Intrapleural targeted therapies (anti-VEGF and anti-EGFR) in the model of malignant pleural effusion

Factors Affecting Rate of Pleural Fluid Accumulation in Patients with Malignant Pleural Effusions

Purpose of Review

Malignant pleural effusions (MPEs) are initially treated with thoracocentesis but usually reaccumulate. There is wide variation in the rate of recurrence. Those with rapid recurrence could benefit from early definitive treatment, whilst those with slower recurrences may not. Here, we discuss pleural fluid homeostasis, MPE pathophysiology, and factors associated with reaccumulation.

Recent Findings

Few studies have investigated markers of MPE reaccumulation. Suggested features of rapid reaccumulation include lactate dehydrogenase, effusion size, positive cytology, and dyspnoea. Vascular endothelial growth factor (VEGF) correlates with MPE size and treatment response, but its association with reaccumulation rate is unknown. Some anti-VEGF therapies have shown promise in MPE management.

Summary

Further work is needed to validate hypothesised biomarkers of rapid recurrence and to characterise other biomarkers, such as VEGF. The Reaccumulation rate of Malignant Pleural Effusions After Therapeutic Aspiration (REPEAT) study aims to address these gaps in the literature and is currently in recruitment.

Treatment of malignant pleural effusion in non-small cell lung cancer with VEGF-directed therapy

BACKGROUND

Vascular endothelial growth factor (VEGF) is a critical regulator of malignant pleural effusion (MPE) in non-small-cell lung cancer (NSCLC). Bevacizumab (BEV) and apatinib (APA) are novel VEGF blockers that inhibit lung cancer cell proliferation and the development of pleural effusion.

METHODS

In this study, we established Lewis lung cancer (LLC) xenograft mouse models to compare the therapeutic effect of APA and BEV in combination with cisplatin (CDDP) against MPE. The anti-tumour and anti-angiogenic effects of this combination therapy were evaluated by ¹⁸F-FDG PET/CT imaging, TUNEL assay and Immunohistochemistry.

RESULTS

The triple drug combination significantly prolonged the overall survival of the tumour-bearing mice by reducing MPE and glucose metabolism and was more effective in lowering VEGF/soluble VEGFR-2 levels in the serum and pleural exudates compared to either of the monotherapies. Furthermore, CDDP + APA + BEV promoted in vivo apoptosis and decreased microvessel density.

CONCLUSIONS

Mechanistically, LLC-induced MPE was inhibited by targeting the VEGF-MEK/ERK pathways. Further studies are needed to establish the synergistic therapeutic effect of these drugs in NSCLC patients with MPE.KEY MESSAGESCombined treatment of MPE with apatinib, bevacizumab and cisplatin can prolong the survival time of mice, reduce the content of MPE, decrease the SUV_max of thoracic tumour tissue, down-regulate the content of VEGF and sVEGFR-2 in serum and pleural fluid, and promote the apoptosis of tumour cells. Angiogenesis and MPE formation can be inhibited by down-regulation of HIF-1α, VEGF, VEGFR-2, MEK1 and MMP-2 molecular signalling pathway proteins.

The Meta-Analysis of Bevacizumab Combined with Platinum-Based Treatment of Malignant Pleural Effusions by Thoracic Perfusion

Objective

To evaluate the safety of bevacizumab combined with platinum-based thoracic perfusion for treating lung cancer-related malignant pleural effusion (MPE) through meta-analysis.

Methods

The CNKI, PubMed, Cochrane Library, Embase, Chinese Science and Technology Journal Database (VIP), and Wanfang Databases were searched for randomized controlled trials (RCTs) of bevacizumab combined with platinum-based thoracic perfusion for the treatment of MPE. The references included in the articles were manually searched for additional studies. A meta-analysis of the RCTs was conducted using the RevMan 5.3 application.

Results

A total of 8 studies involving 540 patients (271 cases in the test group and 269 cases in the control group) were included in the meta-analysis. The test group had a significantly greater risk of elevated blood pressure as well as a higher rate of complete remission (CR) compared to the control group (P < 0.05). In contrast, the incidence of partial remission (PR) was only slightly higher in the test group (P > 0.05), and the risks of leukopenia, vomiting or nausea, rhinorrhea, diarrhea, gastrointestinal bleeding or hemoptysis, proteinuria, abnormal kidney and liver function, arrhythmia, and rashes were not significantly different between the test and control groups (P > 0.05).

Conclusion

Bevacizumab combined with platinum-based thoracic perfusion can achieve CR of MPE in patients with advanced lung cancer without significantly increasing the risk of adverse effects. The rate of PR was similar for the combination treatment and platinum-based infusion.

Narrative review of theoretical considerations regarding HITHOC between past and future

Hyppocrates constructed the medicines-surgery-energy triangle which includes all therapeutical modalities. Hyperthermic intraoperative chemotherapy (HITHOC) is a synergy-based single stage multimodality treatment encompassing the locoregional manifestation of the systemic malignant process. Pleural space, thermal effect, lavage/irrigation and chemotherapy represent the basic science ports of the network hub: HITHOC. The malignant transformation and process of the pleural surface (and underlying lung) challenges space management and tissue control. Thermotherapy without local chemotherapy is insufficient, similar to the normothermic local irrigation aligned with anticancer agents. The local administration of combined heat-transfer fluid and chemotherapy with or without subsequent surgical removal offers reasonable outcome in extensive primary pleural neoplasms (malignant mesothelioma), advanced (> Stage IIIA) NSCLC, functionally inoperable lung cancer and pleural carcinosis from extrathoracic malignancies. Measured by symptom-free survival and the quality of life, HITHOC in its present form, offers a modest yet fully substantiated solution. HITHOC in combination with the local application of targeted therapy and/or immunotherapy administered in the pleural space are currently under investigation. Additional development including new acting substances, their solvents and the means regarding surgical delivery and anesthesiology techniques are sign posts up ahead. Level 2 evidence are required in order to stepping up the recommendation levels, rewriting protocols and guidelines, in which HITHOC earns its revered position in the decision making process it deserves.

Influence of the progression of pleural neoplasia on the outcome of pleurodesis in mice

Purpose: Experimental study aimed at evaluating whether pleural neoplastic disease is associated with the degree of pleural fibrosis over time caused by talc pleurodesis. The study describes changes in levels of inflammatory mediators and determines whether the course of time involved in progression of neoplastic pleural disease is the factor that influences safety of talc pleurodesis usage in mice.

Materials and Methods: Animals were randomized into two groups: Cancer group (CG) that received intrapleural injection of Lewis cells or Saline group (SG) that received saline injection. After, the animals were subdivided into Early (pleurodesis 3 days after pleural injection) and Late (pleurodesis 7 days after pleural injection) groups. Half of the animals in each group were euthanized 24 hours after pleurodesis (to obtain the inflammatory data); the remaining animals were killed after 8 days (to obtain the scores of pleural fibrosis).

Results: CGs had lower fibrosis scores than SGs comparing early phases to late phases. Inflammation scores were lower in CGs, particularly in Late group. In SGs the inflammation was intense in 100% of the animals.

In Late CG group pleural adhesions had the lowest scores; we found intense fibrosis only in SGs. VEGF and LDH levels had increased in animals with cancer, particularly in Late group. Systemic distribution of talc occurred only in Late CG.

Conclusions: The time for pleural neoplasia to evolve is inversely proportional to the degree of pleural fibrosis. Earlier pleurodesis yielded the best results related to fibrosis, with less systemic inflammation and is safer in mice.

An improved method of delivering a sclerosing agent for the treatment of malignant pleural effusion

Background

Malignant pleural effusion (MPE) is a devastating sequela associated with cancer. Talc pleurodesis is a common treatment strategy for MPE but has been estimated to be unsuccessful in up to 20–50% of patients. Clinical failure of talc pleurodesis is thought to be due to poor dispersion. This monograph reports the development of a foam delivery system designed to more effectively coat the pleural cavity.

Methods

C57BL/6 mice were injected with Lewis lung carcinoma (LL/2) cells intrapleurally to induce MPE. The mice then received either normal saline (NS) control, foam control (F), talc slurry (TS, 2 mg/g) or talc foam (TF, 2 mg/g). Airspace volume was evaluated by CT, lungs/pleura were collected, and percent fibrosis was determined.

Results

The TF group had significantly better survival than the TS group (21 vs 13.5 days, p < 0.0001). The average effusion volume was less in the talc groups compared to the control group (140 vs 628 μL, p < 0.001). TF induced significant lung fibrosis (p < 0.01), similar to TS. On CT, TF significantly (p < 0.05) reduced loss of right lung volume (by 30–40%) compared to the control group. This was not seen with TS (p > 0.05).

Conclusions

This report describes using a novel talc foam delivery system for the treatment of MPE. In the LL/2 model, mice treated with the TF had better survival outcomes and less reduction of lung volume than mice treated with the standard of care TS. These data provide support for translational efforts to move talc foam from animal models into clinical trials.