Prognostic Comparison Of Different Histological Subtypes Of Invasive Peripheral Small Lung Adenocarcinoma (≤2cm)

Objective: To explore whether there are differences in clinical pathologicalfeatures and the prognosis of the five major histological subtypes of the invasiveadenocarcinoma and to probe whether the new classification criteria provides guidingsignificance for clinical prognosis under the2011version of the internationalmultidisciplinary lung adenocarcinoma classification criteria.Methods: By collecting the clinical and pathological data of163patients withperipheral small lung adenocarcinoma who went through surgical excision and werepathologically confirmed of invasive adenocarcinoma in the First Affiliated Hospital ofDalian Medical University from January2006to December2009.According to thelatest2011international multidisciplinary classification of lung adenocarcinoma jointlyformulated by the International Association for the Study of Lung Cancer(IASLC)/American Thoracic Society (ATS)/European Respiratory Society (ERS),thisstudy re-examined the tumor biopsy and determined the main pathological subtypes,thepathological subtypes were divided into five groups: lepidic group, acinar group,papillary group, micro-papillary group, and solid group. The clinical and pathologicaldata of the patients were retrospectively analyzed, and follow-up visits were made untilDecember2012. Statistical analysis of the differences between the five groups in age,gender, pleural traction, CEA level and other6aspects was made in this study byadopting Chi-square test and rank sum test. In addition, Kaplan–Meier, Log-rank andCox regression were used respectively to make survival analysis, univariate analysisand multivariate analysis so as to evaluate the prognostic impact of various factors.Result: The statistics showed that the differences between the five groups in age,gender, CEA levels, degree of tumor differentiation, tumor size were not significant (P>0.05) and displayed statistical significance in whether there is pleural traction, lymphnode metastasis, N stage, clinical stage, and postoperative recurrence and metastasis (P<0.05). Among all the five groups, the micro-papillary group had the highest rate of lymph node metastasis (63.6%) and postoperative recurrence and metastasis (36.4%).The Kaplan-Meier survival analysis showed that lepidic group had the best prognosis,the5-year survival rate was95.6%.The acinar group and the papillary group hadrelatively good prognosis, the5-year survival rate were85.5%and78.6%.The solidgroup had poor prognosis, the5-year survival rate was71.8%.The micro-papillarygroup had the worst prognosis,the5-year survival rate was63.6%,which wasstatistically significant (P <0.05).Univariate analysis displayed that new lungadenocarcinoma classification criteria, lymph node metastasis, N stage, and clinicalstage were the factors that influenced the prognostic of invasive peripheral small lungadenocarcinoma(P <0.05). Multivariate analysis demonstrated that the new lungadenocarcinoma classification criteria and N stage were independent prognostic factorsof the invasive peripheral small lung adenocarcinoma(P <0.05).Conclusion:The five histological subtypes of invasive peripheral small lung adenocarcinomahad different clinicopathological factors and clinical prognosis. The new2011versionof lung adenocarcinoma classification criteria was an independent prognostic factor thataffects the invasive peripheral small lung adenocarcinoma.