Bisphosphonates and other bone agents for breast cancer

Palliative Care Needs of Patients with Musculoskeletal Malignancies

PURPOSE OF REVIEW

This review aims to assess the literature regarding current treatment options for the palliative care of patients with advanced musculoskeletal malignancies whether primary or metastatic.

RECENT FINDINGS

The inclusion of specialized palliative care physicians, in conjunction with surgeons, medical oncologists, radiation oncologists, interventional radiologists, and mental health professionals, results in better control of end-of-life symptoms in both children and adults with terminal musculoskeletal malignancies. The palliative care of patients with musculoskeletal malignancies requires a multi-disciplinary team and benefits from specialized palliative care physicians. The unique impacts of musculoskeletal malignancies on ambulation and independence creates additional mental and physical burdens on patients and care-takers alike. Palliative care should focus on preserving ambulatory function and patient independence, in addition to managing chronic pain and other end-of-life symptoms common to these malignancies.

Multidimensional analysis to elucidate the possible mechanism of bone metastasis in breast cancer

BACKGROUND

Breast cancer (BC) patients tend to suffer from distant metastasis, especially bone metastasis.

METHODS

All the analysis based on open-accessed data was performed in R software, dependent on multiple algorithms and packages. The RNA levels of specific genes were detected using quantitative Real-time PCR as a method of detecting the RNA levels. To assess the ability of BC cells to proliferate, we utilized the CCK8 test, colony formation, and the 5-Ethynyl-20-deoxyuridine assay. BC cells were evaluated for invasion and migration by using Transwell assays and wound healing assays.

RESULTS

In our study, we identified the molecules involved in BC bone metastasis based on the data from multiple BC cohorts. Then, we comprehensively investigated the effect pattern and underlying biological role of these molecules. We found that in the identified molecules, the EMP1, ACKR3, ITGA10, MMP13, COL11A1, and THY1 were significantly correlated with patient prognosis and mainly expressed in CAFs. Therefore, we explored the CAFs in the BC microenvironment. Results showed that CAFs could activate multiple carcinogenic pathways and most of these pathways play an important role in cancer metastasis. Meanwhile, we noticed the interaction between CAFs and malignant, endothelial, and M2 macrophage cells. Moreover, we found that CAFs could induce the remodeling of the BC microenvironment and promote the malignant behavior of BC cells. Then, we identified MMP13 for further analysis. It was found that MMP13 can enhance the malignant phenotype of BC cells. Meanwhile, biological enrichment and immune infiltration analysis were conducted to present the effect pattern of MMP13 in BC.

CONCLUSIONS

Our result can improve the understanding of researchers on the underlying mechanisms of BC bone metastasis.

Oral health conditions in patients under antiresorptive therapy are comparable to unexposed during supportive periodontal care

OBJECTIVES

To investigate oral health and oral health-related quality of life (OHRQoL) of patients under antiresorptive therapy (ART) during supportive periodontal care (SPC) considering history of medication-related osteonecrosis of the jaw (MRONJ).

MATERIALS AND METHODS

In this cross-sectional study, 100 patients (50 receiving ART (exposed) and 50 without ART (unexposed)) in regular SPC were enrolled for a clinical oral examination and the evaluation of OHRQoL using the OHIP-G14-questionnaire. History of MRONJ was assessed by anamnesis and reviewing patient records.

RESULTS

There were no statistically significant group differences in age (exposed: 70.00 ± 9.07 versus unexposed: 71.02 ± 8.22 years), sex, distribution of systemic diseases and duration of SPC (on average 8.61 ± 5.73 years). Number of teeth (21.02 ± 5.84 versus 21.40 ± 5.42), DMFT (18.38 ± 3.85 versus 17.96 ± 4.08), probing pocket depth (2.31 ± 0.20 versus 2.38 ± 0.26), clinical attachment level (3.25 ± 0.76 versus 3.46 ± 0.58) and bleeding on probing (15.07 ± 11.53 versus 15.77 ± 13.08) were also not significantly different. The OHIP-G14 sum-score was significantly higher in exposed participants (6.10 ± 6.76 versus 3.62 ± 5.22, p = 0.043). History of MRONJ was prevalent in 8% of patients under ART. Periodontal/peri-implant-related MRONJ were reported in three participants with cancer (n = 1 before and n = 2 after active periodontal therapy). History of MRONJ due to endodontic/restorative reasons was reported in one patient with osteoporosis.

CONCLUSIONS

Patients under ART in SPC demonstrated similar clinical periodontal and dental status but lower OHRQoL compared to unexposed (not statistically significant). Patient awareness of the MRONJ-risk and appropriate preventive measures should be ensured.

CLINICAL RELEVANCE

SPC in osteoporotic patients under ART appeared safe regarding MRONJ, but further investigations on the MRONJ-risk in patients with different risk-profiles are necessary.

STUDY REGISTRATION

clinicaltrials.gov (#NCT04192188).

Mechanism of regulating macrophages/osteoclasts in attenuating wear particle-induced aseptic osteolysis

Joint replacement surgery is the most effective treatment for end-stage arthritis. Aseptic loosening caused by periprosthetic osteolysis is a common complication after joint replacement. Inflammation induced by wear particles derived from prosthetic biomaterials is a major cause of osteolysis. We emphasize that bone marrow-derived macrophages and their fusion-derived osteoclasts play a key role in this pathological process. Researchers have developed multiple intervention approaches to regulate macrophage/osteoclast activation. Aiming at wear particle-induced periprosthetic aseptic osteolysis, this review separately discusses the molecular mechanism of regulation of ROS formation and inflammatory response through intervention of macrophage/osteoclast RANKL-MAPKs-NF-κB pathway. These molecular mechanisms regulate osteoclast activation in different ways, but they are not isolated from each other. There is also a lot of crosstalk among the different mechanisms. In addition, other bone and joint diseases related to osteoclast activation are also briefly introduced. Therefore, we discuss these new findings in the context of existing work with a view to developing new strategies for wear particle-associated osteolysis based on the regulation of macrophages/osteoclasts.

Atypical tibial fracture in breast cancer patient with bone metastasis receiving denosumab therapy: a case report and review of the literature

BACKGROUND

Denosumab therapy is often used to reduce skeletal-related events in metastatic bone disease. On the other hand, there have been some instances of atypical femoral fracture in patients with metastatic bone disease treated with denosumab. In this case report, we describe a patient with metastatic bone disease due to breast cancer who had been using denosumab for 4 years to prevent skeletal-related events and suffered an atypical tibial fracture.

CASE PRESENTATION

We report here the case of an 82-year-old Japanese woman who had received yearly intravenous denosumab for 4 years and presented with a fracture fulfilling the criteria for an atypical fracture, except for being located at the tibial diaphysis. She was found to have stage 4 breast cancer with multiple bone metastases 4 years prior. She had difficulty walking due to her tibial pain and underwent surgical treatment. Four months after surgery, the tibial fracture site exhibited bone fusion.

CONCLUSION

In patients with long-term use of denosumab to prevent skeletal-related events in metastatic bone disease, it is important to be aware of shin and thigh pain and to examine for signs of atypical tibial fractures to pay attention to atypical femoral fractures.

Alterations in macrophage polarization in the craniofacial and extracranial skeleton after zoledronate application and surgical interventions - an in vivo experiment

Purpose

Medication-related osteonecrosis occurs exclusively in the jaw bones. However, the exact pathogenesis of medication-related osteonecrosis of the jaw (MRONJ) and the unique predisposition of the jaw bones have not been elucidated, making its treatment a challenge. Recent evidence indicates that macrophages might play a pivotal role in MRONJ pathogenesis. The aim of the present study was to compare the macrophage populations between the craniofacial and extracranial skeleton and to investigate the changes induced by zoledronate (Zol) application and surgical interventions.

Materials and methods

An in vivo experiment was performed. 120 wistar rats were randomized to 4 groups (G1, G2, G3, G4). G1 served as an untreated control group. G2 and G4 received Zol injections for 8 weeks. Afterwards, the right lower molar of the animals from G3 and G4 was extracted and the right tibia osteotomized followed by osteosynthesis. Tissue samples were taken from the extraction socket and the tibia fracture at fixed time points. Immunohistochemistry was conducted to determine the labeling indexes of CD68+ and CD163+ macrophages.

Results

Comparing the mandible and the tibia, we observed a significantly higher number of macrophages and a heightened pro-inflammatory environment in the mandible compared to the tibia. Tooth extraction caused an increase of the overall number of macrophages and a shift toward a more pro-inflammatory microenvironment in the mandible. Zol application amplified this effect.

Conclusion

Our results indicate fundamental immunological differences between the jaw bone and the tibia, which might be a reason for the unique predisposition for MRONJ in the jaw bones. The more pro-inflammatory environment after Zol application and tooth extraction might contribute to the pathogenesis of MRONJ. Targeting macrophages might represent an attractive strategy to prevent MRONJ and improve therapy. In addition, our results support the hypothesis of an anti-tumoral and anti-metastatic effect induced by BPs. However, further studies are needed to delineate the mechanisms and specify the contributions of the various macrophage phenotypes.

Incidence of Bone Metastases and Skeletal-Related Events in Patients With EGFR-Mutated NSCLC Treated With Osimertinib

Introduction

Bone metastases are frequent in patients with EGFR-mutated (EGFR+) NSCLC. Skeletal-related events (SREs) are common in these patients; however, no data on SRE in osimertinib-treated patients are reported. We investigated the development of bone metastases and SREs in patients with EGFR+ NSCLC treated with osimertinib.

Methods

This is a retrospective multicenter cohort study that included patients with metastatic EGFR+ NSCLC who were treated with osimertinib between February 2016 and September 2021. Demographics, bone metastases-related outcomes, SREs, treatment efficacy, and overall survival (OS) were collected.

Results

In total, 250 patients treated with osimertinib (43% first line) were included. Of the patients, 51% had bone metastases at initiation of osimertinib. Furthermore, 16% of the patients with bone metastases used bone-targeted agents. Median follow-up from initiation of osimertinib was 23.4 months (95% confidence interval [CI]: 19.9-26.9 mo). During osimertinib treatment, 10% developed new bone metastases or bone progression. Of the patients with bone metastases, 39% had more than or equal to one SREs: 28% developed first SRE before osimertinib treatment, 1% after, and 11% during. Median OS post-bone metastasis was 30.8 months (95% CI: 21.9-39.7). Median OS after first SRE was 31.1 months (95% CI: 15.8-46.5).

Conclusions

Bone metastases and SREs are frequent before and during treatment with osimertinib in EGFR+ NSCLC. Because of these findings and the long OS post-bone metastases, we advocate prescription of bone-targeted agents in these patients and recommend adding bone-specific end points in clinical trials.

Clinical and sociodemographic risk factors associated with the development of second primary cancers among postmenopausal breast cancer survivors

BACKGROUND

Advancement in breast cancer (BC) diagnosis and treatment have increased the number of long-term survivors. Consequently, primary BC survivors are at a greater risk of developing second primary cancers (SPCs). The risk factors for SPCs among BC survivors including sociodemographic characteristics, cancer treatment, comorbidities, and concurrent medications have not been comprehensively examined. The purpose of this study is to assess the incidence and clinicopathologic factors associated with risk of SPCs in BC survivors.

METHODS

We analyzed 171, 311 women with early-stage primary BC diagnosed between January 2000 and December 2015 from the Medicare-linked Surveillance Epidemiology and End Results (SEER-Medicare) database. SPC was defined as any diagnosis of malignancy occurring within the study period and at least 6 months after primary BC diagnosis. Univariate analyses compared baseline characteristics between those who developed a SPC and those who did not. We evaluated the cause-specific hazard of developing a SPC in the presence of death as a competing risk.

RESULTS

Of the study cohort, 21,510 (13%) of BC survivors developed a SPC and BC was the most common SPC type (28%). The median time to SPC was 44 months. Women who were white, older, and with fewer comorbidities were more likely to develop a SPC. While statins [hazard ratio (HR) 1.066 (1.023-1.110)] and anti-hypertensives [HR 1.569 (1.512-1.627)] increased the hazard of developing a SPC, aromatase inhibitor therapy [HR 0.620 (0.573-0.671)] and bisphosphonates [HR 0.905 (0.857-0.956)] were associated with a decreased hazard of developing any SPC, including non-breast SPCs.

CONCLUSION

Our study shows that specific clinical factors including type of cancer treatment, medications, and comorbidities are associated with increased risk of developing SPCs among older BC survivors. These results can increase patient and clinician awareness, target cancer screening among BC survivors, as well as developing risk-adapted management strategies.

Current comprehensive understanding of denosumab (the RANKL neutralizing antibody) in the treatment of bone metastasis of malignant tumors, including pharmacological mechanism and clinical trials

Denosumab, a fully humanized monoclonal neutralizing antibody, inhibits activation of the RANK/RANKL/OPG signaling pathway through competitive binding with RANKL, thereby inhibiting osteoclast-mediated bone resorption. Denosumab inhibits bone loss; therefore, it is used to treat metabolic bone diseases (including postmenopausal osteoporosis, male osteoporosis, and glucocorticoid-induced osteoporosis), in clinical practice. Since then, multiple effects of denosumab have been discovered. A growing body of evidence suggests that denosumab has a variety of pharmacological activities and broad potential in clinical diseases such as osteoarthritis, bone tumors, and other autoimmune diseases. Currently, Denosumab is emerging as a treatment for patients with malignancy bone metastases, and it also shows direct or indirect anti-tumor effects in preclinical models and clinical applications. However, as an innovative drug, its clinical use for bone metastasis of malignant tumors is still insufficient, and its mechanism of action needs to be further investigated. This review systematically summarizes the pharmacological mechanism of action of denosumab and the current understanding and clinical practice of the use of denosumab for bone metastasis of malignant tumors to help clinicians and researchers deepen their understanding of denosumab.

Survival in Breast Cancer Patients with Bone Metastasis: A Multicenter Real-World Study on the Prognostic Impact of Intensive Postoperative Bone Scan after Initial Diagnosis of Breast Cancer (CSBrS-023)

The prognostic value of intensive postoperative bone scan (BS) screening, which is performed in asymptomatic patients with breast cancer (BC) after surgery, remained unclear. Patients diagnosed with BC with bone metastasis (BM) from five medical centers in China during the years 2005−2013 were retrospectively collected. Propensity score matching (PSM) was performed to balance the baseline characteristics. The survival outcomes were overall survival (OS) and overall survival after BM (OSABM). Among 1059 eligible patients, 304 underwent intensive postoperative BS while 755 did not. During a median follow-up of 6.67 years (95%CI 6.45, 7.21), intensive postoperative BS prolonged the median OS by 1.63 years (Log-Rank p = 0.006) and OSABM by 0.66 years (Log-Rank p = 0.002). Intensive postoperative BS was an independent prognostic factor for both OS (adjusted HR 0.77, 95%CI 0.64, 0.93, adjusted p = 0.006) and OSABM (adjusted HR 0.71, 95%CI 0.60, 0.86, adjusted p < 0.001). The prognostic value of intensive postoperative BS was consistently favorable for OS among clinical high-risk patients, including those with ages younger than 50, stage II, histology grade G3 and ER-Her2- subtype. This multicenter real-world study showed that intensive postoperative BS screening improved survival for BC patients with BM and should probably be recommended for postoperative surveillance, especially for patients at clinical high-risk.

Metastatic Endometrioid Carcinoma Mimicking a Subungual Melanoma

CASE

We report a case of a 76-year-old female with a stage IB, grade I endometrioid endometrial carcinoma who presented with right-hip pain and an enlarging black, exophytic, subungual lesion on her right-small-finger distal phalanx. Clinically, the distal phalanx lesion was suspicious for a subungual melanoma; however, advanced imaging suggested metastatic disease, with lesions in the acetabulum, lungs, brain, vulva, and vagina.

CONCLUSION

Partial amputation of the right, small finger and vulvar biopsies confirmed an endometrial carcinoma. To our knowledge, this is the first described case of endometrial adenocarcinoma metastasis to the phalanx of an upper extremity, mimicking a subungual melanoma.

Bone Health and Denosumab Discontinuation in Oncology Populations

Managing bone health after denosumab cessation is a commonly encountered challenge. Although the “rebound phenomenon” is generally recognized by endocrinologists in the context of osteoporosis, it is not as widely understood in the context of bone metastases and cancer. This commentary reviews the evidence on the efficacy and safety of various bone health agents in mitigating the “rebound phenomenon” in cancer populations.

Incidence of Post-denosumab Rebound Hypercalcaemia in Bony-Metastatic Breast Cancer

Denosumab reduces incidence of skeletal related events in patients with bony-metastatic breast cancer, however cessation is associated with a rebound phenomenon which, rarely, has been associated with hypercalcaemia. We aimed to identify the incidence of post-denosumab cessation rebound hypercalcaemia amongst patients with breast cancer-related bony metastases. We performed a single-centre retrospective cohort analysis to determine the incident of rebound hypercalcaemia amongst patients treated with antiresorptive agents for bony metastatic breast cancer between 2016-2020. 22,320 outpatient encounters were reviewed, which identified 97 patients with bonymetastatic disease treated with antiresorptive therapy. Of the 21 patients who had denosumab ceased, six (28.6%) developed hypercalcaemia. Interval between last denosumab dose and onset of hypercalcaemia was a median 7.5 (range 2-13) months. There was a significant difference in both denosumab treatment duration as well as total treatment dose exposure between patients who developed hypercalcaemia post-denosumab cessation (median 41 months, 40 doses) and those who remained normocalcaemic (median 10 months, 5 doses), p = 0.009. In our study, hypercalcaemia occurred between two and thirteen months after denosumab cessation. Greater denosumab treatment duration as well as total denosumab dose exposure was associated with higher risk of hypercalcaemia after denosumab cessation. Hormonal therapy or previous bisphosphonate treatment was not seen to impact upon development of hypercalcaemia. Rebound hypercalcaemia is a rare but important diagnosis to consider in patients experiencing hypercalcaemia after denosumab cessation.

Palliative radiotherapy of bone metastases in octogenarians: How do the oldest olds respond? Results from a tertiary cancer center with 288 treated patients

BACKGROUND

Accompanied by the demographic change, the number of octogenarian cancer patients with bone metastases will increase in the future. Palliative radiotherapy constitutes an effective analgesic treatment; however, as pain perception and bone metabolism change with increasing age, the analgesic efficacy of radiotherapy may be altered in elderly patients. We therefore investigated the treatment outcomes of palliative radiotherapy for bone metastases in octogenarians.

METHODS

Patients between 80 and 89 years undergoing radiotherapy for bone metastases between 2009 and 2019 at a tertiary cancer center were analyzed for patterns-of-care, pain response and overall survival (OS). Logistic regression analyses were carried out to examine parameters associated with pain response, and Cox analyses were conducted to reveal prognostic parameters for OS.

RESULTS

A total of 288 patients with 516 irradiated lesions were included in the analysis. The majority (n = 249, 86%) completed all courses of radiotherapy. Radiotherapy led to pain reduction in 176 patients (61%) at the end of treatment. Complete pain relief at the first follow-up was achieved in 84 patients (29%). Bisphosphonate administration was significantly associated with higher rates of pain response at the first follow-up (p < 0.05). Median OS amounted to 9 months, and 1-year, 2-year and 3-year OS were 43%, 28% and 17%. In the multivariate analysis, ECOG (p < 0.001), Mizumoto score (p < 0.01) and Spinal Instability Neoplastic Score (SINS) (p < 0.001) were independent prognosticators for OS.

CONCLUSION

Palliative radiotherapy for bone metastases constitutes a feasible and effective analgesic treatment in octogenarian patients. ECOG, Mizumoto score and SINS are prognosic variables for survival and may aid treatment decisions regarding radiotherapy fractionation in this patient group. Single-fraction radiotherapy with 8 Gy should be applied for patients with uncomplicated bone metastases and poor prognosis. Prospective trials focusing on quality of life of these very old cancer patients with bone metastases are warranted to reveal the optimal radiotherapeutic management for this vulnerable population.

Mechanism of bisphosphonate-related osteonecrosis of the jaw (BRONJ) revealed by targeted removal of legacy bisphosphonate from jawbone using competing inert hydroxymethylene diphosphonate

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) presents as a morbid jawbone lesion in patients exposed to a nitrogen-containing bisphosphonate (N-BP). Although it is rare, BRONJ has caused apprehension among patients and healthcare providers and decreased acceptance of this antiresorptive drug class to treat osteoporosis and metastatic osteolysis. We report here a novel method to elucidate the pathological mechanism of BRONJ by the selective removal of legacy N-BP from the jawbone using an intra-oral application of hydroxymethylene diphosphonate (HMDP) formulated in liposome-based deformable nanoscale vesicles (DNV). After maxillary tooth extraction, zoledronate-treated mice developed delayed gingival wound closure, delayed tooth extraction socket healing and increased jawbone osteonecrosis consistent with human BRONJ lesions. Single cell RNA sequencing of mouse gingival cells revealed oral barrier immune dysregulation and unresolved proinflammatory reaction. HMDP-DNV topical applications to nascent mouse BRONJ lesions resulted in accelerated gingival wound closure and bone socket healing as well as attenuation of osteonecrosis development. The gingival single cell RNA sequencing demonstrated resolution of chronic inflammation by increased anti-inflammatory signature gene expression of lymphocytes and myeloid-derived suppressor cells. This study suggests that BRONJ pathology is related to N-BP levels in jawbones and demonstrates the potential of HMDP-DNV as an effective BRONJ therapy.

Comparison of pregnancy and live birth rates between fresh day 5 morula transfer and fresh day 6 blastocyst transfer following extended culture for slow growing embryos

PURPOSE

The aim of this study is to evaluate and compare the outcomes of fresh day 5 morula transfers and fresh day 6 blastocyst transfers after extended culture, in women with a whole cohort of slow growing embryos.

METHODS

Fresh embryo transfer cycles of patients that underwent intracytoplasmic sperm injection between 2013 and 2020 with a whole cohort of slow developing embryos on 5th day of fertilization were evaluated for this retrospective cohort study. Outcomes of day 5 morula transfers and day 6 blastocyst transfers after extended culture were compared.

RESULTS

Out of 479 patients, day 5 morula transfers were performed to 194 and embryo culturing was extended to day 6 in 285 women. Blastocyst formation was observed in 129 of 285 patients in extended culture group. Implantation rate of day 6 blastocyst transfer group was significantly higher than day 5 morula transfer group (27% vs. 12%, p < 0.001). However, clinical pregnancy (17% vs 15.4%) and live birth rates (14.4% vs 13%) were found similar in day 5 morula transfer and extended culture group per initiated cycle.

CONCLUSION

Although implantation capacity of day 6 blastocysts seems higher comparing to day 5 morulas, clinical pregnancy and live birth rates are similar among intention to treat population in fresh day 5 morula transfers and day 6 blastocyst transfers after extended culture for women that cohorts consist of only slow developing embryos.

Appraising Adjuvant Endocrine Therapy in Hormone Receptor Positive HER2-Negative Breast Cancer—A Literature Review

Background: Approximately 75% of breast cancer (BC) is associated with luminal differentiation expressing endocrine receptors (ER). For ER+ HER2− tumors, adjuvant endocrine therapy (ET) is the cornerstone treatment. Although relapse events steadily continue, the ET benefits translate to dramatically lengthen life expectancy with bearable side-effects. This review of ER+ HER2− female BC outlines suitable adjuvant treatment strategies to help guide clinical decision making around appropriate therapy. Methods: A literature search was conducted in Embase, Medline, and the Cochrane Libraries, using ER+ HER−, ET BC keywords. Results: In low-risk patients: five years of ET is the standard option. While Tamoxifen remains the preferred selection for premenopausal women, AI is the choice for postmenopausal patients. In the high-risk category: ET plus/minus OFS with two years of Abemaciclib is recommended. Although extended ET for a total of ten years is an alternative, the optimal AI duration is undetermined; nevertheless an additional two to three years beyond the initial five years may be sufficient. In this postmenopausal group, bisphosphonate is endorsed. Conclusions: Classifying the risk category assists in deciding the treatment route and its optimal duration. Tailoring the breadth of ET hinges on a wide array of factors to be appraised for each individualized case, including weighing its benefits and harms.

Bone loss induced by cancer treatments in breast and prostate cancer patients

Cancer and cancer therapies are a major factor risk for osteoporosis due to bone loss and deterioration of bone microarchitecture. Both factors contribute to a decrease in bone strength and, consequently, increased bone fragility and risk of fracture. Cancer-associated bone loss is a multifactorial process, and optimal interdisciplinary management of skeletal health, accurate assessment of bone density, and early diagnosis are essential when making decisions aimed at reducing bone loss and fracture risk in patients who have received or are receiving treatment for cancer. In this document, a multidisciplinary group of experts collected the latest evidence on the pathophysiology of osteoporosis and its prevention, diagnosis, and treatment with the support of the Spanish scientific society SEOM. The aim was to provide an up-to-date and in-depth view of osteoporotic risk and its consequences, and to present a series of recommendations aimed at optimizing the management of bone health in the context of cancer.

A Multimodal Clinical Approach for the Treatment of Bone Metastases in Solid Tumors

Context

Bone metastasis (BM) is a frequent complication of cancer, representing the third most common site of secondary spread in solid cancers behind the lung and liver. Bone metastasis is found in up to 90% of prostate and breast cancer patients. They can cause significant complications, such as pathological fractures and paralysis of the spine, which decrease daily functioning and quality of life (QoL) and worsen prognosis. The growing life expectancy of cancer patients due to improvements in systemic therapies may further increase BM's eventuality and clinical burden in cancer patients.

Evidence Acquisition

Four physicians from five different specialties were interviewed and resumed the most relevant literature of the last 20 years focusing on pain treatment in BM patients.

Results

Treatment for BM ideally involves various types of specialists and assessments. The disease status and patient background should be considered, requiring holistic care and expertise from various medical specialties.

Conclusions

Interventional, nuclear medicine, radiotherapy, and mini-invasive techniques can be safe and effective for relieving pain and modifying health-related QoL in BM patients.

Tumor-Associated Macrophages and Ovarian Cancer: Implications for Therapy

The tumor microenvironment (TME) has been implicated to play an important role in the progression of ovarian cancer. One of the most important components of the TME is tumor associated macrophages (TAMs). Phenotypically, macrophages are broadly categorized as M1 pro-inflammatory or M2 anti-inflammatory, based on the cytokines and chemokines that they secrete. The tumor microenvironment is associated with macrophages of an M2 phenotype which suppress the surrounding immune environment, assist tumor cells in evading immune targeting, and support tumor growth and metastasis. Contrarily, M1 macrophages help mount an immune response against tumors, and are associated with a more favorable prognosis in solid tumors. One of the characteristic indicators of a poor prognosis in ovarian cancer is the overrepresentation of M2-type TAMs. As such, therapeutic modalities targeting TME and TAMs are of increasing interest. Pharmacological approaches to eliminate TAMs, include decreasing macrophage survival and recruitment and increasing phagocytosis, have been underwhelming. Clinical strategies targeting these macrophage subtypes via repolarization to an M1 antitumoral state deserve increasing attention, and may serve as a new modality for immunotherapy.

CST6 protein and peptides inhibit breast cancer bone metastasis by suppressing CTSB activity and osteoclastogenesis

Background: Bone metastasis is a frequent symptom of breast cancer and current targeted therapy has limited efficacy. Osteoclasts play critical roles to drive osteolysis and metastatic outgrowth of tumor cells in bone. Previously we identified CST6 as a secretory protein significantly downregulated in bone-metastatic breast cancer cells. Functional analysis showed that CST6 suppresses breast-to-bone metastasis in animal models. However, the functional mechanism and therapeutic potential of CST6 in bone metastasis is unknown.

Methods: Using in vitro osteoclastogenesis and in vivo metastasis assays, we studied the effect and mechanism of extracellular CST6 protein in suppressing osteoclastic niches and bone metastasis of breast cancer. A number of peptides containing the functional domain of CST6 were screened to inhibit bone metastasis. The efficacy, stability and toxicity of CST6 recombinant protein and peptides were evaluated in preclinical metastasis models.

Results: We show here that CST6 inhibits osteolytic bone metastasis by inhibiting osteoclastogenesis. Cancer cell-derived CST6 enters osteoclasts by endocytosis and suppresses the cysteine protease CTSB, leading to up-regulation of the CTSB hydrolytic substrate SPHK1. SPHK1 suppresses osteoclast maturation by inhibiting the RANKL-induced p38 activation. Importantly, recombinant CST6 protein effectively suppresses bone metastasis in vitro and in vivo. We further identified several peptides mimicking the function of CST6 to suppress cancer cell-induced osteoclastogenesis and bone metastasis. Pre-clinical analyses of CTS6 recombinant protein and peptides demonstrated their potentials in treatment of breast cancer bone metastasis.

Conclusion: These findings reveal the CST6-CTSB-SPHK1 signaling axis in osteoclast differentiation and provide a promising approach to treat bone diseases with CST6-based peptides.

Fracture Risk Evaluation of Bone Metastases: A Burning Issue

Major progress has been achieved to treat cancer patients and survival has improved considerably, even for stage-IV bone metastatic patients. Locomotive health has become a crucial issue for patient autonomy and quality of life. The centerpiece of the reflection lies in the fracture risk evaluation of bone metastasis to guide physician decision regarding physical activity, antiresorptive agent prescription, and local intervention by radiotherapy, surgery, and interventional radiology. A key mandatory step, since bone metastases may be asymptomatic and disseminated throughout the skeleton, is to identify the bone metastasis location by cartography, especially within weight-bearing bones. For every location, the fracture risk evaluation relies on qualitative approaches using imagery and scores such as Mirels and spinal instability neoplastic score (SINS). This approach, however, has important limitations and there is a need to develop new tools for bone metastatic and myeloma fracture risk evaluation. Personalized numerical simulation qCT-based imaging constitutes one of these emerging tools to assess bone tumoral strength and estimate the femoral and vertebral fracture risk. The next generation of numerical simulation and artificial intelligence will take into account multiple loadings to integrate movement and obtain conditions even closer to real-life, in order to guide patient rehabilitation and activity within a personalized-medicine approach.

Computer-Assisted Surgical Navigation for Primary and Metastatic Bone Malignancy of the Pelvis: Current Evidence and Future Directions

Computer-assisted navigation and robotic surgery have gained popularity in the treatment of pelvic bone malignancies, given the complexity of the bony pelvis, the proximity of numerous vital structures, and the historical challenges of pelvic bone tumor surgery. Initial interest was on enhancing the accuracy in sarcoma resection by improving the quality of surgical margins and decreasing the incidence of local recurrences. Several studies have shown an association between intraoperative navigation and increased incidence of negative margin bone resection, but long-term outcomes of navigation in pelvic bone tumor resection have yet to be established. Historically, mechanical stabilization of pelvic bone metastases has been limited to Harrington-type total hip arthroplasty for disabling periacetabular disease, but more recently, computer-assisted surgery has been employed for minimally invasive percutaneous fixation and stabilization; although still in its incipient stages, this procedure is potentially appealing for treating patients with bone metastases to the pelvis. The authors review the literature on navigation for the treatment of primary and metastatic tumors of the pelvic bone and discuss the best practices and limitations of these techniques.

Temporal subtraction CT with nonrigid image registration improves detection of bone metastases by radiologists: results of a large-scale observer study

To determine whether temporal subtraction (TS) CT obtained with non-rigid image registration improves detection of various bone metastases during serial clinical follow-up examinations by numerous radiologists. Six board-certified radiologists retrospectively scrutinized CT images for patients with history of malignancy sequentially. These radiologists selected 50 positive and 50 negative subjects with and without bone metastases, respectively. Furthermore, for each subject, they selected a pair of previous and current CT images satisfying predefined criteria by consensus. Previous images were non-rigidly transformed to match current images and subtracted from current images to automatically generate TS images. Subsequently, 18 radiologists independently interpreted the 100 CT image pairs to identify bone metastases, both without and with TS images, with each interpretation separated from the other by an interval of at least 30 days. Jackknife free-response receiver operating characteristics (JAFROC) analysis was conducted to assess observer performance. Compared with interpretation without TS images, interpretation with TS images was associated with a significantly higher mean figure of merit (0.710 vs. 0.658; JAFROC analysis, P = 0.0027). Mean sensitivity at lesion-based was significantly higher for interpretation with TS compared with that without TS (46.1% vs. 33.9%; P = 0.003). Mean false positive count per subject was also significantly higher for interpretation with TS than for that without TS (0.28 vs. 0.15; P < 0.001). At the subject-based, mean sensitivity was significantly higher for interpretation with TS images than that without TS images (73.2% vs. 65.4%; P = 0.003). There was no significant difference in mean specificity (0.93 vs. 0.95; P = 0.083). TS significantly improved overall performance in the detection of various bone metastases.

Bone Metastatic Breast Cancer: Advances in Cell Signaling and Autophagy Related Mechanisms

Bone metastasis is a frequent complication of breast cancer with nearly 70% of metastatic breast cancer patients developing bone metastasis during the course of their disease. The bone represents a dynamic microenvironment which provides a fertile soil for disseminated tumor cells, however, the mechanisms which regulate the interactions between a metastatic tumor and the bone microenvironment remain poorly understood. Recent studies indicate that during the metastatic process a bidirectional relationship between metastatic tumor cells and the bone microenvironment begins to develop. Metastatic cells display aberrant expression of genes typically reserved for skeletal development and alter the activity of resident cells within the bone microenvironment to promote tumor development, resulting in the severe bone loss. While transcriptional regulation of the metastatic process has been well established, recent findings from our and other research groups highlight the role of the autophagy and secretory pathways in interactions between resident and tumor cells during bone metastatic tumor growth. These reports show high levels of autophagy-related markers, regulatory factors of the autophagy pathway, and autophagy-mediated secretion of matrix metalloproteinases (MMP's), receptor activator of nuclear factor kappa B ligand (RANKL), parathyroid hormone related protein (PTHrP), as well as WNT5A in bone metastatic breast cancer cells. In this review, we discuss the recently elucidated mechanisms and their crosstalk with signaling pathways, and potential therapeutic targets for bone metastatic disease.

TGFB-induced factor homeobox 1 (TGIF) expression in breast cancer

BACKGROUND

Breast cancer (BC) is the most frequent female cancer and preferentially metastasizes to bone. The transcription factor TGFB-induced factor homeobox 1 (TGIF) is involved in bone metabolism. However, it is not yet known whether TGIF is associated with BC bone metastasis or patient outcome and thus of potential interest.

METHODS

TGIF expression was analyzed by immunohistochemistry in 1197 formalin-fixed, paraffin-embedded tissue samples from BC patients treated in the GAIN (German Adjuvant Intergroup Node-Positive) study with two adjuvant dose-dense schedules of chemotherapy with or without bisphosphonate ibandronate. TGIF expression was categorized into negative/low and moderate/strong staining. Endpoints were disease-free survival (DFS), overall survival (OS) and time to primary bone metastasis as first site of relapse (TTPBM).

RESULTS

We found associations of higher TGIF protein expression with smaller tumor size (p = 0.015), well differentiated phenotype (p < 0.001) and estrogen receptor (ER)-positive BC (p < 0.001). Patients with higher TGIF expression levels showed a significantly longer disease-free (DFS: HR 0.75 [95%CI 0.59-0.95], log-rank p = 0.019) and overall survival (OS: HR 0.69 [95%CI 0.50-0.94], log-rank p = 0.019), but no association with TTPBM (HR 0.77 [95%CI 0.51-1.16]; p = 0.213). Univariate analysis in molecular subgroups emphasized that elevated TGIF expression was prognostic for both DFS and OS in ER-positive BC patients (DFS: HR 0.68 [95%CI 0.51-0.91]; log-rank p = 0.009, interaction p = 0.130; OS: HR 0.60 [95%CI 0.41-0.88], log-rank p = 0.008, interaction p = 0.107) and in the HER2-negative subgroup (DFS:HR 0.67 [95%CI 0.50-0.88], log-rank p = 0.004, interaction p = 0.034; OS: HR 0.57 [95%CI 0.40-0.81], log-rank p = 0.002, interaction p = 0.015).

CONCLUSIONS

Our results suggest that moderate to high TGIF expression is a common feature of breast cancer cells and that this is not associated with bone metastases as first site of relapse. However, a reduced expression is linked to tumor progression, especially in HER2-negative breast cancer.

TRIAL REGISTRATION

This clinical trial has been registered with ClinicalTrials.gov ; registration number: NCT00196872 .

Bisphosphonates and breast cancer survival: a meta-analysis and trial sequential analysis of 81508 participants from 23 prospective epidemiological studies

BACKGROUND

We assessed the effect of bisphosphonates (BPs) on breast cancer (BCa) patient survival and explored how long the effect can persist after treatment.

METHODS

We performed a meta-analysis and trial sequential analysis (TSA) of prospective studies including randomized controlled trials (RCTs) and cohort studies. We performed extensive sensitivity analyses to assess the robustness of the findings.

RESULTS

Seventeen RCTs and eight cohorts with 81508 BCa patients were identified. A significant beneficial effect of BPs on BCa survival was found (RR, 0.725; 95% CI, 0.627-0.839), and the TSA results also suggested firm evidence for this beneficial effect. Both summarized results from RCTs and cohorts provided firm evidence for this effect, although the effect estimates were stronger from cohorts than RCTs (RR, 0.892; 95% CI, 0.829-0.961; 0.570; 95% CI, 0.436-0.745; respectively). This beneficial effect was confirmed for bone-metastases (RR, 0.713; 95% CI, 0.602-0.843) and postmenopausal women (RR, 0.737; 95% CI, 0.640-0.850). Importantly, our results demonstrated that this beneficial effect was retained at least 1-2 years after treatment completion (RR, 0.780; 95% CI, 0.638-0.954) and could persist for up to more than 4 years after treatment completion (RR, 0.906; 95% CI, 0.832-0.987). Extensive sensitivity analyses showed the robustness of our results. The GRADE quality of evidence was generally judged to be moderate to high.

CONCLUSIONS

The present study provides firm evidence for a significant beneficial effect of BPs on BCa survival in patients with early-stage BCa, and this effect was retained at least 1-2 years after BP treatment completion.

The American Society of Pain and Neuroscience (ASPN) Best Practices and Guidelines for the Interventional Management of Cancer-Associated Pain

Moderate to severe pain occurs in many cancer patients during their clinical course and may stem from the primary pathology, metastasis, or as treatment side effects. Uncontrolled pain using conservative medical therapy can often lead to patient distress, loss of productivity, shorter life expectancy, longer hospital stays, and increase in healthcare utilization. Various publications shed light on strategies for conservative medical management for cancer pain and a few international publications have reviewed limited interventional data. Our multi-institutional working group was assembled to review and highlight the body of evidence that exists for opioid utilization for cancer pain, adjunct medication such as ketamine and methadone and interventional therapies. We discuss neurolysis via injections, neuromodulation including targeted drug delivery and spinal cord stimulation, vertebral tumor ablation and augmentation, radiotherapy and surgical techniques. In the United States, there is a significant variance in the interventional treatment of cancer pain based on fellowship training. As a first of its kind, this best practices and interventional guideline will offer evidenced-based recommendations for reducing pain and suffering associated with malignancy.

The genomic architecture of metastasis in breast cancer: focus on mechanistic aspects, signalling pathways and therapeutic strategies

Breast cancer is a multifactorial, heterogeneous disease and the second most frequent cancer amongst women worldwide. Metastasis is one of the most leading causes of death in these patients. Early-stage or locally advanced breast cancer is limited to the breast or nearby lymph nodes. When breast cancer spreads to farther tissues/organs from its original site, it is referred to as metastatic or stage IV breast cancer. Normal breast development is regulated by specific genes and signalling pathways controlling cell proliferation, cell death, cell differentiation and cell motility. Dysregulation of genes involved in various signalling pathways not only leads to the formation of primary tumour but also to the metastasis as well. The metastatic cascade is represented by a multi-step process including invasion of the local tumour cell followed by its entry into the vasculature, exit of malignant cells from the circulation and ultimately their colonization at the distant sites. These stages are referred to as formation of primary tumour, angiogenesis, invasion, intravasation and extravasation, respectively. The major sites of metastasis of breast cancer are the lymph nodes, bone, brain and lung. Only about 28% five-year survival rate has been reported for stage IV breast cancer. Metastasis is a serious concern for breast cancer and therefore, various therapeutic strategies such as tyrosine kinase inhibitors have been developed to target specific dysregulated genes and various signalling pathways involved in different steps of metastasis. In addition, other therapies like hyperbaric oxygen therapy, RNA interference and CRISPR/Cas9 are also being explored as novel strategies to cure the stage IV/metastatic breast cancer. Therefore, the current review has been compiled with an aim to evaluate the genetic basis of stage IV breast cancer with a focus on the molecular mechanisms. In addition, the therapeutic strategies targeting these dysregulated genes involved in various signalling pathways have also been discussed. Genome editing technologies that can target specific genes in the affected areas by making knock-in and knock-out alternations and thereby bring significant treatment outcomes in breast cancer have also been summarized.

[Oncologic aspects in treatment of pathologic fractures]

BACKGROUND

Pathological fractures are not only incisive events for tumor patients often with the need of surgical treatment but also often represent a relevant challenge in the overall concept of oncological treatment.

OBJECTIVE

The aim of this article is to illustrate the necessity of a pre-interventional interdisciplinary consideration of disease-specific and patient-specific characteristics.

MATERIAL AND METHODS

A literature search and evaluation of existing guidelines were carried out including the keywords "bone metastases" and "pathological fractures" with respect to the oncological and radiotherapeutic treatment.

RESULTS

An essential classification of the surgical and other needs for treatment is carried out by the identification of the underlying disease and dissemination situation. For tumor-related pathological fractures a palliative treatment situation is present in most cases. Nevertheless, a possible oligometastasis and an increasing number of effective systemic treatment methods must be taken into consideration when planning the surgical treatment. In addition to the therapeutic emergency indications in spinal compression or symptomatic hypercalcemia, both additive radiotherapy and supplementary pharmaceutical osteoprotection have to be addressed in this context. Radiotherapy in particular represents an effective alternative option for symptom and tumor control.

CONCLUSION

The work-up of the multifaceted oncological treatment concept represents an interdisciplinary challenge, which ideally defines the further treatment procedure, including fracture treatment, in an interdisciplinary tumor board within an overall oncological concept.

Reporting of Incidence and Outcome of Bone Metastases in Clinical Trials Enrolling Patients with Epidermal Growth Factor Receptor Mutated Lung Adenocarcinoma-A Systematic Review

Bone metastases, occurring in 30-60% of patients with non-small cell lung cancer (NSCLC), are associated with decreased survival, cancer-induced bone pain, and skeletal-related events (SREs). Those with an activating epidermal growth factor mutation (EGFR+) seem to be more prone to develop bone metastases. To gain more insight into bone metastases-related outcomes in EGFR+ NSCLC, we performed a systematic review on Pubmed (2006-2021). Main inclusion criteria: prospective, phase II/III trials evaluating EGFR-tyrosine kinase inhibitors, ≥10 EGFR+ patients included, data on bone metastases and/or bone-related outcomes available. Out of 663 articles, 21 (3176 EGFR+ patients) met the eligibility criteria; 4 phase III (one double blind), 17 phase II trials (three randomized) were included. In seven trials dedicated bone imaging was performed at baseline. Mean incidence of bone metastases at diagnosis was 42%; 3-33% had progression in the bone upon progression. Except for one trial, it was not specified whether the use of bone target agents was permitted, and in none of the trials, occurrence of SREs was reported. Despite the high incidence of bone metastases in EGFR+ adenocarcinoma, there is a lack of screening for, and reporting on bone metastases in clinical trials, as well as permitted bone-targeted agents and SREs.

Breast Cancer with Bone Metastasis: Molecular Insights and Clinical Management

Despite the remarkable advances in the diagnosis and treatment of breast cancer patients, the presence or development of metastasis remains an incurable condition. Bone is one of the most frequent sites of distant dissemination and negatively impacts on patient's survival and overall frailty. The interplay between tumor cells and the bone microenvironment induces bone destruction and tumor progression. To date, the clinical management of bone metastatic breast cancer encompasses anti-tumor systemic therapies along with bone-targeting agents, aimed at slowing bone resorption to reduce the risk of skeletal-related events. However, their effect on patients' survival remains controversial. Unraveling the biology that governs the interplay between breast neoplastic cells and bone tissue would provide means for the development of new therapeutic agents. This article outlines the state-of-the art in the characterization and targeting the bone metastasis in breast cancer, focusing on the major clinical and translational studies on this clinically relevant topic.

Upregulation of mmu_circ_0001066 attenuates the inhibitory effect of bisphosphonates on osteoclastogenesis

OBJECTIVE

Medication-related osteonecrosis of the jaw (MRONJ) is the main adverse side effect of bisphosphonates (BPs), mainly owing to the inhibitory effect of BPs on osteoclastogenesis. CircRNAs were identified to be an important factor in regulating cellular processes. The aim of this study was to explore the effect of mmu_circ_0001066 on BP-inhibited osteoclastogenesis.

MATERIALS AND METHODS

The expression of MRONJ-related miRNA in RANKL-induced RAW264.7 cells treated with BP was analyzed using qRT-PCR analysis. Bioinformatics techniques were applied to screen potential circRNAs. Tartrate-resistant acid phosphatase (TRAP) staining and bone resorption assays were used to examine the effect of mmu_circ_0001066 on osteoclastogenesis. Bioinformatics analysis, luciferase reporter assays, and Western blotting assays were performed to investigate the underlying mechanism.

RESULTS

Four MRONJ-related miRNAs were upregulated in BP-treated RAW264.7 cells, and the expression of mmu_circ_0001066 was negatively correlated with those of MRONJ-related miRNAs. Furthermore, the upregulation of mmu_circ_0001066 partially attenuated the inhibitory effect of BP on osteoclastogenesis in RAW264.7 cells. Mechanistically, upregulated miR-16 suppressed osteoclastogenesis and miR-16 inhibitor increased osteoclastogenesis. Furthermore, we have identified that miR-16 is a downstream effector of mmu_circ_0001066.

CONCLUSION

Our results suggest that mmu_circ_0001066 played an important role in the BP-mediated suppression of osteoclastogenesis, which lays a foundation for identifying mmu_circ_0001066 as a potential biomarker for MRONJ.

Intramedullary rod failure in metastatic breast cancer: Do triple negative cancer patients have more revision surgery?

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Intramedullary rodding can be considered for bone lesions in breast cancer.

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No difference in revision rate among patients with different receptor-status.

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Mean intramedullary rod revision time was 19 months.

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Revision cumulative incidence: 6% at 12 months and 20% at 60 months.

Background

Breast cancer is the most common cancer and second cause of death in women worldwide. Patients with breast cancer are classified into subgroups based on the presence or absence of hormone receptors and the human epidermal growth factor 2-neu (HER-2) marker, the different molecular profiles come with an associated prognosis and variety of possible treatment options. Patients with triple negative cancer have a worse prognosis, a more aggressive behavior, higher likelihood of spreading, a higher risk of recurrence and a poorer outcome overall. Intramedullary rod fixation has proven to provide a good outcome and function in patients with metastatic breast cancer, but no study has addressed the receptor-status potential outcome differences that may affect disease progression at an orthopaedic surgery site.

Questions/Purposes

(1) Do patients with triple negative breast cancer have a higher revision rate of intramedullary rod fixation of bone metastases? (2) Do patients with metastatic triple negative breast cancer have a higher revision rate of intramedullary rod fixation due to local disease progression?

Methods

This was a single-center, observational, retrospective cohort study. Fifty-seven patients with a diagnosis of breast cancer metastatic to long bones who underwent surgical fixation with an intramedullary rod for a pathological fracture or an impending fracture due to a bone metastasis with a Mirels’ score equal or above 8 between January 2004 and December 2016 at our institution were included. All implants used were from the same manufacturer (Stryker Corp., Mahwah, NJ, USA). Patients were divided into two groups based on the receptor status of the tumor and were classified either as triple negative, when the tumor lacked progesterone, estrogen and HER-2 receptors, or as receptor-positive when the presence of one or a combination of either three was proven. In the triple-negative tumor group the mean follow up time was 26 months (SD 29) and median follow up time was 16 months. In the receptor-positive tumor group mean follow up was 27 months (SD 24) with a median follow up of 19 months. To assess possible associations between different factors and the outcomes of interest, we used either the chi-square test or Fisher’s exact test for categorical variables and the ANOVA test for continuous variables. For the survival assessment, a Kaplan-Meier analysis was performed and for the cumulative incidence a competing risk analysis was utilized.

Results

The intramedullary rod revision rate for patients in the triple-negative tumor group was 17%, while for the receptor-positive group it was 12%, this was not statistically different for our sample size. The mean time for revision of the intramedullary rod in the whole sample was 19 months (SD 11, range 6–40). The causes of revision were disease progression (43%), nonunion (29%) and surgeon error (29%). The cumulative incidence of revision surgery was 6% (CI 95%, 2–14%) at 12 months and 20% (CI 95%, 8–36%) at 60 months.

Conclusions

Intramedullary rodding can be considered for the treatment of long bones metastases in breast cancer patients for an impending or actual pathological fracture. There is no difference in the intramedullary rod revision rate among patients with different receptor-status when comparing triple-negative tumor patients and receptor-positive ones.

Level of Evidence

Level III, therapeutic study.

Cellular Fitness Phenotypes of Cancer Target Genes from Oncobiology to Cancer Therapeutics

To define the growing significance of cellular targets and/or effectors of cancer drugs, we examined the fitness dependency of cellular targets and effectors of cancer drug targets across human cancer cells from 19 cancer types. We observed that the deletion of 35 out of 47 cellular effectors and/or targets of oncology drugs did not result in the expected loss of cell fitness in appropriate cancer types for which drugs targeting or utilizing these molecules for their actions were approved. Additionally, our analysis recognized 43 cellular molecules as fitness genes in several cancer types in which these drugs were not approved, and thus, providing clues for repurposing certain approved oncology drugs in such cancer types. For example, we found a widespread upregulation and fitness dependency of several components of the mevalonate and purine biosynthesis pathways (currently targeted by bisphosphonates, statins, and pemetrexed in certain cancers) and an association between the overexpression of these molecules and reduction in the overall survival duration of patients with breast and other hard-to-treat cancers, for which such drugs are not approved. In brief, the present analysis raised cautions about off-target and undesirable effects of certain oncology drugs in a subset of cancers where the intended cellular effectors of drug might not be good fitness genes and that this study offers a potential rationale for repurposing certain approved oncology drugs for targeted therapeutics in additional cancer types.

Molecular Biomarkers for Contemporary Therapies in Hormone Receptor-Positive Breast Cancer

Systemic treatment of hormone receptor-positive (HR+) breast cancer is undergoing a renaissance, with a number of targeted therapies including CDK4/6, mTOR, and PI3K inhibitors now approved for use in combination with endocrine therapies. The increased use of targeted therapies has changed the natural history of HR+ breast cancers, with the emergence of new escape mechanisms leading to the inevitable progression of disease in patients with advanced cancers. The identification of new predictive and pharmacodynamic biomarkers to current standard-of-care therapies and discovery of new therapies is an evolving and urgent clinical challenge in this setting. While traditional, routinely measured biomarkers such as estrogen receptors (ERs), progesterone receptors (PRs), and human epidermal growth factor receptor 2 (HER2) still represent the best prognostic and predictive biomarkers for HR+ breast cancer, a significant proportion of patients either do not respond to endocrine therapy or develop endocrine resistant disease. Genomic tests have emerged as a useful adjunct prognostication tool and guide the addition of chemotherapy to endocrine therapy. In the treatment-resistant setting, mutational profiling has been used to identify ESR1, PIK3CA, and AKT mutations as predictive molecular biomarkers to newer therapies. Additionally, pharmacodynamic biomarkers are being increasingly used and considered in the metastatic setting. In this review, we summarise the current state-of-the-art therapies; prognostic, predictive, and pharmacodynamic molecular biomarkers; and how these are impacted by emerging therapies for HR+ breast cancer.

Review of Bone Modifying Agents in Metastatic Breast Cancer

Bone is the most common site for distant metastases in breast cancer and can cause significant morbidity and mortality. Bone modifying agents (BMAs) that include bisphosphonates (BPAs) and denosumab help in decreasing and delaying skeletal-related events (SREs) associated with metastatic breast cancer. BPAs approved for use by the Food and Drug Administration (FDA) in bone metastases (BM) in the United States are pamidronate and zolendronic acid, while clodronate and ibandronate are licensed for use in other countries. Current American Society of Clinical Oncology (ASCO) guidelines recommend denosumab 120 mg subcutaneously every four weeks, or zolendronic acid 4 mg every four weeks or every 12 weeks, or intravenous pamidronate 90 mg every four weeks. Current guidelines do not recommend one BMA over another, however, zolendronic acid and denosumab were the most commonly used BMAs in population-based studies. Side effects of BMAs include acute phase reactions, hypocalcemia, nephrotoxicity, osteonecrosis of jaw, etc. While other side effects are common with both BPAs and denosumab, the latter has less nephrotoxic potential and is preferred for use in patients with renal failure. Current ASCO guidelines recommend continuing BMAs indefinitely, however, in clinical practice, this decision needs to be individualized, especially since there is no data on the impact of long-term use of BMAs. Further studies would need to be developed to develop an algorithm of SRE risk assessment and to determine which patients would benefit from BMAs.

The adverse effects of bisphosphonates in breast cancer: A systematic review and network meta-analysis

BACKGROUND

Bisphosphonate drugs can be used to improve the outcomes of women with breast cancer. Whilst many meta-analyses have quantified their potential benefits for patients, attempts at comprehensive quantification of potential adverse effects have been limited. We undertook a meta-analysis with novel methodology to identify and quantify these adverse effects.

METHODS

We systematically reviewed randomised controlled trials in breast cancer where at least one of the treatments was a bisphosphonate (zoledronic acid, ibandronate, pamidronate, alendronate or clodronate). Neoadjuvant, adjuvant and metastatic settings were examined. Primary outcomes were adverse events of any type or severity (excluding death). We carried out pairwise and network meta-analyses to estimate the size of any adverse effects potentially related to bisphosphonates. In order to ascertain whether adverse effects differed by individual factors such as age, or interacted with other common adjuvant breast cancer treatments, we examined individual-level patient data for one large trial, AZURE.

FINDINGS

We identified 56 trials that reported adverse data, which included a total of 29,248 patients (18,301 receiving bisphosphonate drugs versus 10,947 not). 24 out of the 103 different adverse outcomes analysed showed a statistically and practically significant increase in patients receiving a bisphosphonate drug compared with those not (2 additional outcomes that appeared statistically significant came only from small studies with low event counts and no clinical suspicion so are likely artifacts). Most of these 24 are already clinically recognised: 'flu-like symptoms, fever, headache and chills; increased bone pain, arthralgia, myalgia, back pain; cardiac events, thromboembolic events; hypocalcaemia and osteonecrosis of the jaw; as well as possibly stiffness and nausea. Oral clodronate appeared to increase the risk of vomiting and diarrhoea (which may also be increased by other bisphosphonates), and there may be some hepatotoxicity. Four additional potential adverse effects emerged for bisphosphonate drugs in this analysis which have not classically be recognised: fatigue, neurosensory problems, hypertonia/muscle spasms and possibly dysgeusia. Several symptoms previously reported as potential side effects in the literature were not significantly increased in this analysis: constipation, insomnia, respiratory problems, oedema or thirst/dry mouth. Individual patient-level data and subgroup analysis revealed little variation in side effects between women of different ages or menopausal status, those with metastatic versus non-metastatic cancer, or between women receiving different concurrent breast cancer therapies.

CONCLUSIONS

This meta-analysis has produced estimates for the absolute frequencies of a range of side effects significantly associated with bisphosphonate drugs when used by breast cancer patients. These results show good agreement with previous literature on the subject but are the first systematic quantification of side effects and their severities. However, the analysis is limited by the availability and quality of data on adverse events, and the potential for bias introduced by a lack of standards for reporting of such events. We therefore present a table of adverse effects for bisphosphonates, identified and quantified to the best of our ability from a large number of trials, which we hope can be used to improve the communication of the potential harms of these drugs to patients and their healthcare providers.

Bisphosphonates, Old Friends of Bones and New Trends in Clinics

Bisphosphonates, used for a long time in osteoporosis management, are currently the target of intensive research, from pre-formulation studies to more advanced stages of clinical practice. This review presents an overview of the contributions of this family of compounds to human health, starting with the chemistry and clinical uses of bisphosphonates. Following this, their pharmacology is described, highlighting administration-borne handicaps and undesirable effects. The last three sections of the review describe the research efforts that seek to curb delivery-related issues and expand bisphosphonate use. Innovative routes and strategies of administration, such as nano-encapsulation for oral intake or injectable cements for local or in-bone delivery are presented, as well as the latest results of case studies or preclinical studies proposing new therapeutic indications for the clinically approved bisphosphonates. Finally, a selection of anti-infectious bisphosphonate new drug candidates is shown, with focus on the molecules reported in the last two decades.

Zoledronate Causes a Systemic Shift of Macrophage Polarization towards M1 In Vivo

BACKGROUND

Immunomodulatory properties of bisphosphonates (BP) are suggested to contribute to the development of medication-associated osteonecrosis of the jaw (MRONJ). Furthermore, bisphosphonate-derived immune modulation might contribute to the anti-metastatic effect observed in breast cancer patients. Macrophages are potential candidates for the mediation of immunomodulatory effects of bisphosphonates. The study aimed to investigate the influence of bisphosphonates alone and in combination with surgical trauma on systemic macrophage polarization (M1 vs. M2) using an in vivo rat model.

METHODS

A total of 120 animals were divided into four groups. Groups 2 and 4 were treated with 8 × 40 μg/kg body weight of the BP Zoledronate i.p. (week 0-7). Groups 3 and 4 were exposed to surgical trauma (week 8, tooth extraction + tibia fracture), whereas in Group 1 neither medication nor surgical trauma was applied. After 8, 10, 12 and 16 weeks, skin, lung and spleen were immunohistochemically examined for macrophage polarization via expression analysis of CD68, CD163 and iNOS using a tissue microarray (TMA).

RESULTS

A significant shift of macrophage polarization towards M1 was observed in skin, spleen and lung tissue of animals, with and without surgical trauma, treated with BP when compared to those without BP application. Surgical trauma did not cause a significant increase towards M1 polarization.

CONCLUSIONS

BP application leads to a systemic pro-inflammatory situation in vivo, independent of surgical trauma, as evidenced by the shift in macrophage polarization towards M1 in various somatic tissues. This provides a possible explanation for the clinically observed anti-tumor effect of bisphosphonates and might also contribute to pathogenesis of MRONJ.

Real-life prognosis of 5041 bone-only metastatic breast cancer patients in the multicenter national observational ESME program

BACKGROUND

Bone-only (BO) metastatic breast cancer (MBC) is considered a more favorable entity than other MBC presentations. However, only few retrospective series and data from selected randomized controlled trials have been reported so far.

METHODS

Using the French national multicenter ESME (Epidemiological Strategy and Medico Economics) Data Platform, the primary objective of our study was to compare the overall survival (OS) of patients with BO versus non-BO MBC at diagnosis, with adjustment on main prognostic factors using a propensity score. Secondary objectives were to compare first-line progression-free survival (PFS1), describe treatment patterns, and estimate factors associated with OS.

RESULTS

Out of 20,095 eligible women, 5041 (22.4%) patients had BO disease [hormone-receptor positive (HR+)/human epidermal growth-factor-receptor-2 negative (HER2-), n = 4 102/13,229 (31%); HER2+, n = 644/3909 (16.5%); HR-/HER2-, n = 295/2 957 (10%)]. BO MBC patients had a better adjusted OS compared with non-BO MBC [52.1 months (95% confidence interval (CI) 50.3-54.1) versus 34.7 months (95% CI 34.0-35.6) respectively]. The 5-year OS rate of BO MBC patients was 43.4% (95% CI 41.7-45.2). They also had a better PFS1 [13.1 months (95% CI 12.6-13.8) versus 8.5 months (95% CI 8.3-8.7), respectively]. This observation could be repeated in all subtypes. BO disease was an independent prognostic factor of OS [hazard ratio 0.68 (95% CI 0.65-0.72), p < 0.0001]. Results were concordant in all analyses.

CONCLUSION

BO MBC patients have better outcomes compared with non-BO MBC, consistently, through all MBC subtypes.

Non-opioid Analgesics and Emerging Therapies

Pain is a common and debilitating symptom of cancer. Cancer-related pain can occur at any point along the continuum from diagnosis to treatment to survivorship¹. A systematic review published in 2016 estimated the prevalence of cancer pain to be 55% in those undergoing antineoplastic treatment, 66.4% in advanced cancer, and 39.3% in the post-treatment population. Thirty-eight percent of cancer patients in this pooled analysis experienced moderate to severe pain².

Targeting metastatic cancer

Despite recent therapeutic advances in cancer treatment, metastasis remains the principal cause of cancer death. Recent work has uncovered the unique biology of metastasis-initiating cells that results in tumor growth in distant organs, evasion of immune surveillance and co-option of metastatic microenvironments. Here we review recent progress that is enabling therapeutic advances in treating both micro- and macrometastases. Such insights were gained from cancer sequencing, mechanistic studies and clinical trials, including of immunotherapy. These studies reveal both the origins and nature of metastases and identify new opportunities for developing more effective strategies to target metastatic relapse and improve patient outcomes.

Oestradiol Contributes to Differential Antitumour Effects of Adjuvant Zoledronic Acid Observed Between Pre- and Post-Menopausal Women

Clinical trials have demonstrated that adding zoledronic acid (Zol) to (neo)adjuvant standard of care has differential antitumour effects in pre- and post-menopausal women: Both benefit from reduced recurrence in bone; however, while postmenopausal women also incur survival benefit, none is seen in premenopausal women treated with adjuvant bisphosphonates. In the current study, we have used mouse models to investigate the role of oestradiol in modulating potential antitumour effects of Zol. Pre-, peri-, and post-menopausal concentrations of oestradiol were modelled in BALB/c wild-type, BALB/c nude, and C57BL/6 mice by ovariectomy followed by supplementation with oestradiol. Mice also received 40 mg/kg/day goserelin to prevent ovariectomy-induced increases in follicle-stimulating hormone (FSH). Metastasis was modelled following injection of MDA-MB-231, 4T1, or E0771 cells after ovariectomy and saline or 100 μg/kg Zol administered weekly. Supplementing ovariectomised mice with 12.5 mg/ml, 1.38 mg/ml, and 0 ng/ml oestradiol, in the presence of goserelin, resulted in serum concentrations of 153.16 ± 18.10 pg/ml, 48.64 ± 18.44 pg/ml, and 1.00 ± 0.27 pg/ml oestradiol, which are equivalent to concentrations found in pre-, peri-, and post-menopausal humans. Osteoclast activity was increased 1.5-1.8-fold with peri- and post-menopausal compared with premenopausal oestradiol, resulting in a 1.34-1.69-fold reduction in trabecular bone. Zol increased trabecular bone in all groups but did not restore bone to volumes observed under premenopausal conditions. In tumour-bearing mice, Zol reduced bone metastases in BALB/c (wild-type and nude), with greatest effects seen under pre- and post-menopausal concentrations of oestradiol. Zol did not affect soft tissue metastases in immunocompetent BALB/c mice but increased metastases 3.95-fold in C57BL/6 mice under premenopausal concentrations of oestradiol. In contrast, Zol significantly reduced soft tissue metastases 2.07 and 4.69-fold in immunocompetent BALB/c and C57BL/6 mice under postmenopausal oestradiol, mirroring the results of the clinical trials of (neo)adjuvant bisphosphonates. No effects on soft tissue metastases were observed in immunocompromised mice, and differences in antitumour response did not correlate with musculoaponeurotic fibrosarcoma (MAF), macrophage capping protein (CAPG), or PDZ domain containing protein GIPC1 (GIPC1) expression. In conclusion, oestradiol contributes to altered antitumour effects of Zol observed between pre- and post-menopausal women. However, other immunological/microenvironmental factors are also likely to contribute to this phenomenon.

Drug-repositioning screening identified fludarabine and risedronic acid as potential therapeutic compounds for malignant pleural mesothelioma

Objectives Malignant pleural mesothelioma (MPM) is an occupational disease mainly due to asbestos exposure. Effective therapies for MPM are lacking, making this tumour type a fatal disease. Materials and Methods In order to meet this need and in view of a future "drug repositioning" approach, here we screened five MPM (Mero-14, Mero-25, IST-Mes2, NCI-H28 and MSTO-211H) and one SV40-immortalized mesothelial cell line (MeT-5A) as a non-malignant model, with a library of 1170 FDA-approved drugs. Results Among several potential compounds, we found that fludarabine (F-araA) and, to a lesser extent, risedronic acid (RIS) were cytotoxic in MPM cells, in comparison to the non-malignant Met-5A cells. In particular, F-araA reduced the proliferation and the colony formation ability of the MPM malignant cells, in comparison to the non-malignant control cells, as demonstrated by proliferation and colony formation assays, in addition to measurement of the phospho-ERK/total-ERK ratio. We have shown that the response to F-araA was not dependent upon the expression of DCK and NT5E enzymes, nor upon their functional polymorphisms (rs11544786 and rs2295890, respectively). Conclusion This drug repositioning screening approach has identified that F-araA could be therapeutically active against MPM cells, in addition to other tumour types, by inhibiting STAT1 expression and nucleic acids synthesis. Further experiments are required to fully investigate this.

Bisphosphonates or RANK-ligand-inhibitors for men with prostate cancer and bone metastases: a network meta-analysis

BACKGROUND

Different bone-modifying agents like bisphosphonates and receptor activator of nuclear factor-kappa B ligand (RANKL)-inhibitors are used as supportive treatment in men with prostate cancer and bone metastases to prevent skeletal-related events (SREs). SREs such as pathologic fractures, spinal cord compression, surgery and radiotherapy to the bone, and hypercalcemia lead to morbidity, a poor performance status, and impaired quality of life. Efficacy and acceptability of the bone-targeted therapy is therefore of high relevance. Until now recommendations in guidelines on which bone-modifying agents should be used are rare and inconsistent.

OBJECTIVES

To assess the effects of bisphosphonates and RANKL-inhibitors as supportive treatment for prostate cancer patients with bone metastases and to generate a clinically meaningful treatment ranking according to their safety and efficacy using network meta-analysis.

SEARCH METHODS

We identified studies by electronically searching the bibliographic databases Cochrane Controlled Register of Trials (CENTRAL), MEDLINE, and Embase until 23 March 2020. We searched the Cochrane Library and various trial registries and screened abstracts of conference proceedings and reference lists of identified trials.

SELECTION CRITERIA

We included randomized controlled trials comparing different bisphosphonates and RANKL-inihibitors with each other or against no further treatment or placebo for men with prostate cancer and bone metastases. We included men with castration-restrictive and castration-sensitive prostate cancer and conducted subgroup analyses according to this criteria.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the quality of trials. We defined proportion of participants with pain response and the adverse events renal impairment and osteonecrosis of the jaw (ONJ) as the primary outcomes. Secondary outcomes were SREs in total and each separately (see above), mortality, quality of life, and further adverse events such as grade 3 to 4 adverse events, hypocalcemia, fatigue, diarrhea, and nausea. We conducted network meta-analysis and generated treatment rankings for all outcomes, except quality of life due to insufficient reporting on this outcome. We compiled ranking plots to compare single outcomes of efficacy against outcomes of acceptability of the bone-modifying agents. We assessed the certainty of the evidence for the main outcomes using the GRADE approach.

MAIN RESULTS

Twenty-five trials fulfilled our inclusion criteria. Twenty-one trials could be considered in the quantitative analysis, of which six bisphosphonates (zoledronic acid, risedronate, pamidronate, alendronate, etidronate, or clodronate) were compared with each other, the RANKL-inhibitor denosumab, or no treatment/placebo. By conducting network meta-analysis we were able to compare all of these reported agents directly and/or indirectly within the network for each outcome. In the abstract only the comparisons of zoledronic acid and denosumab against the main comparator (no treatment/placebo) are described for outcomes that were predefined as most relevant and that also appear in the 'Summary of findings' table. Other results, as well as results of subgroup analyses regarding castration status of participants, are displayed in the Results section of the full text. Treatment with zoledronic acid probably neither reduces nor increases the proportion of participants with pain response when compared to no treatment/placebo (risk ratio (RR) 1.46, 95% confidence interval (CI) 0.93 to 2.32; per 1000 participants 121 more (19 less to 349 more); moderate-certainty evidence; network based on 4 trials including 1013 participants). For this outcome none of the trials reported results for the comparison with denosumab. The adverse event renal impairment probably occurs more often when treated with zoledronic acid compared to treatment/placebo (RR 1.63, 95% CI 1.08 to 2.45; per 1000 participants 78 more (10 more to 180 more); moderate-certainty evidence; network based on 6 trials including 1769 participants). Results for denosumab could not be included for this outcome, since zero events cannot be considered in the network meta-analysis, therefore it does not appear in the ranking. Treatment with denosumab results in increased occurrence of the adverse event ONJ (RR 3.45, 95% CI 1.06 to 11.24; per 1000 participants 30 more (1 more to 125 more); high-certainty evidence; 4 trials, 3006 participants) compared to no treatment/placebo. When comparing zoledronic acid to no treatment/placebo, the confidence intervals include the possibility of benefit or harm, therefore treatment with zoledronic acid probably neither reduces nor increases ONJ (RR 1.88, 95% CI 0.73 to 4.87; per 1000 participants 11 more (3 less to 47 more); moderate-certainty evidence; network based on 4 trials including 3006 participants). Compared to no treatment/placebo, treatment with zoledronic acid (RR 0.84, 95% CI 0.72 to 0.97) and denosumab (RR 0.72, 95% CI 0.54 to 0.96) may result in a reduction of the total number of SREs (per 1000 participants 75 fewer (131 fewer to 14 fewer) and 131 fewer (215 fewer to 19 fewer); both low-certainty evidence; 12 trials, 5240 participants). Treatment with zoledronic acid and denosumab likely neither reduces nor increases mortality when compared to no treatment/placebo (zoledronic acid RR 0.90, 95% CI 0.80 to 1.01; per 1000 participants 48 fewer (97 fewer to 5 more); denosumab RR 0.93, 95% CI 0.77 to 1.11; per 1000 participants 34 fewer (111 fewer to 54 more); both moderate-certainty evidence; 13 trials, 5494 participants). Due to insufficient reporting, no network meta-analysis was possible for the outcome quality of life. One study with 1904 participants comparing zoledronic acid and denosumab showed that more zoledronic acid-treated participants than denosumab-treated participants experienced a greater than or equal to five-point decrease in Functional Assessment of Cancer Therapy-General total scores over a range of 18 months (average relative difference = 6.8%, range -9.4% to 14.6%) or worsening of cancer-related quality of life.

AUTHORS' CONCLUSIONS

When considering bone-modifying agents as supportive treatment, one has to balance between efficacy and acceptability. Results suggest that Zoledronic acid likely increases both the proportion of participants with pain response, and the proportion of participants experiencing adverse events However, more trials with head-to-head comparisons including all potential agents are needed to draw the whole picture and proof the results of this analysis.

Oestrogen and zoledronic acid driven changes to the bone and immune environments: Potential mechanisms underlying the differential anti-tumour effects of zoledronic acid in pre- and post-menopausal conditions

Late stage breast cancer commonly metastasises to bone and patient survival averages 2-3 years following diagnosis of bone involvement. One of the most successful treatments for bone metastases is the bisphosphonate, zoledronic acid (ZOL). ZOL has been used in the advanced setting for many years where it has been shown to reduce skeletal complications associated with bone metastasis. More recently, several large adjuvant clinical trials have demonstrated that administration of ZOL can prevent recurrence and improve survival when given in early breast cancer. However, these promising effects were only observed in post-menopausal women with confirmed low concentrations of circulating ovarian hormones. In this review we focus on potential interactions between the ovarian hormone, oestrogen, and ZOL to establish credible hypotheses that could explain why anti-tumour effects are specific to post-menopausal women. Specifically, we discuss the molecular and immune cell driven mechanisms by which ZOL and oestrogen affect the tumour microenvironment to inhibit/induce tumour growth and how oestrogen can interact with zoledronic acid to inhibit its anti-tumour actions.

Biomechanical Properties of Metastatically Involved Osteolytic Bone

PURPOSE OF REVIEW

Skeletal metastasis involves the uncoupling of physiologic bone remodeling resulting in abnormal bone turnover and radical changes in bony architecture, density, and quality. Bone strength assessment and fracture risk prediction are critical in clinical treatment decision-making. This review focuses on bone tissue and structural mechanisms altered by osteolytic metastasis and the resulting changes to its material and mechanical behavior.

RECENT FINDINGS

Both organic and mineral phases of bone tissue are altered by osteolytic metastatic disease, with diminished bone quality evident at multiple length-scales. The mechanical performance of bone with osteolytic lesions is influenced by a combination of tissue-level and structural changes. This review considers the effects of osteolytic metastasis on bone biomechanics demonstrating its negative impact at tissue and structural levels. Future studies need to assess the cumulative impact of cancer treatments on metastatically involved bone quality, and its utility in directing multimodal treatment planning.

Osteoporosis: A Long-Term and Late-Effect of Breast Cancer Treatments

Simple Summary

Osteoporosis is a prevalent condition affecting 200 million individuals world-wide. Estimates are about one in three women will experience a fragility fracture of hip, spine or wrist. Common breast cancer treatments, such as aromatase inhibitors in postmenopausal women and chemotherapy-induced ovarian failure in premenopausal women, cause bone loss that in some women will lead to osteoporosis and fragility fractures. Fragility fractures cause morbidity and mortality and are entirely preventable. Prevention or treatment of osteoporosis includes lifestyle modifications (e.g., reducing smoking and excessive alcohol consumption, and increasing physical activity), taking calcium and vitamin D3, screening for osteoporosis with dual-energy absorptiometry, and treatment, if clinically indicated, with ether oral bisphosphonates, intravenous zoledronic acid, or subcutaneous denosumab. This chapter reviews the pathogenesis of osteoporosis, the magnitude of bone loss related to common breast cancer treatments, osteoporosis risk factor assessment and screening, and the specific drugs to treat or prevent osteoporosis.

Abstract

Osteoporosis is both a long-term effect (occurs during treatment and extends after treatment) and a late-effect (occurs after treatment ends) of breast cancer treatments. The worldwide prevalence of osteoporosis is estimated to be some 200 million patients. About one in three postmenopausal women will experience an osteoporotic (or fragility) fracture of the hip, spine, or wrist. breast cancer treatments, including gonadotropin-releasing hormone (GnRH) agonists, chemotherapy-induced ovarian failure (CIOF), and aromatase inhibitors (AIs), cause bone loss and increase the risks of osteoporosis. Also, breast cancer is a disease of aging, and most of the “one in eight” lifetime risks of breast cancer are in women in their sixth, seventh, and eighth decades. The majority of women diagnosed with breast cancers today will be long-term survivors and experience personal cures. It is the coalescence of osteoporosis with breast cancer, two common and age-related conditions that make osteoporosis relevant in women with breast cancer throughout the continuum from diagnosis, treatment, and survivorship. It is critical to remember that women (and men) will lose bone after age thirty years. However, only certain women will lose bone of sufficient magnitude to merit treatment with anti-osteoporosis drugs. The narrative review is intended for medical, surgical, radiation oncologists, and other mid-level providers, and provides an overview of bone loss and the prevention and treatment of osteoporosis.