Chemical pleurodesis in malignant pleural effusions: a randomised prospective study of mepacrine versus bleomycin

Repurposing of Anti-Malarial Drug Quinacrine for Cancer Treatment: A Review

Quinacrine (QC), a synthetic drug belonging to the 9-aminoacridine family, has been used extensively to treat malaria and multiple ailments over the past several decades. Following its discovery in the 1920s and extensive use for the treatment of malaria for nearly two decades, numerous studies have explored its antineoplastic potential in both preclinical and clinical settings. Multiple studies spanning over seven decades have examined a wide range of QC anticancer activities across various types of cancers, along with the underlying mechanisms. Many of these mechanisms, including activation of the p53 signaling cascade and simultaneous NF-κB signaling inhibition, have been reported in various studies, bringing QC to a unique polypharmacological category drug possessing the potential to treat a wide variety of diseases, including cancer. This article summarizes most of the research conducted over several decades to uncover new molecular mechanisms activated or inactivated and directly correlate with antineoplastic activity QC.

Interventions for the management of malignant pleural effusions: a network meta-analysis

BACKGROUND

Malignant pleural effusion (MPE) is a common problem for people with cancer and usually associated with considerable breathlessness. A number of treatment options are available to manage the uncontrolled accumulation of pleural fluid, including administration of a pleurodesis agent (via a chest tube or thoracoscopy) or placement of an indwelling pleural catheter (IPC). This is an update of a review published in Issue 5, 2016, which replaced the original, published in 2004.

OBJECTIVES

To ascertain the optimal management strategy for adults with malignant pleural effusion in terms of pleurodesis success and to quantify differences in patient-reported outcomes and adverse effects between interventions.

SEARCH METHODS

We searched CENTRAL, MEDLINE (Ovid), Embase (Ovid) and three other databases to June 2019. We screened reference lists from other relevant publications and searched trial registries.

SELECTION CRITERIA

We included randomised controlled trials of intrapleural interventions for adults with symptomatic MPE, comparing types of sclerosant, mode of administration and IPC use.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data on study design, characteristics, outcome measures, potential effect modifiers and risk of bias. The primary outcome was pleurodesis failure rate. Secondary outcomes were adverse events, patient-reported breathlessness control, quality of life, cost, mortality, survival, duration of inpatient stay and patient acceptability. We performed network meta-analyses of primary outcome data and secondary outcomes with enough data. We also performed pair-wise meta-analyses of direct comparison data. If we deemed interventions not jointly randomisable, or we found insufficient available data, we reported results by narrative synthesis. For the primary outcome, we performed sensitivity analyses to explore potential causes of heterogeneity and to evaluate pleurodesis agents administered via a chest tube only. We assessed the certainty of the evidence using GRADE.

MAIN RESULTS

We identified 80 randomised trials (18 new), including 5507 participants. We found all except three studies at high or unclear risk of bias for at least one domain. Due to the nature of the interventions, most studies were unblinded. Pleurodesis failure rate We included 55 studies of 21 interventions in the primary network meta-analysis. We estimated the rank of each intervention's effectiveness. Talc slurry (ranked 6, 95% credible interval (Cr-I) 3 to 10)  is an effective pleurodesis agent (moderate certainty for comparison with placebo) and may result in fewer pleurodesis failures than bleomycin and doxycycline (bleomycin versus talc slurry: odds ratio (OR) 2.24, 95% Cr-I 1.10 to 4.68; low certainty; ranked 11, 95% Cr-I 7 to 15; doxycycline versus talc slurry: OR 2.51, 95% Cr-I 0.81 to 8.40; low certainty; ranked 12, 95% Cr-I 5 to 18). There is little evidence of a difference between the pleurodesis failure rate of talc poudrage and talc slurry (OR 0.50, 95% Cr-I 0.21 to 1.02; moderate certainty). Evidence for any difference was further reduced when restricting analysis to studies at low risk of bias (defined as maximum one high risk domain in the risk of bias assessment) (pleurodesis failure talc poudrage versus talc slurry: OR 0.78, 95% Cr-I 0.16 to 2.08). IPCs without daily drainage are probably less effective at obtaining a definitive pleurodesis (cessation of pleural fluid drainage facilitating IPC removal) than talc slurry (OR 7.60, 95% Cr-I 2.96 to 20.47; rank = 18/21, 95% Cr-I 13 to 21; moderate certainty). Daily IPC drainage or instillation of talc slurry via IPC are likely to reduce pleurodesis failure rates. Adverse effects Adverse effects were inconsistently reported. We performed network meta-analyses for the risk of procedure-related fever and pain. The evidence for risk of developing fever was of low certainty, but suggested there may be little difference between interventions relative to talc slurry (talc poudrage: OR 0.89, 95% Cr-I 0.11 to 6.67; bleomycin: OR 2.33, 95% Cr-I 0.45 to 12.50; IPCs: OR 0.41, 95% Cr-I 0.00 to 50.00; doxycycline: OR 0.85, 95% Cr-I 0.05 to 14.29). Evidence also suggested there may be little difference between interventions in the risk of developing procedure-related pain, relative to talc slurry (talc poudrage: OR 1.26, 95% Cr-I 0.45 to 6.04; very-low certainty; bleomycin: OR 2.85, 95% Cr-I 0.78 to 11.53; low certainty; IPCs: OR 1.30, 95% Cr-I 0.29 to 5.87; low certainty; doxycycline: OR 3.35, 95% Cr-I 0.64 to 19.72; low certainty). Patient-reported control of breathlessness Pair-wise meta-analysis suggests there is likely no difference in breathlessness control, relative to talc slurry, of talc poudrage ((mean difference (MD) 4.00 mm, 95% CI -6.26 to 14.26) on a 100 mm visual analogue scale for breathlessness; studies = 1; participants = 184; moderate certainty) and IPCs without daily drainage (MD -6.12 mm, 95% CI -16.32 to 4.08; studies = 2; participants = 160; low certainty). Overall mortality There may be little difference between interventions when compared to talc slurry (bleomycin and IPC without daily drainage; low certainty) but evidence is uncertain for talc poudrage and doxycycline. Patient acceptability Pair-wise meta-analysis demonstrated that IPCs probably result in a reduced risk of requiring a repeat invasive pleural intervention (OR 0.25, 95% Cr-I 0.13 to 0.48; moderate certainty) relative to talc slurry. There is likely little difference in the risk of repeat invasive pleural intervention with talc poudrage relative to talc slurry (OR 0.96, 95% CI 0.59 to 1.56; moderate certainty).

AUTHORS' CONCLUSIONS

Based on the available evidence, talc poudrage and talc slurry are effective methods for achieving a pleurodesis, with lower failure rates than a number of other commonly used interventions. IPCs provide an alternative approach; whilst associated with inferior definitive pleurodesis rates, comparable control of breathlessness can probably be achieved, with a lower risk of requiring repeat invasive pleural intervention.  Local availability, global experience of agents and adverse events (which may not be identified in randomised trials) and patient preference must be considered when selecting an intervention. Further research is required to delineate the roles of different treatments according to patient characteristics, such as presence of trapped lung. Greater attention to patient-centred outcomes, including breathlessness, quality of life and patient preference is essential to inform clinical decision-making. Careful consideration to minimise the risk of bias and standardise outcome measures is essential for future trial design.

Repurposing quinacrine for treatment-refractory cancer

Quinacrine, also known as mepacrine, has originally been used as an antimalarial drug for close to a century, but was recently rediscovered as an anticancer agent. The mechanisms of anticancer effects of quinacrine are not well understood. The anticancer potential of quinacrine was discovered in a screen for small molecule activators of p53, and was specifically shown to inhibit NFκB suppression of p53. However, quinacrine can cause cell death in cells that lack p53 or have p53 mutations, which is a common occurrence in many malignant tumors including high grade serous ovarian cancer. Recent reports suggest quinacrine may inhibit cancer cell growth through multiple mechanisms including regulating autophagy, FACT (facilitates chromatin transcription) chromatin trapping, and the DNA repair process. Additional reports also suggest quinacrine is effective against chemoresistant gynecologic cancer. In this review, we discuss anticancer effects of quinacrine and potential mechanisms of action with a specific focus on gynecologic and breast cancer where treatment-refractory tumors are associated with increased mortality rates. Repurposing quinacrine as an anticancer agent appears to be a promising strategy based on its ability to target multiple pathways, its selectivity against cancer cells, and the synergistic cytotoxicity when combined with other anticancer agents with limited side effects and good tolerability profile.

Interventions for the management of malignant pleural effusions: a network meta-analysis

BACKGROUND

Malignant pleural effusion (MPE) is a common problem for people with cancer as a result of malignant infiltration of the pleura. It is usually associated with considerable breathlessness. A number of treatment options are available to manage the uncontrolled accumulation of pleural fluid including administration of a pleurodesis agent (either via a chest tube or at thoracoscopy) or indwelling pleural catheter insertion.

OBJECTIVES

To ascertain the optimal management strategy for adults with malignant pleural effusion in terms of pleurodesis success. Additionally, to quantify differences in patient-reported outcomes and adverse effects between management strategies.

SEARCH METHODS

We searched The Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE, Ovid EMBASE; EBSCO CINAHL; SCI-EXPANDED and SSCI (ISI Web of Science) to April 2015.

SELECTION CRITERIA

We included randomised controlled trials of intrapleural interventions for adults with symptomatic MPE in the review.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data on study design, study characteristics, outcome measures, potential effect modifiers and risk of bias.The primary outcome measure was pleurodesis failure rate. Secondary outcome measures were adverse effects and complications, patient-reported control of breathlessness, quality of life, cost, mortality, duration of inpatient stay and patient acceptability.We performed network meta-analysis with random effects to analyse the primary outcome data and those secondary outcomes with enough data. We also performed pair-wise random-effects meta-analyses of direct comparison data. If interventions were not deemed jointly randomisable, or insufficient data were available, we reported the results by narrative synthesis. We performed sensitivity analyses to explore heterogeneity and to evaluate only those pleurodesis agents administered via a chest tube at the bedside.

MAIN RESULTS

Of the 1888 records identified, 62 randomised trials, including a total of 3428 patients, were eligible for inclusion. All studies were at high or uncertain risk of bias for at least one domain.Network meta-analysis evaluating the rate of pleurodesis failure, suggested talc poudrage to be a highly effective method (ranked second of 16 (95% credible interval (Cr-I) 1 to 5)) and provided evidence that it resulted in fewer pleurodesis failures than eight other methods. The estimated ranks of other commonly used agents were: talc slurry (fourth; 95% Cr-I 2 to 8), mepacrine (fourth; 95% Cr-I 1 to 10), iodine (fifth; 95% Cr-I 1 to 12), bleomycin (eighth; 95% Cr-I 5 to 11) and doxycyline (tenth; 95% Cr-I 4 to 15). The estimates were imprecise as evidenced by the wide credible intervals and both high statistical and clinical heterogeneity.Most of the secondary outcomes, including adverse events, were inconsistently reported by the included studies and the methods used to describe them varied widely. Hence the majority of the secondary outcomes were reported descriptively in this review. We obtained sufficient data to perform network meta-analysis for the most commonly reported adverse events: pain, fever and mortality. The fever network was imprecise and showed substantial heterogeneity, but suggested placebo caused the least fever (ranked first of 11 (95% Cr-I 1 to 7)) and mepacrine and Corynebacterium parvum (C. parvum) appeared to be associated with the most fever (ranked tenth (95% Cr-I 6 to 11) and eleventh (95% Cr-I 7 to 11) respectively). No differences between interventions were revealed by the network meta-analysis of the pain data. The only potential difference in mortality identified in the mortality network was that those receiving tetracycline appeared to have a longer survival than those receiving mitoxantrone (OR 0.16 (95% Confidence Interval (CI) 0.03 to 0.72)). Indwelling pleural catheters were examined in two randomised studies, both of which reported improved breathlessness when compared to talc slurry pleurodesis, despite lower pleurodesis success rates.The risk of bias in a number of the included studies was substantial, for example the vast majority of studies were unblinded, and the methods used for sequence generation and allocation concealment were often unclear. Overall, however, the risk of bias for all studies was moderate. We have not reported the GRADE quality of evidence for the outcomes, as the role of GRADE is not well established in the context of Network Meta-analysis (NMA).

AUTHORS' CONCLUSIONS

Based on the available evidence, talc poudrage is a more effective pleurodesis method in MPE than a number of other frequently used methods, including tetracycline and bleomycin. However further data are required to definitively confirm whether it is more effective than certain other commonly used interventions such as talc slurry and doxycycline, particularly in view of the high statistical and clinical heterogeneity within the network and the high risk of bias of many of the included studies. Based on the strength of the evidence from both direct and indirect comparisons of randomised data of sclerosants administered at the bedside, there is no evidence to suggest large differences between the other highly effective methods (talc slurry, mepacrine, iodine and C. parvum). However, local availability, global experience of these agents and their adverse events, which may not be identified in randomised trials, must also be considered when selecting a sclerosant. Further research is required to delineate the roles of different treatments according to patient characteristics (e.g. according to their prognosis or presence of trapped lung) and to explore patient-centred outcomes, such as breathlessness and quality of life, in more detail. Careful consideration to minimise the risk of bias and standardise outcome measures is essential for future trial design.

WITHDRAWN: Pleurodesis for malignant pleural effusions

A new review team are preparing a new protocol to replace this review. The new review is entitled 'Interventions for the management of malignant pleural effusions'. Publication of the full review is anticipated in early 2015.

The editorial group responsible for this previously published document have withdrawn it from publication.

Sclerotic effect of bleomycin on the submandibular gland: an experimental model

OBJECTIVES

To evaluate the sclerotic effect of bleomycin on the submandibular gland histopathologically and assess it as a possible alternative therapy for sialorrhea.

METHODS

An experimental model was designed and 18 New Zealand white rabbits were used. The rabbits were divided into two groups: a bleomycin group (n=9) and a sham group (n=9). The submandibular glands of the bleomycin group were injected with 0.3 ml bleomycin (3mg/ml) while the sham group received 0.3 ml saline. Four weeks after the procedure, the glands were removed. Histopathological studies including hematoxylin-eosin and Masson's trichrome stain were carried out. The glands were evaluated for tissue inflammation, fibrosis, edema, lipomatosis, atrophy and congestion. To investigate apoptosis, terminal deoxynucleotidyl transferase (TdT)-mediated digoxigenin-11-dUTP nick-end labeling (TUNEL) immunohistochemical staining was used.

RESULTS

In the group injected with bleomycin, inflammation (n=8), edema (n=4), fibrosis (n=3), congestion (n=4) and lipomatosis (n=7) were observed. In the sham group, only lipomatosis was observed. The TUNEL assay results were 5.06 ± 1.18 (p<0.05) for acinar cells and 8.46 ± 0.82 (p<0.05) for ductal cells in the bleomycin group. This was significantly different from the results in the sham group.

CONCLUSIONS

Apoptosis, inflammation, fibrosis, edema, lipomatosis and congestion were observed in the ductal and acinar cells of the bleomycin group. Bleomycin may be an alternative treatment for sialorrhea cases. However, more research is needed.

Identification of inhibitors of ovarian cancer stem-like cells by high-throughput screening

Background

Ovarian cancer stem cells are characterized by self-renewal capacity, ability to differentiate into distinct lineages, as well as higher invasiveness and resistance to many anticancer agents. Since they may be responsible for the recurrence of ovarian cancer after initial response to chemotherapy, development of new therapies targeting this special cellular subpopulation embedded within bulk ovarian cancers is warranted.

Methods

A high-throughput screening (HTS) campaign was performed with 825 compounds from the Mechanistic Set chemical library [Developmental Therapeutics Program (DTP)/National Cancer Institute (NCI)] against ovarian cancer stem-like cells (CSC) using a resazurin-based cell cytotoxicity assay. Identified sets of active compounds were projected onto self-organizing maps to identify their putative cellular response groups.

Results

From 793 screening compounds with evaluable data, 158 were found to have significant inhibitory effects on ovarian CSC. Computational analysis indicates that the majority of these compounds are associated with mitotic cellular responses.

Conclusions

Our HTS has uncovered a number of candidate compounds that may, after further testing, prove effective in targeting both ovarian CSC and their more differentiated progeny.

Intrapleural therapy

Numerous intrapleural therapies have been adopted to treat a vast array of pleural diseases. The first intrapleural therapies proposed focused on the use of fibrinolytics and DNase to promote fluid drainage in empyema. Numerous case series and five randomized controlled trials have been published to determine the outcomes of fibrinolytics in empyema treatment. In the largest randomized trial, the use of streptokinase had no reduction in mortality, decortication rates or hospital days compared with placebo in the treatment of empyema. Criticism over study design and patient selection may have potentially affected the outcomes in this study. The development of dyspnoea is common in the setting of malignant pleural effusions. Pleural fluid evacuation followed by pleurodesis is often attempted. Numerous sclerosing agents have been studied, with talc emerging as the most effective agent. Small particle size of talc should be avoided because of increased systemic absorption potentiating toxicity, such as acute lung injury. Over the past several years, the use of chronic indwelling pleural catheters have emerged as the preferred modality in the treating a symptomatic malignant pleural effusion. For patients with malignant-related lung entrapment, pleurodesis often fails due to the presence of visceral pleural restriction; however, chronic indwelling pleural catheters are effective in palliation of dyspnoea. Finally, the use of staphylococcal superantigens has been proposed as a therapeutic model for the treatment of non-small lung cancer. Intrapleural instillation of staphylococcal superantigens increased median survival by 5 months in patients with non-small cell lung cancer with a malignant pleural effusion.

Beyond DNA binding - a review of the potential mechanisms mediating quinacrine's therapeutic activities in parasitic infections, inflammation, and cancers

This is an in-depth review of the history of quinacrine as well as its pharmacokinetic properties and established record of safety as an FDA-approved drug. The potential uses of quinacrine as an anti-cancer agent are discussed with particular attention to its actions on nuclear proteins, the arachidonic acid pathway, and multi-drug resistance, as well as its actions on signaling proteins in the cytoplasm. In particular, quinacrine's role on the NF-κB, p53, and AKT pathways are summarized.

Diagnosis and management of malignant pleural effusions

Malignant pleural effusions (MPEs) complicate the clinical course of patients with a broad array of malignancies, which are most often due to lymphomas or carcinomas of the breast, lung, gastrointestinal tract or ovaries. Patients may present with a MPE as the initial manifestation of a cancer or develop an effusion during the advanced phases of a known malignancy. In either circumstance, the median survival after presentation with a MPE is 4 months. Effusions may result from direct pleural invasion (MPE) or indirect effects (paraneoplastic effusions), such as impairment of fluid efflux from the pleural space by lymphatic obstruction or pleural effects of cancer radiation or drug therapy. Because only 50% of patients with cancer who develop a pleural effusion during their clinical course have a MPE, careful evaluation of the effusion to establish its aetiology is required to direct therapy. Management is palliative with interventions directed towards decreasing the volume of intrapleural fluid and the severity of associated symptoms.

Recent advances in the diagnosis and management of malignant pleural effusions

Malignant pleural effusions (MPEs) are an important complication for patients with intrathoracic and extrathoracic malignancies. Median survival after diagnosis of an MPE is 4 months. Patients can present with an MPE as a complication of far-advanced cancer or as the initial manifestation of an underlying malignancy. Common cancer types causing MPEs include lymphomas, mesotheliomas, and carcinomas of the breast, lung, gastrointestinal tract, and ovaries. However, almost all tumor types have been reported to cause MPEs. New imaging modalities assist the evaluation of patients with a suspected MPE; however, positive cytologic or tissue confirmation of malignant cells is necessary to establish a diagnosis. Even in the presence of known malignancy, up to 50% of pleural effusions are benign, underscoring the importance of a firm diagnosis to guide therapy. Rapidly evolving interventional and histopathologic techniques have improved the diagnostic yield of standard cytology and biopsy. Management of an MPE remains palliative; it is critical that the appropriate management approach is chosen on the basis of available expertise and the patient's clinical status. This review summarizes the pathogenesis, diagnosis, and management of MPE. Studies in the English language were identified by searching the MEDLINE database (1980-2007) using the search terms pleura, pleural, malignant, pleurodesis, and thoracoscopy.

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.

Chemotherapeutic management of malignant pleural effusion

The management of malignant pleural effusions are a common, and sometimes difficult, therapeutic problem. This article reviews the currently available sclerosing agents and discusses novel agents that show promise for the future. Talc, tetracycline and bleomycin are currently the most widely used agents but none is an ideal sclerosant and certain adverse effects are of concern. Novel agents, particularly transforming growth factor (TGF)-beta(2) and metalloproteinase inhibitors, are being investigated, and the increase in knowledge into the mechanisms of pleural fluid formation and pleurodesis will hopefully lead to the development of targeted therapy in the future.

Talc and Silver Nitrate Induce Systemic Inflammatory Effects During the Acute Phase of Experimental Pleurodesis in Rabbits

STUDY OBJECTIVE

s: To determine whether talc (TL) and silver nitrate (SN), two effective pleurodesis agents, induce a systemic inflammatory response in the acute phase of experimental pleurodesis in rabbits.

DESIGN

Samples of blood and pleural fluid were collected after 6, 24, and 48 h from rabbits injected intrapleurally with 3 mL saline solution, TL (400 mg/kg), or 0.5% SN, and were assayed for WBC count, percentage of neutrophils, and levels of lactate dehydrogenase (LDH), interleukin (IL)-8, and vascular endothelial growth factor (VEGF). The pleural liquid production was compared in the three different groups. A sample of blood collected from animals preinjection was used as the control.

RESULTS

At 6 h after pleural injection, the mean blood WBC count and percentage of neutrophils were significantly elevated in the TL group, whereas the mean LDH and IL-8 levels were significantly increased in the SN group. VEGF was undetectable in the preinjection serum and saline solution-injected animals, but was increased in the serum after the pleural injection of both TL and SN to a comparable degree. SN elicited a more intense acute pleural inflammation reaction than did TL, with higher WBC count and IL-8 levels found in the pleural fluid, mainly within the first 6 h. LDH and VEGF levels, and pleural liquid production were also higher for SN, and they increased with time.

CONCLUSIONS

In the acute phase of pleural injection, TL induced a transient increase in blood WBC count and percentage of neutrophils, while SN induced increases in blood LDH and IL-8 levels. Both TL and SN induced significant increases in blood VEGF levels. SN induced an earlier and more intense acute pleural inflammation than TL. Pleural liquid VEGF levels were higher after SN injection and increased, as did pleural liquid production. These findings suggest that the intrapleural injection of TL and SN produce a systemic inflammatory response that may have a role in the pathogenesis of fever and ARDS, which occur with pleurodesis.

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

Management of recurrent malignant pleural effusion, a common complication of malignancy, poses a challenge to clinicians. Although almost one century has elapsed since the introduction of the pleurodesis procedure, the ideal approach and best agent are still to be defined. Optimally, pleurodesis should be done at the bedside with a minimally invasive procedure, and suitable agents to achieve pleural symphysis should be inexpensive, available worldwide and free of adverse effects. To date, no substance completely fulfills these requirements. Silver nitrate should be considered for pleurodesis because of its low cost and ease of handling. Although talc has been used most frequently to induce pleurodesis, reports of death due to acute respiratory failure have raised concerns about the safety of this agent. Tetracycline, an effective alternative used in the past, is no longer commercially available. This agent has been substituted with derivatives of tetracycline, such as minocycline and doxycycline with success rates similar to those with tetracycline. Several antineoplastic agents have been injected into the pleural space with the aim of producing pleural symphysis, the most representative of this group being bleomycin. Recent knowledge of the molecular mechanisms involved in pleural inflammation has brought into focus new substances, such as transforming growth factor beta and vascular endothelial growth factor, which may be used as pleurodesis agents in the future. Nevertheless, more studies are necessary to better define the potential of these substances in the induction of pleural symphysis.Ideally, a sclerosing agent should be cost-effective, available worldwide and easily administered. Talc will probably stand as the preferred agent to be used for pleurodesis in malignant pleural effusion because of its efficacy, easy manipulation and handling. However, further investigation is necessary to minimize adverse effects related to talc.

Pleurodesis for malignant pleural effusions

BACKGROUND

Approximately half of all patients with metastatic cancer develop a malignant pleural effusion which is likely to lead to a significant reduction in quality of life secondary to symptoms such as dyspnoea and cough. The aim of pleurodesis in these patients is to prevent re-accumulation of the effusion and thereby of symptoms, and avoid the need for repeated hospitalization for thoracocentesis. Numerous clinical studies have been performed to try to determine the optimal pleurodesis strategy, and synthesis of the available evidence should facilitate this.

OBJECTIVES

The aims of this review were to ascertain the optimal technique of pleurodesis in cases of malignant pleural effusion; to confirm the need for a sclerosant; and to clarify which, if any, of the sclerosants is the most effective.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials was searched for studies on 'pleurodesis'. Studies for inclusion were also identified from MEDLINE (1980 to June 2002) and EMBASE (1980 to May 2002). No language restriction was applied.

SELECTION CRITERIA

RCTs of adults subjects undergoing pleurodesis for pleural effusion in the context of metastatic malignancy (or a malignant process leading to pleural effusion) were included.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected studies for inclusion in the review, and extracted data using a standard data collection form. Primary outcome measures sought were effectiveness of pleurodesis as defined by freedom from recurrence of effusions, and mortality after pleurodesis. Secondary outcomes were adverse events due to pleurodesis. Dichotomous data were meta-analysed using a fixed effect model and expressed as relative risk. The number-needed-to-treat (NNT) was calculated for pleurodesis efficacy. In addition, for adverse events, the overall percentage of patients across studies exhibiting a particular adverse effect such as fever, pain, or gastrointestinal symptoms was calculated.

MAIN RESULTS

A total of 36 RCTs with 1499 subjects were eligible for meta-analysis. The use of sclerosants (mitozantrone, talc and tetracycline combined)compared with control (instillation of isotonic saline or equivalent pH isotonic saline or tube drainage alone) was associated with an increased efficacy of pleurodesis. The relative risk (RR) of non-recurrence of an effusion is 1.20 (95% CI 1.04 to 1.38) in favour of the use of sclerosants based on five studies with a total 228 subjects. Comparing different sclerosants, talc was found to be the most efficacious. The RR of effusion non-recurrence was 1.34 (95% CI 1.16 to 1.55) in favour of talc compared with bleomycin, tetracycline, mustine or tube drainage alone based on 10 studies comprising 308 subjects. This was not associated with increased mortality post pleurodesis. The RR of death was 1.19 (95% CI 0.08 to 1.77) for talc compared to bleomycin, tetracycline, mustine and tube drainage alone based on six studies of 186 subjects. Death was not reported in all studies and, when reported, was attributed to underlying disease, only one death being reported as procedure-related. In the comparison of thoracoscopic versus medical pleurodesis, thoracoscopic pleurodesis was found to be more effective. The RR of non-recurrence of effusion is 1.19 (95% CI 1.04 to 1.36) in favour of thoracoscopic pleurodesis compared with tube thoracostamy pleurodesis utilizing talc as sclerosant based on two studies with 112 subjects. Comparing thoracoscopic versus bedside instillation (with different sized chest tubes) of various sclerosants (tetracycline, bleomycin, talc or mustine) the RR of non-recurrence of effusion is 1.68 (95% CI 1.35 to 2.10) based on five studies with a total of 145 participants.Adverse events were not reported adequately to enable meta-analysis.

REVIEWER'S CONCLUSIONS

The available evidence supports the need for chemical sclerosants for successful pleurodesis, the use of talc as the sclerosant of choice, and thoracoscopic pleurodesis as the preferred technique for pleurodesis based on efficacy. There was no evidence for an increase in mortality following talc pleurodesis.

Interstitial quinacrine for elimination of abnormal tissue; therapy of experimental glioma

BACKGROUND

When quinacrine is injected interstitially, an intense migration of leukocytes and accumulation of various lymphokines is obtained locally, and the reaction is followed by cicatricial fibrosis. This property has been used in humans to induce tubal fibrosis in women and pleurodesis in patients with pleural effusion.

METHODS

In a controlled study, a single dose of 150 mg of quinacrine was injected interstitially into a C6 glioma implanted in the subcutaneous tissue of Wistar rats. Changes in size, histologic variations, and microscopic characteristics of leukocyte subpopulations infiltrating the tumor were studied by immunohistochemistry. Tumor necrosis factor and interleukin-1 beta were measured at different times in tumor homogenates.

RESULTS

The day after the injection of quinacrine, infiltration of leukocytes and macrophages was observed, accompanied by an accumulation of proinflammatory endogenous cytokines. Tumoral necrosis soon ensued; complete tumor disappearance was obtained in 72% of the animals. Cicatrization proceeded without injury of perilesional structures. In all controls injected with the vehicle, a large tumor developed (P <.0001).

CONCLUSIONS

Quinacrine, when administered interstitially in a single dose, elicits an intense local recruitment and proliferation of activated immune cells that, at the dose used in this study, induces tissue necrosis within a radius of 1 cm around the site of quinacrine injection, leaving the surrounding tissue unharmed.

Management of malignant pleural effusions

Malignant pleural effusions (MPEs) represent a common complication of advanced malignancies. However, adequate palliation of this highly symptomatic accompaniment to cancer can be achieved in most patients by adopting the appropriate therapy. Several options are available for the treatment of MPE. Systemic therapy may control the effusion in patients whose underlying malignancy is sensitive to anti-cancer agents. Repeated thoracocentesis can be appropriate for patients with limited life expectancy or slowly recurrent effusions. In the majority of the remaining cases the treatment of choice is pleurodesis with sclerosing agents administered via tube thoracostomy. Controversy still exists as to which drug produces the best results: talc and bleomycin appear to be among the most cost-effective agents. The debate over the best agent to be used for pleurodesis refers to the difficulty in comparing results of studies using different eligibility criteria, response assessment and end-points. This article describes the various treatments which have been reported in the literature to play a role in the management of MPEs. It is also aimed at providing guidelines in allocating patients to appropriate treatments.

Effects of intrapleural mitoxantrone and mepacrine on malignant pleural effusion--a randomised study

30 patients with malignant pleuritis were randomised to be treated, either with intrapleural instillation of mepacrine chloride or with mitoxantrone. The patients were evaluated with chest X-ray and a symptom questionnaire during a follow-up period of 12 weeks. Mitoxantrone levels in the pleural space and plasma were measured at different time points in some of the patients. High concentrations of mitoxantrone were found in the pleural fluid while the plasma concentrations were low, giving a plasma/intracavity ratio generally of less than 1:60. The chest X-rays showed excellent results for both treatment modalities. However, the patients treated with mepacrine chloride experienced greater discomfort with fever and pain, and those treated with mitoxantrone reported significantly less dyspnoea and less asthenia after 4 weeks. We conclude that both treatments are equally effective in preventing the recurrence of malignant effusion. However, mitoxantrone seems to have further advantages when it comes to improving the quality of life.

Pleurodesis with doxycycline or Corynebacterium parvum in malignant pleural effusion

Pleurodesis with doxycycline (100 mg and 600 mg) and Corynebacterium parvum (1 mg and 7 mg) were compared in 41 patients with malignant effusion. To evaluate the mechanisms, pleural fluid pH, leukocytes, granulocytes, interleukin-6 (IL-6) and serum IL-6, as well as C-reactive protein (CRP) were measured before and on 2 consecutive days after treatment. Corynebacterium parvum produced a greater acute-phase response measured with fever, serum CRP and IL-6 than doxycycline. However, no change in pleural fluid IL-6 was demonstrated. Among the 35 assessed patients, 26 had objective response, similar in all four treatment groups. Side-effects were more common with Corynebacterium parvum. Based on this preliminary study we conclude that doxycycline, even in low doses, is a highly effective and well tolerated agent for palliative treatment of malignant pleural effusion. As the responses were similar despite different inflammatory reactions, the two agents probably induce pleural obliteration through different mechanisms.

Intrapleural talc for the prevention of recurrence in benign or undiagnosed pleural effusions

Chemical pleurodesis has become the preferred treatment for definitive management of malignant pleural effusions. The treatment of patients with recurrent benign or undiagnosed pleural effusions, however, remains a difficult clinical problem. Tetracycline has been widely used as a sclerosing agent, but parenteral tetracycline is no longer available. Therefore, alternative sclerosing agents are needed. Talc was used for the first time in 1935, and subsequently there have been several reports documenting its effectiveness in the treatment of malignant pleural effusion and pneumothorax. The objective of this study is to present our experience with a low dose of aerosolized talc for controlling nonmalignant pleural effusions. Between May 1985 and October 1992, twenty-two patients underwent talc pleurodesis at the time of thoracoscopy for control of a nonmalignant effusion. The cause of the effusion was cirrhosis in six patients, systemic lupus erythematosus in two, chylothorax in five, and no diagnosis in nine patients. Follow-up has ranged from 18 days to 5 years. Only two patients (9 percent), one with cirrhosis and another with an undiagnosed pleural effusion, had a recurrence of the effusions. We conclude that the intrapleural administration of 2 g of aerosolized talc is an effective treatment for recurrent benign (including chylothorax) or undiagnosed pleural effusions.