P1.16-18 Pleural Malignant Effusion. Is it Possible to Predict Recurrence After Palliative Pleural Procedure?

Abstract

Malignant pleural effusion (MPE) accounts for several hospital admissions. MPE recurs rapidly in a considerable number of patients. Since MPE is associated with poor survival, a detailed prognosis may help to recognize patients with at higher risk of recurrence, aiming to individualize treatment strategies. However, there have been few studies that evaluated factors, including systemic therapy, associated with MPE recurrence. The aim of this study was to recognize risk factors of recurrence in symptomatic patients only, who required a pleural approach. A prospectively assembled database was analyzed to search for patients with symptomatic MPE. The obtained data included basic demographics, primary tumor site, performance status, neutrophil/lymphocyte ratio (NLR) and platelets/lymphocyte ratio. Metastatic sites were also evaluated, which was defined as presence of any numbers of metastasis at each organ. Regarding the postoperative period, we analyzed pleural effusion recurrence, the palliative approach used, in addition to the biochemical profile of pleural fluid. Pleural thickening and pulmonary infiltrate were also described. Systemic treatment was evaluated. Patients were classified into three groups at MPE diagnosis: systemic treatment-naïve patients, patients who received first-line systemic treatment and patients receiving second-line systemic treatment or further therapy. The quantitative variables without definite cutoff points were submitted to the ROC (Receiver Operating Characteristic) curve, using a sub-sample of 50% of the recorded cases. Cutoff points were defined as the ones with sensitivity and specificity values >0.80. Univariate and multiple Cox regression models were used to evaluate the risk of recurrence (HR) and their respective 95% confidence intervals (95%CI). Of the 288 analyzed patients, the most frequent main procedure was pleurodesis (43.1%). Disease recurrence occurred in 58 patients (20.1%). Recurrence-free survival was 73.3% at 12 months. Patients submitted to the pleurodesis procedure had a longer recurrence-free survival of 84.6%, with HR = 0.33 (95%CI = 0.17 - 0.63) when compared to patients who underwent the pleural drainage. Regarding the chemotherapy lines of treatment, Cox univariate analysis showed that the risk of recurrence for those submitted to the 1st line of palliative CT was HR = 3.19 (95% CI = 1.32 - 7.70) and for the 2nd line of palliative CT, HR = 7.32 (95% CI = 3.34 - 16.07) when compared to the systemic treatment-naïve patients. The independent factors for recurrence-free survival were procedure and chemotherapy lines. Patients who were submitted to pleurodesis had a protective factor for recurrence, with an HR = 0.34 (95% CI = 0.15 - 0.74, p = 0.007). On the other hand, patients submitted to the 1st and 2nd line of palliative CT had, respectively, an HR risk = 2.81 (95% CI = 1.10-7.28, p = 0.034) and HR = 3.23 (95% CI = 1.33 - 7.84, p = 0.010). Patients receiving the first or second line of systemic treatment have a higher risk of MPE recurrence when compared to patients who underwent MPE treatment before starting the systemic treatment. The definitive treatment of MPE, such as pleurodesis, was associated with a lower risk of MPE recurrence.