Following covariate adjustment using a Cox regression model, it was indicated that the level of abnormal expression of the ALK protein was an independent prognostic factor for patients with SCLC (HR: 0.486, 95% CI: 0.271-0.871, <i>p</i> = 0.015).<h4>Conclusion</h4>The prognosis for patients with SCLC with strong abnormal expression of the ALK protein was significantly better than those with weak expression. Here, ALK is linked to small cell lung carcinoma.