Significance of serum bombesin as a tumor marker for small-cell lung carcinoma

Using a radioimmunoassay, we studied the significance of bombesin as a specific marker for small-cellcarcinoma of the lung (SCCL). Bombesin-like immunoreactivity (BLI) was detectable in serum 4 of 15 patients with SCCL (27%), but was undetectable in serum of ail 15 healthy subjects. BLI was also detectable in 7 of 31 patients with non-SCCL tumors (23%) and 4 of 31 patients with other types of lung disease (13%). The present results indicate that bombesin is unlikely to be a specific marker for the early detection of SCCL though bombesin could be formed by SCCL and its metastasis, and might be released into the circulation.