Disease and Patient Characteristics related to Survival in a large population-based cohort of patients with Malignant Pleural Mesothelioma (MPM) — ASN Events
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  3. Disease and Patient Characteristics related to Survival in a large population-based cohort of patients with Malignant Pleural Mesothelioma (MPM)

Disease and Patient Characteristics related to Survival in a large population-based cohort of patients with Malignant Pleural Mesothelioma (MPM) (#51)

Anthony Linton 1 2 3 , Nick Pavlakis 3 4 , Steven Kao 1 3 , Stephen Clarke 3 4 , Janette Vardy 2 3 , Nico van Zandwijk 1 3
  1. Asbestos Diseases Research Institute, Concord, NSW, Australia
  2. Concord Repatriation General Hospital, Sydney
  3. University of Sydney, Sydney
  4. Royal North Shore Hospital, Sydney

Aims
Although the prognosis of MPM remains poor, a small proportion of patients demonstrate long-term survival. We assess what factors independent of treatment predict for an improved prognosis.
Methods
We reviewed patients registered with the NSW Dust Diseases Board (2002-2009) evaluating a-priori prognostic factors including age, gender, histological subtype, stage and Neutrophil-Lymphocyte ratio (NLR) using Kaplan-Meier and Cox-regression analysis, and by treatment interventions, smoking and asbestos exposure. Exploratory subgroup analyses compared these factors in long-term survivors(>20 months) versus the remainder of the study population.
Results:
We identified 913 patients: 90% male; median age 71.9 years; histological subtype (epithelioid 54%; biphasic 11%; sarcomatoid 16.3%; unknown 19%); stage (Tx-I-II 49%; III-IV 51%). Treatment: chemotherapy 51%, extrapleural pneumonectomy (EPP) 6% (with 67% receiving chemotherapy). Median age of first occupational asbestos exposure was 18 years, cumulative exposure 24 years, latency from exposure to diagnosis 50 years.
Median overall survival (OS) was 10.0 months; 15.0 months in chemotherapy and/or EPP patients, 5.8 months in patients receiving neither. Younger age (<70 vs. >70yrs; 13.1 vs. 8.5 months;p<0.001); female gender (12.0 vs. 9.8months;p<0.001); epithelioid subtype (11.8 vs. 7.2 months;p>0.001); and NLR <5 (12.9 vs. 7.5months;p<0.001) were associated with prolonged OS. Patients who underwent chemotherapy (13.6 vs. 7.2 months; p<0.001) and EPP (17.9 vs. 9.6 months; p<0.001) had improved survival. Smoking history and cumulative asbestos exposure did not affect survival. On multivariate analysis, age, gender, subtype, NLR, EPP and chemotherapy administration remained significant.
24% of patients survived over 20 months:14% underwent EPP, 63% received chemotherapy. Epithelioid histology (p<0.001), chemotherapy (p=0.002), EPP(p=0.01) and NLR<5(p=0.007) were independently associated with survival over 20 months.
Conclusions
In this large, population-based cohort, we have validated age, gender, histological subtype and NLR as significant prognostic factors. Patients undergoing EPP/chemotherapy demonstrated better survival; however 86% and 37% of long survivors respectively did not receive radical surgery or chemotherapy.