Rearrangement in Small-Cell Lung Cancer and Durable Response to Alectinib: A Case Report.

BACKGROUND

With the development of next-generation sequencing (NGS), several anaplastic lymphoma kinase () fusion partner genes have been identified. However, fusion is extremely rare in small cell lung cancer (SCLC), and there is no standard treatment option. Here, we report a patient with SCLC who carried an - Intergenic Region (IR) rearrangement and responded to Alectinib.

CASE PRESENTATION

A 26-year-old man was pathologically diagnosed with extensive-stage SCLC. After 2 cycles of first-line chemotherapy, CT showed a large soft tissue mass in the middle lobe of the right lung and increased liver nodules, left kidney lesions and right kidney lesions. To seek potential therapeutic regimens, rearrangement was identified. The patient achieved a rapid and durable partial response with Alectinib (600 mg BID). The patient experienced a significant clinical response with a progression-free survival of more than 6 months. There were no grade 3 or more adverse events reported, and there was no dose reduction during treatment. Following Alectinib treatment, the allele frequency of rearrangement and and mutations in plasma circulating tumor DNA decreased with the reduction in tumor size.

CONCLUSION

This case provides a meaningful reference for the treatment of SCLC patients with rearrangement. This case also provides valuable information on the response to ALK inhibitors in patients with rearrangement and better understanding of ALK-TKI applications in the future.