Validation Of UICC-AJCC 8th Lung Cancer Staging System In Predicting Prognosis Of Patients With Pulmonary Neuroendocrine Tumors

ObjectiveTo investigate the clinical characteristics,and prognostic factors of pulmonary neuroendocrine tumors(pNETs).And to validate the prognostic significance of the 8th Union for International Cancer Control/American Joint Committee on Cancer(UICC-AJCC)lung cancer staging system among pNETs patients.MethodThe SEER*Stat software was used to identify patients whose pathological diagnosis were pNETs(large cell neuroendocrine carcinoma,LCNEC;pulmonary carcinoid,PC)from 2004 to 2014.The clinical date of pNETs patients were retrospectively analyzed,including general information(gender,age at diagnosis,race,etc.),primary tumor characteristics(size,location,grading,etc.),distant metastasis,operation,and survival time.Patients were staged according to both 7th and 8th UICC-AJCC lung cancer staging system.And we used the Akaik's Information Criterion to measure goodness of fit of both staging system.In this analysis,T-test was adopted in numerical variables,Chi-square test was used to compare categorical variables.Kaplan-Meier methods were used to perform single factor analysis and draw survival curve.The survival rates were analyzed by life table method and compared by log-rank test.Cox multivariate regression analyses were applied to evaluate factors that influenced prognosis.A result was considered statistically significant if a two-side P value <0.05 was achieved.ResultA total of 3320 patients were enrolled,involving 1352 males(40.7%)and 1968females(59.3%).The ratio of male to female was 1:1.46.Of them,2890(87.0%)were white while 307(9.2%)were black.The average age was(61.2±13.0)years and median age was 65.0.1829(55.1%)were married and 1321(39.8%)were single,including people who were divorce or separation.The most common tumor site was in the upper lobe.Morbidity in right pulmonary was higher than that in left.The main pathology type was PC.The constituent ratio of age,sex,operation numbers and TNM stages inLCNEC group and PC group had significant difference.For LCNEC patients,the univariable predictors of survival were gender,age,primary site,laterality,surgery,and TNM stage.Multivariate analysis demonstrated that independent prognostic factors were gender,age,surgery,and TNM stage.For PC patients,the univariable predictors of survival were gender,race,age,primary site,laterality,surgery,and TNM stage.Multivariate analysis demonstrated that independent prognostic factors were gender,age,surgery,and TNM stage.Results of surgical group were better than non-surgical group under different TNM stages.According to UICC-AJCC 7th and 8th lung cancer staging system,differences of appropriate survival curves between two staging systems were statistically significant.The Akaike's Information Criterion value was 12149.894 for the 8th edition of lung cancer staging system and 12164.896 for the 7th edition.Conclusion1.The patients with PC were more than LCNEC.The majority of LCNEC were male while PC were female.The LCNEC patients' age at diagnosis were older than PC patients'.2.In LCNEC and PC,the common tumor site was in the right pulmonary.3.As compared with PC,LCNEC often presented advanced stage,with a much worse prognosis.4.Sex,age,surgery and TNM stage were correlated with LCNEC and PC prognosis.5.The UICC-AJCC 8th lung cancer staging system can better reflect the prognosis of patients with pulmonary neuroendocrine tumors,and its prognostic value is superior to the 7th edition.