P2.17-29 Impact of Second Predominant Pattern on Recurrence in Early Stage Resected Lung Adenocarcinoma: A Multicentric Study

Abstract

resection was defined by free resection margins, but with less rigorous lymph node evaluation than systematic dissection and/or positivity of the highest mediastinal lymph node removed. Incomplete resection was defined by the presence of gorss or microscopic residual disease. Patient follow-up was updated until Jan/2019. Overall survival was analyzed by the Kaplan-Meier method, Log rank test and Cox proportional regression. Result: A total of 663 patients were identified. Mean age was 65.64 years, 338 men(50.9%). The predominant histological type was adenocarcinoma(n ¼ 466, 70.2%), followed by squamous cell carcinoma(n ¼ 162, 24.4%). Lobectomy was the most commonly performed procedure(n ¼ 576, 86.8%), followed by segmentectomy and pneumonectomy(n ¼ 40, 6.0% and n ¼ 34, 5.1%, respectively). There was 388 patientes(59.81%) classified as stage I, 146(23.1%) stage II, 97(15.3%) stage III and 11(1.74%) stage IV. Resection was complete in 374 cases (56.4%), uncertain in 252 cases(38.0%) and incomplete in 37 cases(5.5%). Mediastinal lymphadenectomy was adequate in 421 cases (63.4%) and inadequate in 242 (36.5%). Reasons for inadequate lymphadenectomy were: no nodal station sampling (n ¼ 30, 4.5%), no station 7 sampling (n ¼ 103, 15.5%) and sampling of less than 3 mediastinal stations (n ¼ 109, 16.4%). The highest mediastinal lymph node removed was positive in 45 cases (6.7%). Surgical margins were positive in 37 cases (5.5%). The median follow-up was 19.5 months (IQR 7.4 -42.5), and 5 years follow-up was completed in in 15.5%. During follow-up, 133 (20.4%) patients had recurrence of the disease. Median disease-free survival was 64 months in the general group and 84.0, 58.6 and 31.5 months in the complete, uncertain and incomplete resection groups, respectively (log rank p ¼ 0.15). Median overall survival in the complete resection group was 98.3 months, in the uncertain resection group it was 64 months. The incomplete resection group did not reach the median. There was no statistical difference in survival between groups (log rank p ¼ 0.22). Conclusion: The analysis showed a high prevalence of uncertain resection, but comparable to other studies already published. This demonstrates that lymphadenectomy is not being performed according to IASLC recommendations. However, in this study, there was no impact on overall survival and disease-free survival at 5 years, which may be due to the small sample size and the short follow-up time of the vast majority of patients included in the PLCR.

Prognosis of the second predominant subtype in lung adenocarcinoma: a retrospective single-center cohort study

“…Regarding the investigation of the second predominant pathological subtype, Bertoglio et al ( 13 ) found the high-grade second predominant subtype was often associated with a poor prognosis as its proportion increased, while in an earlier study by Ito et al ( 14 ) evaluting the intermediate-grade dominant subtype, the lepidic subtype and nonlepidic subtype components could be used as factors for further grading and exhibited significance for prognoses. Furthermore, Bertoglio et al ( 15 ) found that as the second predominant subtype, the lepidic subtype had a better level of DFS, whereas the micropapillary type often predicted a poorer prognosis. Recently, Tsai et al ( 28 ) found no significant difference in DFS between the two groups, regardless of whether the second pathological subtype was invasive (acinar, papillary, micropapillary, and solid) or noninvasive (lepidic).…”

“…The second predominant subtype was defined as the pathological subtype accounting for the second-largest percentage of lung adenocarcinoma. While the prognostic effects of the predominant pathological subtypes of LUAD have been confirmed (7)(8)(9)(10)(11)(12), the possible prognostic effects of the second predominant pathological subtypes have rarely been mentioned in the literature, and there are no consistent results among relevant studies (13)(14)(15).…”