Progress Report on the Palliative Therapy of 100 Patients with Neoplastic Effusions by Intracavitary Low-Dose Interleukin-2

OBJECTIVE: Several cytokines, particularly IL-2 and interferons, are thought to be effective in the palliative therapy of neoplastic effusions. We report on the activity and toxicity of intracavitary administration of low-dose IL-2 in a case series of 100 cancer patients with neoplastic effusions. METHODS: One hundred patients with advanced solid tumors and neoplastic effusions underwent IL-2 intracavitary injection as first-line treatment. The most common sites of fluid accumulation were pleura (n = 68), peritoneum (n = 21) and pericardium (n = 11). Breast cancer, lung cancer and mesothelioma were the most frequent neoplasms in our series. One cycle consisted of intracavitary IL-2 at 6,000,000 IU on days 1 and 7. RESULTS: According to Paladine's criteria, an objective clinical response was achieved in 72% (complete response in 27% and partial response in 45%), with a median duration of 5 months (range: 1-11 months). The peritoneum was the least responsive site for neoplastic effusion reduction. IL-2 intracavitary injection was well tolerated in all patients; the only toxicity observed was fever >38 degrees C in 6% of the patients. CONCLUSION: This study shows that intracavitary injection of IL-2 represents a feasible, well-tolerated and effective therapy of neoplastic fluid accumulation. Further studies are needed in order to compare the effectiveness of intracavitary IL-2 with other standard treatments.