Fatal pulmonary toxicity following oral etoposide therapy

Profiling alveolar macrophage responses to inhaled compounds using in vitro high content image analysis

One of the main hurdles in the development of new inhaled medicines is the frequent observation of foamy macrophage (FM) responses in non-clinical studies in experimental animals, which raises safety concerns and hinders progress into clinical trials. We have investigated the potential of a novel multi-parameter high content image analysis (HCIA) assay as an in vitro safety screening tool to predict drug induced FM. Rat (NR8383) and human U937-derived alveolar macrophages were exposed in vitro to a panel of model compounds with different biological activity, including inhaled bronchodilators, inhaled corticosteroids (ICS), phospholipidosis inducers and proapoptotic agents. An HCIA was utilized to produce drug-induced cell response profiles based on individual cell health, morphology and lipid content parameters. The profiles of both rat and human macrophage cell lines differentiated between cell responses to marketed inhaled drugs and compounds known to induce phospholipidosis and apoptosis. Hierarchical clustering of the aggregated data allowed identification of distinct cell profiles in response to exposure to phospholipidosis and apoptosis inducers. Additionally, in NR8383 cell responses formed two distinct clusters, associated with increased vacuolation with or without lipid accumulation. U937 cells presented a similar trend but appeared less sensitive to drug exposure and presented a narrower range of responses. These results indicate that our multi-parameter HCIA assay is suitable to generate characteristic drug-induced macrophage response profiles, thus enabling differentiation of foamy macrophage phenotypes associated with phospholipidosis and apoptosis. This approach shows great potential as pre-clinical in vitro screening tool for safety assessment of candidate inhaled medicines.

Anticancer therapy and lung injury: molecular mechanisms

INTRODUCTION

Chemotherapy and radiation therapy are two mainstream strategies applied in the treatment of cancer that is not operable. Patients with hematological or solid tumor malignancies substantially benefit from chemotherapeutic drugs and/or ionizing radiation delivered to the site of malignancy. However, considerable adverse effects, including lung inflammation and fibrosis, are associated with the use of these treatment modalities. Areas covered: As we move toward the era of precision health, we are compelled to understand the molecular basis of chemoradiation-induced pathological lung remodeling and to develop effective treatment strategies that mitigate the development of chronic lung disease (i.e. fibrosis) in cancer patients. The review discusses chemotherapeutic agents that are reported to induce or associate with acute and/or chronic lung injury. Expert commentary: There is a need to molecularly understand how chemotherapeutic drugs induce or associate with respiratory toxicities and whether such characteristics are inherently related to their antitumor effect or are collateral. Once such mechanisms have been identified and/or fully characterized, they may be able to guide disease-management decisions including effective intervention strategies for the adverse effects. In the meantime, radiation oncologists should be judicious on the dose of radiation delivered to the lungs, the volume of lung irradiated, and concurrent use of chemotherapeutic drugs.

Lung

The lungs are particularly sensitive to RT, and are often the primary dose-limiting structure during thoracic therapy.

The alveolar/capillary units and pneumocytes within the alveoli appear to be particularly sensitive to RT.

Hypoxia may be important in the underlying physiology of RT-associated lung injury.

The cytokine transforming growth factor-beta (TGF-β), plays an important role in the development of RT-induced fibrosis.

The histopathological changes observed in the lung after RT are broadly characterized as diffuse alveolar damage.

The interaction between pre-treatment PFTs and the risk of symptomatic lung injury is complex. Similarly, the link between changes in PFTs and the development of symptoms is uncertain.

The incidence of symptomatic lung injury increases with increase in most dosimetric parameters. The mean lung dose (MLD) and V20 have been the most-often considered parameters. MLD might be a preferable metric since it considers the entire 3D dose distribution.

Radiation to the lower lobes appears to be more often associated with clinical symptoms than is radiation to the upper lobes. This might be related to incidental cardiac irradiation. In pre-clinical models, there appears to be a complex interaction between lung and heart irradiation.

TGF-β has been suggested in several studies to predict for RT-induced lung injury, but the data are still somewhat inconsistent.

Oral prednisone (Salinas and Winterbauer 1995), typically 40–60 mg daily for 1–2 weeks with a slow taper, is usually effective in treating pneumonitis. There are no widely accepted treatments for fibrosis.

A number of chemotherapeutic agents have been suggested to be associated with a range of pulmonary toxicities.

Pulmonary complications of novel antineoplastic agents for solid tumors

Antineoplastic agent-induced pulmonary toxicity is an important cause of respiratory failure. Although the incidence of antineoplastic agent-induced pulmonary toxicity seems to be low, more cases can be expected, with increasing numbers of patients receiving the new generations of antineoplastic agents. Antineoplastic agents have previously been associated with bronchospasm, hypersensitivity reactions, venous thromboembolism, and pulmonary hemorrhage. Physicians should be aware of the clinical and radiographic presentations of the pulmonary toxicities associated with the newer antineoplastic agents. The approach to diagnosis, risk factors, and possible mechanisms of antineoplastic agent-induced pulmonary toxicity are discussed in this article.

PET Scintigraphy of Etoposide-Induced Pulmonary Toxicity

A patient with chronic myelomonocytic leukemia developed drug-induced pulmonary toxicity after using low dose oral etoposide. Because etoposide-induced pulmonary toxicity is an uncommon but serious adverse event, clinicians must be vigilant about the possibility of it, so that the optimal treatment can start as soon as possible. This report demonstrates that PET scintigraphy might be a helpful tool in the early diagnosis of drug-induced pulmonary toxicity.

Drug-induced pneumonitis: thin-section CT findings in 60 patients

PURPOSE

To describe thin-section computed tomographic (CT) findings in patients with drug-induced pneumonitis, to compare these CT findings, and to correlate them with arterial oxygen tension level.

MATERIALS AND METHODS

Thin-section CT scans obtained in 60 patients with drug-induced pneumonitis were evaluated retrospectively. The patients had 31 cases of antineoplastic agent-induced pneumonitis and 29 cases of nonneoplastic agent-induced pneumonitis (antibiotic agent, 20 cases; herbal medicine [sho-saiko-to], four cases; antirheumatic agent, three cases; phenytoin, one case; disodium cromoglycate, one case). CT scans were reviewed by two chest radiologists in consensus. Correlation between arterial oxygen tension level and the extent of disease at CT was available in 21 patients. These two factors were compared by using the Spearman rank correlation coefficient.

RESULTS

The predominant findings in antineoplastic agent-induced pneumonitis were diffuse or multifocal ground-glass opacities with intralobular interstitial thickening. The predominant CT findings in antibiotic agent-induced pneumonitis were patchy ground-glass opacities with centrilobular opacities and interlobular septal lines. The predominant CT findings in herbal medicine-induced pneumonitis were diffuse ground-glass opacities with patchy consolidation. Interlobular septal lines and centrilobular opacities were observed more frequently in antibiotic agent-induced pneumonitis, and intralobular interstitial thickening was observed more frequently in antineoplastic agent-induced pneumonitis. A significant correlation was established between arterial oxygen tension level and extent of disease at CT (r = -0.84, P <.05).

CONCLUSION

In addition to ground-glass opacities and interlobular septal lines, the most common thin-section CT findings were intralobular interstitial thickening, observed in antineoplastic agent-induced pneumonitis, and centrilobular opacities, observed in antibiotic-induced pneumonitis.

Chemotherapy-induced pulmonary toxicity in lung cancer management

Chemotherapy is the cornerstone of therapy in many stages of lung cancer. Many diagnostic options have to be taken into account when a patient suffering from lung cancer presents with nonspecific, respiratory, clinical manifestations. A multidisciplinary diagnostic approach is then warranted. The top priority is to rule out those life-threatening causes, such as lung infection, that could be properly treated if a right diagnosis is early. To reach a definite diagnosis frequently requires that one or more diagnostic, pneumologic techniques are performed. Regarding to drug-induced pulmonary disease, prevention is mandatory. In this review we have tried to highlight the risk and characteristics of cytostatic-induced pulmonary toxicity caused by those agents that have been commonly employed to treat lung cancer for the last decades. When treating lung cancer patients, a high clinical suspicion of chemotherapy-induced lung toxicity should be kept in mind since an early withdrawal of the offending drug is the most efficacious therapy.

A pilot study of protracted low dose cisplatin and etoposide with concurrent thoracic radiotherapy in unresectable stage III nonsmall cell lung cancer

PURPOSE

A Phase II study to evaluate the response rate and toxicity of daily protracted cisplatin and etoposide with concurrent chest irradiation in patients with locally advanced, unresectable nonsmall cell lung cancer (NSCLC).

METHODS AND MATERIALS

Twenty-one patients with histologically confirmed locally advanced inoperable NSCLC (Stage IIIA or IIIB) were entered on study. Radiotherapy consisted of 50.4 Gy in 1.8 Gy fractions followed by a 10 Gy boost in 2 Gy fractions. Chemotherapy included the following: Cisplatin was given at 5 mg/m2 i.v. Monday-Friday before RT weeks 1-6. Etoposide was given at 25 mg/m2 i.v. M-F weeks 1, 2, 5, and 6, with 50 mg/m2 p.o. daily on the same weekends. Because of severe myelosuppression in the first two patients, etoposide only was subsequently changed to 20 mg/m2 i.v. M-F weeks 1, 2, 5, and 6.

RESULTS

Twenty patients were eligible and evaluable. The overall response rate was 65% (95% confidence interval 41-85%). The median progression-free survival was 43 weeks. The median overall survival was 50.2 weeks with a 1-year survival rate of 45%. Five patients (25%) developed severe radiation pneumonitis, leading to early closure of the study.

CONCLUSIONS

Combining daily protracted cisplatin and etoposide with concurrent thoracic irradiation in patients with locally advanced unresectable NSCLC yields a high overall response rate and a median survival that is at least comparable to other combined modality trials. However, future studies using protracted radiosensitizing chemotherapy should be approached cautiously in light of the high incidence of severe radiation pneumonitis encountered in this trial.