Oral Bisphosphonates and Improved Survival of Breast Cancer

Prophylactic Radiation Therapy Versus Standard of Care for Patients With High-Risk Asymptomatic Bone Metastases: A Multicenter, Randomized Phase II Clinical Trial

PURPOSE

External-beam radiation therapy (RT) is standard of care (SOC) for pain relief of symptomatic bone metastases. We aimed to evaluate the efficacy of radiation to asymptomatic bone metastases in preventing skeletal-related events (SRE).

METHODS

In a multicenter randomized controlled trial, adult patients with widely metastatic solid tumor malignancies were stratified by histology and planned SOC (systemic therapy or observation) and randomly assigned in a 1:1 ratio to receive RT to asymptomatic high-risk bone metastases or SOC alone. The primary outcome of the trial was SRE. Secondary outcomes included hospitalizations for SRE and overall survival (OS).

RESULTS

A total of 78 patients with 122 high-risk bone metastases were enrolled between May 8, 2018, and August 9, 2021, at three institutions across an affiliated cancer network in the United States. Seventy-three patients were evaluable for the primary end point. The most common primary cancer types were lung (27%), breast (24%), and prostate (22%). At 1 year, SRE occurred in one of 62 bone metastases (1.6%) in the RT arm and 14 of 49 bone metastases (29%) in the SOC arm (P < .001). There were significantly fewer patients hospitalized for SRE in the RT arm compared with the SOC arm (0 v 4, P = .045). At a median follow-up of 2.5 years, OS was significantly longer in the RT arm (hazard ratio [HR], 0.49; 95% CI, 0.27 to 0.89; P = .018), which persisted on multivariable Cox regression analysis (HR, 0.46; 95% CI, 0.23 to 0.85; P = .01).

CONCLUSION

Radiation delivered prophylactically to asymptomatic, high-risk bone metastases reduced SRE and hospitalizations. We also observed an improvement in OS with prophylactic radiation, although a confirmatory phase III trial is warranted.

Liposome-encapsulated zoledronate increases inflammatory macrophage population in TNBC tumours

BACKGROUND

Tumour associated macrophages (TAMs) are important players in breast tumour progression and metastasis. Clinical and preclinical evidence suggests a role for zoledronate (ZOL) in breast cancer metastasis prevention. Further, zoledronate is able to induce inflammatory activation of monocytes and macrophages, which can be favourable in cancer treatments. The inherent bone tropism of zoledronate limits its availability in soft tissues and tumours. In this study we utilised an orthotopic murine breast cancer model to evaluate the possibility to use liposomes (EMP-LIP) to target zoledronate to tumours to modify TAM activation.

METHODS

Triple-negative breast cancer 4T1 cells were inoculated in the 4th mammary fat pad of female Balb/c mice. Animals were divided according to the treatment: vehicle, ZOL, EMP-LIP and liposome encapsulated zoledronate (ZOL-LIP). Treatment was done intravenously (with tumour resection) and intraperitoneally (without tumour resection). Tumour growth was followed by bioluminescence in vivo imaging (IVIS) and calliper measurements. Tumour-infiltrating macrophages were assessed by immunohistochemical and immunofluorescence staining. Protein and RNA expression levels of inflammatory transcription factors and cytokines were measured by Western Blotting and Taqman RT-qPCR.

RESULTS

Liposome encapsulated zoledronate (ZOL-LIP) treatment suppressed migration of 4T1 cell in vitro. Tumour growth and expression of the angiogenic marker CD34 were reduced upon both ZOL and ZOL-LIP treatment in vivo. Long-term ZOL-LIP treatment resulted in shift towards M1-type macrophage polarization, increased CD4 T cell infiltration and activation of NF-κB indicating changes in intratumoural inflammation, whereas ZOL treatment showed similar but non-significant trends. Moreover, ZOL-LIP had a lower bisphosphonate accumulation in bone compared to free ZOL.

CONCLUSION

Results show that the decreased bisphosphonate accumulation in bone promotes the systemic anti-tumour effect of ZOL-LIP by increasing inflammatory response in TNBC tumours via M1-type macrophage activation.

CD73 regulates zoledronate-induced lymphocyte infiltration in triple-negative breast cancer tumors and lung metastases

Introduction

Bisphosphonates (BPs) are bone-protecting osteoclast inhibitors, typically used in the treatment of osteoporosis and skeletal complications of malignancies. When given in the adjuvant setting, these drugs may also prevent relapses and prolong overall survival in early breast cancer (EBC), specifically among postmenopausal patients. Because of these findings, adjuvant nitrogen-containing BPs (N-BPs), such as zoledronate (ZOL), are now the standard of care for high-risk EBC patients, but there are no benefit-associated biomarkers, and the efficacy remains low. BPs have been demonstrated to possess anti-tumor activities, but the mechanisms by which they provide the beneficial effects in EBC are not known.

Methods

We used stably transfected 4T1 breast cancer cells together with suppression of CD73 (sh-CD73) or control cells (sh-NT). We compared ZOL effects on tumor growth and infiltrating lymphocytes (TILs) into tumors and lung metastases using two mouse models. B cell depletion was performed using anti-CD20 antibody.

Results

Sh-CD73 4T1 cells were significantly more sensitive to the growth inhibitory effects of n-BPs in vitro. However, while ZOL-induced growth inhibition was similar between the tumor groups in vivo, ZOL enhanced B and T lymphocyte infiltration into the orthotopic tumors with down-regulated CD73. A similar trend was detected in lung metastases. ZOL-induced tumor growth inhibition was found to be augmented with B cell depletion in sh-NT tumors, but not in sh-CD73 tumors. As an internal control, ZOL effects on bone were similar in mice bearing both tumor groups.

Discussion

Taken together, these results indicate that ZOL modifies TILs in breast cancer, both in primary tumors and metastases. Our results further demonstrate that B cells may counteract the growth inhibitory effects of ZOL. However, all ZOL-induced TIL effects may be influenced by immunomodulatory characteristics of the tumor.

Honey: A Promising Therapeutic Supplement for the Prevention and Management of Osteoporosis and Breast Cancer

Osteoporosis and breast cancer are serious diseases that have become a significant socioeconomic burden. There are biochemical associations between the two disorders in terms of the amended function of estrogen, receptor activator of nuclear factor kappa beta ligand, oxidative stress, inflammation, and lipid accumulation. Honey as a functional food with high antioxidant and anti-inflammatory properties can contribute to the prevention of various diseases. Its health benefits are mainly related to the content of polyphenols. This review aims to summarize the current knowledge from in vitro, animal, and human studies on the use of honey as a potential therapeutic agent for osteoporosis and breast cancer. Preclinical studies have revealed a beneficial impact of honey on both bone health (microstructure, strength, oxidative stress) and breast tissue health (breast cancer cell proliferation and apoptosis, tumor growth rate, and volume). The limited number of clinical trials, especially in osteoporosis, indicates the need for further research to evaluate the potential benefits of honey in the treatment. Clinical studies related to breast cancer have revealed that honey is effective in increasing blood cell counts, interleukin-3 levels, and quality of life. In summary, honey may serve as a prospective therapeutic supplement for bone and breast tissue health.

Aged bone matrix-derived extracellular vesicles as a messenger for calcification paradox

Adipocyte differentiation of bone marrow mesenchymal stem/stromal cells (BMSCs) instead of osteoblast formation contributes to age- and menopause-related marrow adiposity and osteoporosis. Vascular calcification often occurs with osteoporosis, a contradictory association called “calcification paradox”. Here we show that extracellular vesicles derived from aged bone matrix (AB-EVs) during bone resorption favor BMSC adipogenesis rather than osteogenesis and augment calcification of vascular smooth muscle cells. Intravenous or intramedullary injection of AB-EVs promotes bone-fat imbalance and exacerbates Vitamin D3 (VD3)-induced vascular calcification in young or old mice. Alendronate (ALE), a bone resorption inhibitor, down-regulates AB-EVs release and attenuates aging- and ovariectomy-induced bone-fat imbalance. In the VD3-treated aged mice, ALE suppresses the ovariectomy-induced aggravation of vascular calcification. MiR-483-5p and miR-2861 are enriched in AB-EVs and essential for the AB-EVs-induced bone-fat imbalance and exacerbation of vascular calcification. Our study uncovers the role of AB-EVs as a messenger for calcification paradox by transferring miR-483-5p and miR-2861.

This study uncovers the role of extracellular vesicles from bone matrix as a messenger in the development of osteoporosis and vascular calcification (calcification paradox) during skeletal aging and menopause by transferring miR-483-5p and miR-2861.

Alfaleh M, H. Abdulaal W, Bakhaidar RB, Alselami MO, Zahrani MAL, Alqarni HM, F. Alghaith A, Alshehri S, Badr-Eldin SM, Aldawsari HM, Al-hejaili OD, Aldhabi BM, Mahdi WA. Wasp venom peptide improves the proapoptotic activity of alendronate sodium in A549 lung cancer cells

BACKGROUND

Lung cancer in men and women is considered the leading cause for cancer-related mortality worldwide. Anti-cancer peptides represent a potential untapped reservoir of effective cancer therapy.

METHODOLOGY

Box-Behnken response surface design was applied for formulating Alendronate sodium (ALS)-mastoparan peptide (MP) nanoconjugates using Design-Expert software. The optimization process aimed at minimizing the size of the prepared ALS-MP nanoconjugates. ALS-MP nanoconjugates' particle size, encapsulation efficiency and the release profile were determined. Cytotoxicity, cell cycle, annexin V staining and caspase 3 analyses on A549 cells were carried out for the optimized formula.

RESULTS

The results revealed that the optimized formula was of 134.91±5.1 nm particle size. The novel ALS-MP demonstrated the lowest IC50 (1.3 ± 0.34 μM) in comparison to ALS-Raw (37.6 ± 1.79 μM). Thus, the results indicated that when optimized ALS-MP nanoconjugate was used, the IC50 of ALS was also reduced by half. Cell cycle analysis demonstrated a significantly higher percentage of cells in the G2-M phase following the treatment with optimized ALS-MP nanoconjugates.

CONCLUSION

The optimized ALS-MP formula had significantly improved the parameters related to the cytotoxic activity towards A549 cells, compared to control, MP and ALS-Raw.

Selective serotonin reuptake inhibitors associated with increased mortality risk in breast cancer patients in Northern Israel

BACKGROUND

Approximately one in six women in the USA takes antidepressants and a third use selective serotonin reuptake inhibitors (SSRIs) after breast cancer diagnosis. Recent investigation demonstrated serotonin receptor (5-HTR2B) expression in the breast and serotonin production as an indicator of poor breast cancer prognosis. This study investigates the association between SSRI use at different time intervals relative to breast cancer diagnosis on survival.

METHODS

A population-based sample of 6959 consecutive, newly diagnosed breast cancer cases in Northern Israel was included. Patients were recruited from January 2000 and followed up through March 2020. Participants completed risk factor questionnaires regarding medical, reproductive and family history, medication use and health habits. Full prescription data were available through the Israeli national Clalit medical database. Multivariate Cox proportional hazard models were used to determine survival based on time of SSRI use.

RESULTS

Use of SSRIs in the 5 years prior to breast cancer diagnosis was associated with a 66% increase in overall mortality (HRadj = 1.66; CI: 1.05-2.63). SSRI use that initiated after breast cancer diagnosis was associated with an 81% increase in mortality (HRadj = 1.81; CI: 1.58-2.06). Use of SSRIs in the 5 years post-diagnosis was associated with a dose-response increase (P < 0.001) in long-term mortality (>5 years). Heavy SSRI use (≥24 prescription fills) after diagnosis was associated with nearly doubling in mortality (HR = 1.99; CI: 1.39-2.83).

CONCLUSION

SSRI use prior to and after breast cancer diagnosis is associated with increased mortality in breast cancer patients. Additional research is needed to better understand mechanisms mediating this association.

Soy Foods and the Risk of Fracture: A Systematic Review of Prospective Cohort Studies

OBJECTIVES

The primary objective of our study was to systematically review all available prospective cohort studies which investigated the association of soy food intake and incident fracture risk.

METHODS

We searched PubMed, Scopus, and Embase databases for relevant studies up to June 2021.

SYNTHESIS

Of 695 records, a total of 5 cohort studies were included in the current systematic review. Two studies that were performed in China evaluated hip fracture while 2 studies that were done in Singapore evaluated any kind of fractures. The other study was conducted in Japan and evaluated osteoporosis fractures. All studies used a face-to-face interview to assess the dietary intake of soy foods. All 5 cohort studies were determined to be of high quality. One study considered soy food as a part of a vegetables-fruit-soy food dietary pattern. Others reported the association of dietary intake of soy foods with the risk of fractures.

CONCLUSION

The evidence from prospective cohort studies was suggestive for a protective role of soy foods, alone or within a dietary pattern, in the risk of incident fracture among Asian women, particularly for those in early menopause and those who used fermented soy products. But for men, the association was not significant. However, more cohort studies, including non-Asian populations, are required to confirm this association fully.

Bisphosphonate-Based Conjugates and Derivatives as Potential Therapeutic Agents in Osteoporosis, Bone Cancer and Metastatic Bone Cancer

Metastatic bone cancer occurs in every type of cancer but is prevalent in lung, breast, and prostate cancers. These metastases can cause extensive morbidity, including a range of skeletal-related events, often painful and linked with substantial hospital resource usage. The treatment used is a combination of chemotherapy and surgery. However, anticancer drugs are still limited due to severe side effects, drug resistance, poor blood supply, and non-specific drug uptake, necessitating high toxic doses. Bisphosphonates are the main class of drugs utilized to inhibit metastatic bone cancer. It is also used for the treatment of osteoporosis and other bone diseases. However, bisphosphonate also suffers from serious side effects. Thus, there is a serious need to develop bisphosphonate conjugates with promising therapeutic outcomes for treating metastatic bone cancer and osteoporosis. This review article focuses on the biological outcomes of designed bisphosphonate-based conjugates for the treatment of metastatic bone cancer and osteoporosis.

Updated guidance on the management of cancer treatment-induced bone loss (CTIBL) in pre- and postmenopausal women with early-stage breast cancer

INTRODUCTION

Adjuvant endocrine therapy induces bone loss and increases fracture risk in women with hormone-receptor positive, early-stage breast cancer (EBC). We aimed to update a previous position statement on the management of aromatase inhibitors (AIs) induced bone loss and now included premenopausal women.

METHODS

We conducted a systematic literature search of the medical databases from January 2017 to May 2020 and assessed 144 new studies.

RESULTS

Extended use of AIs beyond 5 years leads to persistent bone loss in breast cancer extended adjuvant trials and meta-analyses. In addition to bone mineral density (BMD), vertebral fracture assessment (VFA) and trabecular bone score (TBS) were shown to independently predict fracture risk in real life prospective studies. FRAX® tool does not seem to be reliable for assessing fracture risk in CTIBL. In premenopausal women, there is strong evidence that intravenous zoledronate prevents bone loss but weak conflicting evidence on reducing disease recurrence from independent randomised controlled trials (RCTs). In postmenopausal women, the strongest evidence for fracture prevention is for denosumab based on a well-powered RCT while there is strong evidence for bisphosphonates (BPs) to prevent and reduce CTIBL but no convincing data on fractures. Adjuvant denosumab has failed to show anticancer benefits in a large, well-designed RCT.

DISCUSSION AND CONCLUSIONS

Extended use of AIs and persistent bone loss from recent data reinforce the need to evaluate fracture risk in EBC women initiated on AIs. Fracture risk should be assessed with clinical risk factors and BMD along with VFA, but FRAX is not adapted to CTIBL. Anti-resorptive therapy should be considered in those with a BMD T-score < -2.0 SD or with ≥ 2 clinical risk factors including a BMD T-score < -1.0 SD. In premenopausal women, intravenous zoledronate is the only drug reported to prevent bone loss and may have additional anticancer benefits. In postmenopausal women, either denosumab or BPs can be prescribed for fracture prevention with pertinent attention to the rebound phenomenon after stopping denosumab. Adjuvant BPs, in contrast to denosumab, have shown high level evidence for reducing breast cancer recurrence in high-risk post-MP women which should be taken into account when choosing between these two.

Targeting Histone Modifications in Bone and Lung Metastatic Cancers

PURPOSE OF REVIEW

Breast cancer frequently metastasizes to the bone and lung, but the ability to treat metastatic tumor cells remains a pressing clinical challenge. Histone deacetylases (HDACs) and histone acetyltransferases (HATs) have emerged as promising targets since these enzymes are aberrantly expressed in numerous cancers and regulate the expression of genes that drive tumorigenesis and metastasis. This review focuses on the abnormal expression of histone-modifying enzymes in cancers that have a high tropism for the bone and lung and explores the clinical use of histone deacetylase inhibitors for the treatment and prevention of metastasis to these sites.

RECENT FINDINGS

Preclinical studies have demonstrated that the role for HDACs is highly dependent on tumor type and stage of disease progression. HDAC inhibitors can induce apoptosis, senescence, cell differentiation, and tumor dormancy genes and inhibit angiogenesis, making these promising therapeutics for the treatment of metastatic disease. HDAC inhibitors are already FDA approved for hematologic malignancies and are in clinical trials with standard-of-care chemotherapies and targeted agents for several solid tumors, including cases of metastatic disease. However, these drugs can negatively impact bone homeostasis. Although HDAC inhibitors are not currently administered for the treatment of bone and lung metastatic disease, preclinical studies have shown that these drugs can reduce distant metastasis by targeting molecular factors and signaling pathways that drive tumor cell dissemination to these sites. Thus, HDAC inhibitors in combination with bone protective therapies may be beneficial in the treatment of bone metastatic cancers.

A Review of Literature on Updates of Bisphosphonates Administration, Cancer Biomarkers for Bisphosphonate Therapy, and Bisphosphonate-related Osteonecrosis of the Jaw in Breast Cancer

Context: The emergence of bone health maintenance in breast cancer patients is known as an indispensable aspect in survival and morbidity improvement; therefore, bisphosphonates play a substantial role in the prevention/delaying of cancer treatment induced bone loss and skeletal-related events (SREs) in these patients, although this drug can cause necrosis of the jaw. In this article, we aimed at summarizing updated evidence on bisphosphonates administration, biomarkers representative of the efficacy of bisphosphonate therapy, and bisphosphonate-related osteonecrosis of the jaw (BRONJ) affection in patients involved in breast cancer. Methods: Associated published articles were searched for in EMBASE, MEDLINE, CDSR, PubMed, Google Scholar, and CINAHL, using the following keywords or, in the case of PubMed database, medical subject headings (MeSH): ‘Diphosphonate’, ‘osteonecrosis’, ‘breast cancer’, and ‘biomarker’ in the abstract or title, and was limited by "clinical trials, meta-analysis and randomized controlled trial” published in English language from 2015 to 2020-09-15. Results: Bisphosphonates depicted remarkable advantages in improving SREs, skeletal morbidity rate (SMR), survival rate, and treatment-emergent adverse events in breast cancer patients in almost all aspects of breast cancer therapy, from adjuvant therapy for the early stage breast cancer to bone metastatic breast cancer (BMBC). The identification of breast cancer biomarkers that are capable of reflecting the outcomes of bisphosphonates therapy is a highly advantageous aid in the optimal utilization of these drugs. Breast cancer biomarkers such as MAF, DOCK4, CD73, TLR9, and CAPG/GIPC1 composite illustrated a significant correlation with bisphosphonates administration. Medication-related osteonecrosis of the jaw (MRONJ) stands out as the most hazardous adverse event of the bisphosphonates with a rationally high incidence among breast cancer patients, which requires cautious prescription of bisphosphonates as well as regular dental health counseling for being prevented. Conclusions: Bisphosphonates are great weapons in the arsenal of breast cancer treatment and, therefore, comprehensive studying of their features leads to the optimal and safe administration of them. Unfortunately, as this procedure can cause necrosis of the jaw, dental procedures should be performed in these patients before starting bisphosphonate treatment.

From Good to Bad: The Opposing Effects of PTHrP on Tumor Growth, Dormancy, and Metastasis Throughout Cancer Progression

Parathyroid hormone related protein (PTHrP) is a multifaceted protein with several biologically active domains that regulate its many roles in normal physiology and human disease. PTHrP causes humoral hypercalcemia of malignancy (HHM) through its endocrine actions and tumor-induced bone destruction through its paracrine actions. PTHrP has more recently been investigated as a regulator of tumor dormancy owing to its roles in regulating tumor cell proliferation, apoptosis, and survival through autocrine/paracrine and intracrine signaling. Tumor expression of PTHrP in late stages of cancer progression has been shown to promote distant metastasis formation, especially in bone by promoting tumor-induced osteolysis and exit from dormancy. In contrast, PTHrP may protect against further tumor progression and improve patient survival in early disease stages. This review highlights current knowledge from preclinical and clinical studies examining the role of PTHrP in promoting tumor progression as well as skeletal and soft tissue metastasis, especially with regards to the protein as a regulator of tumor dormancy. The discussion will also provide perspectives on PTHrP as a prognostic factor and therapeutic target to inhibit tumor progression, prevent tumor recurrence, and improve patient survival.

Exploiting bone niches: progression of disseminated tumor cells to metastasis

Many solid cancers metastasize to the bone and bone marrow (BM). This process may occur even before the diagnosis of primary tumors, as evidenced by the discovery of disseminated tumor cells (DTCs) in patients without occult malignancies. The cellular fates and metastatic progression of DTCs are determined by complicated interactions between cancer cells and BM niches. Not surprisingly, these niches also play important roles in normal biology, including homeostasis and turnover of skeletal and hematopoiesis systems. In this Review, we summarize recent findings on functions of BM niches in bone metastasis (BoMet), particularly during the early stage of colonization. In light of the rich knowledge of hematopoiesis and osteogenesis, we highlight how DTCs may progress into overt BoMet by taking advantage of niche cells and their activities in tissue turnover, especially those related to immunomodulation and bone repair.

Effects of metformin on the prevention of bisphosphonate-related osteonecrosis of the jaw-like lesions in rats

PURPOSE

In this study, we aimed to investigate the effect of glucose metabolism on bone healing after tooth extraction in an osteoporosis rat model administered zoledronic acid (ZA) and dexamethasone (DX).

METHODS

In total, 24 male Wistar rats (4 weeks old) were randomly assigned to four groups: Control (subcutaneous physiological saline), ZD (subcutaneous ZA and DX twice a week), Ins+ZD (subcutaneous insulin followed by ZD treatment), and Met+ZD (oral metformin followed by ZD treatment). Blood was collected every two weeks . Two weeks after treatment initiation, the first molar tooth on the right maxilla was extracted from all rats. Four weeks later, the rats were sacrificed, and bone healing was assessed. Maxillae samples were fixed and scanned using micro-computed tomography for quantifying areas of bone defects. Hematoxylin-eosin and tartrate-resistant acid phosphatase (TRAP) staining were performed to evaluate bone apoptosis and osteoclast number.

RESULTS

In all experimental groups, body weight was statistically lower than that in the Control group, with no changes observed in uncarboxylated osteocalcin concentrations. The radiological analysis revealed that insulin or metformin administration improved healing in the tooth extraction socket (p < 0.01). Histological examination revealed that the osteonecrosis area was reduced in the Ins+ZD and Met+ZD groups (p < 0.01). TRAP staining presented increased osteoclast numbers in the ZD group when compared with that observed in the Control.

CONCLUSIONS

Tooth extraction with long-term ZA and DX administration inhibited bone remodeling and induced bisphosphonate-related osteonecrosis of the jaw-like lesions. Metformin exerted protective effects ag ainst osteonecrosis of the jaw.

Use of metformin and risk of breast and colorectal cancer

BACKGROUND

Diabetes has been associated with increased risk of cancer, including breast cancer and colorectal cancer. Metformin, an oral hypoglycemic drug, but not other anti-diabetic drugs, has been associated with reduced risk of breast and of colon cancers in some, but not in other, studies.

METHODS

Data from two large-scale, population-based, case-control studies of breast and colorectal cancers etiology, conducted in Northern Israel since 1998 were analyzed to evaluate the association between regular use (>3 times) of metformin prior to diagnosis and risk of developing cancer. The multivariate analyses for both cancer sites included age, family history of breast/colorectal cancer, history of diabetes, sports participation, fruits/vegetables consumption, aspirin and statins use, and for breast cancer, also included use of oral contraceptives and postmenopausal hormones and number of pregnancies. Use of metformin and diabetes status were determined based on valid electronic medical records of the participants.

RESULTS

Metformin use prior to diagnosis of cancer was associated with a decrease in risk of both breast cancer (OR = 0.821, 0.726-0.928, p = 0.002) and colorectal cancer (OR = 0.754, 0.623-0.912, p = 0.004). An inverse association was not identified with use of other anti-diabetic medications. Diabetes was found to be associated with risk of colorectal cancer (OR = 1.204, 1.014-1.431, p = 0.034) but not of breast cancer. No dose response by years of use of metformin was found.

CONCLUSION

These analyses of large population-based studies provide evidence of a strong inverse association of metformin with breast and, even more so, with colorectal cancer risk.

Breast cancer outcome in relation to bone mineral density and bisphosphonate use: a sub-study of the DATA trial

Purpose

The phase III DATA study compared 6 and 3 years of adjuvant anastrozole following 2–3 years of tamoxifen in postmenopausal breast cancer patients. This pre-planned side-study assessed the relationship between a reduced bone mineral density (BMD) and distant recurrence-free survival (DRFS), and evaluated the effect of bisphosphonates on DRFS.

Methods

We selected all patients with a BMD measurement within 3 years after randomisation (landmark) without any DRFS events. Kaplan–Meier methods and Cox proportional hazards models were used for analyses.

Results

Of 1860 eligible patients, 1142 had a DEXA scan before the landmark. The BMD was normal in 436 (38.2%) and showed osteopenia in 565 (49.5%) and osteoporosis in 141 (12.3%) patients. After a median follow-up of 5.0 years from the landmark, neither osteopenia nor osteoporosis (compared with normal BMD) were associated with DRFS in both the 6-year [osteopenia HR 0.82 (95% CI 0.45–1.49), osteoporosis HR 1.10 (95% CI 0.26–4.67)] and the 3-year arm [osteopenia HR 0.75 (95% CI 0.40–1.42), osteoporosis HR 1.86 (95% CI 0.43–8.01)]. Moreover, bisphosphonate use did not impact DRFS.

Conclusion

No association was observed between a reduced BMD and DRFS. Neither did we observe an impact of bisphosphonates on DRFS.

Electronic supplementary material

The online version of this article (10.1007/s10549-020-05567-9) contains supplementary material, which is available to authorized users.

Bisphosphonates Zometa and Fosamax Synergize with Metformin to Prevent AOM-Induced Colon Cancer in F344 Rat Model

Recent observational studies suggest that bisphosphonates (BP) and antidiabetic drugs are associated with colorectal cancer risk reduction. Hence, we evaluated the colorectal cancer preventive effects of BPs (zometa and fosamax), individually and when combined with metformin, in azoxymethane-induced rat colon cancer model. Rat (30/group) were randomized and treated subcutaneously with azoxymethane to induce colorectal cancer. Dietary intervention with zometa or fosamax (0, 20, or 100 ppm) or metformin (1,000 ppm) or the combinations (zometa/fosamax 20 ppm plus metformin 1,000 ppm) began 4 weeks after azoxymethane treatment, at premalignant lesions stage. Rats were killed 40 weeks post drug intervention to assess colorectal cancer preventive efficacy. Dietary zometa (20 ppm) inhibited noninvasive adenocarcinomas multiplicity by 37% (P < 0.03) when compared with control diet fed group. Fosamax at 20 ppm and 100 ppm significantly reduced adenocarcinoma incidence (P < 0.005) and inhibited the noninvasive adenocarcinoma multiplicities by 43.8% (P < 0.009) and 60.8% (P < 0.004), respectively, compared with the group fed control diet. At 1,000 ppm dose, metformin failed to suppress colon adenocarcinoma formation. However, the lower dose combinations of zometa or fosamax with metformin resulted in significant inhibition of noninvasive adenocarcinoma by 48% (P < 0.006) and 64% (P < 0.0002), and invasive adenocarcinoma by 49% (P < 0.0005) and 38% (P < 0.006), respectively. Biomarker analysis of combination drug-treated tumors showed a decrease in cell proliferation with increased apoptosis when compared with untreated tumors. Overall, our results suggest that the combination of low doses of zometa or fosamax with metformin showed synergistic effect and significantly inhibited colon adenocarcinoma incidence and multiplicity.

Bisphosphonates-much more than only drugs for bone diseases

α,α-Bisphosphonates (BPs) are well established in the treatment of bone diseases such as osteoporosis and Paget's disease. Their successful application originates from their high affinity to hydroxyapatite. While the initially appreciated features of BPs are already beneficial to many patients, recent developments have further expanded their pleiotropic applications. This review describes the background of the interactions of BPs with bone cells that form the basis of the classical treatment. A better understanding of the mechanism behind their interactions allows for the parallel application of BPs against bone cancer and metastases followed by palliative pain relief. Targeted therapy with bone-seeking BPs coupled with a diagnostic agent in one particle resulted in theranostics which is also described here. For example, in such a system, BP moieties are bound to contrast agents used in magnetic resonance imaging or radionuclides used in positron emission tomography. In addition, another example of the pleiotropic function of BPs which involves targeting the imaging agents to bone tissues accompanied by pain reduction is presented in this work.

Bisphosphonates and mortality: confounding in observational studies?

Numerous observational studies suggest that bisphosphonates reduce mortality. This study showed that bisphosphonate use is associated with lower mortality within days of treatment, although the association was not significant until the second week. Such an early association is consistent with confounding, although an early treatment effect cannot be ruled out.

INTRODUCTION

The purpose of this study was to examine whether confounding explains why numerous observational studies show that bisphosphonate use is associated with lower mortality. To this end, we examined how soon after treatment initiation a lower mortality rate can be observed. We hypothesized that, due to confounding, the association would be observed immediately.

METHODS

This was a retrospective cohort study of hip fracture patients discharged from Swedish hospitals between 1 July 2006 and 31 December 2015. The data covered 260,574 hip fracture patients and were obtained from the Swedish Hip Fracture Register and national registers. Of the 260,574 patients, 49,765 met all eligibility criteria and 10,178 were pair matched (bisphosphonate users to controls) using time-dependent propensity scores. The matching variables were age, sex, diagnoses, prescription medications, type of hip fracture, type of surgical procedure, known or suspected dementia, and physical functioning status.

RESULTS

Over a median follow-up of 2.8 years, 2922 of the 10,178 matched patients died. The mortality rate was 7.9 deaths per 100 person-years in bisphosphonate users and 9.4 deaths in controls, which corresponded to a 15% lower mortality rate in bisphosphonate users (hazard ratio 0.85, 95% confidence interval 0.79-0.91). The risk of death was lower in bisphosphonate users from day 6 of treatment, although the association was not significant until the second week.

CONCLUSION

Bisphosphonate use was associated with lower mortality within days of treatment initiation. This finding is consistent with confounding, although an early treatment effect cannot be ruled out.

Prognostic Effect of Bisphosphonate Exposure for Patients With Diagnosed Solid Cancer: A Systematic Review With Meta-Analysis of Observational Studies

Background: Bisphosphonates are widely prescribed for the prevention and treatment of osteoporosis. Recent epidemiological studies indicate that people with bisphosphonate use may have lower cancer risk and have improved survival. The aim of this study is to determine the association between bisphosphonate use and survival outcomes in solid cancer patients using systematic review and meta-analysis.

Methods: A systematic literature search was performed using the PubMed, Embase, and Cochrane databases. Original articles published until April, 2018 were selected. The survival outcome measures assessed included overall survival (OS), cancer-specific survival (CSS) and recurrence-free survival (RFS). Pooled hazard ratio (HR) and their 95% confidence interval (95% CI) were derived using a random-effects model.

Results: Out of 9,742 retrieved citations, six cohort studies and two nested case-control studies satisfying the inclusion criteria were included for analyses. Bisphosphonate use was significantly associated with improved OS (HR 0.84, 95% CI 0.76–0.93), CSS (HR 0.73, 95% CI 0.58–0.90) and RFS (HR 0.72, 95% CI 0.53–0.96). The results of subgroup analyses stratified by major study characteristics were generally consistent with the main findings. For individual cancer type, we found that bisphosphonate use was significantly associated with longer OS for patients with gastroesophageal cancer (HR 0.62, 95% CI 0.40–0.98), as well as longer CSS for patients with breast cancer (HR 0.73, 95% CI 0.55–0.95).

Conclusions: Current evidence indicates that bisphosphonate use is significantly associated with improved survival for patients with solid cancer. However, the prognostic effects in specific solid tumors remains to be confirmed by further large prospective cohort studies.

Exposure to alendronate is associated with a lower risk of bone metastases in osteoporotic women with early breast cancer

BACKGROUND

Bisphosphonate (BP) treatment to prevent bone loss in breast cancer patients is already well established. However, data on the association between oral BP exposure before cancer diagnosis and disease outcomes in patients with early breast cancer are still scarce. Limited information is available on alendronate, the most common oral agent for the treatment of post-menopausal osteoporosis, regarding the association with bone metastases.

AIM

To examine the association between oral bisphosphonate exposure before cancer diagnosis and the risk of bone metastases in osteoporotic women diagnosed with early breast cancer.

SUBJECTS AND METHODS

This historical cohort study was conducted at the oncology division at Tel Aviv Medical Center. The study population included post-menopausal women with early breast cancer, diagnosed between 2002 and 2012. Data on cancer characteristics, diagnosis of osteoporosis, prior bisphosphonate exposure and outcome were collected from medical files.

RESULTS

Among 297 osteoporotic women identified, 145 (49%) were treated with bisphosphonates (alendronate in 90% of the cases) before cancer diagnosis. BP-treated women were significantly older than the BP-naïve ones (67.9 years vs 64.6 years, p = 0.01), but comparable in risk factors and disease characteristics. Over a mean follow up of 5.6 years, nine cases of bone metastases were identified, eight of them among BP-naïve patient (cumulative incidence of 9.9%) and one among BP-treated patients (0.7%). In a multivariable Cox's proportional hazards survival model the use of BP prior to cancer diagnosis was associated with a hazard ratio of 0.04 (95%CI:0.004-0.403, p = 0.006) for bone metastasis. The HR remained similar after further adjustment for tumor stage and cancer therapy.

CONCLUSIONS

History of alendronate use is associated with a lower likelihood of bone metastases in postmenopausal women with early breast cancer. Oral bisphosphonate treatment could be sufficient for reducing the risk of bone metastases.

Estradiol impairs the antiproliferative and proapoptotic effect of Zoledronic acid in hormone sensitive breast cancer cells in vitro

Background

Zoledronic acid (ZA) has antiresorptive effects and protects from bone metastasis in women with early breast cancer. In addition, in postmenopausal women with endocrine responsive breast cancer ZA prolongs DFS. The exact mechanism is still unclear. We have therefore investigated the effect of increasing concentrations of ZA in breast cancer cell lines in the absence or presence of estradiol to mimic the hormonal environment in vitro.

Materials and methods

Using assays for cell proliferation (EZ4U, BrdU) and cell death (Annexin/PI), we have analyzed the dose-dependent antiproliferative and pro-apoptotic effects of ZA in two hormone sensitive cell lines (MCF-7 and T47D) and a hormone insensitive, triple negative cell line (MDA-MB-231) in the presence of 0, 1 and 10 nM estradiol.

Results

In the absence of estradiol, ZA exerts dose-dependent antiproliferative and pro-apoptotic antitumor effects in both, hormone sensitive (MCF-7, T47D) and -insensitive (MDA-MB-231) breast cancer cell lines (p<0.0001). In the presence of estradiol, the antitumoral effect of ZA was significantly decreased only in the hormone sensitive MCF-7 and T47D cell lines (p = 0.0008 and p = 0.0008, respectively).

Conclusion

We have demonstrated that estradiol impairs the antiproliferative and proapoptotic effect of ZA in hormone sensitive, but not in hormone insensitive breast cancer cell lines. Our findings provide a possible explanation for the differential effect of ZA on DFS in pre- and postmenopausal patients with hormone sensitive early breast cancer, which has been demonstrated clinically. We further hypothesize that endocrine insensitive tumors such as triple negative breast cancer (TNBC) should benefit from ZA irrespective of their menopausal status.

Women with cancer in low-income countries

In the 1 November issue of The Lancet in 2016, three papers and three accompanying editorials reviewed the descriptive epidemiology of breast and cervical cancer in low-income countries, highlighting the shortcomings of current efforts at cancer control and the need for improvement [...]

Anti-Tumor Activity and Immunotherapeutic Potential of a Bisphosphonate Prodrug

Bisphosphonates have benefits in breast cancer and multiple myeloma patients and have been used with adoptive immunotherapy with γδ T cells expressing Vγ2 Vδ2 TCRs. Although treatment with γδ T cells is safe, it has shown limited efficacy. Present bisphosphonates stimulate γδ T cells but were designed to inhibit bone resorption rather than treating cancer and have limited oral absorption, tumor cell entry, and cause bone side effects. The development of phosphate and phosphonate nucleotide prodrugs has led to important drugs for hepatitis C and HIV. Using a similar approach, we synthesized bisphosphonate prodrugs and found that they efficiently limit tumor cell growth. Pivoxil bisphosphonate esters enter cells where esterases convert them to their active acids. The bisphosphonate esters stimulated γδ T cells to secrete TNF-α in response to a variety of tumor cells more efficiently than their corresponding acids. The most active compound, tetrakis-pivaloyloxymethyl 2-(thiazole-2-ylamino)ethylidene-1,1- bisphosphonate (7), specifically expanded γδ T cells and stimulated them to secrete interferon-γ and kill tumor cells. In preclinical studies, combination therapy with compound 7 and γδ T cells prolonged survival of mice inoculated with either human bladder cancer or fibrosarcoma cells. Therefore, bisphosphonate prodrugs could enhance the effectiveness of adoptive cancer immunotherapy with γδ T cells.

Management of Aromatase Inhibitor-Associated Bone Loss (AIBL) in postmenopausal women with hormone sensitive breast cancer: Joint position statement of the IOF, CABS, ECTS, IEG, ESCEO IMS, and SIOG

BACKGROUND

Several guidelines have been reported for bone-directed treatment in women with early breast cancer (EBC) for averting fractures, particularly during aromatase inhibitor (AI) therapy. Recently, a number of studies on additional fracture related risk factors, new treatment options as well as real world studies demonstrating a much higher fracture rate than suggested by randomized clinical controlled trials (RCTs). Therefore, this updated algorithm was developed to better assess fracture risk and direct treatment as a position statement of several interdisciplinary cancer and bone societies involved in the management of AI-associated bone loss (AIBL).

PATIENTS AND METHODS

A systematic literature review identified recent advances in the management of AIBL. Results with individual agents were assessed based on trial design, size, follow-up, and safety.

RESULTS

Several fracture related risk factors in patients with EBC were identified. Although, the FRAX algorithm includes fracture risk factors (RF) in addition to BMD, it does not seem to adequately address the effects of AIBL. Several antiresorptive agents can prevent and treat AIBL. However, concerns regarding compliance and long-term safety remain. Overall, the evidence for fracture prevention is strongest for denosumab 60 mg s.c. every 6 months. Additionally, recent studies as well as an individual patient data meta-analysis of all available randomized trial data support additional anticancer benefits from adjuvant bisphosphonate treatment in postmenopausal women with a 34% relative risk reduction in bone metastasis and 17% relative risk decrease in breast cancer mortality that needs to be taken into account when advising on management of AIBL.

CONCLUSIONS

In all patients initiating AI treatment, fracture risk should be assessed and recommendation with regard to exercise and calcium/vitamin D supplementation given. Bone-directed therapy should be given to all patients with a T-score<-2.0 or with a T-score of <-1.5 SD with one additional RF, or with ≥2 risk factors (without BMD) for the duration of AI treatment. Patients with T-score>-1.5 SD and no risk factors should be managed based on BMD loss during the first year and the local guidelines for postmenopausal osteoporosis. Compliance should be regularly assessed as well as BMD on treatment after 12 - 24 months. Furthermore, because of the decreased incidence of bone recurrence and breast cancer specific mortality, adjuvant bisphosphonates are recommended for all postmenopausal women at significant risk of disease recurrence.