The new case for cervical mediastinoscopy in selection for radical surgery for malignant pleural mesothelioma

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 pre-operative nodal staging are undetermined.

From a prospective database, we identified 212 patients with non-sarcomatoid MPM (160 epithelioid and 52 biphasic). A total of 127 patients underwent extrapleural pneumonectoctomy (EPP) and 85 lung-sparing total pleurectomy (LSTP) with lymphadenectomy. We investigated the effect of nodal burden and distribution in survival by testing for differences between N0, N1 and N2 disease and constructing a theoretical model dividing the patients into four groups according to diseased nodes identified in the surgical specimen: Group 0, no nodal disease; Group CM, nodes accessible by cervical mediastinoscopy (CM): Stations 2, 3a, 4 and 7; Group EBUS/EUS, nodes accessible by endobronchial (EBUS) or endoscopic (EUS) ultrasound: Stations 2, 3a, 4 and 7-11. Group EM, extramediastinal nodes not accessible by CM or EBUS/EUS: Stations 5, 6, internal mammary, pericardial and diaphragmatic lymph nodes.

There was no difference in overall median survival between EPP and LSTP [15.6, SE 1.8, 95% confidence interval (CI) 12-19 months versus 13.4, SE 2.3, 95% CI 9-18 months, P=0.41]. Patients with N0 disease (n=94) had the best prognosis: median survival was 19.6 months (SE 3, 95% CI 13.2-26) versus 12 months for the 19 patients with N1 (SE 1.5, 95% CI 9-15) and 13.6 months for 99 patients with N2 (SE 1.7, 95% CI 10-17), P=0.015. Subgroup analysis of patients with nodal metastases revealed no significant survival difference between group CM and group EBUS/EUS: achieving maximum theoretical diagnostic yield CM could detect 63 (54%) of patients with nodal disease and the median survival of this group was 13.6 months (SE 2, 95% CI 9.6-17.6). EBUS/EUS could detect an additional 30 cases (26%) with survival of 11.3 months (SE 1, 95% CI 9-13.6). The survival in group EM (25 cases, 21%, median survival 18.7 months, SE 6, 95% CI 7-30) was significantly better than groups CM or EBUS/EUS, P=0.002.

There is a strong case for routine CM as a method of prognostic staging in all patients undergoing radical surgery for MPM. The addition of EUS staging and the detection of nodal metastases inaccessible to mediastinoscopy had no prognostic benefit.