4 +/- 1.2; final 10.4 +/- 1.2). Electron microscopy demonstrated smooth endothelialization of both pulmonary and systemic venous stent devices. No thrombosis was found on gross morphology. The data indicate that there is no intrinsic difference in the response of the pulmonary vein to the presence of a stent device. The clinical experience of restenosis following stent implantation for pulmonary vein stenosis appears to be more related to variables of final stent diameter combined with the marked intrinsic abnormal vessel architecture, as seen with this condition.

Randomized controlled trial of dexamethasone treatment in very-low-birth-weight infants with ventilator-dependent chronic lung disease

This randomized controlled trial was designed to answer the question: does administration of dexamethasone to neonates with bronchopulmonary dysplasia decrease the need for assisted ventilation? Twenty-five infants with a birth weight < 1501 g, requiring mechanical ventilation and FiO2 of > or = 0.30 at 21-35 days of age, were randomized to treatment with iv dexamethasone or to sham injections for 12 days. The primary outcome criterion was extubation within seven days after study entry. Treatment (n = 12) and control (n = 13) groups were well matched at entry. Dexamethasone facilitated weaning from assisted ventilation (p = 0.0154). There was no increased incidence of infection. Dexamethasone treatment resulted in a significant increase in glucosuria (p = 0.0002) and in systolic blood pressure (p = 0.0034). There was a significant decrease in heart rate (p = 0.0001) and a significant weight loss (p = 0.0002) following dexamethasone treatment. Dexamethasone treatment facilitated weaning from assisted ventilation but several systemic effects were noted that deserve further evaluation before dexamethasone becomes routine treatment.

Proteinuria and renal function in diabetic patients fed a diet moderately restricted in protein

Protein restriction has been used in the treatment of renal disease and may also be beneficial in the management of diabetic nephropathy. We evaluated the effects of moderate protein restriction (0.6 g/kg ideal body weight per day) for a 3-mo period on renal function in seven diabetic patients. Moderate protein restriction led to a decrease of approximately 50% in the albumin excretion rate in patients with overt proteinuria or microalbuminuria. This decrease occurred in some patients without a decrease in glomerular filtration rate, renal plasma flow, or plasma albumin concentration and may reflect subtle changes in filtration properties or permeability of glomeruli. In this pilot study moderate protein restriction has marked effects on albumin excretion irrespective of the initial degree of renal impairment. It is therefore suitable for longer-term study of its effects on the progression of renal disease in both patients with overt and incipient diabetic nephropathy.

Complications following oral administration of exchange resins in extremely low-birth-weight infants

Complications of the oral use of sodium polystyrene sulfonate and calcium polystyrene sulfonate are reported in five extremely low-birth-weight infants in which exchange resins were used to treat hyperkalemia. Radio opaque masses outlining the stomach were seen in all infants and could be palpated in the left upper quadrant of the abdomen. In two infants, at autopsy the palpable mass could be identified as a solid chalk-like concretion outlining the stomach. X-ray diffraction studies identified the material as Brushite. Administration of exchange resins by the gastric route should be avoided in the treatment of hyperkalemia in critically sick, extremely low-birth-weight infants.

Outpatient stabilization programme--an innovative approach in the management of diabetes

An outpatient stabilization programme for diabetic patients was established to overcome the disadvantages of inpatient treatment. The day to day management of patients was carried out by experienced nurse/educators under the supervision of physicians. The telephone was used extensively for communication between the patients and staff of the Diabetes Centre. In a 12 month period, 73 patients were commenced on insulin and 83 patients (62 on insulin) had their diabetic control re-stabilized. In both groups of patients there was a significant fall in glycosylated haemoglobin levels indicating improved metabolic control. Results were similar to those for patients admitted to hospital for stabilization. There are important social and economic benefits from the avoidance of repeated hospitalization.

Long-acting contraceptive agents: esters of norethisterone with alpha- and/or beta-chain branching

The synthesis of eighteen esters of norethisterone (17 alpha-ethynyl-17 beta-hydroxyestr-4-en-3-one) is described. These all possess some form of alpha- and/or beta-substitution in the ester side-chain. The work was undertaken in order to evaluate any long-acting fertility control effect intrinsic in such compounds. A pentamethyl disiloxy ether was also included in the group of substances prepared for testing because of its similar substitution pattern.

The influence of a wide range of absorbed cholesterol on plasma cholesterol levels in man

The influence of absorbed dietary cholesterol on plasma cholesterol concentration was studied in two populations, one Seventh Day Adventist (SDA) vegetarian and one nonvegetarian, representing a broad range of plasma cholesterol values and dietary cholesterol intakes. As a group, the SDA vegetarians had significantly lower levels of plasma cholesterol and triglycerides than did the nonvegetarians. This hypolipidemic pattern in the SDA vegetarians was apparently closely related to dietary habits, sinceanother group of SDA who were nonvegetarian had significantly higher plasma cholesterol and triglyceride levels than their vegetarian counterparts. Both the dietary intake of cholesterol and the percentage absorption of cholesterol were lower in vegetarians than in nonvegetarians. The mass of cholesterol absorbed increased linearly with the mass of cholesterol ingested in all groups, but no relationship could be demonstrated between absorbed cholesterol and plasma cholesterol concentration.