CEA, Cyfra21‐1, and NSE had similar utilization rates and increased slightly from around 50% in 2013 to around 78% in 2017 in NSCLC patients (Figure 1A) and from around 70% in 2013 to around 92% in 2017 in SCLC patients (Figure 1B). Here, CEACAM5 is linked to small cell lung carcinoma.