The case for cervical mediastinoscopy prior to radical surgery for malignant pleural mesothelioma

Abstract

Eur J Cardiothorac Surg 2004;25:497–501. Pilling JE, Stewart DJ, Martin-Ucar AE, Muller S, O’Byrne KJ, Waller DA. Study Summary: This study was performed to assess whether cervical mediastinoscopy is necessary before radical surgery for malignant pleural mesothelioma (MPM). The authors also study whether lymph nodes size predicts metastatic involvement in patients with MPM. The study included 55 patients who underwent radical excision of MPM. Preoperative assessment included computed tomography (CT) scan of the thorax and upper abdomen in all patients. Only 1 patient had evidence of mediastinal lymph node enlargement on chest CT. Extrapleural pneumonectomy was performed in 51 patients and radical pleurectomy was performed in 4 patients. Most patients had an epithelioid variety of MPM. Mediastinal lymph node dissection showed lymph node metastasis in 17 patients. The mean long axis diameter of malignant lymph nodes was 15.2 mm, whereas that of disease-free lymph nodes was 16.9 mm. According to the authors, malignant lymph nodes in 15 of 17 (88%) patients were accessible by cervical mediastinoscopy. The median survival of 17 patients with extrapleural lymph nodes (4.4 months) was considerably shorter than those without (16.3 months, P = 0.012). The authors concluded that extrapleural metastasis is related to poor survival, and pathologic involvement cannot be predicted from lymph node size. Based on these results, the authors recommend routine mediastinoscopy before radical surgery for MPM. Comments: Malignant pleural mesothelioma has a poor prognosis. Median survival is 8 to 14 months in different studies (Thorax 2001;56:250–256). No form of treatment is conclusively proven to be better than palliative care (Chest 2004;125:1103–1117). Radical surgery as a part of multimodality treatment is an important therapeutic option (BMJ 2004;328:237–238). In a surgical series, overall survival rates were 45% at 2 years and 22% at 5 years. The lymph node-negative patients with epithelial variety of MPM had a 2- and 5-year survival rate of 74% and 39%, respectively (Ann Surg 1996;224:288–294). Mediastinal lymph node involvement is an important predictor of adverse outcome after the surgery (J Thorac Cardiovasc Surg 1996;111:815–825, J Thorac Cardiovasc Surg 1999;117:54–65). Several studies have shown a 28% to 52% incidence of N2 nodal involvement in the resected surgical specimen (Eur J Cardiothorac Surg 2001;19:346–350, J Thorac Cardiovasc Surg 1996;111:815–825). Lymph nodes were found in 31% of patients in the current study, and these patients did not appear to benefit from the radical surgery. Accurate preoperative staging is, therefore, important before surgery. In a prior study, the sensitivity, specificity, and accuracy of CT were 60% 71%, and 67%, respectively, for mediastinal lymph nodes in MPM patients. In contrast, the sensitivity, specificity, and accuracy of cervical mediastinoscopy were 80%, 100%, and 93%, respectively (Ann Thorac Surg 2003;75:1715–1718). The results from current study confirm that chest CT is not sufficient for staging. Chest magnetic resonance imaging (Eur J Cardiothorac Surg 2003;24:1019–1024) and PET scan (J Thorac Cardiovasc Surg 2003;126:11–16) are not reliable and are unlikely to contribute to nodal staging. Cervical mediastinoscopy, therefore, appears to be the only practical way to identify lymph node involvement in MPM. Extrapleural pneumonectomy, the most frequently performed radical surgery, carries a more than 5% operative mortality and more than 25% morbidity (Thorax 2003;58:809–813). Patient selection is of paramount importance. The results of the current study make a strong case for routine preoperative cervical mediastinoscopy before radical surgery for MPM.