[Efficacy of zoledronic acid combined with chemotherapy in treatment of skeletal metastases of non-small cell lung cancer and the bone metabolic markers].

OBJECTIVE: To evaluate the clinical efficacy of zoledronic acid combined with chemotherapy in the management of skeletal metastasis of non-small cell lung cancer (NSCLC) and investigate the value in urine amino-terminal telopeptide of type I collagen (uNTX) and serum bone specific alkaline phosphatase (sBALP) in monitoring skeletal metastasis of NSCLC.

METHODS: From February, 2007 to January, 2009, 32 NSCLC patients with bone metastases received treatment with zoledronic acid at the dose of 4 mg given every 3 weeks and platinum-based chemotherapy (each cycle lasting for 3 weeks). Before and during the treatments, uNTX and sBALP were measured in these patients using ELISA and precipitation with wheat germ lectin, respectively. The patients were followed up for skeletal-related events (SREs) and status of survival.

RESULTS: A significant decrease occurred in the pain scores and analgesic use in the patients after the therapy. SREs were not observed during the treatment. Serum creatinine and calcium levels underwent no significant variation during the treatment. Eleven patients reported 14 possible zoledronic acid-related adverse events. The concentration of uNTX and sBALP in patients with bone metastases was above the upper limit of the normal range. A positive correlation was observed between the levels of the markers and the extent of bone metastases. At the third month, uNTX and sBALP were significantly lowered, but radionuclide whole-body bone imaging showed no obvious changes. Of the 32 patients, 24 had elevated uNTX values, which became normal after the treatment in 15 patients and remained elevated in the other 9 patients. SREs occurred in these two subgroups at the rates of 53% and 89% (P=0.039), respectively. Twenty-six patients had elevated sBALP level, and 16 of them exhibited normal sBALP level after the treatment. The incidences of SREs in the patients with elevated and normal sBALP level were 50% and 90% (P=0.038), respectively. The levels of uNTX/Cr and sBALP were not correlated to the survival of the patients.

CONCLUSIONS: Zoledronic acid combined with chemotherapy is an effective treatment for NSCLC with bone metastases. Zoledronic acid is safe and well tolerated. Urinary NTX and serum BALP have a high value in the diagnosis, therapeutic effect monitoring and SRE prediction of NSCLC with bone metastases.