Survival impact of thoracic cavity reduction during neoadjuvant chemotherapy in patients undergoing surgery for malignant pleural mesothelioma.
e20067 Background: It is difficult to predict prognosis for malignant pleural mesothelioma (MPM). The association of thoracic asymmetry and survival in patients with MPM was reported by Cho et al. in at the 18th World Conference on Lung Cancer. Here we investigated the survival impact of thoracic cavity reduction during neoadjuvant chemotherapy (NAC). Methods: The subjects were patients with resectable epithelioid MPM who underwent NAC with platinum and pemetrexed followed by surgery at the Hyogo College of Medicine from Jan 2009 to Aug 2018. The length of the ant-post and med-lat extent of both hemithoraces at the level of carina was measured before and after NAC. Asymmetric ratio (ASR) was defined as the product of the ant-post and med-lat extent of affected side divided by those of healthy side. Results: One hundred thirty-three patients were enrolled: median age 66 (16-79) years, M/F 112/21, R/L 70/63, extrapleural pneumonectomy 40 and pleurectomy/decortication 93. Significantly poor prognosis was associated with ≥ 10mm reduction of the med-lat extent of affected side during NAC and ≥ 10% reduction of the product of the ant-post and med-lat extent of affected side during NAC (p = 0.0021). ASR ≤ 0.9 before or after NAC was not associated with significantly poor survival. Conclusions: This study revealed that thoracic cavity reduction during NAC was associated with significantly poor prognosis of MPM.