Dissecting the clinicopathologic, genomic, and prognostic significance of anaplastic lymphoma kinase rearrangement in resected lung adenocarcinoma.

Objectives: The ALINA trial introduced anaplastic lymphoma kinase (ALK) inhibitors in an early-stage context, generating notable interest. This study aims to investigate the characteristics and prognostic implications of ALK rearrangement in patients with resected lung adenocarcinoma (LUAD).

Methods: We retrospectively evaluated resected LUAD cases with documented ALK status from 2008 to 2020. The association between ALK positivity and clinicopathologic characteristics, molecular profiles, and outcomes was explored.

Results: Among 4944 cases, 238 (4.8%) were ALK-positive, correlating with younger age and nonsmokers. ALK positivity was also significantly associated with pure-solid nodules, spread through air spaces, and solid-predominant adenocarcinoma. ALK-positive tumors exhibited an overall low frequency of co-mutations (eg, TP53, STK11). ALK positivity was associated with inferior recurrence-free survival (RFS) in patients with stage I who did not receive adjuvant chemotherapy whereas it was associated with prolonged RFS in patients with stage II and III who received adjuvant chemotherapy. Notably, 6 patients treated with adjuvant ALK inhibitors experienced no recurrence or metastasis during the follow-up period. In addition, the administration of ALK inhibitors significantly improved postrecurrence survival in patients positive for ALK.

Conclusions: ALK positivity was associated with specific aggressive pathologic features and inferior RFS in stage I LUAD. Patients positive for ALK seemed to benefit more from adjuvant chemotherapy. Active treatment with ALK inhibitors or chemotherapy should be considered for patients with ALK-positive LUAD, although further evidence is warranted to expand their utility in early-stage disease management.