Tartrate-resistant acid phosphatase isoform 5b (TRACP 5b) as serum marker of bone metastases from non-small cell lung cancer (NSCLC) and breast cancer. Preliminary results

The skeleton is a frequent site of metastasis from both non-small cell lung cancer (NSCLC) and breast cancer (BC). It can also be the only site in patients with advanced or aggressive tumors. Delayed diagnosis of bone metastases (BMs) may seriously affect the quality of life of patients, and is associated with several adverse skeletal-related events. Thus, there is the need of early diagnosis of BMs. Tartrate-resistant acid phosphatase isoform 5b (TRACP 5b) is a well-established serum marker of osteoclast activity and bone resorption. The aim of this study was to evaluate the usefulness of TRACP 5b measurement in patients with BMs. TRACP 5b was a marker significantly more sensitive and specific in patients with metastatic NSCLC than in those with metastatic BC. Our preliminary results suggest that it should be routinely used in patients with advanced NSCLC with the aim of early detection of BMs.