Transient relief of metastatic cancer bone pain by oral administration of etidronate.

Abstract

The aims of the present study were to determine whether patients with painful bone metastases from primary cancer sites showed a higher level of a bone resorption marker than those with no evidence of skeletal-related events, and to clarify the efficacy of oral administration of etidronate for pain due to bone metastases and bone resorption. Thirty outpatients with cancer were recruited: 10 with pain due to bone metastasis from the primary cancer site; lung (4), prostate (3), and breast (3) (M group), and 20 with primary cancer of the stomach (11), colon (4), breast (3), lung (1), and bladder (1) with no such evidence of skeletal-related events (non-M group). None of the patients in the M group either needed morphine for pain relief or had hypercalcemia, although all of them had been taking nonsteroidal anti-inflammatory drugs (NSAIDs). During the study, they continued taking NSAIDs, as they had before the study. The level of urinary cross-linked N-telopeptides of type I collagen (NTx) at baseline was significantly higher in the M group than in the non-M group ( P < 0.01). Oral administration of etidronate (400 mg/day for 2 weeks) to patients in the M group significantly reduced bone pain 2 and 12 weeks after the start of treatment; however, the pain relief effect was diminished 12 weeks after the start of treatment, despite a significant decrease in urinary NTx level ( P < 0.05 by one-way analysis of variance [ANOVA] with repeated measurements). The present study provides evidence suggesting that patients with painful bone metastases from primary cancer sites may have a higher level of urinary NTx than those with no evidence of skeletal-related events, and that oral administration of etidronate at the dose we used may have the potential to transiently relieve their bone pain by decreasing abnormally raised bone resorption. Although the present study had a small sample size, and had no placebo controls, the results may be useful, especially as they raise additional questions that could stimulate further research in Japan.