Increase of bone alkaline phosphatase after androgen deprivation therapy in patients with prostate cancer

Higher serum alkaline phosphatase value indicates the need for bone mineral density testing in non-metastatic prostate cancer patients undergoing androgen deprivation therapy

PURPOSE

Osteoporosis is a well-known adverse effect of androgen deprivation therapy for prostate cancer. This study aimed to reveal the factors associated with the diagnosis of osteoporosis in prostate cancer patients undergoing androgen deprivation therapy.

METHODS

This retrospective cross-sectional study included 106 prostate cancer patients treated with androgen deprivation therapy. Patients with bone metastasis at the initiation of androgen deprivation therapy and those with castration-resistant prostate cancer were excluded. Bone mineral density was measured at the lumbar spine and femoral neck using dual-energy X-ray absorptiometry. Osteoporosis was defined as bone mineral density equal to or below either -2.5 SD or 70% of the mean in young adults. The association between clinicopathological variables and bone mineral density or diagnosis of osteoporosis was investigated.

RESULTS

Thirty-six (34%) patients were found to have osteoporosis. The incidence of osteoporosis increased in a stepwise manner depending on the duration of androgen deprivation therapy. Multivariate logistic regression analysis identified a longer duration of androgen deprivation therapy (months, odd's ratio = 1.017, P = 0.006), lower body mass index (kg/m2, odd's ratio = 0.801, P = 0.005) and higher serum alkaline phosphatase value (U/l, odd's ratio 1.007, P = 0.014) as the factors independently associated with the diagnosis of osteoporosis. Eleven out of 50 (22%), 14 out of 35 (40%) and 11 out of 20 patients (55%) were osteoporotic in the patients with serum alkaline phosphatase values <238 U/l, 238-322 U/l and >322 U/l, respectively (P = 0.022).

CONCLUSIONS

Osteoporosis is common in prostate cancer patients undergoing androgen deprivation therapy; furthermore, its incidence increases depending on the duration of androgen deprivation therapy. Bone mineral density testing should be considered for all patients on androgen deprivation therapy, especially for those with a lower body mass index and higher serum alkaline phosphatase value.

Co-Treatment of Purified Annatto Oil (Bixa orellana L.) and Its Granules (Chronic®) Improves the Blood Lipid Profile and Bone Protective Effects of Testosterone in the Orchiectomy-Induced Osteoporosis in Wistar Rats

This study aimed to evaluate and compare the effects of co-treatment with purified annatto oil (PAO) or its granules (GRA, Chronic®) with that of testosterone on the orchiectomy-induced osteoporosis in Wistar rats. After surgery, rats were treated from day 7 until day 45 with testosterone only (TES, 7 mg/kg, IM) or TES + PAO or GRA (200 mg/kg, p.o.). The following parameters were evaluated: food/water intake, weight, HDL, LDL, glucose, triglycerides (TG), total cholesterol (TC), alkaline phosphatase levels, blood phosphorus and calcium contents, femur weight, structure (through scanning electron microscopy), and calcium content (through atomic absorption spectrophotometry). Our results show that orchiectomy could significantly change the blood lipid profile and decrease bone integrity parameters. Testosterone reposition alone could improve some endpoints, including LDL, TC, bone weight, and bone calcium concentration. However, other parameters were not significantly improved. Co-treatment with PAO or GRA improved the blood lipid profile and bone integrity more significantly and improved some endpoints not affected by testosterone reposition alone (such as TG levels and trabeculae sizes). The results suggest that co-treatment with annatto products improved the blood lipid profile and the anti-osteoporosis effects of testosterone. Overall, GRA had better results than PAO.

Engineering osteoblastic metastases to delineate the adaptive response of androgen-deprived prostate cancer in the bone metastatic microenvironment

While stromal interactions are essential in cancer adaptation to hormonal therapies, the effects of bone stroma and androgen deprivation on cancer progression in bone are poorly understood. Here, we tissue-engineered and validated an in vitro microtissue model of osteoblastic bone metastases, and used it to study the effects of androgen deprivation in this microenvironment. The model was established by culturing primary human osteoprogenitor cells on melt electrowritten polymer scaffolds, leading to a mineralized osteoblast-derived microtissue containing, in a 3D setting, viable osteoblastic cells, osteocytic cells, and appropriate expression of osteoblast/osteocyte-derived mRNA and proteins, and mineral content. Direct co-culture of androgen receptor-dependent/independent cell lines (LNCaP, C4-2B, and PC3) led cancer cells to display functional and molecular features as observed in vivo. Co-cultured cancer cells showed increased affinity to the microtissues, as a function of their bone metastatic potential. Co-cultures led to alkaline phosphatase and collagen-I upregulation and sclerostin downregulation, consistent with the clinical marker profile of osteoblastic bone metastases. LNCaP showed a significant adaptive response under androgen deprivation in the microtissues, with the notable appearance of neuroendocrine transdifferentiation features and increased expression of related markers (dopa decarboxylase, enolase 2). Androgen deprivation affected the biology of the metastatic microenvironment with stronger upregulation of androgen receptor, alkaline phosphatase, and dopa decarboxylase, as seen in the transition towards resistance. The unique microtissues engineered here represent a substantial asset to determine the involvement of the human bone microenvironment in prostate cancer progression and response to a therapeutic context in this microenvironment.

Analysis of Bone Alkaline Phosphatase as a Marker for the Diagnosis of Osteoporosis in Men under Androgen Ablation

The objective of this study was to evaluate the usefulness of serum determination of bone alkaline phosphatase (BAP) in the diagnosis of osteoporosis in men with prostate cancer under androgen ablation. Serum levels of BAP and bone mineral density (BMD) were assessed in 110 patients with non-metastatic, treated prostate cancer. Fifty-eight patients were under androgen deprivation during a period between two and 96 months and 52 had been submitted only to radical prostatectomy. Mean serum BAP was 11.8 ng/mL in patients with normal BMD, 16.7 ng/mL in patients with osteopenia (p. 0.058), and 19.3 ng/mL in patients with osteoporosis (p=0.044). The correlation between serum BAP and BMD was significant (p. 0.006) but with an index of only 0.26. Receiver operating characteristic analysis for the diagnosis of osteoporosis showed an area under the curve of 0.608. None of the cutoff points that provided specificities of 75%, 90% and 95% gave significant distributions. The positive and negative predictive values as well as the odds ratios were not of any clinical usefulness. We conclude that serum BAP should not be considered a good marker for the diagnosis of osteoporosis in men with prostate cancer. Therefore, BAP serum determination cannot replace bone densitometry as a diagnostic tool.

Bone Mineral Density Changes after Orchiectomy using a Scrotal Approach in Rats

Objective

To investigate a suitable animal model for studies of male osteoporosis. Osteoporosis has a particularly high incidence in postmenopausal women, resulting in a substantial amount of research with respect to this disease in women. However, research on osteoporosis in men is still lacking.

Methods

Twenty 10-week-old male Sprague Dawley rats were used in this study, including 4 rats used to establish a baseline bone mineral density (BMD). The other 16 rats were divided into two groups: a sham surgery group (n=8), which underwent a sham operation, and an orchiectomized rat group (OCX) (n=8), which underwent bilateral OCX at 10 weeks of age. Bone mineral density was measured in 4 rats from both the sham surgery group and the OCX group 8 weeks after the surgery, while BMD in the remainder of the rats was measured 10 weeks post-surgery.

Results

Femoral BMD at 8 weeks post-surgery was found to be significantly lower in the OCX group compared to the sham group; a finding that was also similar 10 weeks post-surgery.

Conclusion

8 weeks after undergoing orchiectomy performed via a scrotal, white rats are a suitable model for studies of male osteoporosis.

Bone turnover markers as predictive tools for skeletal complications in men with metastatic prostate cancer treated with zoledronic acid

BACKGROUND

Bone turnover markers are helpful to diagnose bone metastases. The aim of this study was to evaluate the usefulness of these markers in prostate cancer patients with bone metastases before and during the treatment with zoledronic acid as predictive and monitoring tools of skeletal-related events (SRE).

METHODS

One hundred seventeen prostate cancer patients with bone metastases and treated with zoledronic acid (4 mg every 4 weeks) were examined. Fifty-six patients were with and 61 patients without SRE during a 60-week study. Total and bone-specific alkaline phosphatase, and amino-terminal procollagen propeptides of type-I-collagen (PINP), cross-linked N-terminal (NTx), cross-linked C-terminal telopeptides of type-I-collagen (ICTP), and C-terminal telopeptides of type-I-collagen as well as prostate-specific antigen (PSA) were measured before and 12, 24, 36, 48, and 60 weeks after starting treatment.

RESULTS

Higher baseline concentrations were observed in the SRE group. The bone markers except for ICTP and tALP decreased to 20-80% of the baseline values at week 12 after the drug administration showing a generally higher decline in the non-SRE group except for NTx. At all time points during treatment higher and increasing concentrations of bone markers were observed in the SRE group compared with non-SRE group. Cox regression models with clinical data and bone markers showed the baseline NTx concentration as predictor of SREs. During the study, percentage changes of PINP and ICTP were most indicative for SREs.

CONCLUSIONS

Bone markers are useful tools to predict and diagnose SRE in prostate cancer patients with bone metastases under receiving zoledronic acid therapy.

Plasma osteopontin in comparison with bone markers as indicator of bone metastasis and survival outcome in patients with prostate cancer

BACKGROUND

The study was undertaken to evaluate the diagnostic and prognostic value of plasma osteopontin (OPN) in comparison to bone markers as well as the relationships between the markers and clinico-pathological factors in prostate cancer (PCa) patients.

METHODS

OPN and the bone markers carboxyterminal-telopeptide of type I collagen, bone-specific alkaline phosphatase (bALP), and aminoterminal-propeptide of type I procollagen (PINP) were measured in 90 PCa patients with and without bone metastases, 35 patients with benign prostatic hyperplasia, and 29 healthy men.

RESULTS

OPN and bone markers were significantly elevated in patients with bone metastases compared to the other groups. Significant correlations were found between all four-bone markers (r(s) = 0.43-0.79, all P < 0.01). OPN correlated with tumor grade (r(s) = 0.23, P < 0.05). In receiver-operating characteristics (ROC) analyses, OPN and bone markers were effective in distinguishing PCa patients with and without bone metastases showing areas under the curve (AUC) between 0.80 and 0.88 (all P < 0.001). OPN had an AUC of 0.85 that increased in combination with bALP up to 0.93 providing at the point with the highest diagnostic accuracy both a sensitivity and specificity of about 90%. Kaplan-Meier analyses and Cox proportional hazards regression models showed decreased survival of patients with high OPN and bone marker levels, while only high OPN and PINP were independent negative prognostic factors for PCa-related death.

CONCLUSIONS

OPN alone or in combination with bone markers is useful as diagnostic marker in the detection of bone metastases and as prognosticator in the survival prediction in PCa patients.

Serum tartrate-resistant acid phosphatase 5b (TRACP 5b) as a marker of skeletal changes in prostate cancer

Skeletal metastases are a significant problem in prostate cancer (PC). The patients are also exposed to treatment-related skeletal changes. This cross-sectional study evaluated a marker of bone resorption, TRACP 5b in relation to the standard analyte total alkaline phosphatase (tALP) as a marker of skeletal changes. Serum levels of TRACP 5b, tALP and PSA were measured in 130 prostate cancer patients. Comparison was made between patients with (BM+, n = 25) and without (BM-, n = 105) skeletal metastases, and between those treated with (n = 64) or without (n = 66) androgen deprivation (AD). Sensitivities and specificities were calculated for each marker and diagnostic accuracy was evaluated by ROC curve analysis. ROC curves indicated the superior accuracy of tALP, whereas TRACP 5b and PSA were comparable. With tALP the best combination of sensitivity (96%) and specificity of (91%) was reached at a cut-off point 224 U/L, the corresponding values were for TRACP 5b sensitivity (76%), specificity (89%) with a cut-off point 4.89 U/L, and for PSA sensitivity (65%), specificity (81%) at 23 ng/L for skeletal metastases. Patients treated with AD showed with increasing duration an increase in TRACP 5b values. TRACP 5b was less specific than tALP as a marker of skeletal metastases. TRACP 5b may have a role in the diagnostics of skeletal changes in PC with a focus on treatment-related skeletal changes.

Comparison of 10 serum bone turnover markers in prostate carcinoma patients with bone metastatic spread: diagnostic and prognostic implications

Our aim was to assess the diagnostic accuracy of bone markers in serum of patients with prostate cancer (PCa) for early detection of bone metastases and their usefulness as predictors of PCa-caused mortality. In sera of 117 PCa patients (pN0M0, n = 39; pN1M0, n = 34; M1, n = 44), 35 healthy men and 35 patients with benign prostatic hyperplasia, bone formation markers [total and bone-specific alkaline phosphatase (tALP, bALP), amino-terminal procollagen propeptides of type I collagen (P1NP), osteocalcin (OC)], bone resorption markers [bone sialoprotein (BSP), cross-linked C-terminal (CTX) and cross-linked N-terminal (NTX) telopeptides of type I collagen, tartrate-resistant acid phosphatase isoenzyme 5b (TRAP)] and osteoclastogenesis markers [osteoprotegerin (OPG), receptor activator of nuclear factor kappaB ligand (RANKL)] were measured. tALP, bALP, BSP, P1NP, TRAP, NTX and OPG were significantly increased in PCa patients with bone metastases compared to patients without metastases. OPG showed the best discriminatory power to differentiate between these patients. Logistic regression analysis resulted in a model with OPG and TRAP as variables that predicted bone metastasis with an overall correct classification of 93%. Patients with concentrations of OPG, P1NP, tALP, bALP, BSP, NTX, TRAP and CTX above cut-off levels showed significantly shorter survival than patients with low marker concentrations. Multivariate Cox proportional hazards regression revealed that only OPG and BSP were independent prognostic factors for PCa-related death. Thus, the importance of serum OPG in detecting bone metastatic spread, alone or in combination with other bone markers, and predicting survival in PCa patients has been clearly demonstrated.

Bone alkaline phosphatase serum level predicts the response to antiandrogen withdrawal

OBJECTIVE

To analyze if the biochemical response to antiandrogen withdrawal correlates with total and percent free serum prostate specific antigen (PSA) and bone alkaline phosphatase (BAP).

MATERIALS AND METHODS

A group of 46 patients in whom maximal androgen blockade (MAB) failed was included in this study. Flutamide was used in 32 patients and bicalutamide in 14. Total and free PSA and BAP were determined in serum the same day in which antiandrogen was withdrawn. Thereafter, serum PSA was determined every 15 days. A biochemical response was established when a decrease in serum PSA greater than 50% was observed. The duration of biochemical response was considered until the first of two consecutive PSA serum elevations.

RESULTS

The rate of biochemical responses was 23.9%. The mean duration of responses was 5.2 months. The mean serum PSA in patients who responded to the antiandrogen withdrawal was 86.4 ng/ml, while it was 98.6 ng/ml in those who did not respond, P > 0.05. The mean of percent free PSA was 13.9 and 17.7%, respectively, P > 0.05. However, the mean BAP in responder patients was significantly lower, 18.9 ng/ml versus 100.6 ng/ml, P < 0.03. The rate of responses to flutamide withdrawal was 25% and to bicalutamide withdrawal 21.4%, P > 0.05. Other factors as age, Gleason score, initial clinical stage and the period of antiandrogen exposure were also analyzed. However, none of them had statistical significance. Serum BAP was the only predictor of response in the logistic regression analysis and a cut-off point of 50 ng/ml provided a relative risk of 1.46 (95% CI 1.17-1.83).

CONCLUSIONS

Lower serum levels of BAP seems to correlate with a better response to antiandrogen withdrawal. Moreover, a level of BAP higher than 50 ng/ml would predict strongly the absence of response.