Pattern of Spread to N2 Lymph Nodes Predicts Survival in Patients with Biphasic Pleural Malignant Mesothelioma.
Maria G McIntire, William G Richards, David J Sugarbaker, Lucian R Chirieac. Caris Life Sciences, Newton, MA; Brigham and Women's Hospital, Boston, MA
Background: In patients with diffuse malignant mesothelioma (MM), metastases to extrapleural N2 lymph nodes are a poor prognostic characteristic. Studies from our group have shown that metastases to N2 lymph nodes from biphasic MM have either both epithelioid and sarcomatoid histologies or epithelioid histology alone, but the clinical significance of this observation is unknown. In this study we investigated the clinical significance of the component metastatic to N2 lymph nodes from patients with biphasic MM.
Design: We identified 715 consecutive patients with MM (462 epithelioid, 231 biphasic, and 22 sarcomatoid type) treated by extrapleural pneumonectomy at Brigham and Women's Hospital between 1988 and 2009. Of the 231 biphasic MMs, we found 74 with metastases to mediastinal N2 lymph nodes. We evaluated the N2 lymph node metastases of 65 of these patients with biphasic MM and available pathology material and correlated the findings with overall survival.
Results: All 65 patients (11 female/54 male; mean age 60.1; range 31-88) had a diagnosis of biphasic MM metastatic to N2 lymph nodes. Thirty-eight patients (58%) with biphasic MM had both epithelioid and sarcomatoid components in the N2 lymph nodes and twenty-seven patients (42%) showed spread only of the epithelioid component to the N2 lymph nodes. The mean follow-up period after surgery was 10.7 months. The median survival of patients with mixed histology in the N2 lymph nodes was 8.8 months versus 11.5 months for those with an epithelioid component alone (p=0.040).
Conclusions: Our data indicate that the presence of a mixed component in the N2 lymph nodes predicts a worse overall survival in patients with biphasic MM. The results of our study emphasize the importance of histologic classification of not only the surgical specimen but also the lymph node metastases and highlight the biologic complexity of disease progression in biphasic MM.
Tuesday, March 1, 2011 9:30 AM
Poster Session III # 279, Tuesday Morning