Surgical treatment of synchronous multiple lung cancer located in a different lobe or lung: high survival in node-negative subgroup

Background: The International Association for Study of Lung Cancer Staging Committee proposes for the next revision of TNM (tumour, nodes, metastases) classification that additional nodules in a different lobe of the ipsilateral lung moves from an M1 designation to T4, while additional nodule(s) in the contralateral lung should be classified as M1a, because of poorer survival. We analysed the survival after surgery of patients presenting with synchronous lung cancers located in a different lobe or lung. Methods: A database of 1551 patients operated on for non-small-cell lung cancer (NSCLC) between 1990 and 2007 was evaluated for unilateral (other lobe) (n = 15) and bilateral (n = 28) synchronous multiple lung cancers. The relationships among the location of tumours, histology, date of surgery (before and after 2000), lymph node metastasis, type of surgery, adjuvant therapy and survival were analysed. Results: The 5-year survival for all synchronous multiple lung cancers (n = 43) was 34%, with a median survival of 32 months. Postoperative mortality was 7%. On univariate analysis, only lymph node metastasis and surgery before the year 2000 affected the overall survival adversely, and both prognostic factors maintained a statistical significance on multivariate analysis. The 5-year survivals were 57% and 0% for patients without (n = 25) and with (n = 18) lymph node metastasis, respectively (p = 0.004), and were 43% and 18% for patients operated upon after (n = 27) and before (n = 16) the year 2000, respectively (p = 0.01), perhaps reflecting a better selection process related to the extensive use of positron emission tomography (PET) scanning. The 5-year survival was not different between bilateral (43%) and unilateral (27%) synchronous lung cancers (p = n.s.). Conclusions: Our data support complete surgical resection of synchronous multiple lung cancers in patients with node-negative NSCLC. Even patients with bilateral lung cancer should not be treated as metastatic disease. Provided there is no evidence of node and distant metastasis, after an extensive preoperative work-up, including PET scanning and mediastinoscopy, bilateral surgical resection should be performed in fit patients.