Clinicopathological Characteristics And Prognosis Of Young Patients(<50 Years Old)with Non-small Cell Lung Cancer

Purpose:To analyze the clinicopathological characteristics,surgical outcomes and prognosis of young patients(<50 years old)with non-small cell lung cancer(NSCLC),to determine whether they are different from older patients,and to provide more scientific information for the treatment and management of young patients with non-small cell lung cancer.Methods:Based on the SEER database of the National Cancer Institute.A summary analysis of information on patients with non-small cell lung cancer undergoing surgery was performed between 2004 and 2012.Case data were collected by specific methods to analyze the differences in the distribution of clinicopathological features between young and non-young patients.Survival curves were plotted using the Kaplan-Meier method to compare survival differences.At the same time,single factor and multi-factor analysis were used to analyze the related factors affecting the prognosis of non-small cell lung cancer.Results:A total of 45,867 patients were enrolled in the study,including 2850(6.2%)younger patients(<50 years)and 43017(93.8%)older patients(≥50 years).Compared with the older cohort of patients(≥50 years old),more women(55.4%vs 50.7%),more blacks(11.4%vs 8.3%),more Asians or Pacific Islanders(7.0%vs 6.3%),more Secondary radiation therapy patients(18.6%vs 13.0%)are among younger cohort.Among the pathological types,the proportion of adenocarcinoma in younger cohort is higher than that in older cohort(65.4%vs 60.6%),while the proportion of squamous cell carcinoma is lower(20.4%vs 29.4%).Among the younger cohort of patients,advanced cancer accounted for a large proportion,such as stage Ⅲ(20.9%vs 17.4%)and stage Ⅳ(6.6%vs 4.6%),but few patients with lymph node metastasis(67.3%vs 72.6%),distant metastasis patients are more(6.6%vs 4.5%),all of the above differences are statistically significant(P<0.05).Among the tumor sites,there arre 15,256 patients(33.3%)in the superior lobe of right lung,accounted for the most.Young patients had a lower proportion to superior lobe of left lung(22.5%vs 26.6%,P<0.001),while in the inferior lobe of left and the inferior lobe of right ratios were more(P<0.001).Among the different surgical procedures,the majority of young and older patients underwent lobectomy,and more pneumonectomy was performed in young patients(10.1%vs 6.1%,P<0.001).In the survival analysis,the 5-year overall survival rate and lung cancer-specific survival rate of young and non-young patients were(61.5%vs 55.9%,P<0.001)and(68.0%vs 66.0%,P<0.001).After grouping the older cohort of patients,the 5-year overall survival rate of the younger cohort of patients was still optimal compared with the middle-aged group(50-64 years old)and the elderly group(≥65 years old)(61.5%vs 60.0%,P<0.001;61.5%VS 53.6%,P<0.001),After receiving sublobar,lobe,and total lung surgery,the 5-year overall survival rates of younger cohort are 54.3%,64.6%,and 44.0%.However,older cohort are 51.1%,57.9%and 37.9%.The 5-year overall survival rates of younger and older cohort in different pathological stages are:Ⅰa(79.3%vs 71.5%),Ⅰb(69.3%vs 61.5%),Ⅱa(62.6%vs 48.1%),Ⅱb(53.8%vs.46.4%),Ⅲa(44.9%vs 37.3%),Illb(27.3%vs 26.5%)and stase Ⅳ(28.6%vs 26.8%).In addition,a subgroup analysis of younger cohort of patients found that women,Asian ethnicity,and married status showed a higher 5-year overall survival rate,while poor differentiation and advanced tumors are adverse factors attecting prognosis(P<0.01).Multivariate analysis of age.race,gender,marital status,histological grade,tumor stage,surgical procedure,and whether radiotherapy are important factors in the prognosis of patients with non-small cell lung cancer.Compared with the younger cohort,the older cohort of patients(≥50 years old)are independent adverse factors affecting overall survival HR=1.356(95%CI:1.280-1.437),P<0.01.Conclusion:(1)There is a greater representation of African Americans,Asians or Pacific Islanders,women,and adenocarcinoma histology in the younger cohort of patients with NSCLC compared with the older cohort.The younger cohort also received more adjuvant radiation therapy,and the proportion of patients with advanced stage of tumor staging was higher.The younger cohort have better postoperative survival than older cohort,and have a greater survival benefit in the early stage of the tumor.(2)The age,gender,race,marital status,histological grade,pathological type,tumor stage,surgical procedure and radiotherapy are important factors influencing the prognosis of non-small cell lung cancer.The younger cohort have a better prognosis than older cohort,and women,married,lobectomy,and early stage tumors are relative protective factors for the prognosis of younger cohort.