Impact of proposed IASLC/ATS/ERS classification of XXXX : prognostic subgroups and implications for further revision of staging based on analysis of 514 stage I cases.

@entity1 @entity3079 @entity39 @entity5 @entity2 @entity1514 @entity420 @entity2220
A new @entity2220 classification is being proposed by the International Association for the Study of @entity2 , American @entity1514 Society and European Respiratory Society (IASLC/ATS/ERS). This proposal has not yet been tested in clinical datasets to determine whether it defines prognostically significant @entity2220 . In all, 514 @entity1 who had pathological @entity5 of the lung classified according to the Union for International @entity5 Control/American Joint Committee on @entity5 7th Edition, and who had undergone a lobectomy with mediastinal lymph node dissection were retrospectively reviewed. Comprehensive histological subtyping was used to estimate the percentage of each histological subtype and to identify the predominant subtype. @entity5 were classified according to the proposed new IASLC/ATS/ERS @entity420 classification. Statistical analyses were made including Kaplan-Meier and Cox regression analyses. There were 323 females (63%) and 191 males (37%) with a median age of 69 years (33-89 years) and 298 stage IA and 216 stage IB @entity1 . Three overall prognostic groups were identified: low grade: @entity420 in situ (n=1) and minimally invasive @entity420 (n=8) had 100% 5-year disease-free survival; intermediate grade: non-mucinous lepidic predominant (n=29), papillary predominant (n=143) and acinar predominant (n=232) with 90, 83 and 84% 5-year disease-free survival, respectively; and high grade: invasive @entity3079 (n=13), colloid predominant (n=9), solid predominant (n=67) and micropapillary predominant (n=12), with 75, 7170 and 67%, 5-year disease-free survival, respectively (P<0.001). Among the clinicopathological factors, stage 1B versus 1A (P<0.001), male sex (P<0.008), high histological grade (P<0.001), vascular invasion (P=0.002) and @entity39 (P<0.001) were poorer prognostic factors on univariate analysis. Both gross @entity5 size (P=0.04) and invasive @entity5 size adjusted by the percentage of lepidic growth (P<0.001) were significantly associated with disease-free survival with a slightly stronger association for the latter. Multivariate analysis showed the prognostic groups of the IASLC/ATS/ERS histological classification (P=0.038), male gender (P=0.007), @entity5 invasive size (P=0.026) and @entity39 (P=0.002) were significant poor prognostic factors. In summary, the proposed IASLC/ATS/ERS classification of @entity2220 identifies histological categories with prognostic differences that may be helpful in identifying candidates for adjunctive therapy. The slightly stronger association with survival for invasive size versus gross size raises the need for further studies to determine whether this adjustment in measuring @entity5 size could impact TNM staging for small @entity420 .
