The 2023 Impact of Inflammatory Bowel Disease in Canada: Indirect (Individual and Societal) and Direct Out-of-Pocket Costs

People living with inflammatory bowel disease (IBD) and their caregivers are faced with indirect and out-of-pocket costs that they would not otherwise experience. These costs impact one's ability to contribute to the economy to their fullest potential. The indirect costs of IBD in Canada are estimated to be at least $1.51 billion in 2023 and include costs associated with lost productivity resulting from a combination of missed work (absenteeism), decreased workplace productivity (presenteeism), unemployment, premature mortality, and caregiving costs. Unemployment is the largest contributor to indirect costs ($1.14 billion), followed by costs of absenteeism and presenteeism ($285 million). Caregiving costs for children with IBD are estimated to be nearly $58 million. Canadians with IBD also pay $536 million every year for care that is not covered by universal or supplemental private health insurance; this includes allied healthcare (e.g., care provided by psychologists), medication, and other supportive therapy. Combined, the indirect and out-of-pocket costs of IBD in Canada are estimated at more than $2 billion CAD in 2023. This is substantially higher than the estimate of $1.29 billion in Crohn's and Colitis Canada's 2018 Impact of IBD report with differences attributable to a combination of rising prevalence, inflation, and the addition of presenteeism and caregiving costs to the total indirect costs.

Expression and subcellular localization of mitochondrial docking protein, syntaphilin, in oligodendrocytes and CNS myelin sheath

Oligodendrocytes produce lipid-rich myelin sheaths that provide metabolic support to the underlying axon and facilitate saltatory conduction. Oligodendrocyte mitochondria supply the bulk of energy and carbon-chain backbones required for lipid synthesis. The sparsity of mitochondria in the myelin sheath suggests that tight regulation of mitochondrial trafficking is crucial for their efficient distribution in the cell. In particular, retention of mitochondria at axoglial junctions would support local lipid synthesis and membrane remodeling during myelination. How mitochondrial docking in oligodendrocytes is regulated is not known. Our findings indicate that syntaphilin (SNPH), a mitochondrial docking protein that has been characterized in neurons, is expressed by oligodendrocyte precursor cells (OPCs) and mature oligodendrocytes in vitro and present in the myelin sheath in vivo. We have previously reported that bath application of netrin-1 promotes the elaboration of myelin basic protein-positive membranes, and that localized presentation of a netrin-1 coated microbead results in rapid accumulation of mitochondria at the site of oligodendrocyte-bead adhesion. Here we show that netrin-1 increases the redistribution of SNPH to oligodendrocyte processes during the expansion of myelin basic protein-positive membranes and that SNPH clusters at the oligodendrocyte plasma membrane at sites of adhesion with netrin-1-coated beads where mitochondria are retained. These findings suggest roles for SNPH in oligodendrocytes regulating netrin-1-mediated mitochondrial docking and myelin membrane expansion.

Molecular profiling of non-small cell lung cancer

Lung cancer is generally treated with conventional therapies, including chemotherapy and radiation. These methods, however, are not specific to cancer cells and instead attack every cell present, including normal cells. Personalized therapies provide more efficient treatment options as they target the individual’s genetic makeup. The goal of this study was to identify the frequency of causal genetic mutations across a variety of lung cancer subtypes in the earlier stages. 833 samples of non-small cell lung cancer from 799 patients who received resection of their lung cancer, were selected for molecular analysis of six known mutations, including EGFR, KRAS, BRAF, PIK3CA, HER2 and ALK. A SNaPshot assay was used for point mutations and fragment analysis searched for insertions and deletions. ALK was evaluated by IHC +/- FISH. Statistical analysis was performed to determine correlations between molecular and clinical/pathological patient data. None of the tested variants were identified in most (66.15%) of cases. The observed frequencies among the total samples vs. only the adenocarcinoma cases were notable different, with the highest frequency being the KRAS mutation (24.49% vs. 35.55%), followed by EGFR (6.96% vs. 10.23%), PIK3CA (1.20% vs. 0.9%), BRAF (1.08% vs. 1.62%), ALK (0.12% vs. 0.18%), while the lowest was the HER2 mutation (0% for both). The statistical analysis yielded correlations between presence of a mutation with gender, cancer type, vascular invasion and smoking history. The outcome of this study will provide data that helps stratify patient prognosis and supports development of more precise treatments, resulting in improved outcomes for future lung cancer patients.

Longitudinal assessment of right ventricular structure and function by cardiovascular magnetic resonance in breast cancer patients treated with trastuzumab: a prospective observational study

BACKGROUND

There are limited data on the effects of trastuzumab on the right ventricle (RV). Therefore, we sought to evaluate the temporal changes in right ventricular (RV) structure and function as measured by cardiovascular magnetic resonance (CMR), and their relationship with left ventricular (LV) structure and function in breast cancer patients treated with trastuzumab.

METHODS

Prospective, longitudinal, observational study involving 41 women with HER2+ breast cancer who underwent serial CMR at baseline, 6, 12, and 18 months after initiation of trastuzumab. A single blinded observer measured RV parameters on de-identified CMRs in a random order. Linear mixed models were used to investigate temporal changes in RV parameters.

RESULTS

Of the 41 women (age 52 ± 11 years), only one patient experienced trastuzumab-induced cardiotoxicity. Compared to baseline, there were small but significant increases in the RV end-diastolic volume at 6 months (p = 0.002) and RV end-systolic volume at 6 and 12 months (p < 0.001 for both), but not at 18 months (p = 0.82 and 0.13 respectively). RV ejection fraction (RVEF), when compared to baseline (58.3%, 95% CI 57.1-59.5%), showed corresponding decreases at 6 months (53.9%, 95% CI 52.5-55.4%, p < 0.001) and 12 months (55%, 95% CI 53.8-56.2%, p < 0.001) that recovered at 18 months (56.6%, 95% CI 55.1-58.0%, p = 0.08). Although the temporal pattern of changes in LVEF and RVEF were similar, there was no significant correlation between RVEF and LVEF at baseline (r = 0.29, p = 0.07) or between their changes at 6 months (r = 0.24, p = 0.17).

CONCLUSION

In patients receiving trastuzumab without overt cardiotoxicity, there is a subtle but significant deleterious effect on RV structure and function that recover at 18 months, which can be detected by CMR. Furthermore, monitoring of LVEF alone may not be sufficient in detecting early RV injury. These novel findings provide further support for CMR in monitoring early cardiotoxicity.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01022086 . Date of registration: November 27, 2009.