Risk-based lung cancer screening performance in a universal healthcare setting

Globally, lung cancer is the leading cause of cancer death. Previous trials demonstrated that low-dose computed tomography lung cancer screening of high-risk individuals can reduce lung cancer mortality by 20% or more. Lung cancer screening has been approved by major guidelines in the United States, and over 4,000 sites offer screening. Adoption of lung screening outside the United States has, until recently, been slow. Between June 2017 and May 2019, the Ontario Lung Cancer Screening Pilot successfully recruited 7,768 individuals at high risk identified by using the PLCOm2012noRace lung cancer risk prediction model. In total, 4,451 participants were successfully screened, retained and provided with high-quality follow-up, including appropriate treatment. In the Ontario Lung Cancer Screening Pilot, the lung cancer detection rate and the proportion of early-stage cancers were 2.4% and 79.2%, respectively; serious harms were infrequent; and sensitivity to detect lung cancers was 95.3% or more. With abnormal scans defined as ones leading to diagnostic investigation, specificity was 95.5% (positive predictive value, 35.1%), and adherence to annual recall and early surveillance scans and clinical investigations were high (>85%). The Ontario Lung Cancer Screening Pilot provides insights into how a risk-based organized lung screening program can be implemented in a large, diverse, populous geographic area within a universal healthcare system.

Selection of individuals for lung cancer screening based on risk prediction model performance and economic factors - The Ontario experience

INTRODUCTION

Randomized controlled trials have shown that screening with computed tomography reduces lung cancer mortality but is most effective when applied to high-risk individuals. Accurate lung cancer risk prediction models effectively select individuals for screening. Few pilots or programs have implemented risk models for enrolling individuals for screening in real-world, population-based settings. This report describes implementation of the PLCOm2012 risk prediction model in the Ontario Health (Cancer Care Ontario) lung cancer screening Pilot.

METHODS

In the Pilot's Health Technology Assessment, 576 categorical age/pack-years/quit-years scenarios were evaluated using MISCAN microsimulation modeling and cost-effectiveness analyses. A preferred model was selected which provided the most life-years gained per cost. The PLCOm2012 was compared to the preferred MISCAN scenario at a threshold that yielded the same number eligible (risk ≥2.0 %/6-years).

RESULTS

The PLCOm2012 had significantly higher sensitivity and predictive value (68.1 % vs 59.6 %, p < 0.0001; 4.90 % vs 4.29 %, p = 0.044), and an Expert Panel selected it for use in the Pilot. The Pilot cancer detection rate was significantly higher than in the NLST (p = 0.009) or NELSON (p = 0.003) and there was a significant shift to early stage compared to historical Ontario Cancer Registry statistics (p < 0.0001). Pre- and post-Pilot evaluations found that conducting quality risk assessments were not excessively time consuming or difficult, and participants' satisfaction was high.

CONCLUSIONS

The PLCOm2012 was efficiently implemented in the Pilot in a real-world setting and is being used to transition into a provincial program. Compared to categorical age/pack-years/quit-years criteria, risk assessment using the PLCOm2012 can lead to effective and efficient screening.

Organized Lung Cancer Screening Pilot: Informing a Province-Wide Program in Ontario, Canada

BACKGROUND

Lung cancer is the leading cause of cancer deaths in Ontario. The National Lung Screening Trial demonstrated that screening with low-dose computed tomography (LDCT) reduces lung cancer mortality.

METHODS

In June 2017, Ontario Health (Cancer Care Ontario) initiated a pilot for lung cancer screening to inform implementation of a province-wide initiative. The screening pathway includes targeted recruitment strategies, the Tammemägi risk prediction model (PLCOm2012) to determine eligibility, opt-out smoking cessation services for all current smokers, use of the Lung-RADS scoring system to guide abnormal results management, and screening navigators providing end-to-end support. Referral criteria include being 55 years of age to 74 years of age and a current or former daily cigarette smoker for greater than or equal to 20 years, while the screening eligibility criterion is a PLCOm2012 risk greater than or equal to 2% in 6 years. Selected results of the interim pilot evaluation are presented. Four hospitals contributed data in the first year of the pilot.

RESULTS

During 2017 to 2018, 4205 Ontarians were recruited, 3234 risk assessments were conducted, and 2151 (66.5%) individuals were eligible for screening. Baseline LDCT scans were performed in 1624 (50.2%) individuals. Diagnostic evaluation in 120 (7.4%) individuals identified 28 (1.7%) with lung cancer, and proportions of stage I to II and stage III to IV were 71% and 29%, respectively. Of those recruited, 1443 (34.3%) individuals were smokers and 1326 (91.9%) accepted smoking cessation services.

CONCLUSIONS

The pilot is the largest in Canada and aligns with International Agency for Research on Cancer standards for population-based, organized cancer screening. Recruitment of high-risk individuals, high rates of smoking cessation program acceptance, and detection of early-stage cancers are demonstrated.

One, two and three-dimensional ultrasound measurements of carotid atherosclerosis before and after cardiac rehabilitation: preliminary results of a randomized controlled trial

Background

It is still not known how patients who are post-transient ischemic attack (TIA) or post-stroke might benefit from prospectively planned comprehensive cardiac rehabilitation (CCR). In this pilot evaluation of a larger ongoing randomized-controlled-trial, we evaluated ultrasound (US) measurements of carotid atherosclerosis in subjects following TIA or mild non-disabling stroke and their relationship with risk factors before and after 6-months of CCR.

Methods

Carotid ultrasound (US) measurements of one-dimensional intima-media-thickness (IMT), two-dimensional total-plaque-area (TPA), three-dimensional total-plaque-volume (TPV) and vessel-wall-volume (VWV) were acquired before and after 6-months CCR for 39 subjects who had previously experienced a TIA and provided written informed consent to participate in this randomized controlled trial. We maintained blinding for this ongoing study by representing treatment and control groups as A or B, although we did not identify which of A or B was treatment or control. Carotid IMT, TPA, TPV and VWV were measured before and after CCR as were changes in body mass index (BMI), total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglycerides (TG), systolic blood pressure (SBP) and diastolic blood pressure (DBP).

Results

There were no significant differences in US measurements or risk factors between groups A and B. There was no significant change in carotid ultrasound measurements for group A (IMT, p = .728; TPA, p = .629; TPV, p = .674; VWV, p = .507) or B (IMT, p = .054; TPA, p = .567; TPV, p = .773; VWV, p = .431) at the end of CCR. There were significant but weak-to-moderate correlations between IMT and VWV (r = 0.25, p = .01), IMT and TPV (r = 0.21, p = .01), TPV and TPA (r = 0.60, p < .0001) and VWV and TPV (r = 0.22, p = .02). Subjects with improved TC/HDL ratios showed improved carotid VWV although, this was not statistically significant.

Conclusion

In this preliminary evaluation, there were no significant differences in carotid US measurements in the control or CCR group; a larger sample size and/or longer duration is required to detect significant changes in US or other risk factor measurements.

The relationship of carotid three-dimensional ultrasound vessel wall volume with age and sex: comparison to carotid intima-media thickness

The relationship of three-dimensional ultrasound (3DUS)-derived carotid vessel wall volume (VWV) was evaluated with respect to age and sex. B-mode and 3DUS images were acquired for 316 subjects from diverse groups including obese primary prevention, diabetic nephropathy, renal transplant and rheumatoid arthritis populations. The relationship for intima-media thickness (IMT) and VWV with age and sex were determined using Pearson-product-moment correlations. Mean IMT (r = 0.18, p = 0.001) and VWV (r = 0.24, p < 0.01) correlated modestly with age. There were modest correlations in males (IMT, r = 0.19, p = 0.003; VWV, r = 0.34, p < 0.001) and in females for IMT and age (r = 0.30, p = 0.007) but not between 3DUS VWV and age in females (r = 0.10, p = 0.4). Significant associations between plaque and VWV (r = 0.36, p = 0.001) but not IMT suggest different correlations in females that may be attributed to plaque.

Effect of chemically induced propionic acidemia on neurobehavioral development of rats

High levels of propionic acid (PPA) comparable to those of human propionic acidemia were achieved in blood (1-5 mmol/l) and brain (1 micromol/g) of rats by administering saline-buffered propionate (pH 7.4) subcutaneously twice a day from the 6th to the 28th day of life. PPA doses ranged from 1.44 to 1.92 micromol/g body weight as a function of animal age. Control rats were treated with saline in the same volumes. Growth and development of physical landmarks were assessed by monitoring the following parameters daily: body weight, upper incisor eruption, eye opening, and hair coat. Development of some reflexes was also monitored, and a specific subset of motor skills was evaluated at days 14 and 21 of life by the free-fall righting test and the spontaneous alternation test. Chronic PPA administration had no effect on body weight, cerebral cortex weight, or cerebellum weight, but caused slight but significant delays in the day of appearance of hair coat and eye opening, indicating an effect of PPA on the development of physical parameters. Free-fall righting was impaired in PPA-treated animals. On the other hand, PPA administration had no effect on the performance of the animals in the spontaneous alternation tests. Long-term effects of early PPA administration were investigated by assessing animal performance in an aversive task (two-way shuttle avoidance task) and in a nonaversive (open-field task) behavioral task at 60 days of age. PPA-treated rats did not habituate to the open field, and presented a lack of retention of the shuttle-avoidance task. Our results suggest that early postnatal PPA administration to rats alters normal development and induces long-term behavioral deficits in aversive and nonaversive tasks.

Charge Donation by Calcium into the t1g Band of C60

Photoemission spectra of compounds prepared by the reaction of C(60) films with calcium show two distinct metallic phases, whereas alkali-doped C(60) films have only one. In the first phase the bulk t(1u) band, derived from the lowest unoccupied molecular orbital of C(60), is partially occupied. This is followed by an insulating phase that has the composition Ca(3)C(60) in which the t(1u) band is filled and has properties analogous to those of K(6)C(60). Continued exposure to calcium produces a second metallic phase in which electrons are donated into the t(1g) band. The superconductivity of Ca(5)C(60) is associated with the t(1g) band.

Metabolic studies in a mouse model of hepatorenal tyrosinemia: absence of perinatal abnormalities

Radiation induced chromosomal deletions at the albino locus in the mouse, lethal when homozygous, cause abnormalities of expression of several unlinked liver specific genes. Recently, the gene encoding FAH was shown to be included in the deletions. Since in humans FAH mutations cause tyrosinemia type I, deletion homozygous mice were suspected of having tyrosinemia. Studies of plasma amino acids did not confirm this suspicion. Also, succinylacetone levels were normal in fetal and newborn livers of deletion homozygotes. The present evidence, therefore, does not support the assumption that the earlier described ultrastructural and enzyme abnormalities in deletion homozygotes are secondary effects of tyrosinemia caused by the deletion of FAH.

Photoemission Spectra and Electronic Properties of K x C 60

Photoemission spectra of vacuum deposited layers of C(60), before and after exposure to K vapor, show that the K donates its conduction electron into the band derived from the lowest unoccupied molecular orbital. A compound with composition of K(3)C(60), corresponding to the maximum conductivity, has been prepared. In it the potassium atoms presumably occupy both the octahedral and the two tetrahedral interstitial sites of the face-centered-cubic (fcc) C(60) structure.

Metabolic aspects of protection by glycine against hypoxic injury to isolated proximal tubules

To clarify the roles of butyrate and acylglycine formation in hypoxic proximal tubule cell injury and protection by glycine and to test the contribution of iodoacetate-suppressible metabolism to protection, (1) it was determined whether protection by glycine is fully expressed when glucose, lactate, alanine, and butyrate are replaced by alpha-ketoglutarate as the sole substrate for the tubules, (2) butyrate metabolism and acylglycine formation were directly measured in control and hypoxic preparations, and (3) it was assessed whether injury produced by iodoacetate, a potent inhibitor of glycolytic metabolism, is subject to protection by glycine. Susceptibility to hypoxic injury in medium with alpha-ketoglutarate as the sole substrate was similar to that seen in medium containing glucose, lactate, alanine, and butyrate. Tubules in alpha-ketoglutarate medium showed high degrees of protection by glycine against injury produced by 30-min of hypoxia, by iodoacetate alone, and by iodoacetate combined with hypoxia. Protection did not require preservation of cell ATP or glutathione. In glucose-lactate-alanine-butyrate medium, butyrate, measured by gas chromatography, was rapidly metabolized by oxygenated tubules and fully accounted for basal rates of oxygen consumption. Butyrate utilization stopped during hypoxia. Neither aspect of butyrate metabolism was altered by glycine. Formation of acylglycines was assessed by gas chromatography/mass spectroscopy. In preparations treated with glycine, butyrylglycine was detected under both oxygenated and hypoxic conditions; the quantities, however, were small and no other acylglycines were found. These observations indicate that protective effects of glycine are independent of short-chain acylglycine formation and glycolytic metabolism.

Positive-ion thermospray liquid chromatography-mass spectrometry: detection of organic acidurias

Positive-ion thermospray liquid chromatography-mass spectrometry (TSP-LC-MS) is used to detect organic acids via the direct injection of untreated urine from newborns and infants. Two methods are reported for the separation of organic acids. The separation of urinary organic acids is effected in either an acidic, pH 2.5 sulfuric acid, or a non-acidic, 0.05 M ammonium acetate, pH 6.8, mobile phase. Use of pH 2.5 sulfuric acid and an HPX-87H organic acid column produces better separation but has less sensitivity than the use of 0.05 M ammonium acetate, pH 6.8 and a C18 column. Positive ion TSP-LC-MS has been used to detect methylmalonic aciduria, 3-hydroxy-3-methylglutaric aciduria, propionic aciduria, isovaleric aciduria and argininosuccinic aciduria.

Early identification of isovaleric aciduria using photodiode array detection for liquid chromatographic profiling of urinary carboxylic acids

The 190 nm high performance liquid chromatographic photodiode array profiling of the urinary carboxylic acids of the first urine of a newborn affected with isovaleric aciduria afforded an abnormal peak at 27.8 min. This peak was greatly increased in the carboxylic acid profiling of the 14 h urine sample from the same infant. Isolation of this peak by fraction collecting; solvent extraction of the eluent; trimethylsilyl derivatization of the residue and gas chromatographic/mass spectrometric analysis identified the compound as isovalerylglycine. Correlation of the 190 nm absorbance of isovalerylglycine (y) with concentration (x) afforded a least squares curve: y = 476.4x-13.72 (r = 0.99); run-to-run variation 6.92%; day-to-day variation 8.88% with a minimum detectable concentration of 25 micrograms/ml.

Photodiode array detection for liquid chromatographic profiling of carboxylic acids in physiological fluids: 3-hydroxy-3-methylglutaric aciduria

3-Hydroxy-3-methylglutaric aciduria was detected in a newborn. The progress of the dietary therapy for the disorder was monitored by dual-column "high-performance" liquid chromatography with a computer-controlled photodiode array spectrophotometric detector. This procedure is a quick way to detect and monitor the progress of 3-hydroxy-3-methylglutaric aciduria.

Photodiode array detection for liquid chromatographic profiling of carboxylic acids in physiological fluids: 3-hydroxy-3-methylglutaric aciduria

3-Hydroxy-3-methylglutaric aciduria was detected in a newborn. The progress of the dietary therapy for the disorder was monitored by dual-column "high-performance" liquid chromatography with a computer-controlled photodiode array spectrophotometric detector. This procedure is a quick way to detect and monitor the progress of 3-hydroxy-3-methylglutaric aciduria.

Photodiode array ultraviolet spectrophotometric profiling of carboxylic acids in physiological fluids

In this paper the use of a computer-controlled photodiode array spectrophotometric detector for the high-performance liquid chromatographic (HPLC) profiling of carboxylic acids in physiological fluids is reported. The ultraviolet spectrum of the flowing eluent is obtained at 6-sec intervals and is displayed as the absorbance at 190 nm. A three-dimensional (time versus wavelength versus absorbance) presentation of the HPLC profile facilitates peak identification through ultraviolet spectrum matching and relative retention time comparison with carboxylic acid standards. Several examples of HPLC urinary carboxylic acid profiles from infants with various inborn errors of metabolism are shown.

Volatile carboxylic acid profiling in physiological fluids: direct injection into a gas chromatograph/mass spectrometer

We present a procedure for the profiling of the volatile carboxylic acids and neutral compounds in blood or urine using the direct injection of the acidified sample into a gas chromatograph interfaced with a mass spectrometer by a jet separator. The non-volatile components remain at the head of the SP-1000 column while the volatile components move through the column. Up to sixty physiological samples can be analyzed before any degradation in mass spectrometer operating parameters is observed.

Paired-ion high-performance liquid chromatographic assay for plasma choline

Choline was isolated from deproteinized plasma by cation-exchange chromatography. Isolated choline was directly converted to the 3,5-dinitrobenzoate derivative and was analyzed by paired-ion high-performance liquid chromatography with UV detection at 254 nm. An internal standard, 3-hydroxy-N,N,N-trimethylpropanaminium iodide was used for quantitation of plasma choline. Linearity was achieved from 1--500 nmole/ml with a reproducibility of +/- 6%. Plasma choline concentrations below 1 nmole/ml could not be accurately measured while plasma choline concentrations in the micromole/ml range deviated from linearity.