Clinical And Pathological Characteristics And Survival Analysis Of NSCLC Patients With Skip Metastasis In Stage PN2/?

Objective: NSCLC(non-small cell lung cancer)with mediastinal lymph node metastasis is a kind of highly heterogeneous disease.There are significant differences in the treatment strategy and prognosis in different sub-types of N2 NSCLC patients.The lymph node staging(N staging)in the current 8th edition of TNM staging is still staging according to the location of lymph node metastasis,but with the in-depth study of NSCLC patients,it is gradually found that although the same is the N2 stage,after the same treatment,the prognosis of different patients is very different.Therefore,it is very necessary to further divide the N2.The purpose of this study is to investigate the clinical and pathological features of NSCLC patients with mediastinal lymph node metastasis for exploring the influencing factors and to analyze the survival of N2 group for evaluating the value of different staging methods to estimate the prognosis.Methods: From July 1,2011 to December 31,2014,patients with NSCLC in the Department of thoracic surgery in Hunan cancer hospital were treated with surgical treatment and were staged III after operation.The clinical and pathological data were analyzed retrospectively,and the patients were followed up.Patients were grouped according to different N2 lymph node metastasis status.The difference between different groups was analyzed,and the independent influencing factors were evaluated.Survival curves were drawn from follow-up data,and the relationship between N2 lymph node metastasis status and prognosis was analyzed.Results: After screening,162 patients with III/pN2 non-small cell lung cancer were enrolled,27 cases of N2a1(single station N2 skip metastasis),49 cases of N2a2(single station N2 non-skip metastasis),17 cases of N2b1(multi-station N2 skip metastasis)and 69 cases of N2b2(multi-station N2 non-skip metastasis),represent 16.7%,30.2%,10.5%,42.6% respectively.There were significant differences in the mode of operation,the site of the mass(divided into upper and lower lobes),the site of the mass(divided into five lobes),the number of the mediastinal lymph node dissection stations,the number of the mediastinal lymph node metastasis stations,the number of mediastinal lymph node metastasis,the lymph node metastasis and the total dissection rate of lymph nodes in the two groups,including the tumor site(upper left lobe,right lower lobe,P=0.023/0.033),the largest diameter of tumor(P=0.012)were independent risk factors for skip metastasis.In two groups of single station metastasis,there was significant difference in the sex,smoking history,pathological type,mass diameters product,pT stage,the number of mediastinal lymph node dissection stations,the number of mediastinal lymph node metastasis stations,the number of mediastinal lymph node metastases,the rate of mediastinal lymph node metastasis,the subcarinal lymph node metastasis,the rate of entire resected lymph node metastasis and skip metastasis,including pathological type(adenosine squamous cell carcinoma,P=0.041)and pT stage(T3 stage,P=0.046)were independent risk factors for single station metastasis.The prognosis analysis showed that the median PFS of patients with N2a1,N2a2,N2b1 and N2b2 was 54.7 months,27.4 months,23 months and 13.4 months respectively.The median OS was not reached,65.5 months,43.2 months and 35.4 months respectively.The 3 year PFS rate was 65.4%,45.6%,15.4% and 19.4%,respectively.Conclusion: The location and size of tumor are independent factors of skip metastasis.According to whether single metastasis station and whether skip metastasis,the N2 phase is divided into 3 subtypes,and there was significant difference in survival among different subtypes.