Individualized duration of adjuvant alectinib therapy and rechallenge efficacy in ALK-positive non-small cell lung cancer: a case report.

Background: Anaplastic lymphoma kinase (ALK)-rearranged non-small cell lung cancer (NSCLC) is a distinct molecular subtype of cancer that typically affects younger patients and carries a high risk of central nervous system (CNS) metastases. Adjuvant alectinib therapy has demonstrated efficacy in prolonging disease-free survival; however, the optimal duration of adjuvant treatment remains undefined. Moreover, the therapeutic benefit of alectinib rechallenge after disease recurrence post-adjuvant therapy remains unclear. Case description: We report the case of a 64-year-old woman diagnosed with stage pT3N2M0 IIIb ALK-positive lung adenocarcinoma. She underwent surgical resection followed by 36 months of adjuvant alectinib therapy and remained disease-free during treatment. However, 4 months after treatment discontinuation, CNS relapse occurred, manifesting as rapid neurologic progression. Reintroduction of alectinib led to marked clinical improvement and a partial radiographic response in intracranial lesions. Conclusion: This case suggests the aggressive nature of ALK-positive NSCLC and its high propensity for CNS metastasis, raising the possibility that personalized durations of adjuvant therapy guided by molecular biomarkers may be beneficial. Further research is needed to validate these approaches in larger cohorts. Furthermore, the favorable response to alectinib rechallenge observed in this case suggests that rechallenge therapy may offer a potential value in managing post-adjuvant recurrence, which warrants further investigation.