Management of malignancy-associated pleural effusion: current and future treatment strategies

Trends in Pleural Effusion Research

Background:

Research in pleural diseases has traditionally been neglected but is now growing.

Objectives:

This study aimed to analyze scientific research trends on pleural effusions over the last decades.

Method:

We conducted a bibliometric analysis of the Scopus database from its inception to March 2016, searching for original articles and reviews on “pleural effusion” (key word). Journal, year of publication, number of citations, authors and their affiliations, and the Hirsch (H)-index for some of these variables were recorded and analyzed.

Results:

A total of 15 982 documents were retrieved, of which half have been published in the last 18 years and a quarter during the last 8 years. Chest ranked first regarding the number of documents on pleural effusions (both absolute number and yearly rate) and their scientific relevance (H-index of 76). The United States had contributed the most to pleural research productivity (23%). American pulmonologists Dr Richard Light and Dr Steven Sahn exhibited the highest number of papers (206 and 156, respectively) and author H-indexes (44 and 38, respectively).

Conclusion:

There is growing research activity in the field of pleural effusions, which has gained relevance and visibility in clinical respiratory journals. The United States is the leader in quantity and quality of research productivity in pleural medicine.

Minocycline enhances mitomycin C-induced cytotoxicity through down-regulating ERK1/2-mediated Rad51 expression in human non-small cell lung cancer cells

Minocycline is a semisynthetic tetracycline derivative; it has anti-inflammatory and anti-cancer effects distinct from its antimicrobial function. However, the molecular mechanism of minocycline-induced cytotoxicity in non-small cell lung cancer (NSCLC) cells has not been identified. Rad51 plays a central role in homologous recombination and high levels of Rad51 expression are observed in chemo- or radioresistant carcinomas. Our previous studies have shown that the MKK1/2-ERK1/2 signal pathway maintains the expression of Rad51 in NSCLC cells. In this study, minocycline treatment inhibited cell viability and proliferation of two NSCLC cells, A549 and H1975. Treatment with minocycline decreased Rad51 mRNA and protein levels through MKK1/2-ERK1/2 inactivation. Furthermore, expression of constitutively active MKK1 (MKK1-CA) vectors significantly rescued the decreased Rad51 protein and mRNA levels in minocycline-treated NSCLC cells. However, combined treatment with MKK1/2 inhibitor U0126 and minocycline further decreased the Rad51 expression and cell viability of NSCLC cells. Knocking down Rad51 expression by transfection with small interfering RNA of Rad51 enhanced the cytotoxicity and cell growth inhibition of minocycline. Mitomycin C (MMC) is typically used as a first or second line regimen to treat NSCLC. Compared to a single agent alone, MMC combined with minocycline resulted in cytotoxicity and cell growth inhibition synergistically in NSCLC cells, accompanied with reduced activation of phospho-ERK1/2, and reduced Rad51 protein levels. Overexpression of MKK1-CA or Flag-tagged Rad51 could reverse the minocycline and MMC-induced synergistic cytotoxicity. These findings may have implications for the rational design of future drug regimens incorporating minocycline and MMC for the treatment of NSCLC.

Long-term results of pleurodesis in malignant pleural effusions: Doxycycline vs Bleomycin

Background:

The aim of this study was to compare the response of doxycycline and bleomycin in pleurodesis of malignant pleural effusions.

Materials and Methods:

The radiologic and clinical responses of doxycycline and bleomycin in pleurodesis of malignant pleural effusions were compared in this randomized clinical trial. Forty-two patients were randomized to receive either bleomycin 45 mg or doxycycline 600 mg as the sclerotherapy agent. Chest X-rays were taken before and after intervention, 10 days and 2 months later to compare the radiologic response. Dyspnea and other side effects, before and after intervention, 10 days and 2 months later were recorded and compared. Chi-square test was applied to analyze the data.

Results:

The prevalence of dyspnea and its different severities, 10 days and 2 months after intervention were significantly different (P < 0.05) between the two groups. Analysis of pleural effusions revealed a significant difference (P < 0.05) between Doxycycline vs. Bleomycin 2 months after the intervention. Three months after pleurodesis, only one patient in bleomycin group needed pleural fluid drainage.

Conclusion:

Pleural effusions did not change with use of doxycycline and bleomycin in short time but long-term results of doxycycline sclerotherapy was better than bleomycin sclerotherapy in malignant pleural effusions that was supported by this study. However, additional studies with larger sample size are necessary to confirm the results.

Pleurodesis by erythromycin, tetracycline, Aerosil™ 200, and erythromycin plus Aerosil™ 200 in a rat model: a preliminary study

Background

None of the current pleurodesing agents fulfil all the criteria for best pleural sclerosant. Therefore, the search for the ideal agent for chemical pleurodesis still continues. The aim of the present study was to compare the effectiveness of erythromycin, tetracycline, Aerosil™ 200 (hydrophilic fumed amorphous silica), and erythromycin plus Aerosil™ 200 in producing pleurodesis in rats. In the present study, talc was not used as a pleurodesing agent due to an unavailability of its sterile and pure form in Iran.

Methods

Overall, 75 adult male Spraque-Dawley rats were randomized to 5 treatment groups. Each group received an intrapleural injection via 5 Fr Silastic tubes of one of the following sterile agents: 35mg/kg erythromycin in 2 ml of saline, 35mg/kg tetracycline in 2 ml of saline, 35mg/kg Aerosil™ 200 in 2ml of saline, erythromycin (35mg/kg in 2 ml of saline) plus Aerosil™ 200 (35mg/kg in 2 ml of saline), or 2 ml of saline as a control. The animals were euthanized and necropsied 30 days after injection. The pleurae were assessed for macroscopic and microscopic evidence of surrounding inflammation and fibrosis.

Results

The median macroscopic score in the Aerosil™ 200 group was significantly higher than that in the erythromycin group (P < 0.005). The median microscopic score in the erythromycin group was significantly lower than that in the Aerosil™ 200 and erythromycin plus Aerosil™ 200 groups (P < 0.005). Furthermore, maximum and minimum pleural fibrosis was observed in the erythromycin plus Aerosil™ 200 and erythromycin groups, respectively (P < 0.05).

Conclusion

This study suggests that Aerosil™ 200 with or without erythromycin may be more potent pleurodesis agent than erythromycin and tetracycline.

Pleural effusion: diagnosis and management

Pleural effusion is defined as an accumulation of fluid in the pleural space in excess of 15 to 20 mls. The aetiology for the development of a pleural effusion includes changes in hydrostatic or colloid-osmotic pressure of pleural and pulmonary capillaries, changes in pleural vascular permeability and impaired lymphatic drainage. About 5% to 12% of patients referred for emergency medical treatment are diagnosed with a pleural effusion, making it a common finding on hospital admission. The excess of pleural fluid may be triggered by pleuro-pulmonary infection, malignancy, or conditions of cardiac, renal or hepatic origin. Subsequent management is guided mainly by aetiology and to a lesser degree by symptoms. This paper provides a review of pathophysiology, diagnosis and management of the condition and addresses specific issues regarding the perioperative care of these patients.

Doxycycline sclerotherapy as primary treatment of head and neck lymphatic malformations in children

PURPOSE

The authors report their experience with doxycycline sclerotherapy as primary treatment of head and neck lymphatic malformations (LMs) in children.

METHODS

A retrospective chart review was used to collect data on 11 patients treated with doxycycline sclerotherapy for LMs of the head and neck at our institution since 2003. Radiographic imaging allowed classification of patient LM as macrocystic, microcystic, or mixed according to previously published guidelines. Only patients with macrocystic or mixed lesions were offered doxycycline sclerotherapy. Radiographic imaging and physical examination were used to determine efficacy of treatment. After each treatment, the clinical and radiographic response was characterized as excellent (> or = 95% decrease in lesion size), satisfactory (> or = 50% decrease in volume and asymptomatic), or poor (< 50% decrease in volume or symptomatic).

RESULTS

Eleven patients underwent a total of 23 sclerotherapies with an average of 2 treatments per patient (range, 1-4). All 7 patients with macrocystic lesions achieved complete clinical resolution with an average radiographic resolution of 93%. The 4 patients with mixed lesions achieved only partial clinical resolution and an average of 73% radiographic resolution. No patient experienced any adverse effects related to the treatment. At a median follow-up of 8 months, 2 patients (18%) experienced lesion recurrence in the setting of concomitant infection.

CONCLUSION

Doxycycline sclerotherapy is safe and effective as a primary treatment modality for macrocystic and mixed LMs of the head and neck in the pediatric population.

Inflammation and clinical repercussions of pleurodesis induced by intrapleural talc administration

Although reports on pleurodesis date back to the beginning of the 20th century, the search for the ideal sclerosing agent is ongoing. Several agents have been studied and used, but talc continues to be the most popular. However, potentially harmful systemic side effects have been associated with talc pleurodesis. In this article we discuss the likely mechanisms of pleural inflammation and pleurodesis with emphasis on the systemic response due to the instillation of talc into the pleural space.

Pleurodesis: A novel experimental model

BACKGROUND AND OBJECTIVE

The experimental model of pleurodesis in rabbits has been useful in understanding the pathophysiology of the pleural inflammatory injury induced by several sclerosing agents. However, restrictions on the use of rabbits in laboratory investigation are making this model less accessible. The aim of this study was to present a new experimental model of pleurodesis in mice using talc or silver nitrate.

METHODS

Four groups of 10 C57BL/6 mice received talc 2 or 4 mg/g in 0.5 mL saline, or 0.025% or 0.05% silver nitrate in 0.5 mL H(2)O. After 28 days the animals were sacrificed, and the pleural cavity was opened and evaluated for evidence of macroscopic pleural adhesions and haemothorax (scores 0-4), atelectasis (scores 0-2), and microscopic pleural and alveolar inflammation and fibrosis (scores 0-4). Statistical analysis used ANOVA.

RESULTS

Silver nitrate 0.05% produced a more effective pleurodesis in mice than did 0.025% silver nitrate or talc 4 mg/g, with significant higher scores for pleural adhesions, microscopic pleural inflammation and fibrosis. Haemothorax, atelectasis, and microscopic alveolar inflammation and fibrosis were negligible in both groups.

CONCLUSIONS

Both talc 4 mg/g and 0.05% silver nitrate produced an efficient pleurodesis in this experimental model in mice. This new model may overcome the restrictions on the use of large- and medium-sized animals in laboratory investigation and may open new fields of investigation with knockout mice.

Experimental pleurodesis induced by antibiotics (macrolides or quinolones)

PURPOSE

Chemical pleurodesis is a therapeutic tool for the treatment of recurrent pleural effusions, mainly those of neoplastic etiology. In the past, tetracycline was the sclerosant agent of choice in clinical practice, but presently, there is no consensus about an ideal agent. The aim of this study was to evaluate the effectiveness of macrolides (azithromycin and clarithromycin) or quinolones (levofloxacin and gatifloxacin) in inducing experimental pleurodesis in rabbits.

METHOD

Forty New Zealand rabbits randomized into groups of 10 received (at a total volume of 2 mL for each animal) 1 of the 4 drugs by intrapleural injection. After 28 days, the animals were euthanized and the pleural cavity was evaluated macroscopically and microscopically.

RESULTS

The intensity of the macroscopic adhesions was mild in all groups. On microscopic analysis, minimal pleural fibrosis and inflammation were observed in all animals.

CONCLUSION

The macrolides (azithromycin or clarithromycin) and the quinolones (levofloxacin or gatifloxacin) when injected into the normal pleural space of rabbits are not effective in promoting pleurodesis. Additional research is required to identify sclerosing agents capable of inducing pleurodesis.

Pleurodesis induced by talc or silver nitrate: evaluation of collagen and elastic fibers in pleural remodeling

This study evaluated the extracellular matrix (collagen and elastic fibers) in pleurodesis induced by intrapleural talc (TL) or silver nitrate (SN). Study subjects were 420 rabbits divided into two groups and sacrificed from 15 min to 12 months after the injection of the sclerosing agents at intervals previously defined. Pleural adhesions and fibrosis were graded (0-4), and the collagen and elastin were quantified. The maximum score of the pleural adhesions was observed two months after TL (2.80 +/- 0.99) and 15 days after SN (3.75 +/- 0.25). More intense pleural adhesions were observed in the SN group from day 5 (p < 0.05). Pleural thickness and pleural fibrosis were, in general, significantly higher after SN (p < 0.05). Increased deposition of collagen and elastin was observed in both groups but was more evident in the SN group. In the TL group, a linear correlation was observed between pleural adhesions and fibrosis (r = 0.775), between pleural adhesions and collagen (r = 0.779), and between fibrosis and collagen (r = 0.709). In the SN group, these correlations were acceptable (r = 0.605, 0.665, and 0.663). The elastin presented a correlation of 0.707 (p < 0.001) in the TL group and of 0.564 (p < 0.001) in the SN group. In conclusion, intrapleural 0.5% silver nitrate and talc (400 mg/kg) are effective in the induction of pleurodesis. However, the intensity of adhesions and the richness of collagen after SN, in combination with the early onset of tissue remodeling, demonstrate the local superiority of this agent. Considering the easy availability and instillation, the low cost, and the absence of important side effects, silver nitrate might be considered as a sclerosing agent to induce pleurodesis in humans.

Rapid pleurodesis with doxycycline through a small-bore catheter for the treatment of metastatic malignant effusions

GOALS OF WORK

The goal of the study was to evaluate the safety and efficacy of bedside pleurodesis with doxycycline using a short-term indwelling chest catheter for the palliative treatment of malignant effusions.

MATERIALS AND METHODS

A prospective study of 36 rapid pleurodesis procedures in 34 patients with malignant pleural effusions was conducted over a 5-year period in a university hospital. A 12F chest catheter placement was facilitated utilizing the Seldinger percutaneous entry technique. Patients received 500 mg of intrapleural doxycycline combined in half of the cases with mepivacaine. We assessed success or failure of pleurodesis in addition to the frequency of complications and survival.

MAIN RESULTS

Chest tubes were removed within 24 h in 69% and within 48 h in 94% of the patients. Complete success of pleurodesis was achieved in 17 (55%), partial success in eight (26%), and failure in six (19%) out of 31 evaluative procedures. Thus, the overall success rate of pleurodesis was 81%. Toxicity was mild and included pain (36%), fever (8%), and pneumothorax (6%). The median survival was 105 days. There was no relationship between instillation of intrapleural anesthetics and development of pain.

CONCLUSIONS

Rapid pleurodesis with doxycycline, which can be accomplished within 24 to 48 h, is a valid option for the symptomatic treatment of malignant effusions. This technique can be used as a first-line procedure in the majority of cases, particularly if thoracoscopic facilities are not available.

Intrapleural cisplatin and OK432 therapy for malignant pleural effusion caused by non-small cell lung cancer

OBJECTIVE

To evaluate the efficacy of combined intrapleural therapy with cisplatin, an antineoplastic agent, and OK432, a sclerosing agent, in controlling malignant pleural effusions, when compared with monotherapy with either agent.

METHODS

A total of 49 non-small cell lung cancer patients with malignant pleural effusion were randomly assigned to one of three groups: intrapleural cisplatin therapy (n = 17), intrapleural OK432 therapy (n = 17), or both (n = 15). They were compared in terms of success rate, duration of indwelling chest tube and adverse reactions.

RESULTS

Rates of pleural effusion recurrence within 180 days following cisplatin, OK432, or combination therapy were 64.7%, 52.9% and 13.3%, respectively, being significantly lower in the combination therapy group (P = 0.01). The mean duration of chest tube drainage was 8.4 days, 5.5 days and 12.9 days, respectively, being significantly longer in the combination therapy group (P < 0.001). All procedures were well tolerated.

CONCLUSIONS

Although chest tube drainage took longer because of the time required for multiple administration of the agents, intrapleural combination therapy with cisplatin and OK432 was more effective in controlling malignant pleural effusions due to non-small cell lung cancer than monotherapy with either agent.

Intrapleural Low-Dose Silver Nitrate Elicits More Pleural Inflammation and Less Systemic Inflammation Than Low-Dose Talc

STUDY OBJECTIVES

Several systemic effects have been described after talc pleurodesis. The aim of this study was to assess the systemic response induced by low, nonpleurodesis-inducing doses of talc and silver nitrate in an experimental model in rabbits.

DESIGN

Groups of six rabbits were injected intrapleurally with talc, 100 mg/kg or 400 mg/kg, and silver nitrate, 0.1% or 0.5%. After 6, 24, or 48 h, samples of blood and pleural fluid were collected and assayed for leukocytes, percentage of neutrophils, lactate dehydrogenase, interleukin-8, and vascular endothelial growth factor (VEGF) levels. Preinjection blood samples were used as normal blood controls.

MEASUREMENTS AND RESULTS

Silver nitrate 0.1% induced a more intense pleural inflammation than that produced by talc 100 mg/kg. In contrast, talc 100 mg/kg induced a more pronounced acute systemic response with higher values of WBCs and neutrophils, whereas silver nitrate 0.1% produced no significant increases in leukocytes or neutrophils. The serum interleukin-8 and VEGF levels increased in all groups, and decreased with time only in the silver nitrate 0.1% group. The highest serum VEGF levels were observed in the talc 100 mg/kg group.

CONCLUSIONS

In conclusion, 0.1% silver nitrate produced an intense pleural inflammatory response with a less evident systemic response in comparison to 0.5% silver nitrate and talc 100 mg/kg or 400 mg/kg.

Supportive Care in Lung Cancer

Lung cancer often is associated with significant morbidity, which has a detrimental effect on quality of life. Supportive care plays a central role in the multimodal treatment of lung cancer. Palliation of symptoms often improves quality of life and compliance with therapy. New developments in supportive care, reviewed here, include management of symptoms of the disease, such as respiratory problems, pain, and cachexia, as well as effects of treatment, including chemotherapy-induced nausea and vomiting, neutropenia, anemia, and mucositis. In the past few years, significant advances have been made in this field; however, palliation of the symptoms of lung cancer remains an area of active investigation.

Management of malignant pleural effusions

Malignant pleural effusion is a common clinical problem. Evacuation of the pleural fluid and prevention of its reaccumulation are the main aims of management. Pleurodesis should be attempted early, although considerable practice variations exist in the way it is performed. There is a lack of consensus among respiratory physicians worldwide on the optimal method and agent for pleurodesis. Talc remains the most commonly used pleurodesing compound in most countries. While talc produces a higher success rate than other compounds, it generates more side-effects. The association between talc and ARDS continues to be debated. Ambulatory small-bore pleural catheter drainage followed by intrapleural instillation of a pleurodesing agent is increasingly accepted as an alternative to conventional in-patient pleurodesis. Development of novel methods to control pleural fluid formation should be made a high priority in future pleural research.