Lung function decline is mitigated following liver transplantation in people with cystic fibrosis: A retrospective cohort study.

There is paucity of literature on the health outcomes following liver transplantation (LT) in people with cystic fibrosis (pwCF). We aim to evaluate changes in lung function following LT in pwCF. We performed a retrospective cohort study of pwCF who underwent LT between 1987 and 2019 in the United States and Canada. Simultaneous lung-liver transplants and individuals who had lung transplant prior to LT were excluded. We analyzed pre-LT and post-LT percent predicted forced expiratory volume in 1 second, body mass index, rates of pulmonary exacerbation, and post-LT overall survival. A total of 402 LT recipients were included. The median age of transplant was 14.9 years and 69.7% of the transplants were performed in children less than 18 years old. The rate of decline in percent predicted forced expiratory volume in 1 second was attenuated after LT from -2.2% to -0.7% predicted per year with a difference of 1.5% predicted per year (95% CI, 0.8, 2.2; p < 0.001). Following LT, the rate of decline in body mass index was reduced, and there were fewer pulmonary exacerbations (0.6 pre vs. 0.4 post; rate ratio 0.7, p < 0.01). The median survival time post-transplant was 13.9 years and the overall probability of survival at 5 years was 77.6%. Those with higher lung function pre-LT had a lower risk of death post-LT, and those with genotypes other than F508 deletion had worse survival. LT in pwCF occurs most often in children and adolescents and is associated with a slower rate of decline in lung function and nutritional status, and a reduction in pulmonary exacerbations.

Global disparities in cystic fibrosis outcomes prior to CFTR modulators: A CF registries cohort study in South Africa and Canada.

BACKGROUND: Outcomes of cystic fibrosis (CF) differ between low-middle income and high-income countries, but comparative data are lacking. We compared South African (SA) and Canadian CF outcomes to explore what disparities existed prior to access of CFTR modulators in Canada. METHODS: A cross-sectional study of SA and Canadian CF registries data for period 1 January to 31 December 2018. CF registry data were harmonised between countries to compare lung function and nutrition outcomes. Poor nutrition was defined as BMIz-score < -1 in children and < 18.5 kg/m2 in adults. Standardised mean difference (SMD) >10 was considered significant. RESULTS: After excluding Canadians on CFTR modulators and lung transplant recipients, data on 4049 Canadian and 446 SA people was analysed. Compared to Canada, people in SA were younger (median age 15.8 years vs. 24.1 years: SMD 52) with fewer males (47.8% vs 54.2%; SMD 12.5) and White (70.9% vs. 93.3%; SMD 61.3). Class I-III CFTR mutation frequency was similar in SA (n = 384, 86.1%) and Canada (n = 3426, 84.9%). After adjusting for age, gender, diagnosis age, genotype, P.aeruginosa infection and pulmonary treatments, FEV1pp was 8.9% lower (95% CI 6.3% to 11.4%) and poor nutrition 1.7-fold more common (OR 1.70; 95% CI 1.19-2.41) in SA compared to Canada. CONCLUSION: Lung function and nutrition was significantly lower in SA compared to Canada. Global disparities in CF outcomes between high and low-middle income countries are likely to widen as CFTR modulators are rapidly scaled up in only high-income countries.

Cystic fibrosis survival outcomes following second lung transplant: The north American experience.

INTRODUCTION: Re-transplant is an option for those who develop end-stage lung disease due to rejection; however, little data exist following re-transplantation in cystic fibrosis (CF). METHODS: Data from the Canadian CF Registry and US CF Foundation Patient Registry supplemented with data from United Network for Organ Sharing were used. Individuals who underwent a 2nd lung transplant between 2005 and 2019 were included. The Kaplan-Meier method was used to estimate the probability of survival post-second transplant at 1, 3, and 5-years. RESULTS: Of those people who were waitlisted for a second transplant (N = 818), a total of 254 (31%) died waiting, 395 (48%) were transplanted and 169 (21%) people were alive on the waitlist. Median survival time after 2nd lung transplant was 3.3 years (95% CI: 2.8-4.1). The 1-, 3- and 5-year survival rates were 77.4% (95% CI: 73.1-82%), 52% (95% CI: 46.7-58%) and 39.4% (95% CI: 34.1-45.6%). CONCLUSIONS: Survival following second lung transplant in CF patients is lower than estimates following the first transplant. Over half of subjects who are potentially eligible for a second transplant die without receiving a second organ. This warrants further investigation.

Mitochondrial Aconitase ACO2 Links Iron Homeostasis with Tumorigenicity in Non-Small Cell Lung Cancer.

The ability of a patient tumor to engraft an immunodeficient mouse is the strongest known independent indicator of poor prognosis in early-stage non-small cell lung cancer (NSCLC). Analysis of primary NSCLC proteomes revealed low-level expression of mitochondrial aconitase (ACO2) in the more aggressive, engrafting tumors. Knockdown of ACO2 protein expression transformed immortalized lung epithelial cells, whereas upregulation of ACO2 in transformed NSCLC cells inhibited cell proliferation in vitro and tumor growth in vivo. High level ACO2 increased iron response element binding protein 1 (IRP1) and the intracellular labile iron pool. Impaired cellular proliferation associated with high level ACO2 was reversed by treatment of cells with an iron chelator, whereas increased cell proliferation associated with low level ACO2 was suppressed by treatment of cells with iron. Expression of CDGSH iron-sulfur (FeS) domain-containing protein 1 [CISD1; also known as mitoNEET (mNT)] was modulated by ACO2 expression level and inhibition of mNT by RNA interference or by treatment of cells with pioglitazone also increased iron and cell death. Hence, ACO2 is identified as a regulator of iron homeostasis and mNT is implicated as a target in aggressive NSCLC. IMPLICATIONS: FeS cluster-associated proteins including ACO2, mNT (encoded by CISD1), and IRP1 (encoded by ACO1) are part of an "ACO2-Iron Axis" that regulates iron homeostasis and is a determinant of a particularly aggressive subset of NSCLC.

Contemporary cystic fibrosis incidence rates in Canada and the United States.

BACKGROUND: The availability of new diagnostic algorithms for cystic fibrosis (CF), changing population demographics and programs that impact family planning decisions can influence incidence rates. Thus, previously reported incidence rates in Canada and the United States (US) may be outdated. The objectives of this study were to estimate contemporary CF incidence rates in Canada and the US and to determine if the incidence rate has changed over time. METHOD: This population-based cohort study utilized data between 1995-2019 from the Canadian CF Registry (CCFR), Statistics Canada, US CF Foundation Patient Registry (CFFPR) data, and US Center for Disease Control (CDC) National Vital Statistics System. Incidence was estimated using the number of live CF births by year, sex, and geographic region using Poisson regression, with the number of live births used as the denominator. To account for delayed diagnoses, we imputed the proportion of diagnoses expected given historical trends, and varying rates of newborn screening (NBS) implementation by region. RESULTS: After accounting for implementation of NBS and delayed diagnoses, the estimated incidence rate for CF in 2019 was 1:3848 (95% CI: 1:3574, 1:4143) live births in Canada compared to 1:5130 (95% CI:1:4996, 1:5267) in the US. There was substantial regional variation in incidence rates within both Canada and the US. Since 1995, incidence rates have decreased at a rate of 1.6% per year in both countries (p<0.001). CONCLUSION: Contemporary CF incidence rates suggest CF incidence is lower than previously reported and varies widely within North America. This information is important for resource planning and for tracking how programs (e.g., genetic counselling, modulator availability etc.) may impact the incidence of CF moving forward.

Beyond borders: cystic fibrosis survival between Australia, Canada, France and New Zealand.

BACKGROUND: Life expectancy for people with cystic fibrosis (CF) varies considerably both within and between countries. The objective of this study was to compare survival among countries with single-payer healthcare systems while accounting for markers of disease severity. METHODS: This cohort study used data from established national CF registries in Australia, Canada, France and New Zealand from 2015 to 2019. Median age of survival for each of the four countries was estimated using the Kaplan-Meier method. A Cox proportional hazards model was used to compare risk of death between Canada, France and Australia after adjusting for prognostic factors. Due to low number of deaths, New Zealand was not included in final adjusted models. RESULTS: Between 2015 and 2019, a total of 14 842 people (3537 Australia, 4434 Canada, 6411 France and 460 New Zealand) were included. The median age of survival was highest in France 65.9 years (95% CI: 59.8 to 76.0) versus 53.3 years (95% CI: 48.9 to 59.8) for Australia, 55.4 years (95% CI: 51.3 to 59.2) for Canada and 54.8 years (95% CI: 40.7 to not available) for New Zealand. After adjusting for individual-level factors, the risk of death was significantly higher in Canada (HR 1.85, 95% CI: 1.48 to 2.32; p<0.001) and Australia (HR 2.08, 95% CI: 1.64 to 2.64; p<0.001) versus France. INTERPRETATION: We observed significantly higher survival in France compared with countries with single-payer healthcare systems. The median age of survival in France exceeded 60 years of age despite having the highest proportion of underweight patients which may be due to differences in availability of transplant.

Comparison of quadriceps muscle size and quality in adults with cystic fibrosis with different severities of cystic fibrosis transmembrane conductance regulator protein dysfunction.

BACKGROUND: Cystic fibrosis (CF) is characterized by CF transmembrane conductance regulator (CFTR) dysfunction. CFTR protein is expressed in human skeletal muscle; however, its impact on skeletal muscle is unknown. The objectives of this study were to compare quadriceps muscle size and quality between adults with various severities of CFTR protein dysfunction. METHODS: We conducted a prospective, cross-sectional study comparing 34 adults with severe versus 18 with mild CFTR protein dysfunction, recruited from a specialized CF centre. Ultrasound images of rectus femoris cross-sectional area (RF-CSA) and quadriceps layer thickness for muscle size, and rectus femoris echogenicity (RF-ECHO) (muscle quality) were obtained. Multivariable linear regression models were developed using purposeful selection technique. RESULTS: People with severe CFTR protein dysfunction had larger RF-CSA by 3.22 cm2, 95% CI (1.03, 5.41) cm2, p=.0049], after adjusting for oral corticosteroid use and Pseudomonas aeruginosa colonization. However, a sensitivity analysis indicated that the result was influenced by the specific confounders being adjusted for in the model. We did not find any significant differences in quadriceps layer thickness or RF-ECHO between the two groups. CONCLUSION: We found no differential impact of the extent of diminished CFTR protein activity on quadriceps muscle size or quality in our study cohort. Based on these findings, CFTR mutation status cannot be used differentiate leg muscle size or quality in people with CF.

Frailty predicts outcomes in cystic fibrosis patients listed for lung transplantation.

BACKGROUND: Survival predictors are not established for cystic fibrosis (CF) patients listed for lung transplantation (LT). Using the deficit accumulation approach, we developed a CF-specific frailty index (FI) to allow risk stratification for adverse waitlist and post-LT outcomes. METHODS: We studied adult CF patients listed for LT in the Toronto LT Program (development cohort 2005-2015) and the Swiss LT centres (validation cohort 2008-2017). Comorbidities, treatment, laboratory results and social support at listing were utilized to develop a lung disease severity index (LI deficits, d = 18), a frailty index (FI, d = 66) and a lifestyle/social vulnerability index (LSVI, d = 10). We evaluated associations of the indices with worsening waitlist status, hospital and ICU length of stay, survival and graft failure. RESULTS: We studied 188 (Toronto cohort, 176 [94%] transplanted) and 94 (Swiss cohort, 89 [95%] transplanted) patients. The median waitlist times were 69 and 284 days, respectively. The median follow-up post-transplant was 5.3 and 4.7 years. At listing, 44.7% of patients were frail (FI ≥ 0.25) in the Toronto and 21.3% in the Swiss cohort. The FI was significantly associated with all studied outcomes in the Toronto cohort (FI and post-LT mortality, multivariable HR 1.74 [95%CI:1.24-2.45] per 0.1 point of the FI). In the Swiss cohort, the FI was associated with worsening waitlist status, post-LT mortality and graft failure. CONCLUSIONS: In CF patients listed for LT, FI risk stratification was significantly associated with waitlist and post-LT outcomes. Studying frailty in young populations with advanced disease can provide insights on how frailty and deficit accumulation impacts survival.

Development and Internal Validation of a Prognostic Model of the Probability of Death or Lung Transplantation Within 2 Years for Patients With Cystic Fibrosis and FEV1 ≤ 50% Predicted.

BACKGROUND: Improved methods are needed to risk-stratify patients with cystic fibrosis (CF) and reduced FEV1. RESEARCH QUESTIONS: What are the predictors of death or lung transplantation (LTx) within 2 years among patients with CF whose FEV1 ≤ 50% predicted? Do these markers similarly predict outcomes among G551D patients taking ivacaftor since 2012? STUDY DESIGN AND METHODS: Patients with CF, age ≥ 6 years with FEV1 ≤ 50% predicted as of December 31, 2014, were identified in a data set that merged Cystic Fibrosis Foundation and United Network for Organ Sharing (UNOS) registries. The least absolute shrinkage and selection operator (LASSO) method was applied to a randomly selected training set to select important prognostic variables. Accuracy and association of the model with death or LTx with 2 years (2-year death or LTx) were validated via logistic regression on an independent test set. Sensitivity analyses explored predictors for patients with UNOS data. RESULTS: FEV1 percent predicted (OR, 1.51 for 5% decrease; 95% CI, 1.27-1.81), number of pulmonary exacerbations treated with IV antibiotics (OR, 1.35; 95% CI, 1.11-1.65), and continuous or nocturnal oxygen (OR, 3.71; 95% CI, 1.81-7.59) were significantly associated with 2-year death or LTx. Our model predicted outcomes with greater sensitivity (ratio of sensitivity, 1.26; 95% CI, 1.02-1.54), ratio of positive predictive value (1.25; 95% CI, 1.05-1.51), and ratio of negative predictive value (1.04; 95% CI, 1.01-1.07) than FEV1 < 30% predicted. Among those taking ivacaftor in 2014, only FEV1 remained associated with 2-year death or LTx. For patients with UNOS data, LASSO identified additional covariates of interest, including noninvasive ventilation use, low hemoglobin, pulmonary arterial systolic pressure, supplemental oxygen, mechanical ventilation, FEV1 percent predicted, and cardiac index. INTERPRETATION: Among individuals with CF and FEV1 ≤ 50% predicted, FEV1 percent predicted, oxygen therapy, and number of pulmonary exacerbations predicted 2-year death or LTx. Although limited by small sample size, only FEV1 remained predictive in patients receiving highly effective modulator therapy. Additional physiologic variables could improve prognostication in CF.

The negative impact of chronic rhinosinusitis on the health-related quality of life among adult patients with cystic fibrosis.

BACKGROUND: With improved survival in cystic fibrosis (CF) patients, it is crucial to evaluate the impact of chronic co-morbidities such as chronic rhinosinusitis (CRS). The objectives were 1) To determine the prevalence of CRS with a large series of CF patients 2) To evaluate the impact of CRS on the Health-Related Quality of Life (HRQoL) of CF patients and 3) To compare CRS-specific, CF-specific and general HRQoL instruments. METHODS: Consecutive CF patients from the Toronto Adult Cystic Fibrosis Centre were recruited between March 2018 and January 2020. Participants completed the 22-Item Nasal Outcome Test (SNOT-22), Cystic Fibrosis Questionnaire-Revised for adolescents and adults over 14 years of age (CFQ-R), Cystic Fibrosis Quality of Life Evaluative Self-administered Test (CF-QUEST) and the 36-Item Short Form Survey (SF-36). HRQoL scores were correlated using Spearman's correlation coefficients. RESULTS: Out of 195 patients eligible for analysis, the prevalence of CRS with positive endoscopic findings was 42.6% (95% confidence interval: 35.5-49.8%). CRS patients reported significantly lower HRQoL with higher SNOT-22 scores and lower scores in the respiratory domain of CFQ-R and physical health domains of CF-QUEST and SF-36. The physical (ρ= -0.63) and mental (ρ= -0.66) domains of SF-36 and CF-QUEST (ρ= -0.76) had a strong correlation with SNOT-22. Higher scores of SNOT-22 nasal subdomains correlated with lower scores of SF-36, CFQ-R and CF-QUEST. CONCLUSION: CRS is a prevalent co-morbidity of CF patients, which significantly reduces HRQoL. SNOT-22, CFQ-R, CF-QUEST and SF-36 were strongly correlated. Severity of sinonasal symptoms have a strong correlation with HRQoL in CF patients.

Validation of the French 3-year prognostic score for death or lung transplant in the United States cystic fibrosis population.

In 2017, Nkam et al. published a prognostic score to predict death or lung transplant within 3 years among adult cystic fibrosis (CF) patients. Their model was developed using French CF registry data and was subsequently validated in the Canadian CF registry. We evaluated this prognostic score using data from adult patients with CF in the United States (US) CF Foundation Patient registry, combined with lung transplant records from the United Network for Organ Sharing (UNOS) Registry (2013 to 2016) (n=11,542). We found that the prognostic score had a very good discriminative index predicting death or lung transplant in the US CF population (AUC 0.88, 95% CI 0.88-0.89) with an odds ratio (OR) of 2.83 (95% CI 2.69 - 2.97) for each unit increase in the score. However, it did not provide significant additional utility over an FEV1 ≤30% of predicted as a predictor of death or lung transplant.

Impact of a high emergency lung transplantation programme for cystic fibrosis in France: insight from a comparison with Canada.

BACKGROUND: France implemented a high emergency lung transplantation (HELT) programme nationally in 2007. A similar programme does not exist in Canada. The objectives of our study were to compare health outcomes within France as well as between Canada and France before and after the HELT programme in a population with cystic fibrosis (CF). METHODS: This population-based cohort study utilised data from the French and Canadian CF registries. A cumulative incidence curve assessed time to transplant with death without transplant as competing risks. The Kaplan-Meier method was used to estimate post-transplant survival. RESULTS: Between 2002 and 2016, there were 1075 (13.0%) people with CF in France and 555 (10.2%) people with CF in Canada who underwent lung transplantation. The proportion of lung transplants increased in France after the HELT programme was initiated (4.5% versus 10.1%), whereas deaths pre-transplant decreased from 85.3% in the pre-HELT period to 57.1% in the post-HELT period. Between 2008 and 2016, people in France were significantly more likely to receive a transplant (hazard ratio (HR) 1.56, 95% CI 1.37-1.77; p<0.001) than die (HR 0.55, 95% CI 0.46-0.66; p<0.001) compared with Canada. Post-transplant survival was similar between the countries, and there was no difference in survival when comparing pre- and post-HELT periods in France. CONCLUSIONS: Following the implementation of the HELT programme, people living with CF in France were more likely to receive a transplant than die. Post-transplant survival in the post-HELT period in France did not change compared with the pre-HELT period, despite potentially sicker patients being transplanted, and was comparable to Canada.

Survival and Lung Transplant Outcomes for Individuals With Advanced Cystic Fibrosis Lung Disease Living in the United States and Canada: An Analysis of National Registries.

BACKGROUND: Understanding how health outcomes differ for patients with advanced cystic fibrosis (CF) lung disease living in the United States compared with Canada has health policy implications. RESEARCH QUESTION: What are rates of lung transplant (LTx) and rates of death without LTx in the United States and Canada among individuals with FEV1 < 40% predicted? STUDY DESIGN AND METHODS: This was a retrospective population-based cohort study, 2005 to 2016, using the US CF Foundation, United Network for Organ Sharing, and Canadian CF registries. Individuals with CF and at least two FEV1 measurements < 40% predicted within a 5-year period, age ≥ 6 years, without prior LTx were included. Multivariable competing risk regression for time to death without LTx (LTx as a competing risk) and time to LTx (death as a competing risk) was performed. RESULTS: There were 5,899 patients (53% male) and 905 patients (54% male) with CF with FEV1 < 40% predicted living in the United States and Canada, respectively. Multivariable competing risk regression models identified an increased risk of death without LTx (hazard ratio [HR], 1.79; 95% CI, 1.52-2.1) and decreased LTx (HR, 0.66; 95% CI, 0.58-0.74) among individuals in the United States compared with Canada. More pronounced differences were seen in the patients in the United States with Medicaid/Medicare insurance compared with Canadians (multivariable HR for death without LTx, 2.24 [95% CI, 1.89-2.64]; multivariable HR for LTx, 0.54 [95% CI, 0.47-0.61]). Patients of nonwhite race were also disadvantaged (multivariable HR for death without LTx, 1.56 [95% CI, 1.32-1.84]; multivariable HR for LTx, 0.47 [95% CI, 0.36-0.62]). INTERPRETATION: There are lower rates of LTx and an increased risk of death without LTx for US patients with CF with FEV1 < 40% predicted compared with Canadian patients. Findings are more striking among US patients with CF with Medicaid/Medicare health insurance, and nonwhite patients in both countries, raising concerns about underuse of LTx among vulnerable populations.

Real-world use of ivacaftor in Canada: A retrospective analysis using the Canadian Cystic Fibrosis Registry.

BACKGROUND: Ivacaftor is a CFTR potentiator with demonstrated efficacy in clinical trials and has been rapidly adopted within the CF community. Given the uptake of ivacaftor in eligible people, identifying a comparator group not on modulators to measure effectiveness is difficult. We evaluated health outcomes in individuals with G551D and non-G551D genotypes on ivacaftor using real-world longitudinal data. METHODS: This population-based observational study compared clinical trajectories pre-post ivacaftor using the Canadian CF Registry from 2006 to 01-01 through 2018-12-31. Piece-wise linear mixed-effects models were used to compare lung function, nutritional status, pulmonary exacerbations, and Pseudomonas colonization pre- and post-ivacaftor. Multivariable models were used to adjust for confounding factors. RESULTS: Forced expiratory volume in 1 second (FEV1) increased significantly by 5.7 percent predicted (95% confidence interval (CI) 3.9, 7.5; p<0.001) after initiation of ivacaftor. FEV1 decline rate was attenuated to -0.30% (95% CI -0.9, 0.29; p = 0.32) predicted/year post-ivacaftor, compared with -0.75% (95% CI -1.12, -0.37; p<0.001) predicted/year pre-ivacaftor, although this difference did not reach statistical significance. BMI percentiles also increased post-ivacaftor (6.57 percentiles, 95% CI 3.91, 9.24; p<0.001). Pulmonary exacerbations showed a nonsignificant reduction of 18% (RR 0.82, 95% CI 0.61, 1.11; p = 0.19) and the odds of a positive sputum culture for Pseudomonas aeruginosa decreased in the post-ivacaftor period (odds ratio 0.44, 95% CI 0.30, 0.63; p<0.001). CONCLUSIONS: This real-world, observational study demonstrated improvement in health outcomes in a broad population of people with CF. Additional studies are needed to evaluate the impact of ivacaftor on quality of life and survival.

Limb muscle size and contractile function in adults with cystic fibrosis: A systematic review and meta-analysis.

BACKGROUND: There is conflicting evidence regarding the presence of limb muscle impairments in adults with cystic fibrosis (CF), and the factors associated with these muscle impairments. The objectives of this study were to compare limb muscle size and function between adults with CF and healthy controls; and to examine their associations with demographic and clinical variables in adults with CF. METHODS: The systematic review was performed using PRISMA guidelines. Studies were included if they measured any aspect of limb muscle size or function in adults with CF. Meta-analyses were performed to compare muscle variables between CF and healthy controls; and to examine their associations with demographic and clinical variables. RESULTS: Twenty-eight studies were included, with 747 adults with CF. The meta-analyses showed that adults with CF have smaller thigh muscles [standardized mean difference (SMD) = 0.57, p<.0011, I2=0%], and lower handgrip strength (SMD = 0.89, p=.0034, I2=74.03%), which was weakly correlated with forced expiratory volume in one second (FEV1) (r=0.24, p=.035, I2=0%) and lower in females with CF (SMD = 2.05, p<.0001, I2=0%). There is no significant difference between adults with CF and controls in knee extensor strength (SMD = 0.25, p=.095, I2=42.79%). CONCLUSIONS: Leg muscle atrophy and lower handgrip strength were noted. There may be a subgroup of adults with CF with knee extensor (quadriceps) weakness. Future studies are needed to better understand muscle impairments in people with CF; to explore the factors that can predict these muscle impairments; and to investigate their clinical significance in people with CF.

Bridging the survival gap in cystic fibrosis: An investigation of lung transplant outcomes in Canada and the United States.

BACKGROUND: Previous literature in cystic fibrosis (CF) has shown a 10-year survival gap between Canada and the United States (US). We hypothesized that differential access to and survival after lung transplantation may contribute to the observed gap. The objectives of this study were to compare CF transplant outcomes between Canada and the US and estimate the potential contribution of transplantation to the survival gap. METHODS: Data from the Canadian CF Registry and the US Cystic Fibrosis Foundation Patient Registry supplemented with data from United Network for Organ Sharing were used. The probability of surviving after transplantation between 2005 and 2016 was calculated using the Kaplan‒Meier method. Survival by insurance status at the time of transplantation and transplant center volume in the US were compared with those in Canada using Cox proportional hazard models. Simulations were used to estimate the contribution of transplantation to the survival gap. RESULTS: Between 2005 and 2016, there were 2,653 patients in the US and 470 in Canada who underwent lung transplantation for CF. The 1-, 3-, and 5-year survival rates were 88.3%, 71.8%, and 60.3%, respectively, in the US compared with 90.5%, 79.9%, and 69.7%, respectively, in Canada. Patients in the US were also more likely to die on the waitlist (p < 0.01) than patients in Canada. If the proportion of who underwent transplantation and post-transplant survival in the US were to increase to those observed in Canada, we estimate that the survival gap would decrease from 10.8 years to 7.5 years. CONCLUSIONS: Differences in waitlist mortality and post-transplant survival can explain up to a third of the survival gap observed between the US and Canada.

Projecting the impact of delayed access to elexacaftor/tezacaftor/ivacaftor for people with Cystic Fibrosis.

BACKGROUND: Therapies that target the underlying defect in Cystic Fibrosis (CF) will likely impact the future characteristics of the CF population and healthcare utilization. The objectives of this study were to estimate the potential impact of elexacaftor/tezacaftor/ivacaftor on morbidity and mortality, and the impact of delayed access. METHOD: A microsimulation transition model was applied to Canadian CF Registry data to forecast lung disease severity, pulmonary exacerbations, deaths and transplants to 2030 under three scenarios: 1) no availability of elexacaftor/tezacaftor/ivacaftor, 2) availability in 2021 ('early') or 3) availability in 2025 ('delayed'). Published Phase III data on treatment effects were used to estimate transition rates between disease severity states. RESULTS: Under specific assumptions regarding disease state and treatment effect applied to the Canadian CF population it is projected that by 2030, early introduction of elexacaftor/tezacaftor/ivacaftor is expected to reduce the number of individuals with severe lung disease by 60% (95% CI 55.3; 63.9), increase the number of individuals with mild lung disease by 18% (95%CI 18.2; 19.0) and reduce the number of pulmonary exacerbations by 19% (95%CI 18.9; 19.5). Earlier introduction of elexacaftor/tezacaftor/ivacaftor could reduce deaths by 15% (95% 13.2; 18.4) and improve the median age of survival by 9.2 years (7.5; 10.8) over a 10-year period. The expected benefits of therapy are cumulative, therefore delayed access to elexacaftor/tezacaftor/ivacaftor will result in preventable health care utilization and deaths. CONCLUSIONS: Delayed access to elexacaftor/tezacaftor/ivacaftor will have a negative impact on lung health and survival in the CF population.

Evaluation of Nutritional, Inflammatory, and Fatty Acid Status in Patients with Gastric and Colorectal Cancer Receiving Chemotherapy.

Malnutrition is prevalent in gastrointestinal (GI) cancer patients, possibly due to inflammation and altered fatty acids (FA). There is a lack of research describing nutritional decline in these patients during chemotherapy. We described changes in nutritional, inflammatory, and FA status over time and factors relating to change in nutritional status according to tumor presence in 41 GI cancer patients undergoing first-line treatment over four chemotherapy visits, using linear mixed effects models. At baseline, 53% of patients were malnourished. Over time, there was a decrease in the proportion of malnourished vs. well-nourished individuals (ß= -0.564, p < 0.01). Median concentrations of plasma linoleic acid, arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid, total n-3, total n-6 and total plasma phospholipid FA increased over time. Changes over time in nutritional status based on weight (p < 0.001), fat free mass (FFM) measured by bioelectrical impedance analysis (BIA, p = 0.02), and skinfold anthropometry (FSA, p = 0.04) were significantly dependent on tumor presence. There were positive associations between weight and total n-3 (ß = 0.02, p < 0.01), FFM and IL-6 (BIA, ß = 0.028, p = 0.02; FSA, ß = 0.03, p = 0.02), and FFM and total n-6 (BIA, ß = 0.003, p = 0.01). Changes in nutritional status during chemotherapy were negatively impacted by tumor presence, and were associated with increasing concentrations of cytokines and FA.

Small Renal Mass Surveillance: Histology-specific Growth Rates in a Biopsy-characterized Cohort.

BACKGROUND: Most reports of active surveillance (AS) of small renal masses (SRMs) lack biopsy confirmation, and therefore include benign tumors and different subtypes of renal cell carcinoma (RCC). OBJECTIVE: We compared the growth rates and progression of different histologic subtypes of RCC SRMs (SRMRCC) in the largest cohort of patients with biopsy-characterized SRMs on AS. DESIGN, SETTING, AND PARTICIPANTS: Data from patients in a multicenter Canadian trial and a Princess Margaret cohort were combined to include 136 biopsy-proven SRMRCC lesions managed by AS, with treatment deferred until progression or patient/surgeon decision. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Growth curves were estimated from serial tumor size measures. Tumor progression was defined by sustained size ≥4 cm or volume doubling within 1 yr. RESULTS AND LIMITATIONS: Median follow-up for patients who remained on AS was 5.8 yr (interquartile range 3.4-7.5 yr). Clear cell RCC SRMs (SRMccRCC) grew faster than papillary type 1 SRMs (0.25 and 0.02 cm/yr on average, respectively, p = 0.0003). Overall, 60 SRMRCC lesions progressed: 49 (82%) by rapid growth (volume doubling), seven (12%) increasing to ≥4 cm, and four (6.7%) by both criteria. Six patients developed metastases, and all were of clear cell RCC histology. Limitations include the use of different imaging modalities and a lack of central imaging review. CONCLUSIONS: Tumor growth varies between histologic subtypes of SRMRCC and among SRMccRCC, which likely reflects individual host and tumor biology. Without validated biomarkers that predict this variation, initial follow-up of histologically characterized SRMs can inform personalized treatment for patients on AS. PATIENT SUMMARY: Many small kidney cancers are suitable for surveillance and can be monitored over time for change. We demonstrate that different types of kidney cancers grow at different rates and are at different risks of progression. These results may guide better personalized treatment.