Malignant pleural effusions occur in up to 750,000 patients with malignant cancer each year, and are associated with debilitating symptoms requiring frequent intervention. The most successful treatment for malignant pleural effusion is inducing pleurodesis through talc administration. While this is an effective treatment, it requires hospitalization for up to a week. An alternative outpatient option is fluid drainage through an indwelling pleural catheter (IPC), but the likelihood for pleurodesis with this method is lower.
The IPC-PLUS trial was a randomized, placebo-controlled trial that compared the efficacy of inducing pleurodesis with outpatient talc administration through an IPC to a placebo and IPC. After enrollment in the study and placement of IPC, patients underwent pleural fluid drainage regularly on an outpatient basis. Patients without substantial lung entrapment at day 10 after IPC insertion (N = 154) were then randomized to receive either 4 g talc slurry via IPC or a placebo (sodium chloride 0.9% solution). Next drainage took place between 12 and 36 hours after administration of talc or placebo, and subsequently at least twice per week for the duration of the trial. The primary endpoint was successful pleurodesis at 35 days post randomization, and patients were followed for a total of 70 days or until death (whichever occurred first).
At day 35, 43% of patients in the talc group had achieved pleurodesis, while pleurodesis occurred in only 23% of the placebo group (HR 2.2, P = .008). Similar results were seen at day 70 post randomization (51% vs 27%; HR 2.24, P = .003). Total volume of fluid drained over a period of 2 weeks favored talc administration at day 35 and day 70. Patients receiving talc reported a significantly better overall quality of life than the placebo group, and symptom assessment scores were improved in the talc group, with significant differences in the mean scores on the visual-analogue scale for chest pain and pain. There were no significant differences between the two treatment arms in effusion size, length of hospitalization, and adverse events. Importantly, there was no significant difference in blockages of the IPC.
The investigators concluded that administration of talc through an IPC is significantly more effective at inducing pleurodesis than a IPC alone in patients with malignant pleural effusions. They highlighted that while follow up for this study is short, the continued benefit of talc at day 70 is clinically meaningful given the short survival of patients with malignant pleural effusions.