Intrathoracic infusion therapy of thymic peptides and chemical irritants for malignant pleural effusion: a meta-analysis of 24 randomized controlled trials

Background: To further determine the clinical efficacy and survival of intrathoracic infusion with TPs and chemical irritants and their therapeutic threshold and optimal control regimen to achieve a desired response in malignant pleural effusion (MPE). Methods: We collected all randomized controlled trials (RCTs) of TPs with chemical irritants from Chinese and English databases (from inception until September 2019), and performed a new meta-analysis following the PRISMA guidelines. We measured their bias risk, summarized data using meta-analysis, and evidence quality using the Grades of Recommendation Assessment, Development and Evaluation approach. Results: We collected 24 trials involving three TPs and platinum and 1,592 patients. Most trials had unclear bias risk. TPs with platinum significantly improved complete response [4.02 (3.12 to 5.18)] and quality of life [3.64 (2.34 to 5.66)], the 0.5-year overall survival (OS) rate [5.75 (3.02 to 10.92)], and 1-year OS rate [5.29, (1.71 to 16.36)], and reduced the treatment failure, myelosuppression, and gastrointestinal toxicity. For patients with moderate to large volume of pleural effusion, KPS score ≥50 to 60, or AST ≥3 months, the thymosin (200–300mg/time), thymopentin (2mg/time) or thymosin alpha 1 (3.2mg/time) with cisplatin (30–40mg/m 2 ), carboplatin (400mg/m 2 ), or oxaliplatin (100mg/m 2 ) are possible regimens for achieving a desired success, and low failure. Most results were robust and moderate quality. Conclusion: The moderate evidence suggests that the TPs with platinum is beneficial to the patient with MPE, and provides evidence for the therapeutic threshold and possible regimens that may achieve a desired success and reduce the failure.