Clinical and pathological features of three-year survivors of malignant pleural mesothelioma following extrapleural pneumonectomy

Abstract

Objective: Surgery-based multimodality therapy is associated with long-term survival in a significant number of pleural mesothelioma patients. We explored factors associated with 3-year survival in patients with malignant pleural mesothelioma, who underwent extrapleural pneumonectomy, to help refine patient selection criteria for surgery and other therapies.

Methods: With Institutional Review Board approval, we reviewed records in the International Mesothelioma Program Patient Data Registry to identify all patients, who underwent extrapleural pneumonectomy for malignant pleural mesothelioma between 1 January 1988 and 31 May 2007. Vital status as of 31 May 2010 was confirmed. Fisher's exact test was used to compare dichotomous variables for patients who survived at least 3 years with those who did not. Kaplan-Meier analysis was used to estimate the cumulative survival probability for all 3-year survivors.

Results: Among 636 patients who underwent extrapleural pneumonectomy, 117 (18%) survived at least 3 years following surgery, including 26 remaining alive and four lost to follow-up. Of the 3-year survivors, 39 (33%) were female, 61 (52%) had left-sided disease, and the median age was 56 years (range 27-77). Relatively more 3-year survivors were younger than, or at the median age (p=0.0005), or female (p=0.0007), had epithelial tumor histology (p<0.0001) and/or had normal white blood cell count (p=0.0001), hemoglobin (p<0.0001), or platelet count (p<0.0001) preoperatively. The median survival of the 117 patients who survived 3-years was 59 months. Among these patients, a significant association between age and survival was found only for women.

Conclusions: A significant proportion of patients undergoing extrapleural pneumonectomy for pleural mesothelioma experienced extended survival. Although favorable prognostic features were more common, the cohort of 3-year survivors included a substantial number of patients with late-stage disease. The longest survival (median greater than 7 years) was experienced by women under the median age of 56 years. These data support the role of macroscopic cytoreduction through extrapleural pneumonectomy in the context of multimodality therapy to extend survival for malignant pleural mesothelioma. Further efforts to treat micrometastatic disease and improve patient selection are warranted.