Biochemical markers of bone turnover in women with surgically treated carcinoma of the breast

The use of molecular markers of bone turnover in the management of patients with metastatic bone disease

Biochemical markers of bone turnover are widely used in clinical practice. These indices have been shown to be associated with the occurrence, prognosis and therapeutic response of malignant bone lesions. For example, markers of bone resorption are often elevated in patients with established bone metastases and while this may point to a role of these markers in the diagnostic workup of cancer patients, the available evidence does not permit any final conclusions as to the accuracy and validity of the presently used markers in the early diagnosis of bone metastases. Many bone turnover markers appear to respond to antiresorptive and antineoplastic therapies, and recent evidence from prospective trials suggests that the aim of bisphosphonate therapy should be to normalize rates of bone remodelling to optimize therapeutic and prognostic outcomes. However, it remains unknown whether the use of bone markers in the routine clinical setting has any defined beneficial effects on overall outcome in cancer patients. Clearly, bone turnover markers have insufficient diagnostic or prognostic value to be used in isolation; however, the combination of these markers with other diagnostic techniques may improve clinical assessment of patients with bone-seeking cancers. This article reviews the available evidence (as of August 2007) on the clinical use of bone turnover markers in the management of patients with metastatic bone disease.

Clinical use of markers of bone turnover in metastatic bone disease

Bone metastases profoundly perturb normal bone remodeling. Biochemical markers of bone turnover have been shown to reflect these tumor-induced changes in bone remodeling and might therefore be useful in the diagnosis and follow-up of patients with malignant bone disease. Most markers of bone turnover, particularly those of bone resorption, are elevated in patients with established bone metastases. While this might indicate a role for bone markers as diagnostic tools in cancer patients, the available evidence does not provide any final conclusions as to the accuracy and validity of the markers presently used in the early diagnosis of bone metastases. Markers of bone resorption respond promptly and profoundly to bisphosphonate and antineoplastic therapy, and this response is associated with a favorable clinical outcome. Most markers, however, have been more useful in groups of patients monitored in clinical studies than in studies of individuals. While this makes them a good tool for drug development, it remains unknown whether the use of bone markers in a routine clinical setting has any defined beneficial effects on overall outcome in cancer patients. In particular, no study has addressed the question of whether patients with bone metastases should be treated according to their rate of bone turnover and what the treatment goals are in this respect. While it is unlikely that bone-turnover markers have sufficient diagnostic or prognostic value when used in isolation, the combination of these markers with other diagnostic techniques might be the way forward to improve the clinical assessment of patients with cancers of the bone.

Transdermal hormone replacement therapy improves vertebral bone density in primary biliary cirrhosis: results of a 1-year controlled trial

BACKGROUND

Retrospective studies have suggested that hormone replacement therapy may reduce the rate of bone loss in primary biliary cirrhosis, but no controlled data are available.

METHODS

Forty-two post-menopausal women with primary biliary cirrhosis were treated with calcium and vitamin D, either alone (n = 21) or together with transdermal hormone replacement therapy (n = 21). Bone densitometry was performed at baseline and at 1 year, and serum and urinary markers of bone turnover were measured at three-monthly intervals.

RESULTS

At entry, 17 patients (40%) had spinal or femoral osteopenia (T score - 1 to - 2.5) and nine (21%) had osteoporosis (T < - 2.5). In those given hormone replacement therapy, there was a significant decrease in the mean urinary deoxypyridinoline :creatinine ratios at 3 months (7.8 vs. 6.1 nm/mm creatinine for no hormone replacement therapy vs. hormone replacement therapy; P = 0.04) and a 48% reduction in urinary calcium excretion at 1 year (0.66 vs. 0.32 mm/mm creatinine; P = 0.01). Repeat bone densitometry at 1 year revealed a 2.25% increase in the hormone replacement therapy group (P = 0.02), compared with a non-significant 0.87% decrease in L2-L4 bone mineral density in those not given hormone replacement therapy. Both treatment regimens were well tolerated, with no increase in cholestasis.

CONCLUSIONS

Compared with calcium and vitamin D alone, supplemental treatment with transdermal hormone replacement therapy for 1 year improved the vertebral bone density and urinary markers of bone turnover in post-menopausal women with primary biliary cirrhosis.

Clinical review 165: Markers of bone remodeling in metastatic bone disease

Many cancers have a strong propensity to spread to bone. The processes involved in cancer dissemination to bone are complex and variable, and the changes in bone metabolism, once bony metastases have occurred, are usually profound. This review surveys the usefulness of bone markers in the diagnosis and follow-up of patients with malignant bone disease. In patients with established bone metastases, most markers of bone remodeling are abnormal compared with healthy controls or cancer patients without bone lesions. Although bone markers may have a potential as diagnostic tools in cancer patients, the available data do not allow final conclusions regarding the accuracy and validity of any of the presently used markers in the diagnosis of bone metastases. As regards monitoring of anticancer therapy, most markers of bone remodeling respond to active treatments. These indices therefore may have the potential to be used in the monitoring of antitumor therapies. However, most if not all of the available evidence on the use of bone markers in monitoring anticancer therapy is observational, and it remains unclear whether they have any beneficial effects on overall outcome. The same is true for their prognostic value, although evidence suggests that suppressed levels of bone formation or high rates of bone resorption are independent predictors of poor survival.

Morphological, histomorphometric, and microstructural alterations in human bone metastasis from breast carcinoma

Bone is one of the most common sites of breast cancer metastasis. Metastases are often associated with bone destruction and are a major cause of morbidity. We examined structural bone changes induced by metastatic tumor in bone biopsies from 33 patients with metastatic breast carcinoma (20 from patients with pathological femoral fracture and 13 with no fracture) and 20 normal controls. In all metastatic biopsies bone remodeling was shown to be tumor volume-dependent. Bone resorption and bone formation were biphasic with both increasing at earlier stages of metastatic bone disease and decreasing later on. A comparison of patients with fracture and no fracture did not reveal statistically significant differences in the extent of bone destruction or trabecular thinning. Bone histomorphometry showed limited ability to explain the higher bone volume loss in fracture patients (decreases of 42% and 25%, respectively, in fracture and nonfracture patients compared with controls). However, changes in bone quality, including increased disconnectivity and decreased connectivity, as evaluated by node-strut analysis, suggested that there were more structural changes in the fracture compared with the nonfracture group. The nonfracture group included six patients with no radiological evidence of bone metastasis (occult metastasis). They showed a higher tumor volume and a twofold lower eroded surface compared with the rest of the group. The decrease in bone volume (14% lower than controls) was below the limit of X-ray detection. Because we observed no increase in osteoclast-related parameters and no correlation between osteoclast surface and eroded surface, we believe that, in occult metastasis, osteoclastic bone resorption is not an important factor in overall bone resorption. Quantitatively, the eroded surface in direct contact with tumor cells was threefold higher than the osteoclast surface in occult metastasis, whereas the rest of the metastatic group (27 of 33) showed predominantly osteoclast-mediated eroded surface. Node-strut analysis on occult metastasis revealed a significant increase in disconnectivity without a concomitant significant decrease in bone volume and trabecular thinning. We conclude that, in occult metastasis, bone resorption may be more osteoclast-independent and other mechanisms involving the tumor cells may be more prevalent.

Urokinase plasminogen activator system gene expression is increased in human breast carcinoma and its bone metastases--a comparison of normal breast tissue, non-invasive and invasive carcinoma and osseous metastases

The urokinase plasminogen activator (uPA) system has been widely associated with the development of breast carcinoma. However, the role of the urokinase pathway in the development of osseous breast cancer metastases has been largely overlooked. We studied the expression of uPA, urokinase plasminogen activator receptor (uPAR)- and plasminogen activator inhibitor type-1 (PAI-1) in human breast carcinomas and their bone metastases, using in situ hybridisation. Studies were performed using paraffin-embedded tissue from 13 ductal carcinomas, 23 invasive ductal carcinomas, five normal breasts and 25 bone metastases. The majority of the tumours examined expressed low to moderate levels of uPA mRNA and low to high levels of uPAR and PAI-1 mRNA, which was predominantly localised to the epithelial tumour cells. There was slight over-expression of uPA and PAI-1 mRNA and a marked increase in uPAR mRNA expression in the malignant tumours compared with benign tissue. Overall, uPAR and PAI-1 mRNA expression was found to be more variable than uPA mRNA, suggesting a possible role of the receptor and inhibitor in the regulation of uPA activity. Increased alpha1(I) procollagen (COL) and osteopontin (OPN) mRNA expression was detected, primarily in the stromal cells, in malignant tumours compared with the benign tissue. The increased expression of the components of the uPA system on the epithelial tumour cells may account for the activation of the proteolytic cascade that occurs during breast cancer metastasis to bone. Furthermore, the over-expression of COL and OPN suggests a possible interaction between these matrix proteins and the uPA system.

Dissociation of bone turnover in anorexia nervosa

Biochemical markers were measured to assess bone turnover in a cross-sectional study of 43 patients with anorexia nervosa; 28 were at their first assessment (untreated) with a body mass index (BMI) (median interquartile range) of 13.3 (2) kg/m2. A second group of 15 patients undergoing treatment (treated) had a median BMI of 17.6 (2.8) kg/m2. The median, interquartile range of urinary deoxypyridinoline (DPyd), a bone resorption marker, was raised in both groups compared with an age-matched control population [DPyd = 17.8 (15.2), 17.5 (16.4) and 9.2 (4.0) nmol/mmol creatinine, respectively]. Serum type 1 collagen carboxyterminal propeptide (P1CP), a marker of bone formation, was similar to controls in the untreated patients [112 (29) and 112 (78.5) ng/ml, respectively], but was significantly raised in the treated patients [163 (219) ng/ml, P < 0.05]. A second group of 21 patients was followed prospectively, on admission and during 8 weeks of intensive inpatient care (BMI on admission and after 8 weeks was 13.0 (2) and 16.7 (3) kg/m2, respectively). The resorption marker, serum type 1 collagen carboxyterminal telopeptide (1CTP) was raised on admission and remained high during treatment. P1CP and osteocalcin levels were similar to control levels on admission but increased with treatment, and after 8 weeks were 40% and 63% higher respectively than on admission. These findings suggest that in untreated anorexia nervosa there was uncoupling of bone turnover as bone resorption markers were raised without a concomitant increase in bone formation markers. As the condition was treated and patients gained weight, the formation markers also increased, leading to a more balanced, although higher, bone turnover.

A double blind placebo controlled study to determine the effects of intermittent cyclical etidronate on bone mineral density in patients on long-term oral corticosteroid treatment

BACKGROUND

A double blind, placebo controlled study was undertaken to determine the effects of 104 weeks of intermittent cyclical etidronate therapy on bone mineral density (BMD) in patients undergoing long-term oral corticosteroid therapy.

METHODS

Forty nine patients of mean age 59 years on long-term (> 6 months) corticosteroid treatment were randomised to receive either 400 mg/day etidronate or placebo for 14 days followed in both groups by calcium (equivalent to 97 mg elemental Ca/day) with vitamin D (400 IU) for 76 days. The cycle was repeated a total of eight times over a period of two years. Dual energy x ray absorptiometry (DEXA) measurements of the lumbar spine and hip BMD and biochemical bone marker analyses were performed at baseline and every six months.

RESULTS

Twenty six patients (10 men) received cyclical etidronate and 23 (nine men) received placebo. The mean (SD) dose of corticosteroid (prednisone or equivalent) at baseline in the etidronate group was 8 (4) mg/day and in the placebo group was 7 (4) mg/day. Most of the patients (43%) suffered from asthma. Forty one patients completed the study (22 in the etidronate group and 19 in the placebo group). All had a low BMD at entry and with treatment a significant difference was observed between groups in the mean (SE) percentage change from baseline in lumbar spine BMD at week 104 of 4.5 (1.65)% (p = 0.007) with a 95% confidence interval (CI) of 1.12 to 7.87%. No clinically or statistically significant treatment differences were observed at the hip or with bone markers. The incidence of adverse events was similar in the two groups.

CONCLUSIONS

The results show that intermittent cyclical etidronate therapy with calcium and vitamin D supplementation significantly increases lumbar spine BMD in patients with osteoporosis resulting from long-term treatment with corticosteroids.

Effects of inflammation and treatment on bone turnover and bone mass in polymyalgia rheumatica

OBJECTIVE

Polymyalgia rheumatica (PMR) has an abrupt onset of inflammatory symptoms, making it a useful model for studying the effects of inflammation in bone. PMR requires corticosteroid treatment, which may itself have a detrimental effect on bone. This study used serially measured biochemical markers of bone turnover and bone density to address the relative contributions of systemic inflammation and corticosteroid therapy to bone loss.

METHODS

Fifty untreated patients with PMR were randomized to receive oral prednisolone or intramuscular methylprednisolone. Biochemical bone markers (pyridinoline [PYR], deoxypyridinoline [DPYR], procollagen type I carboxy-terminal peptide [PICP]) and bone mineral density (BMD) were measured at baseline and at 6, 12, and 24 months.

RESULTS

The median disease duration at presentation was 12 weeks (range 5-32 weeks). Levels of urinary crosslinks were increased in patients with untreated PMR compared with controls (PYR 74.9 +/- 30.0 nmoles/mmole creatinine, DPYR 14.6 +/- 6.4 nmoles/mmole creatinine [mean +/- SD]; P = 0.0001); the PICP level was normal (115.0 +/- 39.0 microg/liter). With treatment, the crosslinks levels fell and PICP levels rose within 6 months (P = 0.01). Bone resorption (PYR) correlated with untreated disease activity (erythrocyte sedimentation rate [ESR]) (r = 0.5, P = 0.003) and with interleukin-6 levels (r = 0.48, P = 0.05). There was a significant reduction in BMD of both the hip and the spine after 12 months of treatment (P = 0.0002), with no difference between treatment groups. As the steroid dosage was reduced, bone mass improved. Initial ESR influenced the percent change in BMD at 1 year (r = 0.35, P = 0.05), while cumulative steroid dose, mean ESR, and type of steroid used did not.

CONCLUSION

Inflammation in PMR increases bone resorption and appears to have a more detrimental effect on bone than does low-dose corticosteroid. If corticosteroids can be tapered and discontinued, bone loss in PMR can be a transient phenomenon.

Hepatic toxicity caused by adjuvant CMF/CNF in breast cancer patients and reversal by tamoxifen

The purpose of the study was to determine the effect of adjuvant chemotherapy on liver enzymes in breast cancer patients. Furthermore, the effect of tamoxifen on liver enzymes was analyzed. Liver function tests from 194 breast cancer patients who received adjuvant chemotherapy with or without tamoxifen (TAM) were reviewed. Statistically very significant increases were seen in alkaline phosphatase, aspartate acetyl transferase, and gamma glutamyl transferase levels in these patients receiving adjuvant chemotherapy. No statistical changes were noticed in bilirubin levels. If tamoxifen was given together with adjuvant chemotherapy, no changes in liver function tests were detected. Hepatic toxicity was induced in breast cancer patients by adjuvant CMF/CNF therapy (cyclophosphamide, methotrexate, 5-fluorouracil, mitoxantrone). These changes were mostly mild. Adjuvant tamoxifen reduced the increase in liver enzymes caused by adjuvant chemotherapy.

Metabolic effects of pamidronate in patients with metastatic bone disease

We have evaluated the value of specific bone resorption markers in monitoring metastatic bone disease to define the duration of action of a single high-dose pamidronate infusion. Twenty patients received a single infusion of pamidronate 120 mg for painful bone metastases. Ten out of these 20 patients also received a second infusion. They were evaluated at baseline, 2, 4 and 8 weeks after each infusion. A composite pain questionnaire, serum and urine tests were carried out at these time points. Bone resorption markers measured included urinary calcium, hydroxyproline and two new markers: pyridinoline and deoxypyridinoline. Reference values were defined by 20 healthy controls matched by age and sex. Pamidronate induced a profound fall in bone resorption with a maximal effect within the first month after therapy. Changes in urinary calcium levels were confounded by a rise of 100% in the parathyroid hormone levels. Before treatment, pyridinoline and deoxypyridinoline were increased in 70% of patients, while urinary calcium was increased in only 40% of them. Thirteen patients had a > or = 50% fall in deoxypyridinoline levels and were considered as biochemical responders. These patients had a mean reduction in pain score of about 30% of baseline levels, which was significantly higher than the seven non-biochemical responders. In conclusion, urinary calcium is not a precise marker of bone resorption. Deoxypyridinoline seems to be the most specific bone resorption marker in cancer patients. Biochemical responders have the most benefit from pamidronate in terms of pain relief. This suggests that patients may benefit from more potent or repeated infusions of bisphosphonates.