Combined small cell lung carcinoma harboring ALK rearrangement: A case report and literature review

Combined small cell lung cancer (c-SCLC) is a relatively rare subtype of SCLC and is defined by the combination of SCLC and any elements of non-small cell carcinoma (NSCLC). Standard chemotherapy for patients with c-SCLC has not yet been established. Gene mutations such as epidermal growth factor receptor (EGFR) mutations may be detected in patients with c-SCLC. However, little is known about anaplastic lymphoma kinase (ALK) rearrangement in c-SCLC patients. Here, we report a young female patient who was successfully treated with alectinib for ALK-positive c-SCLC after failure of immunochemotherapy for SCLC and cytotoxic chemotherapy for adenocarcinoma. Moreover, we performed a literature review of EGFR- or ALK-positive c-SCLC patients. Our report suggests that ALK testing may be justified in patients with SCLC that contain an adenocarcinoma component. KEY POINTS: SIGNIFICANT FINDINGS OF THE STUDY: • This is the first report describing the treatment course comprising immunochemotherapy and ALK-TKI in a patient with c-SCLC harboring ALK rearrangement. WHAT THIS STUDY ADDS: • Our case and literature review suggest that although ALK mutation is rare in patients with c-SCLC, its identification and treatment with ALK-TKIs may contribute to clinical benefits.