The present and future role of bisphosphonates in the management of patients with breast cancer

At least 25% of patients with breast cancer develop skeletal metastases, with bone the site of disease producing the greatest morbidity. It is apparent that the bisphosphonates present an important component of the treatment strategy. They are now the treatment of choice in tumour-induced hypercalcaemia, and they can reduce bone pain and skeletal complications such as pathological fractures. In addition, bisphosphonates are being increasingly evaluated in the prevention of bone metastases and to prevent and treat cancer therapy-induced osteoporosis. Ongoing research is aimed at trying to define the optimum route, dose, schedule and type of bisphosphonate.     

Effect of zoledronic acid on the doxycycline-induced decrease in tumour burden in a bone metastasis model of human breast cancer

Bone is one of the most frequent sites for metastasis in breast cancer patients often resulting in significant clinical morbidity and mortality. Bisphosphonates are currently the standard of care for breast cancer patients with bone metastasis. We have shown previously that doxycycline, a member of the tetracycline family of antibiotics, reduces total tumour burden in an experimental bone metastasis mouse model of human breast cancer. In this study, we combined doxycycline treatment together with zoledronic acid, the most potent bisphosphonate. Drug administration started 3 days before the injection of the MDA-MB-231 cells. When mice were administered zoledronic acid alone, the total tumour burden decreased by 43% compared to placebo treatment. Administration of a combination of zoledronic acid and doxycycline resulted in a 74% decrease in total tumour burden compared to untreated mice. In doxycycline- and zoledronate-treated mice bone formation was significantly enhanced as determined by increased numbers of osteoblasts, osteoid surface and volume, whereas a decrease in bone resorption was also observed. Doxycycline greatly reduced tumour burden and could also compensate for the increased bone resorption. The addition of zoledronate to the regimen further decreased tumour burden, caused an extensive decrease in bone-associated soft tissue tumour burden (93%), and sustained the bone volume, which could result in a smaller fracture risk. Treatment with zoledronic acid in combination with doxycycline may be very beneficial for breast cancer patients at risk for osteolytic bone metastasis.     

Direct effects of bisphosphonates on breast cancer cells

In addition to inhibiting bone resorption, bisphosphonates have also been shown to exhibit antitumour effects. In vitro, bisphosphonates inhibit proliferation and induce apoptosis in cultured human breast cancer cells. In addition, bisphosphonate treatment interferes with breast cancer cell adhesion to bone matrix, and inhibits cell migration and invasion. The combination of bisphosphonates with other anticancer drugs such as the taxoids markedly enhances these effects. These newly recognized direct actions of bisphosphonates on breast cancer cells indicate that these agents may have a greater role to play in treatment of patients suffering from cancers with a propensity to metastasize to bone.     

双膦酸盐治疗乳腺癌骨转移患者的临床病理特征及预后分析*

目的：探讨乳腺癌骨转移患者的临床、病理、治疗及预后因素。方法：收集2005年1 月至2013年4 月天津医科大学肿瘤医院收治的183 例至少接受6 个月双膦酸盐治疗的乳腺癌骨转移患者的临床资料,根据双膦酸盐类型分为帕米膦酸二钠组、唑来膦酸组及帕米膦酸二钠序贯唑来膦酸组,探讨骨转移的特点、骨相关事件（skeletal-related events,SREs）、治疗及预后特征。结果：胸椎和肋骨为骨转移的常见转移部位,骨转移至发生首次SREs的中位时间为4.2 个月,51.9%（95/ 183）患者发生SREs,累计SREs事件数达167 次,其中110 次（65.9%）发生在骨转移后1 年内,SREs类型以骨放疗为主。患者在不同双膦酸盐药物组的SREs发生率差异无统计学意义（P > 0.05）。 183 例患者骨转移后的中位生存期为43.1 个月,激素受体状态、无病生存期、是否合并内脏转移及脊柱转移与否是乳腺癌骨转移患者的独立预后因素（P < 0.05）。 结论：胸椎和肋骨是乳腺癌骨转移的常见转移部位,SREs主要发生在骨转移后1 年内并以骨放疗为主。激素受体阴性、无病生存期短、合并内脏及脊柱转移是影响乳腺癌患者骨转移不良预后的独立因素。     

乳腺癌骨转移疼痛的综合治疗

目的　探讨缓解乳腺癌骨转移疼痛 ,恢复患者活动能力的方法。方法　 31例乳腺癌骨转移患者采用以CMFP或CAFP方案化疗为主 ,辅以放射性同位素或双磷酸盐类药物综合治疗 ,观察治疗后疼痛缓解、活动能力恢复及骨外转移灶的变化情况。结果　全组骨痛缓解率为 87.1 % (2 7/ 31 ) ,功能活动恢复 85 .7% (6/ 7) ,骨外转移灶的有效率为 67.9% (1 9/ 2 8)。结论　以化疗为主的综合治疗 ,不仅能较好地控制骨外转移灶的发展 ,而且能显著地缓解骨痛 ,恢复患者的活动能力     

乳腺癌骨转移机制与靶向治疗进展

乳腺癌骨转移是晚期乳腺癌常见的症状,乳腺癌细胞通过局部浸润、渗入血管和或淋巴管、随循环系统转移到骨、移出血管和或淋巴管、在骨定居并增殖引起溶骨性骨损伤。乳腺癌骨转移的发生发展取决于乳腺癌细胞与骨局部微环境之间相互作用,最后形成骨的结构破坏及功能受损。本文主要从分子水平阐述乳腺癌骨转移机制,并且综述针对乳腺癌骨转移关键靶点的抗骨转移药物的临床应用。     

Use of aromatase inhibitors and bisphosphonates as an anticancer therapy in postmenopausal breast cancer

Breast cancer is a major cause of morbidity and mortality in postmenopausal women worldwide. Reducing the risk of distant disease recurrence is a primary goal of adjuvant endocrine therapy. As we await data from ongoing Phase III comparison trials, an emerging body of evidence demonstrates important differences between third-generation aromatase inhibitors, particularly with respect to potency and prevention of early distant metastases. Furthermore, a growing body of evidence demonstrates anticancer benefits of bisphosphonates in adjuvant breast cancer and other settings. This article outlines the proceedings from an Expert Panel meeting of regionally diverse breast cancer specialists regarding the appropriate use of aromatase inhibitors in postmenopausal hormone-responsive early breast cancer and bisphosphonates as anticancer therapy in adjuvant breast cancer.     

A phase 2 trial exploring the effects of high‐dose (10,000 IU/day) vitamin D3 in breast cancer patients with bone metastases

BACKGROUND:

Vitamin D deficiency has potential roles in breast cancer etiology and progression. Vitamin D deficiency has also been associated with increased toxicity from bisphosphonate therapy. The optimal dose of vitamin D supplementation is unknown, but daily sunlight exposure can generate the equivalent of a 10,000‐IU oral dose of vitamin D₃. This study therefore aimed to assess the effect of this dose of vitamin D₃ in patients with bone metastases from breast cancer.

METHODS:

Patients with bone metastases treated with bisphosphonates were enrolled into this single‐arm phase 2 study. Patients received 10,000 IU of vitamin D₃ and 1000 mg of calcium supplementation each day for 4 months. The effect of this treatment on palliation, bone resorption markers, calcium metabolism, and toxicity were evaluated at baseline and monthly thereafter.

RESULTS:

Forty patients were enrolled. No significant changes in bone resorption markers were seen. Despite no change in global pain scales, there was a significant reduction in the number of sites of pain. A small but statistically significant increase in serum calcium was seen, as was a significant decrease in serum parathyroid hormone. Treatment unmasked 2 cases of primary hyperparathyroidism, but was not associated with direct toxicity.

CONCLUSIONS:

Daily doses of 10,000 IU vitamin D₃ for 4 months appear safe in patients without comorbid conditions causing hypersensitivity to vitamin D. Treatment reduced inappropriately elevated parathyroid hormone levels, presumably caused by long‐term bisphosphonate use. There did not appear to be a significant palliative benefit nor any significant change in bone resorption. Cancer 2010. © 2010 American Cancer Society.     

Inhibition of hyaluronan synthesis in breast cancer cells by 4-methylumbelliferone suppresses tumorigenicity in vitro and metastatic lesions of bone in vivo

Hyaluronan (HA) has been shown to play crucial roles in the tumorigenicity of malignant tumors. Previous studies demonstrated that inhibition of HA suppressed the tumorigenicity of various malignant tumors including breast cancer. 4-methylumbelliferone (MU) has been reported to inhibit HA synthesis in several cell types. However, few studies have focused on the effects of HA inhibition in breast cancer cells by MU, nor the effects on bone metastasis. We hypothesized that MU would suppress the progression of bone metastasis via inhibition of HA synthesis. Here, we investigated the effects of MU on HA expression in MDA-MB-231 breast cancer cell line in addition to their tumorigenicity in vitro and in vivo. HAS2 mRNA expression was downregulated after 6 and 24 hr treatment with MU. Quantitative analysis of HA revealed that MU significantly inhibited the intracellular and cell surface HA. MU significantly inhibited cell growth and induced apoptosis as determined by cell proliferation and TUNEL assays, respectively. Phosphorylation of Akt was suppressed after 12 and 24 hr treatment with MU. MU treatment also inhibited cell motility as well as cell invasiveness. MU also inhibited cell growth and motility in murine fibroblast cell line NIH3T3. In vivo, administration of MU inhibited the expansion of osteolytic lesions on soft X-rays in mouse breast cancer xenograft models. HA accumulation in bone metastatic lesions was perturbed peripherally. These data suggest that MU might be a therapeutic candidate for bone metastasis of breast cancer via suppression of HA synthesis and accumulation.     

Estrogen receptor profile of patients with breast cancer metastatic to bone marrow

The estrogen receptor (ER) profile of patients with breast cancer metastatic to bone marrow (BM) has not been widely reported. The charts of all patients having a diagnosis of breast cancer and undergoing bone marrow aspiration or biopsy at the Cleveland Clinic during the period of January 1980 through September 1982 were reviewed. Thirty-nine patients were so identified; of these 39 patients, 28 had estrogen receptor determination performed on a primary or a metastatic tumor specimen. Of the 28 patients with known ER, ten (36%) had ER less than 5 fmoles/mg cytosol protein, three (11%) had ER or 5 to 10 fmoles/mg, and 15 (54%) had ER greater than 10 fmoles/mg. Of the 39 patients with BM involvement, 36 (92%) had cortical bone involvement documented on x-ray or isotopic bone scan. Liver involvement was documented in 6/34 (18%) patients, pulmonary involvement in 14/37 (38%) patients, CNS relapses in 3/39 (8%), and locoregional recurrences in 19/39 (49%). The most significant hematologic finding was a hemoglobin of less than 12 gm% in 21/37 (57%). The most frequent biochemical abnormality was an elevation of the alkaline phosphatase in 30/39 (77%). The majority of breast cancer patients have a positive ER and ER-positive breast cancer has a tendency to metastasize to cortical bone. Bone marrow involvement by breast cancer is closely associated with cortical bone involvement; accordingly, bone marrow metastases are often associated with a positive ER.     

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.     

Optimal sequence of bone target drugs in metastatic prostatic cancer

Breast, prostate, lung and kidney cancer all manifest with a high predilection for metastasis to bone, which is a prevalent cause of morbidity, increased risk of death and decreased quality of life for patients. The avidity of some cancers to grow in bone is because of the peculiar microenvironment predisposed by bone. In metastatic prostate cancer, many novel therapeutic agents are programmed to contrast the signal pathway, including the androgen receptor, osteoclast and stromal inhibitors. Therapy with new drugs in prostate cancer has been shown to decrease the risk of skeletal-related complications and, therefore, provide an overall survival and quality of life benefit. An improved sequence of administration of these drugs may improve efficacy.     

趋化性细胞因子与乳腺癌的转移

远处转移是乳腺癌致死和预后较差的重要原因，而在乳腺癌转移中，趋化性细胞因子扮演着重要角色，乳腺癌细胞高表达某些趋化性细胞因子及某些受体，通过趋化性细胞因子与其受体的相互作用，趋化吞噬细胞及淋巴细胞浸润，促使癌细胞侵入正常组织及血管生成，形成转移肿瘤。本文主要综述了近年研究较多的趋化性细胞因子受体CXCR4及趋化性细胞因子RANTES、IL-8、MCP-1等在乳腺癌转移中的作用。     

Patterns of metastasis and survival in breast cancer patients: a preliminary study in an Iranian population

Due to lack of sufficient data on characteristics of breast cancer patients and risk factors for developing metastasis in Iran this study was designed to understand clinical aspects impacting on survival. A cross-sectional study on breast cancer patients was conducted in an oncology clinic of the university hospital between 1995 and 2010. Data were retrieved from medical records and included age, menopausal status, tumor diameter, number of involved nodes, histopathological type, estrogen and progesterone receptor expression, c-erbB-2, primary and secondary metastasis sites, overall survival, disease free interval and type of chemotherapy protocol. The results were analyzed with SPSS 13 software.The mean age of the patients was 49.2 (27-89) years. The primary tumors were mainly ER positive (48%) and PR negative (49.3%). The status of lymph nodes dissected and examined in these patients was unknown in 19 patients (25.3%) while 18 patients (24%) had positive lymph nodes with no report on the number of involved nodes. All of the patients had received antracyclin based chemotherapy in an adjuvant or metastatic setting. Adjuvant hormonal therapy was administered to receptor positive patients. In average, overall survival after recurrence was 30 months (95%CI 24.605-35.325) for non-skeletal versus 42 months (95%CI 31.211-52.789) for skeletal metastasis (P= 0.002). The median survival was also greater for receptor positive patients; 39 months (95%CI 33.716-44.284) for PR+ versus 26 months (95%CI 19.210-32.790) for PR- (P=0.047) and 38 months (95%CI 32.908-43.092) for ER+ versus 27 months (95%CI 18.780-35.220) for ER- patients (P=0.016). No relation was found between site of first metastasis and hormone receptor, age, tumor diameter, DFI and menopausal status. Sites of metastasis were independent of age, size of the tumor, menopausal and hormone receptor status in this study. Overall survival provided significant relations with respect to receptor status and bone metastasis.     

Osteolytic bone metastasis in breast cancer

Summary Metastasis of breast cancer cells to bone consists of multiple sequential steps. To accomplish the process of metastasis to bone, breast cancer cells are required to intrinsically possess or acquire the capacities that are necessary for them to proliferate, invade, migrate, survive, and ultimately arrest in bone. These capacities are essential for any cancer cells to develop distant metastases in organs such as lungs and liver as well as bone. Once breast cancer cells arrest in bone, bone is a storehouse of a variety of cytokines and growth factors and thus provides an extremely fertile environment for the cells to grow. However, breast cancer cells are unable to progress in bone unless they destroy bone with the assistance of bone-resorbing osteoclasts. Thus, the capacity of breast cancer cells to collaborate with osteoclasts is likely to be specific and is likely critical for them to cause osteolytic bone metastases. Evidence to support the concept that there is an intimate relationship between breast cancer cells and osteoclasts is described using anin vivo bone metastasis model in which human breast cancer cells are inoculated into the left ventricle of nude mice. The roles of cell adhesion molecules including cadherins and laminin and matrix metalloproteinases in the development of osteolytic bone metastases by breast cancer are also discussed.     

Baseline serum NTx levels are prognostic in metastatic breast cancer patients with bone-only metastasis.

BACKGROUND: There is significant heterogeneity in survival of patients with metastatic breast cancer who have bone-only metastasis. We studied the correlation of serum N-telopeptide (NTx), a marker of bone resorption, and its correlation with clinical outcomes in patients with metastatic breast cancer with bone-only or bone plus soft tissue metastasis. PATIENTS AND METHODS: Serum was taken from 250 metastatic breast cancer patients with bone-only or bone plus soft tissue metastasis who participated in two similar randomized studies of second-line hormone therapy. An enzyme-linked immunosorbent assay specific for NTx of type I bone collagen was used to detect serum levels. RESULTS: Sixty patients (24%) had elevated serum NTx levels, using the mean + 2 standard deviations (26 nanomoles Bone Collagen Equivalents per liter) of healthy women as a cut-off. The median duration of clinical benefit was significantly shorter in the group with elevated serum NTx levels compared with the group that had normal serum NTx levels (P=0.0004). Time to progression (TTP) was also significantly shorter in the patients with elevated serum NTx at 139 days compared with 220 days (P=0.0006). Median survival was also significantly shorter in patients with elevated baseline serum NTx levels at 663 days compared with 941 days (P<0.0001). CONCLUSION: In this study, breast cancer patients with bone-only or bone plus soft tissue metastasis and elevated serum NTx levels have a shorter duration of clinical benefit, TTP and overall survival.     

早期应用双磷酸盐对老年非小细胞肺癌骨转移的作用

目的:探讨早期静脉应用双磷酸盐对老年非小细胞肺癌骨转移的作用。方法:研究老年非小细胞肺癌患者68例。将骨密度T-Score≤-2.5作为双磷酸盐应用指征,在确诊骨转移之前即开始应用双磷酸盐定义为早期应用。按是否早期应用双磷酸盐,将68例患者按照临床分期分为两组,早期应用双磷酸盐者34例为治疗组,未早期应用者34例为对照组。比较两组骨转移发生率及确诊时间。结果:治疗组骨转移发生率47.06%(16/34),对照组82.35%(28/34),差异有统计学意义（P≤0.01)。治疗组中位骨转移发生时间较对照组延迟87天（218天 vs 131天）,差异有统计学意义（P=0.006）。结论:早期应用双磷酸盐治疗经选择的老年非小细胞肺癌患者,可以减少骨转移发生率,并推迟骨转移发生时间。