Medical treatment of tumor-induced hypercalcemia and tumor-induced osteolysis: challenges for future research

Bisphosphonates for the relief of pain secondary to bone metastases

BACKGROUND

Bisphosphonates form part of standard therapy for hypercalcemia and the prevention of skeletal events in some cancers. However, the role of bisphosphonates in pain relief for bony metastases remains uncertain.

OBJECTIVES

To determine the effectiveness of bisphosphonates for the relief of pain from bone metastases.

SEARCH STRATEGY

MEDLINE (1966-1999), EMBASE (1980-1999), CancerLit (1966-1999), the Cochrane library (Issue 1, 2000) and the Oxford Pain Database were searched using the strategy devised by the Cochrane Pain, Palliative and Supportive Care Group with additional terms 'diphosphonate', 'bisphosphonate', 'multiple myeloma' and 'bone neoplasms'. (Last search: January 2000).

SELECTION CRITERIA

Randomized trials of bisphosphonates compared with open, blinded, or different doses/types of bisphosphonates in cancer patients were included where pain and/or analgesic consumption were outcome measures. Studies where pain was reported only by observers were excluded.

DATA COLLECTION AND ANALYSIS

Article eligibility, quality assessment and data extraction were undertaken by both reviewers. The proportions of patients with pain relief at 4, 8 and 12 weeks were assessed. The proportion of patients with analgesic reduction, the mean pain score, mean analgesic consumption, adverse drug reactions, and quality of life data were compared as secondary outcomes.

MAIN RESULTS

Thirty randomized controlled studies (21 blinded, four open and five active control) with a total of 3682 subjects were included. For each outcome, there were few studies with available data. For the proportion of patients with pain relief (eight studies) pooled data showed benefits for the treatment group, with an NNT at 4 weeks of 11[95% CI 6-36] and at 12 weeks of 7 [95% CI 5-12]. In terms of adverse drug reactions, the NNH was 16 [95% CI 12-27] for discontinuation of therapy. Nausea and vomiting were reported in 24 studies with a non-significant trend for greater risk in the treatment group. One study showed a small improvement in quality of life for the treatment group at 4 weeks. The small number of studies in each subgroup with relevant data limited our ability to explore the most effective bisphosphonates and their relative effectiveness for different primary neoplasms.

REVIEWER'S CONCLUSIONS

There is evidence to support the effectiveness of bisphosphonates in providing some pain relief for bone metastases. There is insufficient evidence to recommend bisphosphonates for immediate effect; as first line therapy; to define the most effective bisphosphonates or their relative effectiveness for different primary neoplasms. Bisphosphonates should be considered where analgesics and/or radiotherapy are inadequate for the management of painful bone metastases.

[Use of disodium pamidronate in patients with bone metastases in patients with pulmonary carcinoma]

Disodium pamidronate (Aredia), a drug of the bisphosphonate group, was administered to 20 patients with pains in the bones due to secondary deposits of lung cancer. The aim of the study was to investigate the analgesic effect of pamidronate to osteolytic metastases of lung cancer in the bone. In 16 (80%) patients non-small-cell lung cancer was diagnosed, and in 4 (20%) patients small-cell-lung cancer was confirmed. Intensive disseminated pains in the bones were present in all the patients. Metastases in the skeleton were confirmed by radiography and scintigraphy of the bones. Initial values of calcium in the plasma were determined in those patients. In 11 (55%) patients, initial values of calcium in the serum were normal, and in 9 (45%) patients, they were elevated. Patients with normal calcium values received 30 mg of pamidronate in 250 ml of normal saline, and patients with hypercalcemia received 45-60 mg in 500 ml of normal saline. Analgesic effect of pamidronate was present in 12 (60%) patients, and the completely painless state was achieved in 4 out of 12 patients. Evaluation of the pain was done by questionnaire, using a simple, descriptive scale. In all 9 (100%) patients with hypercalcemia, values of calcium in plasma were normalized. Pamidronate exerted favorable analgesic effect in the case of metastases of lung cancer in the bones in more than 50% patients. Satisfactory results were also achieved in the patients non-responsive to palliative therapy by irradiation. This enables the use of opiates in lower doses.

[Tumor-induced hypercalcemia. Review of bisphosphonate treatment]

INTRODUCTION

The incidence of tumor-induced hypercalcemia is between 10 to 20%. New treatments justify this review article.

CURRENT KNOWLEDGE AND KEY POINTS

Tumor-induced hypercalcemia (half of all hypercalcemia) is divided into two groups: hematological tumors (10%), and solid tumors (90%), with osteolytic hypercalcemia and humoral hypercalcemia of malignancy (HHM: mediators include PTHrP). The two most common causes of tumor-induced hypercalcemia are lung cancer and breast cancer. Tumor-induced hypercalcemia most commonly disturbs gastrointestinal, neurological, renal and cardiovascular functions. These symptoms may be erroneously attributed to the underlying malignancy or its therapy. Prognosis of tumor-induced hypercalcemia is very poor, with median survival being about 3 months. Bisphosphonates have emerged as the standard treatment of tumor-induced hypercalcemia. The intravenous administration of isotonic saline is the first step in the management of tumor-induced hypercalcemia. Specific treatment of cancer remains essential to prevent TIH relapse.

FUTURE PROSPECTS AND PROJECTS

New bisphosphonates have appeared, the most potent known bisphosphonate today is zoledronate.

Comparative evaluation of markers of bone resorption in patients with breast cancer-induced osteolysis before and after bisphosphonate therapy

The understanding of the pathophysiology and the monitoring of metastatic bone disease remains unsatisfactory. We compared several new markers of bone turnover in normocalcaemic patients with breast cancer-induced osteolysis before and after a single infusion of the bisphosphonate pamidronate. We studied 19 ambulatory patients with advanced breast cancer and extensive bone metastases who did not receive any systemic antineoplastic therapy. Pamidronate was administered at doses of 30, 60, 90 or 120 mg and the patients were followed weekly during a mean of 8 (range 4-10) weeks. Compared with healthy premenopausal women, the percentage of elevated values at baseline was 47% for fasting urinary calcium (uCa), 74% for hydroxyproline, 83% for CrossLaps (a new marker of type I collagen degradation) and 100% for the collagen cross-links (measured by high performance liquid chromatography), namely pyridinoline (Pyr) and deoxyPyr (D-Pyr). Pretreatment levels of uCa did not correlate significantly with any of the four markers of bone matrix resorption, whereas the correlations between these four markers were generally significant (r(s)=0.43-0.71). Alkaline phosphatase correlated significantly with markers of bone matrix resorption (r(s)=0.54-0.74). All parameters, except phosphaturia (uPi) and the bone formation markers (osteocalcin and alkaline phosphatase), fell significantly after pamidronate therapy, up to day 42 for hydroxyproline, D-Pyr and CrossLaps and day 56 for uCa. This longer lasting effect was probably due to the parathyroid hormone (PTH) surge following the decrease in serum calcium, implying that the decrease in uCa can overestimate the effects of bisphophonates on bone resorption. The decrease in bone turnover parameters was most marked for CrossLaps, indicating the potential of this new marker for monitoring therapy. Sequential determinations of markers of bone matrix resorption should be useful in delineating the optimal therapeutic schemes of bisphosphonates and for evaluating treatment effects on bone in cancer patients.

Causes and treatment of bone pain of malignant origin

Pain relief has been one of the oldest and most important duties of the physician. There has been little change with regard to this obligation of all caregivers. One-third of patients with advanced cancer will develop clinically relevant skeletal metastases and chronic pain during the course of their disease. All physicians involved in the treatment of cancer patients should know the basic principles of pain treatment. These are described in the following article with special regard to bone pain of malignant origin. Correct assessment of pain intensity and frequency, as well as of the probable causes of pain, and the administration of adequate analgesic treatment should achieve satisfactory results in the vast majority of patients. Every physician should obtain detailed knowledge of the indications and adequate administration of pain-killing therapy as well as possible adverse effects and their successful treatment. It is important in particular to concentrate on a few nonsteroidal anti-inflammatory drugs (NSAIDs) as well as opiates. Knowledge of adequate doses, maximal recommended daily doses, pharmacological properties, important adverse effects and interactions is essential for success in the daily routine. Only by selecting 2 or 3 drugs from each step in the analgesic ladder (WHO) will the nonspecialised physician obtain sufficient experience for optimal analgesia. Physicians should also not hesitate to contact other specialists (medical oncologists, radiotherapists, neurosurgeons, anaesthesiologists and others) in order to maximise benefit for an individual patient.

Intravenous pamidronate in patients with tumor-induced osteolysis: a biochemical dose-response study

Bisphosphonates are used increasingly in normocalcemic patients for treating tumor-induced osteolysis (TIO) but little is known about the metabolic effects and the most appropriate therapeutic regimen. In 21 patients with breast cancer and TIO, we determined the biochemical effects of a single infusion of pamidronate given at 30 mg (n = 5), 60 mg (n = 5), 90 mg (n = 5), or 120 mg (n = 6). Patients received no other systemic antineoplastic therapy during the trial. We selected patients with baseline fasting urinary Ca/Creat (creatinine) > 0.105 mg/mg (median value of our normal range) and they were followed weekly for up to 14 weeks. The biochemical effects were maximal at day 7. For the whole group, mean (+/- SEM) Ca/Creat levels fell from 0.208 +/- 0.018 to 0.048 +/- 0.008 mg/mg on day 7 and remained significantly ( p < 0.01) lower than baseline up to day 56. Hydroxyproline excretion fell to a lesser degree, from 7.0 +/- 1.2 to 4.0 +/- 0.6 mg x 100/mg of Creat. The falls in Ca/Creat and hydroxyproline excretion were dose-related (ANCOVA, p < 0.05). Changes in serum parameters of calcium metabolism were, however, not significantly dose-related. Serum Ca levels fell from 9.3 +/- 0.1 to 8.7 +/- 0.1 mg/dl on day 7, but not patients developed symptomatic hypocalcemia, and the decrease within each dose group was significant only at 120 mg. Ca2+ levels followed a similar pattern. There was a slight increase in Mg levels and a pronounced fall in Pi levels, from 3.6 +/- 0.2 to 2.8 +/- 0.1 mg/dl. Intact PTH levels increased from 29 +/- 4 to 91 +/- 13 pg/ml and remained significantly (p < 0.05) elevated up to day 28.(ABSTRACT TRUNCATED AT 250 WORDS)

Hypercalcemia in patients with breast cancer: a survival study

In a retrospective study survival after hypercalcemia in breast cancer patients has been investigated. A group of 72 patients were treated with bisphosphonate APD [3-(amino-1,1-hydroxypropylidene)bisphosphonate] and third-generation amino-containing bisphosphonates between January 1980 and October 1992. A median survival of 4.5 months was found. In a multivariate analysis, four independent prognostic factors for survival have been found: the interval between first relapse and hypercalcemia, sites of metastases at the moment of hypercalcemia, primary treatment, and the level of serum alkaline phosphatase. Patients with a "flare" reaction on tamoxifen treatment and patients with a normal serum alkaline phosphatase level and bone metastases only had a prolonged survival. Hypercalcemia associated with visceral metastases carried a very poor prognosis. The level of serum calcium in this series of patients was no prognostic indicator for survival.