Adaptive resistance to lorlatinib via EGFR signaling in ALK-rearranged lung cancer

Anaplastic lymphoma kinase (ALK)-tyrosine kinase inhibitors rarely elicit complete responses in patients with advanced ALK-rearranged non-small cell lung cancer (NSCLC), as a small population of tumor cells survives due to adaptive resistance. Therefore, we focused on the mechanisms underlying adaptive resistance to lorlatinib and therapeutic strategies required to overcome them. We found that epidermal growth factor receptor (EGFR) signaling was involved in the adaptive resistance to lorlatinib in ALK-rearranged NSCLC, activation of which was induced by heparin-binding EGF-like growth factor production via c-Jun activation. EGFR inhibition halted ALK-rearranged lung cancer cell proliferation by enhancing ALK inhibition-induced apoptosis via suppression of Bcl-xL. Xenograft models showed that the combination of EGFR inhibitor and lorlatinib considerably suppressed tumor regrowth following cessation of these treatments. This study provides new insights regarding tumor evolution due to EGFR signaling after lorlatinib treatment and the development of combined therapeutic strategies for ALK-rearranged lung cancer.

Different Types of Myocardial Injury due to the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Omicron Variant

Coronavirus disease 2019 (COVID-19) associated myocardial injury was caused by various mechanisms. We herein describe 2 cases presenting different types of myocardial injury due to Omicron variant. In both patients, diffuse reduced left ventricular (LV) wall motion in transthoracic echocardiography, electrocardiographic abnormality, and elevated myocardial enzymes were demonstrated. In addition, cardiovascular magnetic resonance (CMR) findings fulfilled the 2018 Lake Louise Criteria (LLC) for myocarditis. However, histological findings in 1 patient showed inflammatory cell infiltration with myocyte degeneration, while those in the other showed interstitial edema without inflammatory cell infiltration. Histological findings were crucial for a differential diagnosis of myocardial injury due to Omicron variant.

Assessment of Pseudocoarctation of the Aorta with Saccular Aneurysms by Four-Dimensional Flow Magnetic Resonance Imaging and Histological Analysis

In this study, we present the case of a 21-year-old woman with pseudocoarctation of the aorta with saccular aneurysms that were evaluated by four-dimensional flow magnetic resonance imaging and histological analysis. We observed complete occupation of the aneurysm sacs by vortex flow and high peak wall shear stress in the proximal region of the kinked aorta. The aortic replacement was performed for the thoracic aortic aneurysms and the clinical course was uneventful. The aneurysms were histopathologically diagnosed as pseudoaneurysms based on the disappearance of all three layers and their replacement with collagen-rich connective tissues. These findings indicate that abnormal flow dynamics and the resulting abnormal shear stress in the aorta may play central roles in the formation and development of a saccular aneurysm.

Preliminary results of reduced myocardial blood flow in the subacute phase after radiation therapy for thoracic esophageal cancer: A quantitative analysis with stress dynamic myocardial computed tomography perfusion imaging

BACKGROUND AND PURPOSE

Late adverse cardiac events after radiation therapy (RT) for thoracic malignancies are known, but the underlying mechanisms are poorly understood. This study aimed to determine the radiation dose that can cause MBF alterations in the subacute phase after RT for thoracic esophageal cancer using stress dynamic myocardial computed tomography perfusion imaging (CTP).

MATERIALS AND METHODS

Twenty-five patients with esophageal cancer scheduled for RT were prospectively enrolled. The quantitative analysis of MBF by CTP was performed before and 3 months after RT. The mean radiation dose and hyperemic MBF in 15 segments of the left ventricular (LV) myocardium were determined. ΔMBF was calculated in each segment as MBFafter RT - MBFbeforeRT. The myocardial segments were classified into the following 5 groups according to the mean radiation dose: group A, <10 Gy; B1, 10-15 Gy; B2, 15-20 Gy; C, 20-30 Gy; and D, >30 Gy.

RESULTS

The final cohort included 22 patients who completed pre- and post-RT CTP. A one-way analysis of variance revealed a significant difference (p=0.005) in ΔMBF among the five groups of LV segments classified by the mean radiation dose. ΔMBF was significantly lower in group C (-7.7 ± 28.9 mL/min/100 g, p=0.020) and group D (-8.4 ± 34.8 mL/min/100 g, p=0.004) in comparison to ΔMBF in group A (4.9 ± 26.1 mL/min/100 g).

CONCLUSIONS

This study using CTP early after RT demonstrated a significant reduction of the MBF in the LV segments with ≥20 Gy of radiation. The results might provide important insights into preventing radiotherapy-induced cardiac events.

DNA damage induced by radiation exposure from cardiac catheterization – an analysis in patients and operators

Background

The biological effects of low-dose radiation from cardiac imaging or intervention remain largely unknown. This study aimed to evaluate the effects of ionized radiation from cardiac catheterization on genomic DNA integrity and inflammatory cytokines in patients and operators.

Methods

Peripheral mononuclear cells (MNCs) were isolated from patients (n=52) and operators (n=35) before and after coronary angiography and/or percutaneous coronary intervention. Expression of gammaH2AX, a marker for DNA double-strand breaks, was measured by immunofluorescence. Dicentric chromosomes (DICs), a form of chromosome aberrations, were assayed using a fluorescent in situ hybridization technique.

Results

In the patient MNCs, the numbers of gammaH2AX foci and DICs increased after cardiac catheterization by 101±75% and 28±99%, respectively (P&lt;0.05 for both). The mRNA expressions of interleukin (IL)-1α, IL-1β, leukemia inhibitory factor (LIF) and caspase-1 were significantly increased by radiation exposure from cardiac catheterization. The increase in IL-1β was significantly correlated with that of gammaH2AX, but not with dose area product. In the operators, neither gammaH2AX foci nor DICs level was changed, but IL-1β mRNA was significantly increased. Protein expression of IkappaBα was significantly decreased in both groups.

Conclusions

DNA damage was increased in the MNCs of patients, but not of operators, who underwent cardiac catheterization. Inflammatory cytokines were increased both in the patients and operators, presumably through activation of NF-kappaB. Further efforts to reduce radiation exposure from cardiac catheterization are necessary both for patients and operators.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Grants-in-Aid for Scientific Research (KAKENHI)

Peripartum Mid-Ventricular-Type Takotsubo Cardiomyopathy After Cesarean Delivery

There are several causes of heart failure during pregnancy and the peripartum period, which include peripartum cardiomyopathy, Takotsubo cardiomyopathy or stress cardiomyopathy, exacerbation of a preexisting cardiomyopathy, and acute myocarditis. It is important to determine the cause of the heart failure as the medical treatment may be different based on the diagnosis. However, it has been sometimes challenging to diagnose the cause because of the limited diagnostic tools, especially in pregnant women. Cardiac MRI can characterize myocardial injury and can be used to track the changes in myocardial tissue. We herein report a 35-year-old woman diagnosed with peripartum mid-ventricular-type Takotsubo cardiomyopathy, who was referred to our hospital due to worsening dyspnea the day after cesarean delivery. On admission, electrocardiography showed sinus tachycardia and poor progression of R waves in the precordial leads. Bedside echocardiography revealed severe hypokinesis in the mid- and apical left ventricle (LV) with a LV ejection fraction of 20%. Cardiac catheterization showed normal coronary arteries, and myocardial biopsy revealed contraction band necrosis. On acute phase (Day 4), cardiac MRI showed prolonged native T1 and T2, and severe hypokinesis and decreased regional longitudinal peak strain in the mid-anterior LV wall. During the 1^st week, precordial ST fluctuation was observed, and LV wall motion had gradually recovered. Repeat cardiac MRI revealed normalized LV wall motion and shortened values for global native T1 and T2. Thus, she was diagnosed with peripartum Takotsubo cardiomyopathy. Serial cardiac MRI may be able to differentiate Takotsubo cardiomyopathy during pregnancy and the peripartum period from other preexisting cardiomyopathies.

Efficacy and safety of immuno-chemotherapy in patients with advanced non-small-cell lung cancer harboring oncogenic mutations: a multicenter retrospective study

PURPOSE

The effect of immuno-chemotherapy on patients with advanced non-small-cell lung cancer (NSCLC) harboring oncogenic mutations remains poorly understood. This study aimed to characterize the efficacy of immuno-chemotherapy and determine the optimal treatment strategy for such patients.

METHODS

We conducted this retrospective cohort study on patients with NSCLC harboring oncogenic driver alterations and treated with an immune checkpoint inhibitor combined with chemotherapy at five institutions. The clinical characteristics and outcomes of immuno-chemotherapy for NSCLC with oncogenic mutations in a real-world setting were analyzed.

RESULTS

Among 846 patients diagnosed with advanced or recurrent NSCLC between April 2017 and April 2021, 43 patients with oncogenic mutations were treated with immuno-chemotherapy. The median age of patients was 68 (range 44-78) years; 42% of patients never smoked, and adenocarcinoma was the most common histology (95%). In patients with KRAS mutations (n = 10) or PD-L1 expression of 50% or greater (n = 10), the disease control rate was 100%. The median progression-free survival (PFS) was 5.4, 6.3, and 8.9 months in patients harboring mutations in EGFR, KRAS, and other genes, respectively (P = 0.22). Patients with PD-L1 expression of 50% or greater had significantly longer median PFS than patients with PD-L1 expression of less than 50% (16.4 vs. 5.1 months; P = 0.001). Two patients experienced grade 3 immuno-related adverse events.

CONCLUSION

Immuno-chemotherapy has a clinical benefit and is safe for patients with oncogenic mutations. Notably, patients with PD-L1 expression of 50% or more experience greater benefit from immuno-chemotherapy than those with PD-L1 expression of less than 50%.

Subtle-but-smouldering myocardial injury after immune checkpoint inhibitor treatment accompanied by amyloid deposits

Although cardiac troponin is a highly specific biomarker for myocardial cell injury, it is important to recognize the pitfalls of this test in the diagnosis and management of immune checkpoint inhibitor (ICI) myocarditis. We describe the challenging case of an 81‐year‐old woman with persistently high troponin after undergoing immunotherapy with ipilimumab and nivolumab, and histological evidence of amyloid deposition in the myocardium. The patient received immunosuppressive treatments based on the magnitude of troponin changes because myocarditis was clinically suspected. However, histological examination revealed the deposition of transthyretin amyloid fibrils with only minimal T‐lymphocyte infiltration and no myocyte necrosis, suggesting transthyretin cardiac amyloidosis rather than ICI myocarditis. This case highlights the importance of assessing other causes of persistently high troponin, and the necessity of incorporating comprehensive histological and immunohistochemical examinations of the endomyocardial biopsy, especially when cardiovascular magnetic resonance imaging is inconclusive.

Advances in Myocardial Perfusion MR Imaging: Physiological Implications, the Importance of Quantitative Analysis, and Impact on Patient Care in Coronary Artery Disease

Stress myocardial perfusion imaging (MPI) is the preferred test in patients with intermediate-to-high clinical likelihood of coronary artery disease (CAD) and can be used as a gatekeeper to avoid unnecessary revascularization. Cardiac magnetic resonance (CMR) has a number of favorable characteristics, including: (1) high spatial resolution that can delineate subendocardial ischemia; (2) comprehensive assessment of morphology, global and regional cardiac functions, tissue characterization, and coronary artery stenosis; and (3) no radiation exposure to patients. According to meta-analysis studies, the diagnostic accuracy of perfusion CMR is comparable to positron emission tomography (PET) and perfusion CT, and is better than single-photon emission CT (SPECT) when fractional flow reserve (FFR) is used as a reference standard. In addition, stress CMR has an excellent prognostic value. One meta-analysis study demonstrated the annual event rate of cardiovascular death or non-fatal myocardial infarction was 4.9% and 0.8%, respectively, in patients with positive and negative stress CMR. Quantitative assessment of perfusion CMR not only allows the objective evaluation of regional ischemia but also provides insights into the pathophysiology of microvascular disease and diffuse subclinical atherosclerosis. For accurate quantification of myocardial perfusion, saturation correction of arterial input function is important. There are two major approaches for saturation correction, one is a dual-bolus method and the other is a dual-sequence method. Absolute quantitative mapping with myocardial perfusion CMR has good accuracy in detecting coronary microvascular dysfunction. Flow measurement in the coronary sinus (CS) with phase contrast cine CMR is an alternative approach to quantify global coronary flow reserve (CFR). The measurement of global CFR by quantitative analysis of perfusion CMR or flow measurement in the CS permits assessment of microvascular disease and diffuse subclinical atherosclerosis, which may provide improved prediction of future event risk in patients with suspected or known CAD. Multi-institutional studies to validate the diagnostic and prognostic values of quantitative perfusion CMR approaches are required.

Impact of docetaxel plus ramucirumab in a second-line setting after chemoimmunotherapy in patients with non-small-cell lung cancer: A retrospective study

BACKGROUND

Chemoimmunotherapy has become a standard treatment option for patients with untreated advanced non-small-cell lung cancer (NSCLC). However, numerous patients with advanced NSCLC develop disease progression. Therefore, the selection of second-line treatment after chemoimmunotherapy is crucial for improving clinical outcomes.

METHODS

Of 88 enrolled patients with advanced NSCLC who received chemoimmunotherapy, we retrospectively evaluated 33 who received second-line chemotherapy after progression of chemoimmunotherapy at six centers in Japan. Among them, 18 patients received docetaxel plus ramucirumab and 15 patients received single-agent chemotherapy.

RESULTS

The objective response rate in patients treated with docetaxel plus ramucirumab was significantly higher than that in patients treated with a single-agent chemotherapy regimen (55.6% vs. 0%, p < 0.001). The median progression-free survival (PFS) of patients who received docetaxel plus ramucirumab and single-agent chemotherapy was 5.8 months and 5.0 months, respectively (log-rank test p = 0.17). In the docetaxel plus ramucirumab regimen group, patients who responded to chemoimmunotherapy for ≥8.8 months had a significantly longer response to docetaxel plus ramucirumab than those who responded for <8.8 months (not reached vs. 4.1 months, log-rank test p = 0.003). In contrast, in the single-agent chemotherapy group, there was no significant difference in PFS between the ≥8.8- and <8.8-month PFS groups with chemoimmunotherapy (5.0 vs. 1.6 months, log-rank test p = 0.66).

CONCLUSION

Our retrospective observations suggest that the group with longer PFS with chemoimmunotherapy might be expected to benefit from docetaxel plus ramucirumab treatment in second-line settings for patients with advanced NSCLC.

Wild-type Transthyretin Amyloidosis with Diffuse Alveolar-septal Amyloidosis Diagnosed by a Transbronchial Lung Biopsy

A 69-year-old man visited our pulmonary medicine department for dyspnea. Chest computed tomography (CT) revealed ground-glass opacity bilaterally in the lungs. Upon performing a transbronchial lung biopsy (TBLB), organizing pneumonia was diagnosed. His electrocardiogram revealed low voltage, and the cardiac ultrasound revealed hypertrophy of the interventricular septum. The patient had bilateral carpal tunnel syndrome, and amyloidosis was suspected. Congo red stain was added to the lung biopsy specimen. Amyloid deposition of transthyretin (ATTR) was positive, mutations with amino acid changes were not observed in the TTR gene. Wild-type ATTR Amyloidosis (ATTRwt amyloidosis) was diagnosed using a TBLB. Chest CT after treatment with steroids revealed diffuse alveolar-septal amyloidosis.

Prognostic Markers of Survival among Japanese Patients with Anaplastic Lymphoma Kinase-Positive Non-Small-Cell Lung Cancer Receiving First-Line Alectinib

The prognoses of patients with non-small-cell lung cancer (NSCLC) harboring anaplastic lymphoma kinase (ALK) gene rearrangement have dramatically improved with the use of ALK tyrosine kinase inhibitors. Although immunological and nutritional markers have been investigated to predict outcomes in patients with several cancers, their usefulness in targeted therapies is scarce, and their significance has never been reported in patients receiving first-line treatment with alectinib. Meanwhile, neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio (PLR) has been investigated during crizotinib treatment. This multicenter retrospective study evaluated 42 consecutive Japanese patients with ALK-positive NSCLC who received first-line treatment with alectinib. Immunological and nutritional markers were evaluated at baseline and 3 weeks after alectinib introduction, and their significance in predicting progression-free survival (PFS) was explored. PFS duration was significantly associated with baseline PLR (hazard ratio (HR): 2.49, p = 0.0473), systemic immune-inflammation index (SII; HR: 2.65, p = 0.0337), prognostic nutrition index (PNI; HR: 4.15, p = 0.00185), and the 3-week values for SII (HR: 2.85, p = 0.0473) and PNI (HR: 3.04, p = 0.0125). Immunological and nutritional markers could be useful in predicting the outcomes of first-line treatment with alectinib. Since PLR and SII consist of platelet counts, platelet count could be an important constituent of these markers.

Clinical Validation of the Accuracy of Absolute Myocardial Blood Flow Quantification with Dual-Source CT Using 15O-Water PET

PURPOSE

To determine the fitting equation that can correct for the underestimation of myocardial blood flow (MBF) measurement by using dynamic CT perfusion (CTP) with dual-source CT (MBFCT), using MBF with oxygen 15-labeled water (15O-water) PET (MBFPET) as a reference, and to determine the accuracy of corrected MBFCT (MBFCT-corrected) compared with MBFPET in a separate set of participants.

MATERIALS AND METHODS

In this prospective study (reference no. 2466), 34 participants (mean age, 70 years ± 8 [standard deviation]; 27 men) known or suspected to have coronary artery disease underwent dynamic stress CTP and stress 15O-water PET between January 2014 and December 2018. The participants were randomly assigned to either a pilot group (n = 17), to determine the fitting equation on the basis of the generalized Renkin-Crone model that can explain the relation between MBFCT and MBFPET, or to a validation group (n = 17), to validate MBFCT-corrected compared with MBFPET. The agreement between MBFCT-corrected and MBFPET was evaluated by intraclass correlation and Bland-Altman analysis.

RESULTS

In the pilot group, MBFCT was lower than MBFPET (1.24 mL/min/g ± 0.28 vs 2.51 mL/min/g ± 0.89, P < .001) at the segment level. The relationship between MBFCT and MBFCT-corrected was represented as MBFCT = MBFCT-corrected × {1-exp[-(0.11 × MBFCT-corrected + 1.54)/MBFCT-corrected]}. In the validation group, MBFCT-corrected was 2.66 mL/min/g ± 1.93, and MBFPET was 2.68 mL/min/g ± 1.87 at the vessel level. MBFCT-corrected showed an excellent agreement with MBFPET (intraclass correlation coefficient = 0.93 [95% CI: 0.87, 0.96]). The measurement bias of MBFCT-corrected and MBFPET was -0.02 mL/min/g ± 0.74.

CONCLUSION

Underestimation of MBF by CT was successfully corrected with a correction method that was based on contrast kinetics in the myocardium.Keywords: CT, CT-Perfusion, PET, Cardiac, Heart Supplemental material is available for this article. © RSNA, 2021.

Improving Image Resolution of Whole-Heart Coronary MRA Using Convolutional Neural Network

Whole-heart coronary magnetic resonance angiography (WHCMRA) permits the noninvasive assessment of coronary artery disease without radiation exposure. However, the image resolution of WHCMRA is limited. Recently, convolutional neural networks (CNNs) have obtained increased interest as a method for improving the resolution of medical images. The purpose of this study is to improve the resolution of WHCMRA images using a CNN. Free-breathing WHCMRA images with 512 × 512 pixels (pixel size = 0.65 mm) were acquired in 80 patients with known or suspected coronary artery disease using a 1.5 T magnetic resonance (MR) system with 32 channel coils. A CNN model was optimized by evaluating CNNs with different structures. The proposed CNN model was trained based on the relationship of signal patterns between low-resolution patches (small regions) and the corresponding high-resolution patches using a training dataset collected from 40 patients. Images with 512 × 512 pixels were restored from 256 × 256 down-sampled WHCMRA images (pixel size = 1.3 mm) with three different approaches: the proposed CNN, bicubic interpolation (BCI), and the previously reported super-resolution CNN (SRCNN). High-resolution WHCMRA images obtained using the proposed CNN model were significantly better than those of BCI and SRCNN in terms of root mean squared error, peak signal to noise ratio, and structure similarity index measure with respect to the original WHCMRA images. The proposed CNN approach can provide high-resolution WHCMRA images with better accuracy than BCI and SRCNN. The high-resolution WHCMRA obtained using the proposed CNN model will be useful for identifying coronary artery disease.

Prognostic importance of acute phase extracellular volume evaluated by cardiac magnetic resonance imaging for patients with acute myocardial infarction

Myocardial extracellular volume (ECV) by cardiac magnetic resonance (CMR) in the acute phase of acute myocardial infarction (MI) more precisely predicts the functional recovery of infarct-related wall motion abnormalities and left ventricular (LV) remodeling than late gadolinium enhancement (LGE). The purpose of this study was to evaluate the prognostic importance of acute phase ECV in patients with AMI. We evaluated 61 consecutive AMI patients using 3.0 T CMR. CMR examination was performed median 10 days (7-15 days) after PCI. Primary endpoint was defined as major adverse cardiac event (MACE). The median follow-up duration was 3.1 years, and MACE occurred in 11 (18%) patients. Although LVEF and % infarct LGE volume were not associated with MACE in this study population, higher infarct ECV predicted the MACE with a hazard ratio (HR) of 4.04 (P = 0.02). High global ECV, which was a combined assessment of infarct ECV and remote ECV, also predicted MACE with a HR of 5.24 (P = 0.035). The addition of infarct ECV to remote ECV (global chi-squared score: 1.4) resulted in a significantly increased global chi-squared score (6.7; P = 0.017). Furthermore, after adjusting for the calculated propensity score for high global ECV, it remained an independent predictor of MACE with HR of 5.10 (P = 0.04). The quantification of ECV in the acute phase among AMI patients may provide an incremental prognostic value for predicting MACE beyond that of clinical, angiographic, and functional variables.