Invited Commentary

Abstract

The article by Yu and colleagues [1Yu Y.C. Hsu P.K. Yeh Y.C. et al.Surgical results of synchronous multiple primary lung cancers: similar to the stage-matched solitary primary lung cancers?.Ann Thorac Surg. 2013; 96: 1966-1974Abstract Full Text Full Text PDF PubMed Scopus (67) Google Scholar] concerning synchronous primary lung cancers highlights several points that are important for the diagnosis, staging, and treatment of multiple lung cancers. To begin, there is a lack of clarity concerning synchronous tumors as to whether they represent lung cancers identified on presentation, or one cancer with subsequent further interval growth of another malignant nodule within a 2-year period [2Martini N. Melamed M. Multiple primary lung cancers.J Thorac Cardiovasc Surg. 1975; 7T: 606-612Google Scholar]. This is important for CT lung cancer screening programs in which 20% of patients are identified and followed with nodules [3Bach P.B. Mirkin J.N. Oliver T.K. et al.Benefits and harms of CT screening for lung cancer. A systematic review.JAMA. 2013; 307: 2418-2429Crossref Scopus (957) Google Scholar]. Some of these nodules, if malignant, may also be multicentric on presentation or develop at a later date. It is possible that synchronous tumors from these groups possess different biologic behaviors [4Greenberg A.K. Lu F. Goldberg J.D. et al.CT scan screening for lung cancer: risk factors for nodules and malignancy in a high-risk urban cohort.PLOS one. 2012; 7: e39403Crossref PubMed Scopus (32) Google Scholar]. This study involves a significant number of nonsmoking participants; it is important to note that this might represent a geographic trend that could be associated with specific somatic mutations. These factors might reflect evidence for a gender survival bias, reported elsewhere in a published pooled analysis of prognostic survival factors for synchronous lung cancers [5Tanetyanon T. Finley D.J. Fabian T. et al.Prognostic factors for survival after complete resections of synchronous lung cancers in multiple lobes: pooled analysis based on individual patient data.Ann Oncol. 2013; 24: 89-94Google Scholar]. Age, size, and location are also identified as risk factors for survival. It is not unreasonable to expect age and location (extent of surgical resection) to effect survival; it is also possible that tumor size is associated with lymphovascular and nodal metastases, negatively effecting survival. The authors note that the specific tumor histologic pattern will effect overall survival as has been shown by further subtyping ground-glass nodules [6Shrager J. Approach to the patient with multiple lung nodules.Thorac Surg Clin. 2013; 23: 257-266Abstract Full Text Full Text PDF PubMed Scopus (22) Google Scholar]. Furthermore, routine histology performed on multiple lung nodules, without analysis of clonality by genomic or mutational testing, might not adequately differentiate metastatic from multicentric tumors [7Dacic S. Dilemmas in lung cancer staging.Arch Pathol Lab Med. 2012; 136: 1194-1197Crossref PubMed Scopus (8) Google Scholar]. This differentiation could be of critical importance in separating multiple early stage IA cancers from metastatic stage IV disease, thus effecting treatment decisions. The results of this study imply that synchronous lung tumors, in the absence of multiple disease sites and without metastatic nodal involvement, regardless of clonality, have equivalent survival with early stage lung cancer. The authors suggest that more data are needed to support or refute adjuvant treatment following the removal of synchronous lung tumors. The role of stereotactic body radiation therapy as a treatment modality in combination with surgery remains to be established. In summary, this article reflects the need for a sophisticated multidisciplinary approach to lung cancer. This approach would encompass advanced diagnostic testing and collaboration between oncologists and surgeons for best personalized care. Surgical Results of Synchronous Multiple Primary Lung Cancers: Similar to the Stage-Matched Solitary Primary Lung Cancers?The Annals of Thoracic SurgeryVol. 96Issue 6PreviewTreatment for synchronous multiple primary lung cancers (SMPLC) remains controversial. Some surgeons treat SMPLC like advanced lung cancer, whereas other surgeons treat SMPLC as separate primary lung cancers. In this study, survival of SMPLC patients and matched-stage solitary primary lung cancer (SPLC) patients after surgical treatment were compared. Full-Text PDF