The impact of lymph node station on survival in 348 patients with surgically resected malignant pleural mesothelioma: Implications for revision of the American Joint Committee on Cancer staging system

Flores, Raja M.; Routledge, Tom; Seshan, Venkatraman E.; Dycoco, Joseph; Zakowski, Maureen; Hirth, Yael; Rusch, Valerie W.

doi:10.1016/j.jtcvs.2008.02.069

« Previous Next »The Journal of Thoracic and Cardiovascular Surgery
Volume 136, Issue 3 , Pages 605-610, September 2008

The impact of lymph node station on survival in 348 patients with surgically resected malignant pleural mesothelioma: Implications for revision of the American Joint Committee on Cancer staging system

Raja M. Flores, MD
- Thoracic Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York
- Address for reprints: Raja M. Flores, MD, Thoracic Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, Room C-879, New York, NY 10021.
Tom Routledge, MD
- Thoracic Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York
Venkatraman E. Seshan, PhD
- Biostatistics Service, Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, New York
Joseph Dycoco, BA
- Thoracic Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York
Maureen Zakowski, MD
- Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, New York
Yael Hirth
- Thoracic Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York
Valerie W. Rusch, MD
- Thoracic Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York

Received 3 May 2007; received in revised form 18 October 2007; accepted 12 February 2008. published online 01 July 2008.

Objectives

The propensity of malignant pleural mesothelioma to metastasize to N1 or N2 nodes and their corresponding prognostic value is unclear. The American Joint Committee on Cancer staging system groups N1 and N2 disease together as stage III. The goal of this study was to define the prognostic value of specific nodal stations.

Methods

Patients with malignant pleural mesothelioma who underwent resection were identified from an institutional database. Nodal stations were defined by the American Joint Committee on Cancer lung cancer node map classification. Survival was analyzed by the Kaplan–Meier method, log-rank test, and Cox proportional hazards analysis.

Results

From 1990 to 2006, 348 patients were identified: 279 men and 69 women with a median age of 67 years (range 26–85 years). Extrapleural pneumonectomy was performed in 223 cases, and pleurectomy/decortication was performed in 125 cases. Survival differences (P < .01) were observed between 2 groups: N0 or N1(+) (median survival = 19 months) and N2(+), N2/N1(+) and internal thoracic(+) (median survival = 10 months). Survival was influenced by the number of involved N2 stations (0, 1, 2, or more: P < .001). Multivariate analysis grouping all N2 and internal thoracic(+) versus N1(+) and N0 demonstrated a hazard ratio for survival of 1.7 (P < .0001) controlling for T3/T4 status (hazard ratio = 1.3, P < .01), non-epithelioid histology (hazard ratio = 1.7, P < .0001), extrapleural pneumonectomy (1.1, P = .4), and male gender (hazard ratio 1.4, P < .01).

Conclusion

This study confirms a preferential pattern of drainage of malignant pleural mesothelioma to N2 rather than N1 lymph nodes, but suggests that N1 only nodal involvement should be classified as lower stage disease. Multiple N2 nodal site involvement could potentially be classified as higher stage disease than single station N2. Our results emphasize the need for larger, confirmatory multicenter studies that could lead to revision of the current staging system.

Abbreviations and Acronyms: AJCC, American Joint Commission on Cancer, EPP, extrapleural pneumonectomy, HR, hazard ratio, P/D, pleurectomy/decortication, MPM, malignant pleural mesothelioma