Surgical Treatment And Prognosis For Synchronous Multiple Primary Non-Small Lung Cancers

Background and objective:With the increase in use of high-resolution computed tomography(HRCT),the identification of synchronous multiple primary non-small cell lung cancers(SMPLC)is becoming a rising common clinical problem.But only large scale hospitals possess a certain degree of treatment experiences.And many doctors still lack understanding of SMPLC,they staged the SMPLC patients as metastatic disease according to the 7th(2009)and 8th(2015)edition TNM classification for lung cancer.Thus,many patients with SMPLC were over staged as III/IV stage and finally lost the opportunity to undergo surgical treatment.According to the National Comprehensive Cancer Network(NCCN)guideline for non-small cell lung cancer(2017,version 2),surgical treatment is the first selection for SMPLC patients without contraindications.We carried out this study aiming at providing experiences for clinical diagnosis and treatment for patients with SMPLC.Materials and Methods:A total of 43 SMPLC patients who met the modified Martini-Melamed criteria and with clinical data retained between November 2012 and July 2016 underwent complete resection at the Department of Thoracic surgery,Shandong Provincial Hospital.The relationships between gender,age,family history of cancer,number of tumors,location of tumors,tumor size,tumor histology,regional lymph node metastasis,type of surgery,pathological stage,epidermal growth factor receptor(EGFR)mutation,mortality and survival were further analyzed.Results:Among the 43 patients,26(60.5%)patients were woman,17(39.5%)patients were man.Thirty-four(79.1%)patients were verified with 2 tumors and 9(20.9%)patients with more than 2 tumors.Twenty-nine(67.4%)patients had ipsilateral tumors while 14(32.6%)patients had contralateral tumors.Synchronous multiple primary lung adenocarcinornas(SPLA)were present in 38(88.4%)patients.Eleven patients with contralateral tumors went through one-stage surgical treatment.The mean postoperative hospitalization days was 9.36 which was longer than patients underwent surgeries in ipsilateral lung(average 8.79 days),but there is no statistical difference between the two group(P=0.512).Five patients underwent gene detection for every lesion independently.The results showed different tumors in the same patient could carry different epidermal growth factor receptor(EGFR)mutations.The 1-year and 3-year OS rate were 97.0%and 76.7%,respectively,while the 1-year and 3year DFS were 92.1%and 57.9%.Larger maximal tumor dimension(P=0.015),advanced pN stage(P=0.002),lesions with more solid ingredient(P=0.005)and advanced TNM stage(P=0.013)were correlated with poor OS,while larger maximal tumor dimension(P=0.002)and not all adenocarcinomas histologic type(P=0.002)were correlated with poor DFS.Among the 38 SPLA patients,12 patients were male,26 patients were female.Surgical outcomes verified 29 patients with 2 tumors and 9 patients with more than 2 tumors.The 1-year and 3-year OS rate were 96.6%and 74.2%.The 1-year and 3-year DFS rate were 93.6%and 71.8%.Larger maximal tumor dimension(P<0.001),lymph nodes metastases positive(P=0.001)and advanced TNM stage(P=0.022)were correlated with poor OS.Larger maximal tumor dimension(P<0.001),and lymph nodes metastases positive(P=0.046)were correlated with poor DFS.Conclusion:Multiple lung malignant lesions should not be taken as metastasis for granted and the possibility of MPLC also should be considered.Mutational status of EGFR could be used as a clinical reference to diagnose patients with SPLA.