Bone metabolic markers as gauges of metastasis to bone: a review

Reliability of Alkaline Phosphatase for Differentiating Flare Phenomenon from Disease Progression with Bone Scintigraphy

Simple Summary

Bone scintigraphy is the most widely used radionuclide technique to investigate bone metastasis, primarily due to its reasonable time and cost factor. However, it is important to recognize that bone scintigraphy to assess treatment response sometimes shows a “flare phenomenon”, which can be misinterpreted as disease progression. Distinction between flare phenomenon and disease progression could help in the decision to continue effective treatments in patients with flare phenomenon and to cease ineffective treatments and consider other salvage treatment plans in patients with disease progression. Despite many methods having been tried to answer this question, there was still no reliable way to differentiate between flare phenomenon and progression of bone metastases. Our results suggest that ALP is a useful serologic marker to differentiate flare phenomenon from disease progression on bone scintigraphy in breast or prostate cancer patients with bone metastasis.

Abstract

The flare phenomenon (FP) on bone scintigraphy after the initiation of systemic treatment seriously complicates evaluations of therapeutic response in patients with bone metastases. The aim of this study was to evaluate whether serum alkaline phosphatase (ALP) can differentiate FP from disease progression on bone scintigraphy in these patients. Breast or prostate cancer patients with bone metastases who newly underwent systemic therapy were reviewed. Pretreatment baseline and follow-up data, including age, pathologic factors, type of systemic therapy, radiologic and bone scintigraphy findings, and ALP levels, were obtained. Univariate and multivariate analyses of these factors were performed to predict FP. An increased extent and/or new lesions were found in 160 patients on follow-up bone scintigraphy after therapy. Among the 160 patients, 80 (50%) had an improvement on subsequent bone scintigraphy (BS), while subsequent scintigraphy also showed an increased uptake in 80 (50%, progression). Multiple regression analysis revealed that stable or decreased ALP was an independent predictor for FP (p < 0.0001). ALP was an independent predictor for FP on subgroup analysis for breast and prostate cancer (p = 0.001 and p = 0.0223, respectively). Results of the study suggest that ALP is a useful serologic marker to differentiate FP from disease progression on bone scintigraphy in patients with bone metastasis. Clinical interpretation for scintigraphic aggravation can be further improved by the ALP data and it may prevent fruitless changes of therapeutic modality by misdiagnosis of disease progression in cases of FP.

From Glucose to Lactate and Transiting Intermediates Through Mitochondria, Bypassing Pyruvate Kinase: Considerations for Cells Exhibiting Dimeric PKM2 or Otherwise Inhibited Kinase Activity

A metabolic hallmark of many cancers is the increase in glucose consumption coupled to excessive lactate production. Mindful that L-lactate originates only from pyruvate, the question arises as to how can this be sustained in those tissues where pyruvate kinase activity is reduced due to dimerization of PKM2 isoform or inhibited by oxidative/nitrosative stress, posttranslational modifications or mutations, all widely reported findings in the very same cells. Hereby 17 pathways connecting glucose to lactate bypassing pyruvate kinase are reviewed, some of which transit through the mitochondrial matrix. An additional 69 converging pathways leading to pyruvate and lactate, but not commencing from glucose, are also examined. The minor production of pyruvate and lactate by glutaminolysis is scrutinized separately. The present review aims to highlight the ways through which L-lactate can still be produced from pyruvate using carbon atoms originating from glucose or other substrates in cells with kinetically impaired pyruvate kinase and underscore the importance of mitochondria in cancer metabolism irrespective of oxidative phosphorylation.

Effects of Yishengukang decoction on expression of bone-specific alkaline phosphatase, carboxyterminal propeptide of type Ⅰ procollagen, and carboxyterminal cross-linked telepeptide of type Ⅰ collagen in malignant tumor patients with bone metastasis

OBJECTIVE

To investigate the effect of Yishengukang decoction on the expression of the metabolic bone markers, bone-specific alkaline phosphatase (BAP), carboxyterminal propeptide of type Ⅰ procollagen (PICP), and arboxyterminal cross-linked telepeptide of type Ⅰ collagen (ICTP), in cancer patients with bone metastasis.

METHODS

Patients (n = 180) were divided into three groups: (a) bone metastasis patients treated with Yishengukang and pamidronate disodium injection (treatment group, n = 60); (b) bone metastasis patients treated with pamidronate disodium injection alone (control group, n = 60); (c) cancer patients without metastatic bone lesion (non-bone metastasis group, n = 60). Serum levels of the metabolic markers BAP, PICP, and ICTP were detected by enzyme-linked immunosorbent assay pre- and post-therapy.

RESULTS

A significant decrease in serum BAP level was observed in the treatment group compared with the control group. However there were no significant differences in serum levels of PICP and ICTP before or after treatment compared with the control group.

CONCLUSION

Yishengukang decoction combined with pamidronate disodium injection reduced serum BAP level to a greater extent that pamidronate disodium injection alone. Furthermore, the combined therapy was more beneficial in regulating imbalanced bone metabolism after bone metastasis, and may represent the molecular mechanism underpinning the effects of Yishengukang decoction.

The relationship between skeletal-related events and bone scan index for the treatment of bone metastasis with breast cancer patients

The aim of the present study was to investigate the relationships between the automated bone scan index (aBSI) and skeletal-related events (SRE) in breast cancer patients with bone metastasis. A computer-aided software (BONENAVI™) that was developed using an Artificial Neural Network (Artificial Neural Network) was used for the present analysis. Forty-five patients diagnosed with bone metastasis due to breast cancer from April 2005 through March 2013 were retrospectively analyzed. Before and after the time of initial treatment, aBSI, Artificial Neural Network score, and hotspot number were calculated, and the relationships between these scores and SRE were analyzed. Twenty cases showed decreased (improved) aBSI values after initial treatment (Group A), and 25 cases showed unchanged/increased (worsened) aBSI values (Group B). Chi-square analysis revealed a significant difference in incident numbers of SRE between the two groups--one case in Group A and 12 in Group B (P<0.001). Event-free survival was significantly shorter in Group B (hazard ratio: 8.31, 95% CI: 1.33-12.14, log-rank test; P<0.05). The groups were also divided by the results of 2 radiologists' visual scan interpretations, and no significant differences were shown in the number of SRE (P=0.82, P=0.10). When correlation analyses were performed between aBSI and bone metabolic or tumor markers, alkaline phosphatase was significantly correlated with aBSI at the time of initial treatment (R=0.69, P<0.05). In conclusion, aBSI is proposed as a useful and objective imaging biomarker in the detection of breast-cancer patients with bone metastasis at high risk of SRE.

Serum N-Terminal Propeptide of Collagen Type I is Associated with the Number of Bone Metastases in Breast and Prostate Cancer and Correlates to Other Bone Related Markers

Background

A number of biomarkers have been proven potentially useful for their ability to indicate bone metastases (BM) in cancer patients. The aim of this study was to investigate the relative utility of a newly developed N-terminal propeptide of collagen type I (PINP) human serum assay for the detection of BM in cancer patients. This assay has a corresponding rat PINP assay which in the future might help in translational science between rodent and human trials.

Methods

Participants were 161 prostate, lung and breast cancer patients stratified by number of BM (Soloway score). PINP was assessed and correlated to number of BM. Additionally, the PINP marker was correlated to bone resorption of young (ALPHA CTX-I)- and aged bone (BETA CTX-I); number of osteoclasts (Tartrate-resistant acid phosphatase 5b, TRACP5B) and osteoclast activity (CTX-I/ TRACP5B).

Results

PINP was significantly elevated in breast- and prostate cancer patients +BM, compared to −BM (P < 0.001), however not in lung cancer patients. A strong linear association was seen between PINP and the number of BMs. Significant elevation of PINP was observed at Soloway scores 1–4 (<0 BM) compared with score 0 (0 BM) (P < 0.001). The correlation between bone resorption of young bone or aged bone and bone formation was highly significant in patients +BM and −BM (P < 0.0001).

Conclusions

Data suggest that the present PINP potentially could determine skeletal involvement in patients with breast or prostate cancer. Correlations suggested that coupling between bone resorption and bone formation was maintained in breast- and prostate cancer patients.

Post-operative breast cancer patients diagnosed with skeletal metastasis without bone pain had fewer skeletal-related events and deaths than those with bone pain

BACKGROUND

Skeletal metastases are often accompanied by bone pain. To investigate the clinical meaning of bone pain associated with skeletal metastasis in breast cancer patients after surgery, we explored whether the presence of bone pain was due to skeletal-related events (SREs) or survival (cause specific death, CSD), retrospectively.

METHODS

Consecutive breast cancer patients undergoing surgery between 1988 and 1998 were examined for signs of skeletal metastasis until December 2006. Patients who were diagnosed as having skeletal metastasis were the subjects of this study. Bone scans were performed annually for 5, 7 or 10 years; they were also conducted if skeletal metastasis was suspected. Data concerning bone pain and tumor markers at the time of skeletal metastasis diagnosis, and data relating to various factors including tumors, lymph nodes and hormone receptors at the time of surgery, were investigated. The relationships between factors such as bone pain, SRE and CSD were analyzed using the Kaplan-Meier method and Cox's analysis.

RESULTS

Skeletal metastasis occurred in 668 patients but the pain status of two patients was unknown, therefore 666 patients were included in the study. At the time of skeletal metastasis diagnosis 270 patients complained of pain; however, 396 patients did not. Analysis of data using Cox's and Kaplan-Meier methods demonstrated that patients without pain had fewer SREs and better survival rates than those with pain. Hazard ratios regarding SRE (base = patients without pain) were 2.331 in univariate analysis and 2.243 in multivariate analysis. Hazard ratios regarding CSD (base = patients without pain) were 1.441 in univariate analysis and 1.535 in multivariate analysis. Similar results were obtained when analyses were carried out using the date of surgery as the starting point.

CONCLUSION

Bone pain at diagnosis of skeletal metastasis was an indicator of increased SRE and CSD. However, these data did not support recommendations of follow-up bone surveys in breast cancer patients.

An open cohort study of bone metastasis incidence following surgery in breast cancer patients

Background

To help design clinical trials of adjuvant bisphosphonate therapy for breast cancer, the temporal incidence of bone metastasis was investigated in a cohort of patients. We have tried to draw the criteria to use adjuvant bisphosphonate.

Methods

Consecutive breast cancer patients undergoing surgery between 1988 and 1998 (5459 patients) were followed up regarding bone metastasis until December 2006. Patients' characteristics at the time of surgery were analyzed by Cox's method, with bone metastasis as events. Patient groups were assigned according to Cox's analysis, and were judged either to require the adjuvant bisphosphonate or not, using the tentative criteria: high risk (>3% person-year), medium risk (1-3%), and low risk (<1%).

Results

Bone metastasis incidence was constant between 1.0 and 2.8% per person-year more than 10 years. Non-invasive cancer was associated with a very low incidence of bone metastasis (1/436). Multivariate Cox's analysis indicated important factors for bone metastasis were tumor grade (T), nodal grade (pN), and histology. Because T and pN were important factors for bone metastasis prediction, subgroups were made by pTNM stage. Patients at stages IIIA, IIIB and IV had an incidence of >3% per person-year, patients with stage I <1% per person-year, and those with stages II were between 1 and 3%. Further analysis with histology in stage II patients showed that stage IIB with high risk histology also had a high incidence (3% person year), whereas stage IIA with medium risk histology were <1%.

Conclusions

Bone metastasis incidence remained constant for many years. Using pN, T, and histopathology, patients could be classified into high, medium, and low risk groups.

Prognostic factors and the therapeutic strategy for patients with bone metastasis from differentiated thyroid carcinoma

BACKGROUND

The treatment of bone metastasis in association with thyroid cancer represents a difficult challenge. Given the paucity of patients with bone metastasis and the difficulty of treating this disease, few studies have investigated the clinical features and prognostic factors of bone metastasis from differentiated thyroid cancer.

METHODS

During the 31-year-period from 1976 to 2006, a total of 1,398 patients underwent initial thyroidectomy at Cancer Institute Hospital for differentiated thyroid carcinomas, including standard papillary thyroid carcinoma, papillary microcarcinoma (primary tumor diameter < or =1.0 cm), and follicular thyroid carcinoma. Among these, 25 (2%) patients displayed bone metastasis at initial presentation (synchronous) and 27 patients showed bone metastasis during follow-up (metachronous). The records for these 52 patients were reviewed retrospectively to identify prognostic factors and analyze treatment strategies.

RESULTS

Univariate analysis for disease-specific survival indicated metachronous bone metastasis and the presence of distant metastasis at sites other than bone as indicators of significantly worse prognosis. The type of cancer (papillary thyroid carcinoma versus follicular thyroid carcinoma) was not a significant indicator of prognosis; however, patients with papillary microcarcinoma showed significantly worse survival than patients with standard papillary and follicular thyroid carcinoma. A significant survival advantage was observed among patients who underwent radioactive iodine therapy, and better prognosis seemed to be obtained with greater doses of radioactive iodine. Operative resection of metastatic bone lesions also seemed to be associated with better prognosis. A multivariate analysis for disease-specific survival identified the coexistence of distant metastasis at sites other than bone as the only independent variable indicative of poor prognosis.

CONCLUSION

In the absence of definitive, effective treatments for this disease, radioactive iodine therapy combined with resection of bone metastasis, wherever possible, seems to represent the most potent therapy available. Although bone metastasis is a strong sign of poor prognosis, early detection and administration of appropriate therapy using radioactive iodine seems likely to improve the survival rate and quality of life in patients with bone metastasis from differentiated thyroid carcinoma.

Increased tartrate-resistant acid phosphatase (TRAP) expression in malignant breast, ovarian and melanoma tissue: an investigational study

Background

Tartrate-resistant acid phosphatase (TRAP) is a metalloprotein enzyme that belongs to the acid phosphatases and is known to be expressed by osteoclasts. It has already been investigated as a marker of bone metastases in cancer patients. In this study, which examined the value of serum TRAP concentrations as a marker of bone disease in breast cancer patients, we observed high concentrations of TRAP even in patients without bone metastases. To elucidate this phenomenon, we examined the expression of TRAP in breast cancer cells and the cells of several other malignancies.

Methods

TRAP concentrations in the serum of tumor patients were determined by ELISA. The expression of TRAP in breast, ovarian, and cervical cancer and malignant melanoma was analyzed by immunohistochemistry. RT-PCR and immunocytology were used to evaluate TRAP expression in cultured tumor cells.

Results

A marked increase in serum TRAP concentrations was observed in patients with breast and ovarian cancer, regardless of the presence or absence of bone disease. TRAP expression was found in breast and ovarian cancers and malignant melanoma, while cervical cancer showed only minimal expression of TRAP. Expression of TRAP was absent in benign tissue or was much less marked than in the corresponding malignant tissue. TRAP expression was also demonstrated in cultured primary cancer cells and in commercially available cell lines.

Conclusion

Overexpression of TRAP was detected in the cells of various different tumors. TRAP might be useful as a marker of progression of malignant disease. It could also be a potential target for future cancer therapies.

Breast cancer metastasis to bone: mechanisms of osteolysis and implications for therapy

The most common skeletal complication of breast cancer is osteolytic bone metastasis. Bone metastases are present in 80% of patients with advanced disease and cause significant morbidity. They are most often osteolytic, but can be osteoblastic or mixed. Tumor cells, osteoblasts, osteoclasts and bone matrix are the four components of a vicious cycle necessary for the initiation and development of bone metastases. Tumor cell gene expression is modified by interaction with bone-derived factors. For example, parathyroid hormone related protein (PTHrP), a tumor cell factor, is upregulated by bone-derived transforming growth factor beta (TGFbeta). Tumor cell factors, in turn, act upon bone cells to cause dysregulated bone destruction and formation. PTHrP increases osteoblast expression of RANK (receptor activator of NFkappaB) ligand which, in turn, activates osteoclasts. PTHrP-independent osteolytic factors, such as interleukin [IL]-11 and IL-8, also contribute to the vicious cycle. Other tumor-bone interactions, such as stimulation of tumor-homing through the CXCR4 chemokine receptor by its bone-derived ligand stromal-derived factor-1 (SDF-1), may be responsible for the site-specific predilection of breast cancer for bone. These factors and their roles in fueling the vicious cycle may identify novel targets for therapies to prevent metastasis.

Tartrate-Resistant Acid Phosphatase 5b is a Useful Serum Marker for Extensive Bone Metastasis in Breast Cancer Patients

Purpose: Previous studies showed that serum tartrate-resistant acid phosphatase 5b (TRACP5b) activity was increased in 70% to 94% of breast cancer (BC) patients with bone metastasis (BM). This study aims to determine whether serum TRACP5b is useful for identifying limited or extensive BM in BC patients.

Experimental Design: Serum TRACP5b activity was measured in 168 BC patients, including 81 who were newly diagnosed with early BC, 20 with extraosseous metastasis, 24 with limited BM, and 43 with extensive BM. Serum TRACP5b activity was also measured monthly in 151 patients with early BC until they developed BM. Four hundred and twenty-seven (427) healthy women ages 18 to 90 served as control. One-way ANOVA was used to compare serum TRACP5b among groups. The sensitivity and specificity of serum TRACP5b as a marker for BM were estimated by receiver operator characteristic (ROC) curves.

Results: Serum TRACP5b increased with age in healthy women ( P &lt; 0.0001). It was significantly elevated in patients with extensive BM compared with all other groups ( P &lt; 0.0001). ROC analysis established a cutoff value of 4.026 units/L to identify patients with extensive BM with a specificity of 98% and a sensitivity of 93% (area under the curve = 0.9807; 95% CI = 0.9698-0.9915). Among the 151 patients with early BC, 6 developed limited BM and 2 developed extensive BM during the follow-up period. Serum TRACP5b remained below the cutoff value in patients with limited BM, but became significantly increased in those whose BM became extensive.

Conclusion: Serum TRACP5b activity is a useful diagnostic marker for extensive BM in patients with BC.