Purpose Selection criteria for radical surgery in malignant pleural Mesothelioma (MPM) and related clinical trials remain controversial. The relative importance of nodal metastases and the need for preoperative nodal staging are undetermined.
Methods From a prospective database, we identified 203 patients (175 male and 28 female) with non-sarcomatoid MPM (Epithelioid 154 patients; Biphasic 49 patients). Preoperative staging included CT and mediastinoscopy. We investigated the effect of nodal burden and distribution on overall survival.
Results 125 patients underwent extrapleural pneumonectomy (EPP) and 78 radical pleurectomy/decortication (RPD) all with systematic nodal dissection. There was no difference in survival between EPP or RPD: 1 year 63% vs 56%; 3 year 17% vs 15% and 5 year 8% vs 5% p=0.55. The median number of lymph nodes resected was 10 (1–58); 88 (43%) patients were N0, 18 (9%) N1 and 97 (48%) N2. Patients with N0 disease had the best prognosis: median survival 22 months (SE 3, 95% CI 16 to 28) versus 11 months (SE 3, 95% CI 4 to 18) for N1 and 14 months (SE 1, 95% CI 11 to 17) for N2, p=0.005. There was no significant survival difference between N1 and N2, p=0.85. Overall survival was associated with the absolute number of positive extrapleural lymph nodes (p=0.05) and the number of extrapleural nodal stations involved (p=0.01) but not, the total (intra and extra pleural) number of involved nodes or stations (p=0.13 and 0.23).
Conclusions Extrapleural nodal status remains one of the most important prognostic factors following radical surgery for malignant pleural Mesothelioma. These data have important implications for preoperative staging and revision to the current IMIG staging system.