Application of Lepidic Component Predominance to Adjuvant Chemotherapy with Oral Fluoropyrimidines for Stage I Lung Adenocarcinoma

Background: In the present study we aimed to investigate whether the predominance of the lepidic component in tumors was associated with the outcome of postoperative adjuvant chemotherapy for stage I lung adenocarcinoma. Patients and Methods: Charts for patients with pathological stage I lung adenocarcinoma were retrospectively reviewed and then outcomes of adjuvant chemotherapy were assessed according to the lepidic component predominance in tumors. Prognostic factors were evaluated using a Cox proportional hazard model. Propensity scores were determined using the optimal matching method on the basis of Cox modeling and matched (1:1) analysis was applied after classification into lepidic and nonlepidic predominant tumors. Results: Among 798 patients with stage I lung adenocarcinoma, 168 received adjuvant chemotherapy. Although adjuvant chemotherapy conferred no disease free survival (DFS) advantage upon patients with lepidic predominant tumors, it improved DFS in T1b and T2a nonlepidic predominant tumors (P = .045 and P = .029, respectively). Propensity score matched analysis revealed no survival benefits of adjuvant oral fluoropyrimidines in lepidic predominant tumors (DFS, P = .461 and overall survival, P = .983) and the positive survival advantages in nonlepidic predominant tumors (DFS, P = .015 and overall survival, P = .027). Conclusion: Adjuvant oral fluoropyrimidines conferred a better survival advantage upon patients. with nonlepidic predominant tumors than patients with lepidic predominant tumors. The predominance of a lepidic component could serve as an indicator of adjuvant chemotherapy with oral fluoropyrimidines in stage I lung adenocarcinoma. (C) 2015 Elsevier Inc. All rights reserved.