Diagnostic delays in breast cancer among young women: An emphasis on healthcare providers.

Despite advances in breast cancer care, breast cancer in young women (BCYW) faces unique challenges, diagnostic delays, and limited awareness in many countries. Here, we discuss the challenges and consequences associated with the delayed diagnosis of BCYW. The consequences of delayed diagnosis in young women - which generally varies among developed, developing, or underdeveloped countries - are severe due to a faster breast tumor growth rate than tumors in older women, also contributing to advanced cancer stages and poorer outcomes. Though there are many underlying reasons for diagnostic delays due to age, the article delves explicitly deep into the diagnostic delay of BCYW, focusing on healthcare providers, potential contributing factors, its consequences, and the urgent need to start minimizing such incidences. The article suggests several strategies to address these issues, including increasing awareness, developing educational programs for healthcare providers to identify signs and symptoms in young women, developing clear diagnostic guidelines, and improving screening strategies.

Oncobiology and treatment of breast cancer in young women.

Female breast cancer emerged as the leading cancer type in terms of incidence globally in 2020. Although mortality due to breast cancer has improved during the past three decades in many countries, this trend has reversed in women less than 40 years since the past decade. From the biological standpoint, there is consensus among experts regarding the clinically relevant definition of breast cancer in young women (BCYW), with an age cut-off of 40 years. The idea that breast cancer is an aging disease has apparently broken in the case of BCYW due to the young onset and an overall poor outcome of BCYW patients. In general, younger patients exhibit a worse prognosis than older pre- and postmenopausal patients due to the aggressive nature of cancer subtypes, a high percentage of cases with advanced stages at diagnosis, and a high risk of relapse and death in younger patients. Because of clinically and biologically unique features of BCYW, it is suspected to represent a distinct biologic entity. It is unclear why BCYW is more aggressive and has an inferior prognosis with factors that contribute to increased incidence. However, unique developmental features, adiposity and immune components of the mammary gland, hormonal interplay and crosstalk with growth factors, and a host of intrinsic and extrinsic risk factors and cellular regulatory interactions are considered to be the major contributing factors. In the present article, we discuss the status of BCYW oncobiology, therapeutic interventions and considerations, current limitations in fully understanding the basis and underlying cause(s) of BCYW, understudied areas of BCYW research, and postulated advances in the coming years for the field.

Experience with denosumab (XGEVA®) for prevention of skeletal-related events in the 10 years after approval.

Skeletal-related events (SREs) are complications of bone metastases and carry a significant patient and economic burden. Denosumab is a receptor activator of nuclear factor-κB ligand (RANKL) inhibitor approved for SRE prevention in patients with multiple myeloma and patients with bone metastases from solid tumors. In phase 3 trials, denosumab showed superiority to the bisphosphonate zoledronate in reducing the risk of first on-study SRE by 17% (median time to first on-study SRE delayed by 8.2 months) and the risk of first and subsequent on-study SREs by 18% across multiple solid tumor types, including some patients with multiple myeloma. Denosumab also improved pain outcomes and reduced the need for strong opioids. Additionally, a phase 3 trial showed denosumab was noninferior to zoledronate in delaying time to first SRE in patients with newly diagnosed multiple myeloma. Denosumab has a convenient 120 mg every 4 weeks recommended dosing schedule with subcutaneous administration. Rare but serious toxicities associated with denosumab include osteonecrosis of the jaw, hypocalcemia, and atypical femoral fracture events, with multiple vertebral fractures reported following treatment discontinuation. After a decade of real-world clinical experience with denosumab, we are still learning about the optimal use and dosing for denosumab. Despite the emergence of novel and effective antitumor therapies, there remains a strong rationale for the clinical utility of antiresorptive therapy for SRE prevention. Ongoing studies aim to optimize clinical management of patients using denosumab for SRE prevention while maintaining safety and efficacy.

Fibrotic activity quantified in serum by measurements of type III collagen pro-peptides can be used for prognosis across different solid tumor types.

Due to activation of fibroblast into cancer-associated fibroblasts, there is often an increased deposition of extracellular matrix and fibrillar collagens, e.g. type III collagen, in the tumor microenvironment (TME) that leads to tumor fibrosis (desmoplasia). Tumor fibrosis is closely associated with treatment response and poor prognosis for patients with solid tumors. To assure that the best possible treatment option is provided for patients, there is medical need for identifying patients with high (or low) fibrotic activity in the TME. Measuring unique collagen fragments such as the pro-peptides released into the bloodstream during fibrillar collagen deposition in the TME can provide a non-invasive measure of the fibrotic activity. Based on data from 8 previously published cohorts, this review provides insight into the prognostic value of quantifying tumor fibrosis by measuring the pro-peptide of type III collagen in serum of a total of 1692 patients with different solid tumor types and discusses the importance of tumor fibrosis for understanding prognosis and for potentially guiding future drug development efforts that aim at overcoming the poor outcome associated with a fibrotic TME.

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.

Higher serum PD-L1 level predicts increased overall survival with lapatinib versus trastuzumab in the CCTG MA.31 phase 3 trial.

BACKGROUND: The purpose of this retrospective biomarker study of the Canadian Cancer Trials Group (CCTG) MA.31 randomized phase 3 trial (lapatinib vs trastuzumab) of HER2-positive metastatic breast cancer (MBC) was to evaluate the prognostic and predictive biomarker utility of pretreatment serum programmed death ligand 1 (PD-L1) levels. METHODS: CCTG MA.31 accrued 652 HER2-positive patients; 387 had serum available (185 in the trastuzumab arm and 202 in the lapatinib arm). The Ella immunoassay platform (ProteinSimple, San Jose, California) was used to quantitate serum PD-L1 levels. Stepwise forward Cox multivariable analyses were performed for progression-free survival and overall survival (OS). RESULTS: In the whole trial population, continuous pretreatment serum PD-L1 levels were not associated with OS. However, within the trastuzumab arm, a higher continuous pretreatment serum PD-L1 level was significant for shorter OS (hazard ratio [HR], 3.85; P = .04), but within the lapatinib arm, pretreatment serum PD-L1 was not associated with OS (P = .37). In the whole trial, in a multivariable analysis for OS, serum PD-L1 (median cut point) remained a significant independent covariate (HR, 2.38; P = .001). There was a significant interaction between treatment arm and continuous serum PD-L1 (bootstrap method; P = .0025): at or above 214.2 pg/mL (the 89th percentile), serum PD-L1 was associated with significantly shorter OS with trastuzumab treatment versus lapatinib treatment. CONCLUSIONS: In the CCTG MA.31 trial, serum PD-L1 was a significant predictive factor: a higher pretreatment serum PD-L1 level was associated with shorter OS with trastuzumab treatment but with longer OS with lapatinib treatment. Immune evasion may decrease the effectiveness of trastuzumab therapy. Further evaluation of elevated serum PD-L1 in advanced breast cancer is warranted to identify patients with HER2-positive MBC who may benefit from novel immune-targeted therapies in addition to trastuzumab.

Impact of Extraskeletal Metastases on Skeletal-Related Events in Metastatic Castration-Resistant Prostate Cancer with Bone Metastases.

The therapeutic landscape of metastatic castration-resistant prostate cancer (mCRPC) has substantially evolved over the last decade. Nonetheless, a better understanding of bone-targeted agents (BTAs) action in mCRPC remains an unmet need. Theuse of BTAs aims to reduce the incidence of skeletal-related events (SREs) in patients with mCRPC. Less frequent BTA schedules are currently being studied to minimize adverse events. In this study, the impact of metastatic compartment (bone and extraskeletal metastases (BESM) vs. bone-only metastases (BOM)) on bone biomarker kinetics, time to first on-study SRE, and symptomatic skeletal events (SSEs) is evaluated. This is a retrospective analysis of the prospective, randomized, multicenter clinical trial of denosumab vs. zoledronic acid in patients with mCRPC and bone metastases. A total of 1901 patients were included, 1559 (82.0%) with BOM and 342 with BESM (18.0%). Bone metastases burden was balanced between groups. Baseline levels and normalization rates of corrected urinary N-terminal telopeptide and bone alkaline phosphatase did not differ between groups. However, BESM patients had a higher risk of SREs (adjusted HR 1.21; 95% CI 1.01-1.46; p = 0.043) and SSEs (adjusted HR 1.30; 95% CI 1.06-1.61; p = 0.014). This difference was more pronounced in the first 12 months of BTA treatment.In mCRPC, strategies of BTA schedule de-escalation may take into account presence of extraskeletal metastases.

Collagen fragments quantified in serum as measures of desmoplasia associate with survival outcome in patients with advanced pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) patients have poor prognosis and poor response to treatment. This is largely due to PDAC being associated with a dense and active stroma and tumor fibrosis (desmoplasia). Desmoplasia is characterized by excessive degradation and formation of the extracellular matrix (ECM) generating collagen fragments that are released into circulation. We evaluated the association of specific collagen fragments measured in pre-treatment serum with outcome in patients with PDAC. Matrix metalloprotease (MMP)-degraded type I collagen (C1M), type III collagen (C3M), type IV collagen (C4M) and a pro-peptide of type III collagen (PRO-C3) were measured by ELISA in pre-treatment serum from a randomized phase 3 clinical trial of patients with stage III/IV PDAC treated with 5-fluorouracil based therapy (n = 176). The collagen fragments were evaluated for their correlation (r, Spearman) with serum CA19-9 and for their association with overall survival (OS) based on Cox-regression analyses. In this phase 3 PDAC trial, pre-treatment serum collagen fragment levels were above the reference range for 67%-98% of patients, with median values in PDAC approximately two-fold higher than reference levels. Collagen fragment levels did not correlate with CA19-9 (r = 0.049-0.141, p = ns). On a continuous basis, higher levels of all collagen fragments were associated with significantly shorter OS. When evaluating degradation (C3M) and formation (PRO-C3) of type III collagen further, higher PRO-C3 was associated with poor OS (>25th percentile cut-point, HR = 2.01, 95%CI = 1.33-3.05) and higher C3M/PRO-C3 ratio was associated with improved OS (>25th percentile cut-point, HR = 0.53, 95%CI = 0.34-0.80). When adjusting for CA19-9 and clinical covariates, PRO-C3 remained significant (HR = 1.65, 95%CI = 1.09-2.48). In conclusion, collagen remodeling quantified in pre-treatment serum as a surrogate measure of desmoplasia was significantly associated with OS in a phase 3 clinical PDAC trial, supporting the link between desmoplasia, tumorigenesis, and response to treatment. If validated, these biomarkers may have prognostic and/or predictive potential in future PDAC trials.

High turnover of extracellular matrix reflected by specific protein fragments measured in serum is associated with poor outcomes in two metastatic breast cancer cohorts.

Increased extracellular matrix (ECM) formation and matrix metalloprotease (MMP)-mediated ECM degradation are parts of tumorgenesis and generates collagen fragments that are released into circulation. We evaluated the association of specific collagen fragments measured in serum with outcomes in two independent metastatic breast cancer (MBC) cohorts. ELISAs were used to measure C1M (MMP-generated type I collagen fragment), C3M (MMP-generated type III collagen fragment), C4M (MMP-generated type IV collagen fragment), and PRO-C3 (pro-peptide of type III collagen) in pretreatment serum from a phase 3 randomized clinical trial of second-line hormone therapy (HR+, n = 148), and a first-line trastuzumab-treated cohort (HER2+, n = 55). All sites of metastases were included. The collagen fragments were evaluated by Cox-regression analysis for their association with time-to-progression (TTP) and overall survival (OS). In the HR+ cohort, higher C1M and C3M levels (75th percentile cut-off) were associated with shorter TTP; all fragments were associated with shorter OS. In the HER2+ cohort, higher levels of all fragments were associated with shorter TTP; higher PRO-C3 was associated with shorter OS. In multivariate analysis of the HR+ trial for OS, higher levels of all fragments were significant for reduced OS when added separately (C1M HR = 2.1, p < 0.001; C3M HR = 1.8, p = 0.028; C4M HR = 1.8, p = 0.018; PRO-C3 HR = 1.8, p = 0.017); none other clinical covariates were significant. In conclusion, collagen fragments quantified in pretreatment serum was associated with shorter TTP and OS in two independent MBC cohorts receiving systemic therapy. If validated, quantification of ECM remodeling in serum has potential as prognostic and/or predictive biomarkers in MBC.

The C-Terminal Intact Forms of Periostin (iPTN) Are Surrogate Markers for Osteolytic Lesions in Experimental Breast Cancer Bone Metastasis.

Periostin is an extracellular matrix protein that actively contributes to tumor progression and metastasis. Here, we hypothesized that it could be a marker of bone metastasis formation. To address this question, we used two polyclonal antibodies directed against the whole molecule or its C-terminal domain to explore the expression of intact and truncated forms of periostin in the serum and tissues (lung, heart, bone) of wild-type and periostin-deficient mice. In normal bones, periostin was expressed in the periosteum and specific periostin proteolytic fragments were found in bones, but not in soft tissues. In animals bearing osteolytic lesions caused by 4T1 cells, C-terminal intact periostin (iPTN) expression disappeared at the invasive front of skeletal tumors where bone-resorbing osteoclasts were present. In vitro, we found that periostin was a substrate for osteoclast-derived cathepsin K, generating proteolytic fragments that were not recognized by anti-periostin antibodies directed against iPTN. In vivo, using an in-house sandwich immunoassay aimed at detecting iPTN only, we observed a noticeable reduction of serum periostin levels (- 26%; P < 0.002) in animals bearing osteolytic lesions caused by 4T1 cells. On the contrary, this decrease was not observed in women with breast cancer and bone metastases when periostin was measured with a human assay detecting total periostin. Collectively, these data showed that mouse periostin was degraded at the bone metastatic sites, potentially by cathepsin K, and that the specific measurement of iPTN in serum should assist in detecting bone metastasis formation in breast cancer.

Excessive matrix metalloprotease-mediated degradation of interstitial tissue (type I collagen) independently predicts short-term survival in an observational study of postmenopausal women diagnosed with cancer.

Extensive tissue remodeling mediated by matrix metalloproteases (MMPs) is an important part of cancer. The aim of this study was to investigate whether serum biomarkers reflecting MMP-mediated degradation of type I collagen (C1M), type IV collagen (C4M) and citrullinated vimentin (VICM) were predictive of cancer-specific mortality. Between 1999 and 2001, 5855 Danish postmenopausal women participated in The Prospective Epidemiologic Risk Factor (PERF I) study. Demographics and serum samples were collected at enrolment. Cancer diagnosis, and cause and time of death were obtained from Danish registries. C1M, C4M and VICM were measured by ELISA. Hazard ratios (HR) and Kaplan-Meier curves were applied to assess mortality at 3 and 12 years of follow-up for women diagnosed with cancer within 3 years from blood sampling. Within 3 years from blood sampling, 250 women had been diagnosed with cancer. C1M and VICM were associated with survival over time at 3 years of follow-up. Only C1M was predictive of mortality at 3 years follow-up: the adjusted HR was 2.65 [95% CI: 1.08-6.51]. In conclusion, C1M and VICM are associated with survival in postmenopausal women with cancer, and C1M is an independent risk factor for cancer-specific mortality. Thus, quantification of tissue remodeling is important in cancer.

Osteoporosis therapy and outcomes for postmenopausal patients with hormone receptor-positive breast cancer: NCIC CTG MA.27.

BACKGROUND: Breast cancer patients in the MA.27 trial had similar outcomes with steroidal aromatase inhibitor (AI) exemestane and nonsteroidal anastrozole. AIs increase the risk of osteoporosis. This study examined the effects of self-reported osteoporosis and osteoporosis therapy (OPT) on outcomes. METHODS: The MA.27 phase 3 adjuvant trial enrolled 7576 postmenopausal women. The primary outcome was event-free survival (EFS), and the secondary outcome was distant disease-free survival (DDFS). Patients were permitted bisphosphonates to prevent or treat osteopenia/osteoporosis. In a multivariate, stratified Cox regression, factors were significant with a 2-sided Wald test P value ≤ .05. RESULTS: Osteoporosis was reported at the baseline by 654 of the 7576 women (8.6%) and in total by 1294 patients. Oral OPT was received at the baseline by 815 of the 7576 women (10.8%) and in total by 2711 patients (36%). With a median follow-up of 4.1 years, 693 EFS events (9.15%) and 321 DDFS events (4.2%) occurred. Osteoporosis was not associated with EFS or DDFS. Few EFS events occurred before the initiation of OPT, with no substantive evidence of a time-differing effect on outcomes (nonproportional hazards). OPT (yes vs no) was significantly associated with improved EFS (hazard ratio [HR] for yes vs no, 0.67; 95% confidence interval [CI], 0.57-0.80; P < .001) and DDFS (HR, 0.57; 95% CI, 0.44-0.73; P <. 001). Time-differing (time-dependent) OPT was not (EFS; P = .45). OPT did not alter the incidence of visceral-only metastasis (P = .31). CONCLUSIONS: Oral OPT, administered to postmenopausal breast cancer patients receiving adjuvant AI therapy, was associated with improved EFS and DDFS; the time of OPT initiation (a time-dependent effect) did not affect the outcome. OPT did not alter the risk of visceral metastasis. Cancer 2017;123:2444-51. © 2017 American Cancer Society.

Impact of serum HER2, TIMP-1, and CAIX on outcome for HER2+ metastatic breast cancer patients: CCTG MA.31 (lapatinib vs. trastuzumab).

BACKGROUND: The lapatinib-taxane combination led to shorter PFS than trastuzumab-taxane in HER2+ metastatic breast cancer. We investigated the prognostic and predictive effects of pretreatment serum HER2, CAIX, and TIMP-1. METHODS: MA.31 accrued 652 patients; 537 (82%) were centrally confirmed HER2+. Biomarkers were categorized for univariate and multivariable predictive investigations with a median cut-point, ULN cut-points (15 ng/ml for HER2; 506 pg/ml for CAIX; 454 pg/ml for TIMP-1), and custom cut-points (30 and 100 ng/ml for HER2). Stratified step-wise forward Cox multivariable analysis examined continuous and categorical effects of biomarkers on PFS in the ITT and central HER2+ populations; central HER2+ biomarker results are shown. RESULTS: Serum was banked for 472 (72%) of 652 patients. Higher serum HER2 (>median; >15; >30; or >100 ng/ml; p = 0.05-0.002); higher CAIX (>median; >506 pg/ml; p = 0.02; p = 0.001); and higher TIMP-1 (> median; > 454 pg/ml; p = 0.001; p = 0.02) had shorter univariate PFS. In multivariable analysis, higher continuous TIMP-1 was associated with significantly shorter PFS: HR = 1.001 (95% CI = 1.00-01.002; p = 0.004). Continuous serum HER2 and CAIX were not significantly associated with PFS. HER2 of 15 ng/ml or higher had shorter PFS (p = 0.02); higher categorical CAIX had shorter PFS (p = 0.01-0.08). Interaction terms of HER2, CAIX, and TIMP-1 with treatment were not significant; the predictive test power was low. CONCLUSIONS: Higher levels of serum TIMP-1, CAIX, and HER2 were significant prognostic biomarkers of shorter PFS. We found no significant interaction between serum biomarkers and response to lapatinib versus trastuzumab. Evaluation of TIMP-1 and CAIX-targeted therapy in addition to HER2-targeted therapy appears warranted in patients with elevated serum levels of these biomarkers.

PTHrP(12-48) Modulates the Bone Marrow Microenvironment and Suppresses Human Osteoclast Differentiation and Lifespan.

Bone is a common site for metastasis in breast cancer patients and is associated with a series of complications that significantly compromise patient survival, partially due to the advanced stage of disease at the time of detection. Currently, no clinically-approved biomarkers can identify or predict the development of bone metastasis. We recently identified a unique peptide fragment of parathyroid hormone-related protein (PTHrP), PTHrP(12-48), as a validated serum biomarker in breast cancer patients that correlates with and predicts the presence of bone metastases. In this study, the biological activity and mode of action of PTHrP(12-48) was investigated. Sequence-based and structure-based bioinformatics techniques predicted that the PTHrP(12-48) fragment formed an alpha helical core followed by an unstructured region after residue 40 or 42. Thereafter, detailed structure alignment and molecular docking simulations predicted a lack of interaction between PTHrP(12-48) and the cognate PTH1 receptor (PTHR1). The in silico prediction was confirmed by the lack of PTHrP(12-48)-stimulated cAMP accumulation in PTHR1-expressing human SaOS2 cells. Using a specific human PTHrP(12-48) antibody that we developed, PTHrP(12-48) was immunolocalized in primary and bone metastatic human breast cancer cells, as well as within human osteoclasts (OCLs) in bone metastasis biopsies, with little or no localization in other resident bone or bone marrow cells. In vitro, PTHrP(12-48) was internalized into cultured primary human OCLs and their precursors within 60 min. Interestingly, PTHrP(12-48) treatment dose-dependently suppressed osteoclastogenesis, via the induction of apoptosis in both OCL precursors as well as in mature OCLs, as measured by the activation of cleaved caspase 3. Collectively, these data suggest that PTHrP(12-48) is a bioactive breast cancer-derived peptide that locally regulates the differentiation of hematopoietic cells and the activity of osteoclasts within the tumor-bone marrow microenvironment, perhaps to facilitate tumor control of bone. © 2017 American Society for Bone and Mineral Research.

Continued Treatment Effect of Zoledronic Acid Dosing Every 12 vs 4 Weeks in Women With Breast Cancer Metastatic to Bone: The OPTIMIZE-2 Randomized Clinical Trial.

IMPORTANCE: Zoledronic acid, a potent bisphosphonate, is commonly administered to patients with bone metastases to reduce the risk of skeletal-related events (SREs). However, there have been concerns regarding its long-term monthly administration. OBJECTIVE: To examine whether zoledronic acid every 12 weeks was noninferior to zoledronic acid every 4 weeks in patients with metastatic breast cancer that involved the bone who had previously received a standard dosing regimen of zoledronic acid and/or pamidronate disodium. DESIGN, SETTING, AND PARTICIPANTS: OPTIMIZE-2 was a prospective, randomized, double-blind, multicenter phase 3 trial of intention-to-treat (full analysis set), evaluable (per protocol), and safety populations. Patients were randomized (1:1) to receive 4.0 mg of intravenous zoledronic acid every 4 or every 12 weeks with placebo for interim infusions for 1 year. The study was conducted at 102 clinical trial centers in the United States from March 3, 2006, to July 25, 2013. Data analysis was performed from October 7, 2013, to March 24, 2014. The study randomized 416 women (≥18 years old) with bone metastases from breast cancer who previously received 9 or more doses of zoledronic acid and/or pamidronate during the first 10 to 15 months of therapy. MAIN OUTCOMES AND MEASURES: The primary end point was the proportion of patients with 1 or more SRE on study (SRE rate). The key secondary end points included time to first SRE and skeletal morbidity rate (SMR). RESULTS: A total of 416 women were randomized: 200 patients received zoledronic acid every 4 weeks (mean [SD] age, 59.2 [11.1] years; 173 were white [86.5%]), 203 patients received zoledronic acid every 12 weeks (mean [SD] age, 58.6 [11.2] years; 178 were white [87.7%]), and 13 patients received placebo (mean [SD] age, 60.8 [12.2] years; 13 were white [100%]). Baseline characteristics were similar in both zoledronic acid treatment arms. After 1 year of follow-up, SREs occurred in 44 patients (22.0%) in the zoledronic acid every 4 weeks group and 47 patients (23.2%) in the zoledronic acid every 12 weeks group (proportional difference of -1.2%; 1-sided 97.5% CI bound of the difference in SRE rate between arms, -9.8%; noninferiority P = .02). The time to first SRE between treatment groups was not statistically significantly different (hazard ratio [HR], 1.06; 95% CI, 0.70-1.60; P = .79). The mean (SD) SMR was 0.46 (1.06) vs 0.50 (1.50) events per year in the every 4 weeks vs every 12 weeks groups (P = .85). The safety profiles of the every 4 weeks and every 12 weeks groups were comparable, with 189 patients (95.5%) in the every 4 weeks group having at least 1 adverse event compared with 189 (93.5%) in the every 12 weeks group. CONCLUSIONS AND RELEVANCE: The every 12 weeks regimen of zoledronic acid was noninferior to the every 4 weeks regimen for the proportion of patients experiencing 1 or more SRE. These results may have a substantial influence on current clinical practice for treatment of patients with bone metastasis from breast cancer. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00320710.

N-Telopeptide of Type I Collagen Long-Term Dynamics in Breast Cancer Patients With Bone Metastases: Clinical Outcomes and Influence of Extraskeletal Metastases.

BACKGROUND: Markers of bone metabolism, such as N-telopeptide of type I collagen (NTX), have been demonstrated to be prognostic in previous trials of breast cancer (BC) patients with bone metastases (BMs). In the present study, we tested the survival effect of the NTX response to zoledronic acid (ZA) at 3 and 12 months in a contemporaneous cohort of BC patients with BMs and evaluated the influence of extraskeletal metastatic disease on NTX variation. PATIENTS AND METHODS: The present study was a prospective cohort study of consecutive BC patients diagnosed and treated at a single center. Patients presenting with de novo radiological evidence of BMs who started monthly intravenous ZA were included. Urinary NTX was measured at baseline and 1, 3, 6, 9, and 12 months after ZA introduction. RESULTS: Overall, 71 patients were enrolled, 32 with BMs and 39 with BMs plus extraskeletal metastases. The proportion of patients with elevated NTX at baseline and 3 and 12 months was 49.3%, 26.6%, and 34.2%, respectively. The variables associated with survival included age at diagnosis, tumor estrogen receptor status, and NTX at 3 and 12 months. Multivariate analysis showed that, in addition to age at diagnosis, only the 3-month NTX level was significantly associated with survival. Patients with BMs plus extraskeletal metastases had an erratic NTX variation pattern, unrelated to survival. CONCLUSION: In the present contemporaneous cohort of BC patients with BMs, the NTX response at 3 months was strongly associated with survival. Furthermore, an early response to ZA was strongly associated with long-term NTX control. Finally, patients with BMs plus extraskeletal metastases had an erratic NTX variation. IMPLICATIONS FOR PRACTICE: The present study showed that when accommodating recent therapy innovations and longer patient survival, the N-telopeptide (NTX) variation at 3 months is strongly associated with survival. In this setting, in addition to a few other clinicopathological features, NTX is a powerful prognostic marker. Moreover, early NTX correction associates with persistently normal NTX. This might identify a subgroup of patients with a good prognosis who are eligible for premature zoledronic acid (ZA) de-escalation. Finally, patients with bone plus extraskeletal metastases showed an erratic variation of NTX, raising concerns that a single ZA regimen might not fit all patients. Future trials should test its effect according to the presence of extraskeletal involvement.

Changes in Bone Turnover Marker Levels and Clinical Outcomes in Patients with Advanced Cancer and Bone Metastases Treated with Bone Antiresorptive Agents.

PURPOSE: Bone antiresorptive agents can significantly reduce bone turnover markers (BTM) in patients with advanced cancer. We evaluated association of changes in BTMs with overall survival (OS), disease progression (DP), and disease progression in bone (DPB) in patients with advanced cancer and bone metastases following denosumab or zoledronic acid treatment. EXPERIMENTAL DESIGN: This is an integrated analysis of patient-level data from three identically designed, blinded, phase III trials with patients randomized to subcutaneous denosumab or intravenous zoledronic acid. Levels of the BTMs urinary N-telopeptide (uNTx) and serum bone-specific alkaline phosphatase (sBSAP) measured at study entry and month 3 were analyzed. OS, DP, and DPB were compared in patients with BTMs ≥ median versus < median based on month 3 assessments. RESULTS: uNTx levels ≥ the median of 10.0 nmol/mmol at month 3 were associated with significantly reduced OS compared with levels < median (HR for death, 1.85; P < 0.0001). sBSAP levels ≥ median of 12.6 ng/mL were associated with significantly reduced OS compared with levels < median (HR, 2.44; P < 0.0001). uNTx and sBSAP levels ≥ median at month 3 were associated with significantly greater risk of DP (HR, 1.31; P < 0.0001 and HR, 1.71; P < 0.0001, respectively) and DPB (HR, 1.11; P = 0.0407 and HR, 1.27; P < 0.0001, respectively). CONCLUSIONS: BTM levels ≥ median after 3 months of bone antiresorptive treatment were associated with reduced OS and increased risk of DP and DPB. Assessment of uNTx and sBSAP levels after bone antiresorptive therapy may add to identification of patients at risk for worse clinical outcomes. Clin Cancer Res; 22(23); 5713-21. ©2016 AACR.

Hypocalcaemia in patients with metastatic bone disease treated with denosumab.

BACKGROUND: This analysis was performed to further characterise treatment-emergent hypocalcaemia in patients with bone metastases receiving denosumab. METHODS: Laboratory abnormalities and adverse events of hypocalcaemia in patients with metastatic bone disease were analysed using data from three identically designed phase 3 trials of subcutaneous denosumab 120 mg (n = 2841) versus intravenous zoledronic acid 4 mg (n = 2836). RESULTS: The overall incidence of laboratory events of hypocalcaemia grade ⩾ 2 was higher with denosumab (12.4%) than with zoledronic acid (5.3%). Hypocalcaemia events were primarily grade 2 in severity and usually occurred within the first 6 months of treatment. Patients who reported taking calcium and/or vitamin D supplements had a lower incidence of hypocalcaemia. Prostate cancer or small-cell lung cancer, reduced creatinine clearance and higher baseline bone turnover markers of urinary N-telopeptide of type I collagen (uNTx; > 50 versus ⩽ 50 nmol/mmol) and bone-specific alkaline phosphatase (BSAP; > 20.77 µg/L [median] versus ⩽ 20.77 µg/L) values were important risk factors for developing hypocalcaemia. The risk associated with increased baseline BSAP levels was greater among patients who had > 2 bone metastases at baseline versus those with ⩽ 2 bone metastases at baseline. CONCLUSION: Hypocalcaemia was more frequent with denosumab versus zoledronic acid, consistent with denosumab's greater antiresorptive effect. Low serum calcium levels and potential vitamin D deficiency should be corrected before initiating treatment with a potent osteoclast inhibitor, and corrected serum calcium levels should be monitored during treatment. Adequate calcium and vitamin D intake appears to substantially reduce the risk of hypocalcaemia.

Antiresorptive therapy in the management of cancer treatment-induced bone loss.

Cancer treatment-induced bone loss treatment has an important role to prevent bone loss-related events like fracture, significant morbidity, mortality, disfigurement and loss of self-esteem, and health-care expenditure. Numerous factors, including treatment regimens and bone metastasis, increase the risk of osteoporosis or local bone destruction in most breast and prostate cancer patients. Cytotoxic chemotherapies, radiation, and hormonal therapies can lead to premature menopause and decrease bone mineral density. Over 60 % of breast cancer patients within 1 year of beginning postoperative adjuvant chemotherapy experience ovarian failure. Also, ovarian ablation and aromatase inhibitors used to treat breast cancer and orchiectomy and androgen deprivation therapy (ADT; to treat prostate cancer) cause substantial bone loss. In this article, we will focus mainly on antiresorptive therapy in the management of cancer treatment-induced bone loss (CTIBL). An understanding of CTIBL is critical for determining how to assess the risk and identify which patients may benefit from preventive therapy.