Intrapleural instillation of quinacrine for treatment of recurrent spontaneous pneumothorax

Repurposing approved non-oncology drugs for cancer therapy: a comprehensive review of mechanisms, efficacy, and clinical prospects

Cancer poses a significant global health challenge, with predictions of increasing prevalence in the coming years due to limited prevention, late diagnosis, and inadequate success with current therapies. In addition, the high cost of new anti-cancer drugs creates barriers in meeting the medical needs of cancer patients, especially in developing countries. The lengthy and costly process of developing novel drugs further hinders drug discovery and clinical implementation. Therefore, there has been a growing interest in repurposing approved drugs for other diseases to address the urgent need for effective cancer treatments. The aim of this comprehensive review is to provide an overview of the potential of approved non-oncology drugs as therapeutic options for cancer treatment. These drugs come from various chemotherapeutic classes, including antimalarials, antibiotics, antivirals, anti-inflammatory drugs, and antifungals, and have demonstrated significant antiproliferative, pro-apoptotic, immunomodulatory, and antimetastatic properties. A systematic review of the literature was conducted to identify relevant studies on the repurposing of approved non-oncology drugs for cancer therapy. Various electronic databases, such as PubMed, Scopus, and Google Scholar, were searched using appropriate keywords. Studies focusing on the therapeutic potential, mechanisms of action, efficacy, and clinical prospects of repurposed drugs in cancer treatment were included in the analysis. The review highlights the promising outcomes of repurposing approved non-oncology drugs for cancer therapy. Drugs belonging to different therapeutic classes have demonstrated notable antitumor effects, including inhibiting cell proliferation, promoting apoptosis, modulating the immune response, and suppressing metastasis. These findings suggest the potential of these repurposed drugs as effective therapeutic approaches in cancer treatment. Repurposing approved non-oncology drugs provides a promising strategy for addressing the urgent need for effective and accessible cancer treatments. The diverse classes of repurposed drugs, with their demonstrated antiproliferative, pro-apoptotic, immunomodulatory, and antimetastatic properties, offer new avenues for cancer therapy. Further research and clinical trials are warranted to explore the full potential of these repurposed drugs and optimize their use in treating various cancer types. Repurposing approved drugs can significantly expedite the process of identifying effective treatments and improve patient outcomes in a cost-effective manner.

Targeting tumor hypoxia and mitochondrial metabolism with anti-parasitic drugs to improve radiation response in high-grade gliomas

High-grade gliomas (HGGs), including glioblastoma and diffuse intrinsic pontine glioma, are amongst the most fatal brain tumors. These tumors are associated with a dismal prognosis with a median survival of less than 15 months. Radiotherapy has been the mainstay of treatment of HGGs for decades; however, pronounced radioresistance is the major obstacle towards the successful radiotherapy treatment. Herein, tumor hypoxia is identified as a significant contributor to the radioresistance of HGGs as oxygenation is critical for the effectiveness of radiotherapy. Hypoxia plays a fundamental role in the aggressive and resistant phenotype of all solid tumors, including HGGs, by upregulating hypoxia-inducible factors (HIFs) which stimulate vital enzymes responsible for cancer survival under hypoxic stress. Since current attempts to target tumor hypoxia focus on reducing oxygen demand of tumor cells by decreasing oxygen consumption rate (OCR), an attractive strategy to achieve this is by inhibiting mitochondrial oxidative phosphorylation, as it could decrease OCR, and increase oxygenation, and could therefore improve the radiation response in HGGs. This approach would also help in eradicating the radioresistant glioma stem cells (GSCs) as these predominantly rely on mitochondrial metabolism for survival. Here, we highlight the potential for repurposing anti-parasitic drugs to abolish tumor hypoxia and induce apoptosis of GSCs. Current literature provides compelling evidence that these drugs (atovaquone, ivermectin, proguanil, mefloquine, and quinacrine) could be effective against cancers by mechanisms including inhibition of mitochondrial metabolism and tumor hypoxia and inducing DNA damage. Therefore, combining these drugs with radiotherapy could potentially enhance the radiosensitivity of HGGs. The reported efficacy of these agents against glioblastomas and their ability to penetrate the blood-brain barrier provides further support towards promising results and clinical translation of these agents for HGGs treatment.

Overcoming cancer therapeutic bottleneck by drug repurposing

Ever present hurdles for the discovery of new drugs for cancer therapy have necessitated the development of the alternative strategy of drug repurposing, the development of old drugs for new therapeutic purposes. This strategy with a cost-effective way offers a rare opportunity for the treatment of human neoplastic disease, facilitating rapid clinical translation. With an increased understanding of the hallmarks of cancer and the development of various data-driven approaches, drug repurposing further promotes the holistic productivity of drug discovery and reasonably focuses on target-defined antineoplastic compounds. The "treasure trove" of non-oncology drugs should not be ignored since they could target not only known but also hitherto unknown vulnerabilities of cancer. Indeed, different from targeted drugs, these old generic drugs, usually used in a multi-target strategy may bring benefit to patients. In this review, aiming to demonstrate the full potential of drug repurposing, we present various promising repurposed non-oncology drugs for clinical cancer management and classify these candidates into their proposed administration for either mono- or drug combination therapy. We also summarize approaches used for drug repurposing and discuss the main barriers to its uptake.

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.

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.

[Spontaneous pneumothorax: pleurodesis with an iodo-povidone hydroalcoholic solution]

OBJECTIVE

To analyze the efficacy of an iodo-povidone hydroalcoholic solution for the chemical pleurodesis of spontaneous pneumothorax.

MATERIAL AND METHOD

A descriptive, retrospective study of 81 patients with spontaneous pneumothorax. The patients were treated by video-assisted thoracoscopy and chemical pleurodesis with an iodo-povidone hydroalcoholic solution at the thoracic surgery unit of Hospital de la Santa Creu i Sant Pau in Barcelona (Spain) between January 1993 and December 1999.

RESULTS

Eighty-one patients, 59 men (73%) and 22 women (27%), between 14 and 82 years old (mean age 33 years) were treated. Pneumothorax was most often on the right side (43 cases, 53%). The main indications for surgery were recurrence (52 cases, 64%) and persistent air leaks (25 cases, 31%). All were treated by video-assisted thoracoscopy, with resection of the pulmonary parenchyma in 30 cases (37%) and pleural instillation of the iodo-povidone hydroalcoholic solution as the irritant in all cases. Air leaks were observed during early postoperative recovery in 10 patients (12.3%), self-limited fever in 5 (6.1%) and infection of drainage openings in 2 (2.4%). During the postoperative follow-up period of 6 to 67 months (mean 24 months), 5 recurrences (6.1%) were seen.

CONCLUSIONS

An iodo-povidone hydroalcoholic solution is easy to apply by video-assisted thoracoscopy and is highly effective for pleurodesis in cases of spontaneous pneumothorax.

Spontaneous pneumothorax. Comparison of thoracic drainage vs immediate or delayed needle aspiration

In the first part of this study, 61 patients admitted for the first episode or the first recurrence of a spontaneous pneumothorax (SP) were randomly treated with thoracic drainage (TD; 28 patients) or with simple needle aspiration (NA; 33 patients). Success rate of therapy was significantly higher with TD than with NA (93%, CI 84 to 100 vs 67%, CI 51 to 83; p = 0.01). Hospital stay was similar between the two groups (7 +/- 4.6 vs 7 +/- 5.6 days), mainly because NA was delayed by 72 h in 26 patients. Recurrence rates at 3 months were 29% (CI 11 to 47%) after TD, and 14% (CI 0 to 29%) after NA (p > 0.20, NS). In the second part of the study, an additional population of 35 patients was treated by immediate NA, with a success rate of 68.5% (CI 53.5 to 83.5%), and a recurrence rate at 3 months of 30% (CI 10 to 50%). Taken together, our results indicate that NA may be proposed as a first-line treatment of SP, with a successful result in two thirds of patients and recurrence in one fifth of patients. In patients who do not heal with NA, a combined risk of TD failure and short-term recurrence of 50% may be an incentive for undelayed surgical procedures.

Video-assisted thoracic surgery. Current state of the art

OBJECTIVE

The author reviews the current state of the art of video-assisted thoracic surgery in the context of modern thoracic surgical practice.

SUMMARY BACKGROUND DATA

Thoracoscopy has been a part of thoracic surgical practice for many years, but was used mainly for diagnosis of pleural disease. The development of laparoscopic cholecystectomy awakened a new interest in this technique and led to the development of many new therapeutic and diagnostic applications of video-assisted thoracic surgery.

METHODS

Current literature and the author's personal experience with more than 500 cases are reviewed.

RESULTS

Video-assisted techniques have proven useful for the performance of a broad spectrum of thoracic surgical procedures. Patients may experience less pain and have a shorter hospital stay after a video-assisted procedure. Definitive proof of less morbidity when compared with the analagous open procedure remains to be determined. Patient acceptance has been high, and most thoracic surgeons use these techniques in their practice.

CONCLUSIONS

Video-assisted thoracic surgical procedures have made a significant impact on the practice of thoracic surgery. Advantages and disadvantages of specific procedures remain to be definitively determined. Surgeons have learned these techniques and have kept morbidity to acceptance levels during the learning phase. Where these techniques ultimately fit into the overall practice remains to be determined as more experience is gained.

Method of thoracoscopic pleurectomy

A method of thoracoscopic pleurectomy using hydrodissection is presented. The results of its use in 8 patients are described, and pleurectomy as a form of pleurodesis is discussed.

Intrapleural quinacrine instillation for recurrent pneumothorax or persistent air leak

From 1982 to 1990, 27 patients with recurrent pneumothorax or persistent air leak (28 episodes) underwent pleurodesis with intrapleural administration of quinacrine, according to a standardized scheme. A first evaluation was done about 1 month after the intervention. In August 1990, all patients were invited for a second check-up. In 4 patients quinacrine plasma concentrations were determined. There was one early failure. No late recurrences were observed. Neither serious nor late complications were seen with our low-dose regimen. Transient fever was the only constant side effect. In contrast to other chemicals proposed for pleurodesis, quinacrine did not cause major pain. Only very low quinacrine plasma concentrations (peak, < 10 ng/mL) were found. In conclusion, chemical pleurodesis with quinacrine can be considered a safe and effective treatment. The number of administrations as well as the dosage are important to prevent morbidity and recurrence.

Optimal pleurodesis: a comparison study

With the resurgence of thoracoscopy, there is renewed interest in less invasive methods of pleurodesis. We wished to compare in an animal model a variety of methods suggested in reports. The purpose of the study was to rank the effectiveness of each procedure against the standard mechanical pleurodesis. Twenty-five mongrel dogs (weight, 25 to 35 kg) underwent bilateral thoracotomy. Each animal was randomly assigned to receive two of the following methods of pleurodesis: tetracycline, talc, mechanical abrasion, neodymium: yttrium-aluminum garnet (Nd:YAG) laser (Hereus Inc, E. Rutherford, NJ) photocoagulation, and argon beam coagulator (ABC) (Beacon Lab, Bloomfield, CO) electrocoagulation of the parietal pleura. At evaluation at 30 +/- 2 days, the efficacy of pleurodesis was graded on a scale of 0 to 4, with 0 representing a complete absence of pleural symphysis and 4 the adhesion of more than one lobe to both the chest wall and mediastinum. Mean grade and standard deviation of each method were: talc, 3.0 +/- 0.67; mechanical, 3.0 +/- 0.82; tetracycline, 2.3 +/- 1.4; ABC, 1.5 +/- 0.97; and Nd:YAG laser, 0.7 +/- 0.95. Both the talc and mechanical methods were superior to either the Nd:YAG laser or the ABC (p < 0.01). In this study, neither the Nd:YAG laser nor the ABC proved efficacious in producing pleurodesis. Talc poudrage is the only method of pleural symphysis comparable with mechanical abrasion.

Medical management and therapy of bronchopleural fistulas in the mechanically ventilated patient

Bronchopleural fistulas are associated with high morbidity and mortality and are particularly challenging in the ventilated patient. Familiarity with both basic and more technical medical management techniques may lessen morbidity and improve survival. Prompt recognition of BPFs and appropriate placement of a chest tube with an adequate suction device are crucial to prevent potential tension pneumothorax and to drain an infected pleural space. The chest tube may be used therapeutically to decrease BPF air leak and to promote fistula repair. Appropriate conventional ventilator manipulations aimed at decreasing fistula air leak and maintaining adequate oxygenation and ventilation may fail and necessitate a trial of HFV. Definitive therapy by the bronchoscopic application of a sealing agent to occlude the fistula site can be used, particularly in the poor surgical candidate.

Thoracoscopic ablation of blebs in the treatment of recurrent or persistent spontaneous pneumothorax

Recurrent (6 patients) or persistent (4 patients) spontaneous pneumothorax was treated with thoracoscopic ablation of blebs using an electrocautery as an alternative to lung resection. Patients' ages ranged from 17 to 39 years (mean age, 29 years). Ablation was successful in 9 but failed in 1. The mean postoperative hospital stay of the successful cases was 2.1 days. The only failure in this series had an extensive bullalike air cyst involving the apex, and cauterization could not ablate it completely. The follow-up period ranged from 2 to 22 months. During this period, no recurrence was noted.

Spontaneous pneumothorax: comparison of simple drainage, talc pleurodesis, and tetracycline pleurodesis

From 1978 to 1985 96 patients with their first spontaneous pneumothorax were randomised into three groups, receiving either treatment with simple drainage (34 patients), drainage with tetracycline pleurodesis (33 patients), or drainage with talc pleurodesis (29 patients). There were 58 men and 38 women, aged 18-88 years. There was no significant difference between the three groups in the mean time in hospital or the period for which the drains were retained. The incidence of infection, persistent pneumothorax, and relapse while in hospital was also similar for the three groups. At follow-up in 1987-89 patients could be accounted for, with an average follow-up period of 4.6 years. The incidence of recurrence was 36% in the simple drainage group, 13% in the tetracycline pleurodesis group, and 8% in the talc pleurodesis group. The difference between the talc and simple drainage groups was significant. None of the methods caused severe short or long term side effects or changes in the follow-up chest radiograph. Thoracoscopy, performed on admission in 85 patients, showed normal appearances in 73 patients and small cysts in 12. The thoracoscopic findings were of no value in predicting recurrence. Talc pleurodesis resulted in a significantly lower recurrence rate than simple drainage, tetracycline pleurodesis having intermediate efficacy.

Talc poudrage in the treatment of spontaneous pneumothoraces in patients with cystic fibrosis

As patients with cystic fibrosis live longer, spontaneous pneumothoraces are seen with increasing frequency. Severe underlying pulmonary disease in these patients makes them particularly susceptible to life-threatening respiratory distress. Several modalities, including chemical sclerosis and open thoracotomy with pleurectomy, have been used to treat pneumothoraces in these patients. In the past 4 years, pneumothoraces in five patients (ages 9-22 years) with cystic fibrosis have been treated with thoracoscopy and talc poudrage. All procedures were performed under either regional or general anesthesia, depending on the age of the patient. Thoracoscopy was performed with a rod lens system and a 5.5-mm trocar, using biopsy forceps to lyse pleural adhesions, all of which ensures access to the entire pleural surface. United States Pharmacopeia-certified talc was insufflated to cover the entire pleural surface. There were no complications, and the patients had minimal pleural pain. Follow-up ranged from 6 months to 4 years. No patient has had a recurrent pneumothorax on the treated side. Thoracoscopy with talc poudrage is a preferable alternative to chemical sclerosis or thoracotomy for treating pneumothoraces in patients with cystic fibrosis. The procedure may be performed under regional anesthesia and allows rapid and complete sclerosis of the pleural cavity.

Management of pneumothorax in cystic fibrosis

The increased longevity of patients with cystic fibrosis has resulted in a concomitant increase in the frequency with which pneumothorax is seen. While several approaches to this problem have been available from both a medical and surgical standpoint, unsettled questions remain regarding the efficacy of various modalities of therapy. A review of our own experience with 170 episodes of pneumothorax has provided a basis for proposing what appears to be a reasoned approach to therapy. During the past 12 years, 65 patients ages 5 to 32 years experienced 170 episodes of pneumothorax. Of the 211 trials of treatment, all yielded a high rate of initial resolution (70% to 100%) but rates of recurrence were high. The recurrence rates were: observation 60%, thoracentesis 79%, trochar thoracotomy 63%, tetracycline sclerosis 86%, and silver nitrate 43%. Quinacrine sclerosis yielded an acceptable recurrence rate of 12.5% and partial pleurectomy had no recurrence. There was no statistical difference in the pulmonary function parameters determined before pneumothorax and after chemical pleurodesis or partial pleurectomy. Based upon the data obtained in this review, we recommend that initial management of the pneumothorax include evacuation of the pneumothorax using a chest tube and then chemical pleurodesis using quinacrine sclerosis. In those cases where this pleurodesis fails, upper-partial pleurectomy with obliteration of pleural blebs via a limited thoracentesis is the treatment of choice. An occasional patient requires a concomitant lobectomy.

Pneumothorax in cystic fibrosis: management and outcome

We reviewed our experience over the past 12 years to determine the best method of management, to determine the morbidity and the physiologic outcome of medical vs surgical treatment of pneumothorax complicating CF, and to assess the influence of age, sex, and Shwachman scores on survival. Sixty-five patients, ages ranging from 5 to 32 years (mean 18 years). Shwachman scores ranging from 25 to 87 (mean 57), and a male-female ratio of 1:1, experienced 170 pneumothoraces, 93 first episodes, and 77 recurrences, requiring 211 trials of management. All methods of management except needle aspiration resulted in a fair rate of resolution (70 to 100%), but recurrence rates were high for observation (60%), needle aspiration (79%), trocar thoracotomy (63%), tetracycline sclerosis (86%), and silver nitrate sclerosis (43%). The recurrence rates were 12.5% for quinacrine sclerosis and 0% for parietal pleurectomy. Quinacrine sclerosis and parietal pleurectomy were the most effective methods of management. There was no significant difference in pulmonary function before pneumothorax and after pleural sclerosis or parietal pleurectomy. Age, sex, and severity of pulmonary disease were all independent variables influencing prognosis. Severity of disease, rather than the occurrence of a pneumothorax, appears to be the major cause of death. We recommend that quinacrine sclerosis should be considered for management of the first pneumothorax, and parietal pleurectomy if it fails.

Silver nitrate pleurodesis in spontaneous pneumothorax

Pleurodesis provoked by instillation of silver nitrate as prevention against recurrence in primary spontaneous pneumothorax has been used for many years in the Department of Thoracic Surgery, Gentofte Hospital, University of Copenhagen. The treatment was originally instituted on a theoretical empiric basis. In a prospective, controlled investigation of pleurodesis versus simple drainage the empiric observations have been confirmed. With simple drainage we found ipsilateral recurrence of pneumothorax in 45%, while no recurrences in the pleurodesis group were found during an observation period of 5-19 months. The difference was statistically significant. The therapeutical gain using pleurodesis was 45% +/- 30%. Silver nitrate pleurodesis results in a longer hospitalization, raises the number of pleurocentesis because of increased pleural effusion and results in more pain than simple drainage. It is, however, our experience that the considerable therapeutical gain more than compensates for these negative effects. We recommend pleurodesis as the treatment of choice in primary spontaneous pneumothorax in patients with only tiny blebs on the surface of the lungs.

Transaxillary pleurectomy for treatment of spontaneous pneumothorax

In the 16-year period 1962 to 1978, 409 transaxillary apical pleurectomies were carried out for definitive treatment of spontaneous pneumothorax in 362 patients. Surgical indications included recurrence (336), bilaterality of the disease (23), persistent air leak (22), and nonexpansion of the lung (10). There was 1 operative death (unsuspected brain tumor), and 3 patients required reexploration for clot removal. The average postoperative period of hospitalization was 6 days. Three hundred ten patients (86% of all patients) were contacted for follow-up 1 to 16 years after operation (average, 4.5 years). There were two documented episodes of recurrent ipsilateral pneumothorax (0.6%). Postoperative pulmonary function studies were done in 40 patients (unilateral, 29; bilateral, 11) 2 to 5 years after operation. The results indicate that there are no significant abnormalities compared with predicted values.