Radium-223 in women with hormone receptor-positive bone-metastatic breast cancer receiving endocrine therapy: pooled analysis of two international, phase 2, randomized, double-blind, placebo-controlled trials

BACKGROUND

Most women with advanced breast cancer have skeletal metastases. Radium-223 is an alpha-emitting radionuclide that selectively targets areas of bone metastases.

METHODS

Two double-blind, placebo-controlled studies of radium-223 were conducted in women with hormone receptor-positive (HR+), bone-predominant metastatic breast cancer. All patients received endocrine therapy (ET), as a single agent of the investigator's choice (Study A) or exemestane + everolimus (Study B). Patients were randomized to receive radium-223 (55 kBq/kg) or placebo intravenously every 4 weeks for six doses. Accrual was halted following unblinded interim analyses per protocol amendments, and both studies were terminated. We report pooled analyses of symptomatic skeletal event-free survival (SSE-FS; primary endpoint), radiologic progression-free survival (rPFS) and overall survival (OS; secondary), and time to bone alkaline phosphatase (ALP) progression (exploratory).

RESULTS

In total, 382 patients were enrolled, and 196 SSE-FS events (70% planned total) were recorded. Hazard ratios (95% confidence intervals) and nominal p values for radium-223 + ET versus placebo + ET were: SSE-FS 0.809 (0.610-1.072), p = 0.1389; rPFS 0.956 (0.759-1.205), p = 0.7039; OS 0.889 (0.660-1.199), p = 0.4410; and time to bone ALP progression 0.593 (0.379-0.926), p = 0.0195. Radium-223- or placebo-related treatment-emergent adverse events were reported in 50.3% versus 35.1% of patients (grade 3/4: 25.7% vs. 8.5%), with fractures/bone-associated events in 23.5% versus 23.9%.

CONCLUSIONS

In patients with HR+ bone-metastatic breast cancer, numeric differences favoring radium-223 + ET over placebo + ET for the primary SSE-FS endpoint were suggestive of efficacy, in line with the primary outcome measure used in the underlying phase 2 studies. No similar evidence of efficacy was observed for secondary progression or survival endpoints. Adverse events were more frequent with radium-223 + ET versus placebo + ET, but the safety profile of the combination was consistent with the safety profiles of the component drugs. Clinical trial registration numbers Study A: NCT02258464, registered October 7, 2014. Study B: NCT02258451, registered October 7, 2014.

Use of Adjuvant Bisphosphonates and Other Bone-Modifying Agents in Breast Cancer: ASCO-OH (CCO) Guideline Update

PURPOSE

To update recommendations of the American Society of Clinical Oncology (ASCO)-Ontario Health (Cancer Care Ontario [CCO]) adjuvant bone-modifying agents in breast cancer guideline.

METHODS

An Expert Panel conducted a systematic review to identify new, potentially practice-changing data.

RESULTS

Four articles met eligibility criteria and form the evidentiary basis for revision of the previous recommendations.

RECOMMENDATIONS

Adjuvant bisphosphonate therapy should be discussed with all postmenopausal patients (natural or therapy-induced) with primary breast cancer, irrespective of hormone receptor status and human epidermal growth factor receptor 2 status, who are candidates to receive adjuvant systemic therapy. Adjuvant bisphosphonates, if used, are not substitutes for standard anticancer modalities. The benefit of adjuvant bisphosphonate therapy will vary depending on the underlying risk of recurrence and is associated with a modest improvement in overall survival. The NHS PREDICT tool provides estimates of the benefit of adjuvant bisphosphonate therapy and may aid in decision making. Factors influencing the decision to recommend adjuvant bisphosphonate use should include patients' risk of recurrence, risk of side effects, financial toxicity, drug availability, patient preferences, comorbidities, and life expectancy. When an adjuvant bisphosphonate is used to prevent breast cancer recurrence, the therapeutic options recommended by the Panel include oral clodronate, oral ibandronate, and intravenous zoledronic acid. The Panel supports starting bisphosphonate therapy early, consistent with the points outlined in the parent CCO-ASCO guideline; this is a consensus recommendation. The Panel does not recommend adjuvant denosumab to prevent breast cancer recurrence, because studies did not show a consistent reduction of breast cancer recurrence in any subset of those with early-stage breast cancer.Additional information can be found at www.asco.org/breast-cancer-guideline.

Phase III Randomized Trial of Bisphosphonates as Adjuvant Therapy in Breast Cancer: S0307

BACKGROUND

Adjuvant bisphosphonates, when given in a low-estrogen environment, can decrease breast cancer recurrence and death. Treatment guidelines include recommendations for adjuvant bisphosphonates in postmenopausal patients. SWOG/Alliance/Canadian Cancer Trials Group/ECOG-ACRIN/NRG Oncology study S0307 compared the efficacy of three bisphosphonates in early-stage breast cancer.

METHODS

Patients with stage I-III breast cancer were randomly assigned to 3 years of intravenous zoledronic acid, oral clodronate, or oral ibandronate. The primary endpoint was disease-free survival (DFS) with overall survival as a secondary outcome. All statistical tests were two-sided.

RESULTS

A total of 6097 patients enrolled. Median age was 52.7 years. Prior to being randomly assigned, 73.2% patients indicated preference for oral vs intravenous formulation. DFS did not differ across arms in a log-rank test (P = .49); 5-year DFS was 88.3% (zoledronic acid: 95% confidence interval [CI] = 86.9% to 89.6%), 87.6% (clodronate: 95% CI = 86.1% to 88.9%), and 87.4% (ibandronate: 95% CI = 85.6% to 88.9%). Additionally, 5-year overall survival did not differ between arms (log rank P = .50) and was 92.6% (zoledronic acid: 95% CI = 91.4% to 93.6%), 92.4% (clodronate: 95% CI = 91.2% to 93.5%), and 92.9% (ibandronate: 95% CI = 91.5% to 94.1%). Bone as first site of recurrence did not differ between arms (P = .93). Analyses based on age and tumor subtypes showed no treatment differences. Grade 3/4 toxicity was 8.8% (zoledronic acid), 8.3% (clodronate), and 10.5% (ibandronate). Osteonecrosis of the jaw was highest for zoledronic acid (1.26%) compared with clodronate (0.36%) and ibandronate (0.77%).

CONCLUSIONS

We found no evidence of differences in efficacy by type of bisphosphonate, either in overall analysis or subgroups. Despite an increased rate of osteonecrosis of the jaw with zoledronic acid, overall toxicity grade differed little across arms. Given that patients expressed preference for oral formulation, efforts to make oral agents available in the United States should be considered.

Association of Osteonecrosis of the Jaw With Zoledronic Acid Treatment for Bone Metastases in Patients With Cancer

Importance

Osteonecrosis of the jaw (ONJ) affects patients with cancer and metastatic bone disease (MBD) treated with bone-modifying agents (BMAs), yet the true incidence is unknown.

Objective

To define the cumulative incidence of ONJ at 3 years in patients receiving zoledronic acid for MBD from any malignant neoplasm.

Design, Setting, and Participants

This multicenter, prospective observational cohort study (SWOG Cancer Research Network S0702) included patients with MBD with either limited or no prior exposure to BMAs and a clinical care plan that included use of zoledronic acid within 30 days of registration. Medical, dental, and patient-reported outcome forms were submitted at baseline and every 6 months. Follow-up was 3 years. Osteonecrosis of the jaw was defined using established criteria. Data were collected from January 30, 2009, to December 13, 2013, and analyzed from August 24, 2018, to August 6, 2020.

Interventions/Exposures

Cancer treatments, BMAs, and dental care were administered as clinically indicated.

Main Outcomes and Measures

Cumulative incidence of confirmed ONJ, defined as an area of exposed bone in the maxillofacial region present for more than 8 weeks with no concurrent radiotherapy to the craniofacial region. Risk factors for ONJ were also examined.

Results

The SWOG S0702 trial enrolled 3491 evaluable patients (1806 women [51.7%]; median age, 63.1 [range, 2.24-93.9] years), of whom 1120 had breast cancer; 580, myeloma; 702, prostate cancer; 666, lung cancer; and 423, other neoplasm. A baseline dental examination was performed in 2263 patients (64.8%). Overall, 90 patients developed confirmed ONJ, with cumulative incidence of 0.8% (95% CI, 0.5%-1.1%) at year 1, 2.0% (95% CI, 1.5%-2.5%) at year 2, and 2.8% (95% CI, 2.3%-3.5%) at year 3; 3-year cumulative incidence was highest in patients with myeloma (4.3%; 95% CI, 2.8%-6.4%). Patients with planned zoledronic acid dosing intervals of less than 5 weeks were more likely to experience ONJ than patients with planned dosing intervals of 5 weeks or more (hazard ratio [HR], 4.65; 95% CI, 1.46-14.81; P = .009). A higher rate of ONJ was associated with fewer total number of teeth (HR, 0.51; 95% CI, 0.31-0.83; P = .006), the presence of dentures (HR, 1.83; 95% CI, 1.10-3.03; P = .02), and current smoking (HR, 2.12; 95% CI, 1.12-4.02; P = .02).

Conclusions and Relevance

As the findings show, the cumulative incidence of ONJ after 3 years was 2.8% in patients receiving zoledronic acid for MBD. Cancer type, oral health, and frequency of dosing were associated with the risk of ONJ. These data provide information to guide stratification of risk for developing ONJ in patients with MBD receiving zoledronic acid.

Dural Cells Release Factors Which Promote Cancer Cell Malignancy and Induce Immunosuppressive Markers in Bone Marrow Myeloid Cells

BACKGROUND

Thirty per cent of cancer patients develop spine metastases with a substantial number leading to spinal cord compression and neurological deficits. Many demonstrate a propensity toward metastasis to the posterior third of the vertebral body. The dura, the outer layer of the meninges, lies in intimate contact with the posterior border of the vertebral body and has been shown to influence adjacent bone. The effects of the dura on bone marrow and cancer cells have not been examined. Understanding the biology of spinal metastasis will provide insights into mechanisms of cancer growth and allow for new treatment strategies.

OBJECTIVE

To examine the extent to which dura influences bone marrow/tumor cell metastatic characteristics.

METHODS

Dura conditioned media (DCM) from primary dura was examined for the ability to stimulate tumor cell proliferation/invasion and to alter bone marrow cell populations. RNA sequencing of dural fibroblasts was performed to examine expression of cytokines and growth factors.

RESULTS

DCM induced a significant increase in invasion and proliferation of multiple tumor cell lines, and of patient-derived primary spinal metastatic cells. DCM also increased the proliferation of bone marrow myeloid cells, inducing expression of immunosuppressive markers. RNA sequencing of dural fibroblasts demonstrated abundant expression of cytokines and growth factors involved in cancer/immune pathways.

CONCLUSION

Factors released by primary dural cells induce proliferation of tumor cells and alter bone marrow to create a fertile environment for tumor growth. The dura therefore may play an important role in the increased incidence of metastases to adjacent bone.

Pre- and Postoperative Neratinib for HER2-Positive Breast Cancer Brain Metastases: Translational Breast Cancer Research Consortium 022

PURPOSE

This pilot study was performed to test our ability to administer neratinib monotherapy before clinically recommended craniotomy in patients with HER2-positive metastatic breast cancer to the central nervous system, to examine neratinib's central nervous system penetration at craniotomy, and to examine postoperative neratinib maintenance.

PATIENTS AND METHODS

Patients with HER2-positive brain metastases undergoing clinically indicated cranial resection of a parenchymal tumor received neratinib 240 mg orally once a day for 7 to 21 days preoperatively, and resumed therapy postoperatively in 28-day cycles. Exploratory evaluations of time to disease progression, survival, and correlative tissue, cerebrospinal fluid (CSF), and blood-based analyses examining neratinib concentrations were planned. The study was registered at ClinicalTrials.gov under number NCT01494662.

RESULTS

We enrolled 5 patients between May 22, 2013, and October 18, 2016. As of March 1, 2019, patients had remained on the study protocol for 1 to 75+ postoperative cycles pf therapy. Two patients had grade 3 diarrhea. Evaluation of the CSF showed low concentrations of neratinib; nonetheless, 2 patients continued to receive therapy without disease progression for at least 13 cycles, with one on-study treatment lasting for nearly 6 years. Neratinib distribution in surgical tissue was variable for 1 patient, while specimens from 2 others did not produce conclusive results as a result of limited available samples.

CONCLUSION

Neratinib resulted in expected rates of diarrhea in this small cohort, with 2 of 5 patients receiving the study treatment for durable periods. Although logistically challenging, we were able to test a limited number of CSF- and parenchymal-based neratinib concentrations. Our findings from resected tumor tissue in one patient revealed heterogeneity in drug distribution and tumor histopathology.

Medication-Related Osteonecrosis of the Jaw: MASCC/ISOO/ASCO Clinical Practice Guideline

PURPOSE

To provide guidance regarding best practices in the prevention and management of medication-related osteonecrosis of the jaw (MRONJ) in patients with cancer.

METHODS

Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO) and ASCO convened a multidisciplinary Expert Panel to evaluate the evidence and formulate recommendations. Guideline development involved a systematic review of the literature and a formal consensus process. PubMed and EMBASE were searched for studies of the prevention and management of MRONJ related to bone-modifying agents (BMAs) for oncologic indications published between January 2009 and December 2017. Results from an earlier systematic review (2003 to 2008) were also included.

RESULTS

The systematic review identified 132 publications, only 10 of which were randomized controlled trials. Recommendations underwent two rounds of consensus voting.

RECOMMENDATIONS

Currently, MRONJ is defined by (1) current or previous treatment with a BMA or angiogenic inhibitor, (2) exposed bone or bone that can be probed through an intraoral or extraoral fistula in the maxillofacial region and that has persisted for longer than 8 weeks, and (3) no history of radiation therapy to the jaws or metastatic disease to the jaws. In patients who initiate a BMA, preventive care includes comprehensive dental assessments, discussion of modifiable risk factors, and avoidance of elective dentoalveolar surgery (ie, surgery that involves the teeth or contiguous alveolar bone) during BMA treatment. It remains uncertain whether BMAs should be discontinued before dentoalveolar surgery. Staging of MRONJ should be performed by a clinician with experience in the management of MRONJ. Conservative measures comprise the initial approach to MRONJ treatment. Ongoing collaboration among the dentist, dental specialist, and oncologist is essential to optimal patient care.

Vitamin D insufficiency and risk of paclitaxel-induced peripheral neuropathy

e12027

Background: Peripheral neuropathy (PN) is a severe, dose-limiting toxicity of paclitaxel that occurs in up to 25% of patients and can lead to permanent loss of balance and manual dexterity. Due to the lack of effective strategies for PN prevention or treatment, there is a critical need to identify predictive risk factors for paclitaxel-induced PN. Vitamin insufficiencies are known risk factors for PN in other disease states. However, the effect of vitamin insufficiency on paclitaxel-induced PN has not been adequately investigated. Methods: Baseline levels of vitamin D and other nutrients (vitamin B, homocysteine, folate) were measured, and PN was assessed weekly in an observational trial of patients receiving paclitaxel 80 mg/m2 for 12 weeks for non-metastatic breast cancer (NCT0233811). Nutrient levels were measured by Michigan Medicine and insufficiency defined by institutional standards (vitamin D insufficiency < 20 ng/mL). In the primary analysis, the maximum increase from baseline in the 8-item sensory subscale (ΔCIPN8) of the EORTC CIPN20, a validated patient-reported PN assessment tool, was compared in nutrient insufficient and sufficient patients. The effect of vitamin insufficiencies on PN-induced treatment disruptions (dose decrease, delay, or discontinuation) was conducted as a secondary analysis. Results: Only vitamin D insufficiency was identified in enough patients for analysis (15/37 = 41%). Vitamin D insufficient patients reported a greater mean (+/- SD) ΔCIPN8 (36.39 ±22.8) than vitamin D sufficient patients (16.29 ±16.3) (p = 0.003). However, the increase in treatment disruption for vitamin D insufficient patients was not significant (OR = 2.98, 95% CI [0.72, 12.34], p = 0.16). Conclusions: Paclitaxel-treated patients who were vitamin D insufficient at baseline had greater increases in patient-reported PN. If validated in larger studies, vitamin D insufficiency may be a clinically translatable, modifiable risk factor that can be used to prevent paclitaxel-induced PN in patients with non-metastatic breast cancer.

Osteonecrosis of the jaw in patients with cancer receiving zoledronic acid for bone metastases: SWOG S0702, NCT00874211

11502

Background: Osteonecrosis of the jaw (ONJ) may occur in cancer patients (pts) with metastatic bone disease (MBD) treated with bone modifying agents. No large prospective studies have precisely determined the incidence of ONJ. A better understanding of the true incidence and predictors of ONJ is needed. Methods: SWOG S0702 was a prospective observational study that assessed the cumulative incidence (CI) of ONJ at 3 years in pts with MBD from any malignancy receiving zoledronic acid (Zol). Participants must have had either limited or no prior exposure to bone modifying agents and a clinical care plan that included use of Zol within 30 days of registration. Cancer treatments, bone modifying agents (including Zol), and dental care were administered as clinically indicated and were not directed by S0702. Baseline and every 6 m followup dental exams were recommended. Report forms (medical, dental and pt reported outcomes) were submitted every 6 m but if ONJ was diagnosed, follow up interval became every 3 m. Protocol defined ONJ required exposed bone in the maxillofacial region present 8 weeks or more in a pt who was receiving or had been exposed to a bisphosphonate, and had not had radiation therapy to the craniofacial region. Results: The study enrolled 3,491 evaluable pts (breast 1,120; myeloma 580; prostate 702, lung 666, other 423) between 2009-2013. About 2/3 of pts had a baseline dental exam. Overall, 87 pts had confirmed ONJ. The cumulative incidence of ONJ was 0.8% at year 1 (95% CI: 0.5%-1.1%), 2.0% at year 2 (95% CI: 1.5%-2.5%), and 2.8% at year 3 (95% CI: 2.3-3.5%). Rates of 3-year confirmed ONJ were highest in myeloma pts (4.3%; 95% CI, 2.8%-6.4%). Pts with planned Zol dosing intervals of every 3-4 weeks (n = 3,032, 87.2%) were much more likely to experience ONJ than pts with planned dosing intervals of 5 weeks or greater (n = 447, 12.8%; 3.2% vs 0.7%; HR = 4.80, 95% CI, 1.52-15.18, p = .008). Fewer total number of teeth, the presence of dentures and any oral surgery at baseline were all associated with a higher rate of ONJ. Conclusions: About 1 in 40 patients receiving Zol for MBD developed ONJ. S0702 provides information to guide stratification of risk for developing ONJ in pts with MBD receiving Zol. Cancer type, oral health and frequency of Zol dosing affect risk of ONJ. Clinical trial information: NCT00874211.

EPHA genetics for prediction of paclitaxel-induced peripheral neuropathy sensitivity

532

Background: Chemotherapy induced peripheral neuropathy (CIPN) is a common, debilitating paclitaxel side effect that has been primarily attributed to cumulative systemic paclitaxel exposure. Paclitaxel dose-adjustment to achieve target systemic exposure decreases but does not eliminate severe CIPN, suggesting some patients are inherently CIPN-sensitive. Ephrin ( EPHA) polymorphisms have been reported to increase CIPN occurrence (Baldwin 2012, Leandro-Garcia 2013, Boora 2016) but replication has been challenging, perhaps due to the inability to isolate CIPN-sensitivity by accounting for systemic exposure differences. The study purpose was to determine if EPHA genetic variants previously associated with CIPN occurrence are associated with CIPN-sensitivity. Methods: PN was assessed at baseline and weekly using the 8-item sensory subscale (CIPN8) of the patient-reported EORTC CIPN20 in patients receiving paclitaxel 80 mg/m2 weekly x 12. EPHA4, EPHA5, EPHA6, and EPHA8 were sequenced in germline DNA. Associations with higher PN-sensitivity were tested for three genetic models (total variants, coding variants, and rs7349683) by incorporating genetics into previously published CIPN8 predictive models that included measured paclitaxel exposure. Significant associations were tested for association with higher risk of PN-related treatment disruption (i.e. dose decrease, delay, or discontinuation). Results: In the 59 included patients, carrying EPHA5 rs7349683 was associated with greater CIPN sensitivity (beta coefficient: 0.40, standard error: 0.14, p = 0.005), indicating these patients had a greater increase in CIPN8 during treatment than would be predicted based on cumulative paclitaxel exposure. Rs7349683 was not associated with increased PN-induced treatment disruption, perhaps due to the low number of events (n = 19). Conclusions: Using a novel approach that isolates CIPN-sensitivity by accounting for measured paclitaxel exposure, our results provide further evidence that EPHA5 rs7349683 may be a promising marker for CIPN. If additional validation studies confirm this association, genetic testing could enable personalized treatment strategies to prevent CIPN in patients with breast cancer.

TBCRC 022: A Phase II Trial of Neratinib and Capecitabine for Patients With Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer and Brain Metastases

PURPOSE

Evidence-based treatments for metastatic, human epidermal growth factor receptor 2 (HER2)-positive breast cancer to the CNS are limited. We previously reported modest activity of neratinib monotherapy for HER2-positive breast cancer brain metastases. Here we report the results from additional study cohorts.

PATIENTS AND METHODS

Patients with measurable, progressive, HER2-positive brain metastases (92% after receiving CNS surgery and/or radiotherapy) received neratinib 240 mg orally once per day plus capecitabine 750 mg/m² twice per day for 14 days, then 7 days off. Lapatinib-naïve (cohort 3A) and lapatinib-treated (cohort 3B) patients were enrolled. If nine or more of 35 (cohort 3A) or three or more of 25 (cohort 3B) had CNS objective response rates (ORR), the drug combination would be deemed promising. The primary end point was composite CNS ORR in each cohort separately, requiring a reduction of 50% or more in the sum of target CNS lesion volumes without progression of nontarget lesions, new lesions, escalating steroids, progressive neurologic signs or symptoms, or non-CNS progression.

RESULTS

Forty-nine patients enrolled in cohorts 3A (n = 37) and 3B (n = 12; cohort closed for slow accrual). In cohort 3A, the composite CNS ORR = 49% (95% CI, 32% to 66%), and the CNS ORR in cohort 3B = 33% (95% CI, 10% to 65%). Median progression-free survival was 5.5 and 3.1 months in cohorts 3A and 3B, respectively; median survival was 13.3 and 15.1 months. Diarrhea was the most common grade 3 toxicity (29% in cohorts 3A and 3B).

Neratinib plus capecitabine is active against refractory, HER2-positive breast cancer brain metastases, adding additional evidence that the efficacy of HER2-directed therapy in the brain is enhanced by chemotherapy. For optimal tolerance, efforts to minimize diarrhea are warranted.

Use of Bone-Modifying Agents in Myeloma and Bone Metastases: How Recent Dosing Interval Studies Have Affected Our Practice

The management of bone lesions from advanced solid tumors and multiple myeloma typically includes use of a bone-modifying agent to reduce the risk of skeletal-related events. Recent data demonstrate that when using zoledronic acid to reduce the risk of skeletal-related events in metastatic breast cancer, metastatic prostate cancer, and multiple myeloma, the dosing interval of zoledronic acid may be extended from every 4 weeks to every 12 weeks. The ASCO guidelines on the role of bone-modifying agents in metastatic breast cancer and multiple myeloma address zoledronic acid dosing intervals. Herein, we discuss how new data on dosing of bone-modifying agents influence our clinical practice.

Oral Care: Exploring Education, Attitudes, and Behaviors Among Nurses Caring for Patients With Breast Cancer

BACKGROUND

Patients treated for breast cancer often experience severe oral complications, such as mucositis, xerostomia, and infections, which can result in dose reductions and treatment delays, affecting treatment outcomes.
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OBJECTIVES

The purpose of this article is to explore oncology nurses' perceptions of their educational experiences, professional attitudes, and behavior related to providing oral healthcare education to patients with breast cancer.
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METHODS

The Oncology Nursing Society sent an email to 5,000 nursing team members who cared for patients with breast cancer, requesting participation in a web-based survey; 194 responses were received, with 164 meeting study eligibility.
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FINDINGS

More oral health-related education was received during clinical experiences than during formal or continuing education. Although patient-driven oral care and diagnostic efforts were frequent, actual behavior was less frequent. No major barriers to providing oral care were indicated. Increased oral health-related education and behavior correlated with the reported importance of increased oral health education for nurses.

TBCRC 022: Phase II trial of neratinib + capecitabine for patients (Pts) with human epidermal growth factor receptor 2 (HER2+) breast cancer brain metastases (BCBM)

1005

Background: Evidence-based treatments (tx) for metastatic, HER2+ BCBM are limited. We previously found a central nervous system (CNS) objective response rate (ORR) of 8% (95% CI 2-22%) for the irreversible, EGFR/HER2-targeted kinase inhibitor, neratinib. To enhance CNS activity, we evaluated the combination of neratinib + capecitabine in a subsequent cohort, and report results here. Methods: Pts with measurable BCBM (≥ 1 cm in longest dimension) and no prior lapatinib or capecitabine were eligible. All but 3 had CNS progression after local CNS tx. During 21 day cycles, pts received capecitabine 750 mg/m2 twice daily x 14 days followed by 7 days off + neratinib 240 mg orally once daily. Loperamide prophylaxis (16 mg total daily) was recommended during cycle 1. Brain MRI and non-CNS imaging were repeated every 2 cycles until 18 wks, then every 3 cycles. The primary endpoint was composite CNS ORR, requiring all of the following: ≥50% reduction in volumetric sum of target CNS lesions (central review, VORR), no progression of non-target or non-CNS lesions, no new lesions, no escalating steroids, and no progressive neurologic signs/symptoms. We used a two-stage design with hypotheses ORR 15% and 35% (error rates 5% and 20%), responses in ≥5/19 pts to enter 2ndstage; responses in ≥9/35 [26%] pts to be promising. Results: 39 pts enrolled between 4/2014-11/2016 (2 withdrew before tx, 37 analyzed); median age 51, median prior metastatic lines 2 (range 0-6), 65% had prior WBRT. As of 11/15/16, 23 (62%) patients are alive and 7 remain on protocol tx; median number of cycles initiated = 5 (range 1-26). 18 women (49%) had a VORR (95% CI 32-66%, neurologic exams not yet available on all pts). Overall 12-month survival is 63% (95% CI 43%-77%); 4/7 pts still on protocol therapy have not yet reached 6 cycles. No pts had grade 4 toxicity; 18 (49%) had grade 3 toxicity, with diarrhea most common (32%), and 6 pts discontinued tx for toxicity. Conclusions: The combination of neratinib and capecitabine is active for BCBM with VORR in nearly half of pts, supporting further development of the regimen for BCBM. Updated results will be presented at the meeting. Clinical trial information: NCT01494662.

Use of Adjuvant Bisphosphonates and Other Bone-Modifying Agents in Breast Cancer: A Cancer Care Ontario and American Society of Clinical Oncology Clinical Practice Guideline

Purpose To make recommendations regarding the use of bisphosphonates and other bone-modifying agents as adjuvant therapy for patients with breast cancer. Methods Cancer Care Ontario and ASCO convened a Working Group and Expert Panel to develop evidence-based recommendations informed by a systematic review of the literature. Results Adjuvant bisphosphonates were found to reduce bone recurrence and improve survival in postmenopausal patients with nonmetastatic breast cancer. In this guideline, postmenopausal includes patients with natural menopause or that induced by ovarian suppression or ablation. Absolute benefit is greater in patients who are at higher risk of recurrence, and almost all trials were conducted in patients who also received systemic therapy. Most studies evaluated zoledronic acid or clodronate, and data are extremely limited for other bisphosphonates. While denosumab was found to reduce fractures, long-term survival data are still required. Recommendations It is recommended that, if available, zoledronic acid (4 mg intravenously every 6 months) or clodronate (1,600 mg/d orally) be considered as adjuvant therapy for postmenopausal patients with breast cancer who are deemed candidates for adjuvant systemic therapy. Further research comparing different bone-modifying agents, doses, dosing intervals, and durations is required. Risk factors for osteonecrosis of the jaw and renal impairment should be assessed, and any pending dental or oral health problems should be dealt with prior to starting treatment. Data for adjuvant denosumab look promising but are currently insufficient to make any recommendation. Use of these agents to reduce fragility fractures in patients with low bone mineral density is beyond the scope of the guideline. Recommendations are not meant to restrict such use of bone-modifying agents in these situations. Additional information at www.asco.org/breast-cancer-adjuvant-bisphosphonates-guideline , www.asco.org/guidelineswiki , https://www.cancercareontario.ca/guidelines-advice/types-of-cancer/breast .

Phase II studies of two different schedules of dasatinib in bone metastasis predominant metastatic breast cancer: SWOG S0622

Bone metastases from breast cancer are common, causing significant morbidity. Preclinical data of dasatinib, an oral small molecule inhibitor of multiple oncogenic tyrosine kinases, suggested efficacy in tumor control and palliation of bone metastases in metastatic breast cancer (MBC). This clinical trial aimed to determine whether treatment with either of 2 dose schedules of dasatinib results in a progression-free survival (PFS) >50 % at 24 weeks in bone metastasis predominant MBC, to evaluate the toxicity of the 2 dosing regimens, and explore whether treatment results in decreased serum bone turnover markers and patient-reported "worst pain." Subjects with bone metastasis predominant MBC were randomly assigned to either 100 mg of dasatinib once daily, or 70 mg twice daily, with treatment continued until time of disease progression or intolerable toxicity. Planned accrual was 40 patients in each arm. The primary trial endpoint was PFS, defined as time from registration to progression or death due to any cause. Median PFS for all eligible patients (79) was 12.6 weeks (95 % CI 9.1-16.7). Neither cohort met the threshold for further clinical interest. There were no significant differences in PFS by randomized treatment arm (p = 0.85). Toxicity was similar in both cohorts, with no clear trend in serum biomarkers of bone turnover or patient-reported pain. Dasatinib was ineffective in controlling bone-predominant MBC in a patient population, unselected by molecular markers. Further study of dasatinib in breast cancer should not be pursued unless performed in molecularly determined patient subsets, or rational combinations.

Self-reported oral health and quality of life of postmenopausal breast cancer survivors on aromatase inhibitors and women without cancer diagnoses: a longitudinal analysis

INTRODUCTION

Aromatase inhibitors (AIs) are a well-established component of adjuvant therapy in postmenopausal women with hormone receptor (HR) + early stage breast cancer (BCa). We explored in an 18-month cohort study whether subjective oral health (OH), subjective periodontal health (PH), and oral health-related quality of life (OHRQoL) of postmenopausal BCa survivors on AIs differ from those of women without cancer diagnoses, and whether saliva flow, OH, PH, and OHRQoL are related.

METHODS

Data were collected from 29 postmenopausal BCa survivors on AIs and 29 postmenopausal women without cancer diagnoses. Socio-demographic information, OH, PH, and OHRQoL were collected at baseline and 6, 12, and 18 months later. Unstimulated whole saliva volume per 15 min was determined by drooling.

RESULTS

The two groups did not differ in background characteristics at baseline. Women on AIs had poorer OH (p = .043), PH (p = .04), and OHRQoL (p = .017), and lower saliva flow rate (p < .001) than control respondents. BCa survivors had the poorest PH at the 18-month visit. Xerostomia was correlated with OH at baseline and with OH and PH at 18 months. However, objective saliva flow rate was not correlated with OH or OHRQoL at this visit.

CONCLUSIONS

This study is the first to investigate the effects of AIs on patients' subjective OH, subjective PH, and OHRQoL. The data suggest that women treated with AIs have worse OH, PH, and OHRQoL than women without cancer diagnoses. Interprofessional care is recommended so that women on AIs receive optimal supportive oral care to assure long-term OH and positive OHRQoL.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01272570 https://clinicaltrials.gov/ct2/show/NCT01272570 .

Prognostic Impact of 21-Gene Recurrence Score in Patients With Stage IV Breast Cancer: TBCRC 013

PURPOSE

The objective of this study was to determine whether the 21-gene Recurrence Score (RS) provides clinically meaningful information in patients with de novo stage IV breast cancer enrolled in the Translational Breast Cancer Research Consortium (TBCRC) 013.

PATIENTS AND METHODS

TBCRC 013 was a multicenter prospective registry that evaluated the role of surgery of the primary tumor in patients with de novo stage IV breast cancer. From July 2009 to April 2012, 127 patients from 14 sites were enrolled; 109 (86%) patients had pretreatment primary tumor samples suitable for 21-gene RS analysis. Clinical variables, time to first progression (TTP), and 2-year overall survival (OS) were correlated with the 21-gene RS by using log-rank, Kaplan-Meier, and Cox regression.

RESULTS

Median patient age was 52 years (21 to 79 years); the majority had hormone receptor-positive/human epidermal growth factor receptor 2 (HER2)-negative (72 [66%]) or hormone receptor-positive/HER2-positive (20 [18%]) breast cancer. At a median follow-up of 29 months, median TTP was 20 months (95% CI, 16 to 26 months), and median survival was 49 months (95% CI, 40 months to not reached). An RS was generated for 101 (93%) primary tumor samples: 22 (23%) low risk (< 18), 29 (28%) intermediate risk (18 to 30); and 50 (49%) high risk (≥ 31). For all patients, RS was associated with TTP (P = .01) and 2-year OS (P = .04). In multivariable Cox regression models among 69 patients with estrogen receptor (ER)-positive/HER2-negative cancer, RS was independently prognostic for TTP (hazard ratio, 1.40; 95% CI, 1.05 to 1.86; P = .02) and 2-year OS (hazard ratio, 1.83; 95% CI, 1.14 to 2.95; P = .013).

CONCLUSION

The 21-gene RS is independently prognostic for both TTP and 2-year OS in ER-positive/HER2-negative de novo stage IV breast cancer. Prospective validation is needed to determine the potential role for this assay in the clinical management of this patient subset.

Bone health in adults treated with endocrine therapy for early breast or prostate cancer

Bone is a hormonally responsive organ. Sex hormones and calcium regulating hormones, including parathyroid hormone, 1-25 dihydroxy vitamin D, and calcitonin, have effects on bone resorption and bone deposition. These hormones affect both bone quality and bone quantity. The sex hormone estrogen inhibits bone resorption, and estrogen therapy has been developed to prevent and treat osteoporosis. Androgens are an important source of estrogen through the action of the enzyme aromatase and may themselves stimulate bone formation. Hence, the sex steroids play a role in bone metabolism. Breast cancer and prostate cancer are frequently hormonally responsive and may be treated with antiestrogens or antiandrogens respectfully. In addition, chemotherapy and supportive medications may alter the patient's endocrine system. In general, the suppression of sex hormones has a predictable affect on bone health, as seen by loss of bone mineral density and increased risk of fragility fractures. The bone toxicity of cancer-directed endocrine therapy can be mitigated through screening, counseling on optimization of calcium and vitamin D intake, exercise, and other lifestyle/behavioral actions, as well as the use of medications when the fracture risk is high. Maintaining bone health in patients who are treated with endocrine therapy for breast and prostate cancer is the focus of this review.

Clinical predictors of long-term survival in HER2-positive metastatic breast cancer

Prior to availability of anti-HER2 therapies, HER2-positive metastatic breast cancer (MBC) was associated with a poor prognosis. Prospective randomized trials have demonstrated survival benefit from anti-HER2 treatments. Anecdotal observations have suggested that a small but meaningful fraction of patients with HER2-positive MBC may be "exceptional responders" with long survival. We hypothesized that demographic and/or clinicopathologic characteristics can be identified to distinguish short-term from long-term survivors. A retrospective, single-institution review of 168 patients with HER2-positive MBC who received treatment with anti-HER2 therapy in the metastatic setting was performed. Cox proportional hazards analysis was used to assess factors associated with long-term survival. Median overall survival from the time of breast cancer recurrence was 3.9 years (95 % CI 3.4-5.2). From the time of diagnosis of MBC, 56 (33 %) survived for 5 or more years and 12 (7 %) survived more than 10 years. Of the 66 patients diagnosed with central nervous system metastases, 9 (14 %) survived more than 5 years following that diagnosis. Younger age at diagnosis, lower stage, hormone receptor positive status, and only having one organ involved at diagnosis were associated with longer survival. Four patients discontinued anti-HER2 therapy and are without evidence of progression of disease after a median 7.4 years (0.2-12.0) since stopping therapy. In a cohort of patients with HER2-positive MBC treated primarily with trastuzumab and lapatinib, 7 % of patients were "exceptional responders." Combining these clinical factors with molecular determinants of prolonged survival may provide insights for individualizing treatment selection.

Translational Breast Cancer Research Consortium (TBCRC) 022: A Phase II Trial of Neratinib for Patients With Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer and Brain Metastases

PURPOSE

Evidence-based treatments for metastatic, human epidermal growth factor receptor 2 (HER2)-positive breast cancer in the CNS are limited. Neratinib is an irreversible inhibitor of erbB1, HER2, and erbB4, with promising activity in HER2-positive breast cancer; however, its activity in the CNS is unknown. We evaluated the efficacy of treatment with neratinib in patients with HER2-positive breast cancer brain metastases in a multicenter, phase II open-label trial.

PATIENTS AND METHODS

Eligible patients were those with HER2-positive brain metastases (≥ 1 cm in longest dimension) who experienced progression in the CNS after one or more line of CNS-directed therapy, such as whole-brain radiotherapy, stereotactic radiosurgery, and/or surgical resection. Patients received neratinib 240 mg orally once per day, and tumors were assessed every two cycles. The primary endpoint was composite CNS objective response rate (ORR), requiring all of the following: ≥ 50% reduction in volumetric sum of target CNS lesions and no progression of non-target lesions, new lesions, escalating corticosteroids, progressive neurologic signs/symptoms, or non-CNS progression--the threshold for success was five of 40 responders.

RESULTS

Forty patients were enrolled between February 2012 and June 2013; 78% of patients had previous whole-brain radiotherapy. Three women achieved a partial response (CNS objective response rate, 8%; 95% CI, 2% to 22%). The median number of cycles received was two (range, one to seven cycles), with a median progression-free survival of 1.9 months. Five women received six or more cycles. The most common grade ≥ 3 event was diarrhea (occurring in 21% of patients taking prespecified loperamide prophylaxis and 28% of those without prophylaxis). Patients in the study experienced a decreased quality of life over time.

CONCLUSION

Although neratinib had low activity and did not meet our threshold for success, 12.5% of patients received six or more cycles. Studies combining neratinib with chemotherapy in patients with CNS disease are ongoing.

Associations between genetic variants and the effect of letrozole and exemestane on bone mass and bone turnover

Adjuvant therapy for hormone receptor (HR) positive postmenopausal breast cancer patients includes aromatase inhibitors (AI). While both the non-steroidal AI letrozole and the steroidal AI exemestane decrease serum estrogen concentrations, there is evidence that exemestane may be less detrimental to bone. We hypothesized that single nucleotide polymorphisms (SNP) predict effects of AIs on bone turnover. Early stage HR-positive breast cancer patients were enrolled in a randomized trial of exemestane versus letrozole. Effects of AI on bone mineral density (BMD) and bone turnover markers (BTM), and associations between SNPs in 24 candidate genes and changes in BMD or BTM were determined. Of the 503 enrolled patients, paired BMD data were available for 123 and 101 patients treated with letrozole and exemestane, respectively, and paired BTM data were available for 175 and 173 patients, respectively. The mean change in lumbar spine BMD was significantly greater for letrozole-treated (-3.2 %) compared to exemestane-treated patients (-1.0 %) (p = 0.0016). Urine N-telopeptide was significantly increased in patients treated with exemestane (p = 0.001) but not letrozole. Two SNPs (rs4870061 and rs9322335) in ESR1 and one SNP (rs10140457) in ESR2 were associated with decreased BMD in letrozole-treated patients. In the exemestane-treated patients, SNPs in ESR1 (Rs2813543) and CYP19A1 (Rs6493497) were associated with decreased bone density. Exemestane had a less negative impact on bone density compared to letrozole, and the effects of AI therapy on bone may be impacted by genetic variants in the ER pathway.

Abstract P6-08-50: Clinical predictors of long-term survival in Her2-positive (HER2+) metastatic breast cancer (MBC)

Introduction: Clinical observation suggests that a subset of patients with HER2+ MBC survive for prolonged periods when treated with Her2-targeting regimens. We hypothesized that we could identify clinical and pathological factors associated with prolonged survival.

Methods: An IRB approved, retrospective, single institution review of patients diagnosed with HER2+ MBC was performed. Patients treated with pertuzumab or ado-trastuzumab emtansine were not included because recent FDA approval did not permit long-term follow-up. Clinical and pathologic characteristics were abstracted from the medical record. Kaplan Meier curves were constructed to evaluate time to progression after first metastasis, and overall survival from time of first metastasis. Cox proportional hazards analysis was used to assess for factors associated with long-term survival. A p value of &lt;0.05 is statistically significant.

Results: Review identified 181 patients with HER2+ MBC. Median age was 47 (range 35-80). More than half (N=107) had hormone receptor positive disease; 21% had received adjuvant trastuzumab; and 25% had stage IV disease at diagnosis. Median overall survival from the time of MBC diagnosis was 4.2 yrs (range 0.1-15.5). Since the diagnosis of MBC, 70 (38%) survived for 5 or more yrs and 15 (8%) survived more than 10 yrs. One third (N=59) of patients had brain metastases. These patients had a median survival of 1.5 yrs (range 0-12.5 yrs) with 14% (N=8) living for more than 5 yrs following diagnosis of brain metastasis. Factors associated with decreased survival are listed in Table 1.

Factors Associated with Decreased Survival in Her2+ MBCFactorHazard Ratio (95% C.I.)P ValueAge (continuous)1.03 (1.01-1.04)0.0004Time to recurrence (continuous)0.99 (0.94-1.04)0.74Hormone receptor positive0.70 (0.49-0.99)0.042Brain metastasis1.09 (0.77-1.56)0.63Adjuvant anti-Her2 therapy0.98 (0.61-1.58)0.94Multiple (vs single) sites of disease at initial diagnosis of MBC1.66 (1.17-2.35)0.005

Conclusions: In the treatment era of trastuzumab and lapatinib, 8% of patients within this cohort with HER2+ MBC lived more than 10 yrs. Analysis of current standard clinical and pathologic characteristics are not predictive of survival duration. Identifying factors associated with prolonged survival may provide insights for individualizing treatment selection.

Citation Format: Pooja Murthy, Kelley M Kidwell, Dafydd G Thomas, Jennifer J Griggs, Sofia D Merajver, Anne F Schott, Jeffrey B Smerage, Catherine H Van Poznak, Max Wicha, Daniel F Hayes, N Lynn Henry. Clinical predictors of long-term survival in Her2-positive (HER2+) metastatic breast cancer (MBC) [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P6-08-50.

Abstract P1-09-24: Oral health-related quality of life in women with early stage breast cancer

Introduction: Aromatase inhibitors (AI) are a well-established component of the adjuvant therapy in postmenopausal (PM) women with hormone receptor positive (HR+) early breast cancer (BCA). AIs are associated with side effects that may adversely affect the quality of life (Qol). The impact of AIs and on oral health-related QoL (OHRQoL) in women with BCA is unknown. To generate data on the impact of adjuvant AIs on OHRQoL we performed a prospective, longitudinal, cohort study assessing patient reported outcomes.

Methods: PM women with early BCA were eligible if they were on an adjuvant AI for 3 to 12 months. AI patients were recruited from the Breast Medical Oncology Clinic. The Control group consisted of PM women without BCA who were not on AI therapy and were recruited at the time of screening mammography. Study participants provided socio-demographic information and completed questionnaires OHRQoL which included the Michigan Oral Health-Related Quality of Life (MOHRQoL) Scale, and Oral Health Impact Profile (OHIP-14) which both measure discomfort, dysfunction and disability resulting from oral problems on a 5 point scale. Presence of saliva status as a measure of oral health was measured by the saliva flow rate. Data was collected at baseline and at 6, 12 and 18 months. The baseline data is presented here. The student t-test and chi-square test were used to analyze outcomes. The Pearson correlation coefficient was used to evaluate the correlation between the OHIP-14 and the amount of saliva.

Results: The study met its target accrual of 58 PM women; 29 with BCA on AI and 29 controls. Median time on AIs at study entry was 5.7 months. Demographics were similar regarding age, education, income level, frequency of dental visits, and dental insurance status across both groups. The OHIP-14 score varied by AI use (p=0.02) and duration of AI use (p=0.03) where the lowest poor OHRQOL was found in AI users less than 6 months. Patients receiving AI therapy had significantly lower perception of OHRQoL for the individual OHIP-14 items: "I have had pain in the mouth", "I have had to limit my diet", "I have had painful aching in my mouth", "I have had to limit foods I eat" and "I have felt tense because of problems with my mouth" compared to controls.

Conclusions: This study is the first to report on the OHRQoL among PM women with early BCA using AIs. The baseline data demonstrates a significantly lower OHRQoL in those on AIs compared to controls. Dimensions that were particularly relevant were physical pain, psychological discomfort and physical disability. Analysis of serial time points is ongoing.

Citation Format: Linda S Taichman, William G Giannobile, Thomas M Braun, Marita R Inglehart, Catherine H Van Poznak. Oral health-related quality of life in women with early stage breast cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P1-09-24.

Significance of Circulating Tumor Cells in Metastatic Triple-Negative Breast Cancer Patients within a Randomized, Phase II Trial: TBCRC 019

PURPOSE

Circulating tumor cells (CTC) are prognostic in metastatic breast cancer (MBC). We tested whether EpCAM-based capture system (CellSearch) is effective in patients with triple-negative (TN) MBC, and whether CTC apoptosis and clustering enhances the prognostic role of CTC.

EXPERIMENTAL DESIGN

CTC enumeration and apoptosis were determined using the CXC CellSearch kit at baseline and days 15 and 29 in blood drawn from TN MBC patients who participated in a prospective randomized phase II trial of nanoparticle albumin-bound paclitaxel (nab-paclitaxel) with or without tigatuzumab. Association between levels of CTC and patient outcomes was assessed using logistic regression, Kaplan-Meier curves, and Cox proportional hazards modeling.

RESULTS

Nineteen of 52 (36.5%), 14 of 52 (26.9%), and 13 of 49 (26.5%) patients who were evaluable had elevated CTC (≥5 CTC/7.5 mL whole blood) at baseline and at days 15 and 29, respectively. Patients with elevated versus not elevated CTC at each time point had worse progression-free survival (PFS; P = 0.005, 0.0003, 0.0002, respectively). The odds of clinical benefit response for those who had elevated versus low CTC at baseline and days 15 and 29 were 0.25 (95% CI: 0.08-0.84; P = 0.024), 0.19 (95% CI: 0.05-0.17; P = 0.014), and 0.06 (95% CI: 0.01-0.33; P = 0.001), respectively. There was no apparent prognostic effect comparing CTC apoptosis versus non-apoptosis. Presence of CTC cluster at day 15 and day 29 was associated with shorter PFS.

CONCLUSIONS

CTC were detected using CellSearch assay in approximately one-third of TN MBC patients. Elevated CTC at baseline and days 15 and 29 were prognostic, and reductions in CTC levels reflected response.

TBCRC 019: A Phase II Trial of Nanoparticle Albumin-Bound Paclitaxel with or without the Anti-Death Receptor 5 Monoclonal Antibody Tigatuzumab in Patients with Triple-Negative Breast Cancer

PURPOSE

Tigatuzumab (TIG), an agonistic anti-DR5 antibody, triggers apoptosis in DR5(+) human tumor cells without crosslinking. TIG has strong in vitro/in vivo activity against basal-like breast cancer cells enhanced by chemotherapy agents. This study evaluates activity of TIG and chemotherapy in patients with metastatic triple-negative breast cancer (TNBC).

EXPERIMENTAL DESIGN

Randomized 2:1 phase II trial of albumin-bound paclitaxel (nab-PAC) ± TIG in patients with TNBC stratified by prior chemotherapy. Patients received nab-PAC weekly × 3 ± TIG every other week, every 28 days. Primary objective was within-arm objective response rate (ORR). Secondary objectives were safety, progression-free survival (PFS), clinical benefit, and TIG immunogenicity. Metastatic research biopsies were required.

RESULTS

Among 64 patients (60 treated; TIG/nab-PAC n = 39 and nab-PAC n = 21), there were 3 complete remissions (CR), 8 partial remissions (PR; 1 almost CR), 11 stable diseases (SD), and 17 progressive diseases (PD) in the TIG/nab-PAC arm (ORR, 28%), and no CRs, 8 PRs, 4 SDs, and 9 PDs in the nab-PAC arm (ORR, 38%). There was a numerical increase in CRs and several patients had prolonged PFS (1,025+, 781, 672, 460, 334) in the TIG/nab-PAC arm. Grade 3 toxicities were 28% and 29%, respectively, with no grade 4-5. Exploratory analysis suggests an association of ROCK1 gene pathway activation with efficacy in the TIG/nab-PAC arm.

CONCLUSIONS

ORR and PFS were similar in both. Preclinical activity of TIG in basal-like breast cancer and prolonged PFS in few patients in the combination arm support further investigation of anti-DR5 agents. ROCK pathway activation merits further evaluation.

Activating ESR1 mutations in hormone-resistant metastatic breast cancer

Breast cancer is the most prevalent cancer in women, and over two-thirds of cases express estrogen receptor-α (ER-α, encoded by ESR1). Through a prospective clinical sequencing program for advanced cancers, we enrolled 11 patients with ER-positive metastatic breast cancer. Whole-exome and transcriptome analysis showed that six cases harbored mutations of ESR1 affecting its ligand-binding domain (LBD), all of whom had been treated with anti-estrogens and estrogen deprivation therapies. A survey of The Cancer Genome Atlas (TCGA) identified four endometrial cancers with similar mutations of ESR1. The five new LBD-localized ESR1 mutations identified here (encoding p.Leu536Gln, p.Tyr537Ser, p.Tyr537Cys, p.Tyr537Asn and p.Asp538Gly) were shown to result in constitutive activity and continued responsiveness to anti-estrogen therapies in vitro. Taken together, these studies suggest that activating mutations in ESR1 are a key mechanism in acquired endocrine resistance in breast cancer therapy.

TBCRC 018: Phase II study of iniparib plus chemotherapy to treat triple-negative breast cancer (TNBC) central nervous system (CNS) metastases (mets)

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Background: Nearly half of women with advanced TNBC develop CNS mets. This study evaluated the safety and efficacy of iniparib, a small molecule anti-cancer agent that penetrates the blood brain barrier (BBB), and the topoisomerase I inhibitor, irinotecan, in patients (pts) with TNBC CNS mets. Methods: Eligible pts had TNBC with new or progressive CNS mets with at least 1 measurable (> 5mm) lesion. Pts received irinotecan 125mg/m2 IV days (d) 1, 8 and iniparib (initial dose 5.6mg/kg, later changed to 8mg/kg) IV d 1, 4, 8, 11 every 21d. Tumor response rate (RR) was assessed by brain MRI and body CT every 9 weeks. The Kaplan Meier method estimated the primary endpoint of time to progression (TTP, intracranial [modified RECIST] or extracranial [RECIST 1.1]). Secondary endpoints were RR, PFS, OS, quality of life (QOL) and correlative endpoints. Results: Of 37 pts who began treatment, 34 were evaluable for efficacy. Mean age was 48 yrs (34 – 80 yrs). BRCA status was known for 16 patients of whom 5 had a mutation (4 BRCA1, 1 BRCA2). 88% received prior (neo)adjuvant and 68% prior metastatic chemotherapy (median 2 [1–14] lines). While 15% were CNS radiation (RT) naïve, 32% had received whole brain RT, 21% stereotactic RT, and 32% both. The most common grade (gr) 3/4 adverse events were neutropenia (14%), fatigue (5%), leukopenia (5%), hypokalemia (5%). Diarrhea was common (54%), but gr 3/4 was rare (3%). Median TTP (CNS and non-CNS) was 2.1 months (mos) (95% CI 1.7–4.3) and OS was 7.6 mos (95% CI 5.1-10.2). First progression site was CNS in 39%, non-CNS in 29% or both in 32%. CNS best RR was (12%; 0 CRs, 4 PRs); CNS clinical benefit rate (CBR, CR + PR + SD ≥ 6 mos) was 30%. Non-CNS RR was 5% (0 CRs, 1 PR) and CBR was 11%. Conclusions: Iniparib and irinotecan was well-tolerated among pts with TNBC CNS mets. While TTP was shorter than expected and contribution of iniparib to irinotecan remains uncertain, 30% of pts demonstrated CNS clinical benefit raising the question of whether predictive biomarkers could be identified. QOL, volumetric analysis of CNS lesions and translational studies evaluating molecular subtype, germline BRCA1/2, and DNA repair gene expression/methylation are ongoing. Clinical trial information: NCT01173497.

TBCRC 019: An open label, randomized, phase II trial of nanoparticle albumin-bound paclitaxel (nab-PAC) with or without the anti-death receptor 5 (DR5) monoclonal antibody tigatuzumab (TIG) in patients with metastatic triple negative breast cancer (TNBC)

1052

Background: TIG, an agonistic anti-DR5 monoclonal antibody, triggers apoptosis in DR5+ human tumor cells without the aid of crosslinking. TIG has shown strong in vitro and in vivo activity against basal-like breast cancer cells that is enhanced by chemotherapy like paclitaxel. Methods: Randomized 2:1 phase II trial of nab-PAC with/without TIG in TNBC patients. Patients stratified by prior exposure to chemotherapy in the metastatic setting. Patients received nab-PAC weekly x 3 and TIG every other week, every 28 days. Primary endpoint was overall response rate (ORR). Secondary objectives were safety, progression free survival (PFS), TIG immunogenicity, and PK. Biopsies and circulating tumor cells were collected. The trial was not powered to compare arms but allowed early stopping for futility and was sized to estimate ORR with 95% CI. Results: 64 patients enrolled, 60 treated; 39 in the combination arm and 21 in the nab-PAC arm. Of the 39 in the combination arm, there were 2 CR, 9 PR (1 near CR, 96% tumor reduction), 11 SD and 17 PD; ORR 28% (95% CI 14%-42%). Of the 21 in the single agent arm, there were no CR, 8 PR, 4 SD and 9 PD; ORR 38% (95% CI 17%-59%). Higher ORRs were seen in the chemotherapy naïve patients (58% vs. 15% combination and 42% vs. 35% single agent). 2 patients with CR, 1 near CR, and 1 PR in the combination arm are still on therapy (602+, 531+, 466+, 460+ days). PFS was similar in both groups (3.6 months); higher in chemotherapy naïve patients. Combination was well tolerated (most toxicities grade 1/2); the most common AEs were fatigue, alopecia, peripheral sensory neuropathy, anemia, neutropenia, nausea, thrombocytopenia, anorexia, diarrhea, and vomiting. No grade 4 or 5 toxicity. No apparent added toxicity with TIG was seen. Conclusions: Combination therapy with nab-PAC + TIG was well tolerated, without apparent improvement in ORR relative to nab-PAC alone; however, 4 subjects treated as first-line had prolonged clinical benefit with the combination, and correlative studies will investigate markers that might predict clinical outcome (Next-Gen genomic analysis). Clinical trial information: F101004001.

Hypocalcemia in patients with metastatic bone disease receiving denosumab

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Background: Patients (pts) with metastatic bone disease (MBD) are at risk of skeletal-related events (SREs). Potent antiresorptives reduce the risk of SREs, by inhibiting cancer-induced bone destruction, which also reduces release of skeletal calcium (Ca) into the bloodstream. Hypocalcemia (hypoCa) may occur if Ca and vit D intake is inadequate while taking antiresorptive agents. A combined analysis of 3 phase III trials in pts with MBD showed denosumab (DMAb) was superior to zoledronic acid (ZA) in preventing SREs. The overall safety profiles were similar; hypoCa was more common with DMAb (9.6%) than ZA (5.0%). Characteristics of hypoCa events in DMAb pts in these clinical trials and from post marketing adverse event (AE) reports are presented. Methods: Pts with solid tumors or multiple myeloma and MBD were randomized (1:1) to DMAb 120 mg SC or ZA 4 mg IV (adjusted for renal function) every 4 weeks (Q4W). Pts were advised to take daily Ca (≥ 500 mg) and vit D (≥ 400 IU); intake was collected by pt report. Albumin-corrected serum Ca was measured Q4W by central lab. HypoCa events were collected as decreases in serum Ca per central lab and investigator-reported AEs. Post marketing data from spontaneous reports of hypoCa to the sponsor's global safety department (AGS) were reviewed. Results: In the 3 trials, 2841 pts received DMAb and 2836 pts received ZA. The median Ca levels for both treatment groups were similar over time. Among DMAb pts, hypoCa was most common within 6 months of starting treatment and was more common in pts who did not report use of Ca and vit D vs those who did (15.8% vs 8.7%). Grade 3 or 4 (< 7 mg/dL; < 1.75 mmol/L) decreases in serum Ca were reported in 3.1% of DMAb pts and 1.3% of ZA pts. No fatal cases of hypoCa were reported in the trials. From May to Nov 2012, 37 cases of severe symptomatic hypoCa (seizures, tetany, prolonged QTc, altered mental state) were reported to AGS; fatal outcomes were reported for 3 other pts with advanced cancers and various comorbidities. Conclusions: HypoCa is a known risk with antiresorptive therapy, including DMAb 120 mg. HypoCa occurred less often in pts who reported taking Ca and vit D. HypoCa should be corrected prior to starting DMAb and Ca monitored during treatment. Pts should take adequate Ca and vit D while receiving DMAb. Clinical trial information: NCT00321464, NCT00321620, and NCT00330759.

Prognostic impact of the 21-gene recurrence score in patients presenting with stage IV breast cancer

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Background: The 21-gene Recurrence Score (OncotypeDX Breast Cancer Assay) predicts outcome and benefit from chemotherapy (CT) in early stage ER+ BC treated with adjuvant endocrine therapy. We evaluated the association between Recurrence Score (RS), time to progression (TTP), and overall survival (OS) in patients with stage IV BC enrolled in TBCRC 013. Methods: TBCRC 013 is a registry study evaluating surgery of the primary tumor in pts presenting with Stage IV BC. From 7/09 - 4/12, 128 evaluable pts were enrolled in two cohorts (A: metastases (mets) with intact primary tumor (n=112); B: mets within 3 months of primary surgery (n=16)). This study includes 110 pts with pre-treatment primary tumor samples available for analysis. Clinical variables, TTP and OS were correlated with RS using long-rank, Kaplan-Meier and Cox regression. Results: Median pt age was 52yrs (21-79) and median tumor size 3.1cm (0.7-15). 82 (80%) were ER+, 83 (81%) Her2(-) and 51 (46%) had bone-only mets. Cohorts A and B did not differ. At a median follow-up of 26 mos (1-47), median TTP is 19 mos (95%CI16-25) and surgery is not associated with OS. 102 samples qualified for RS. 23 (23%) had low RS<18, 29 (28%) intermediate RS, 18-30; and 50 (49%) high RS≥31. Age, tumor size or site of 1stmets was not associated with RS. Risk groups were prognostic for TTP in ER+ pts and for 2 yr OS in ER+Her2- pts (Table). In Cox models continuous RS was also prognostic for TTP in ER+ pts (HR 3.5; for 50 point difference (PD) 95%CI 1.5-8.1, p=0.003) and for OS in ER+Her2- pts (HR 21.4, for 50 PD 95%CI 2.2-204.4, p=0.008). In MVA, adjusting for clinical variables, RS remained prognostic for TTP in ER+ pts (p=0.01). Further analysis of surgery in this trial is ongoing. Conclusions: The 21-gene RS is independently prognostic for TTP in ER+ Stage IV BC. RS is also prognostic for OS in ER+Her2- BC, suggesting that a high RS may be a surrogate for endocrine resistance and could be used to select pts with ER+ Stage IV BC for CT. A randomized trial to address this hypothesis is warranted. Clinical trial information: NCT00941759. [Table: see text]

Incidence of osteonecrosis of the jaw in patients receiving denosumab or zoledronic acid for bone metastases from solid tumors or multiple myeloma: Results from three phase III trials

9640

Background: In patients with metastatic bone disease (MBD), the use of antiresorptive therapies such as denosumab or zoledronic acid (ZA) reduces the risk of skeletal-related events but is associated with a small risk of osteonecrosis of the jaw (ONJ). Two phase 3 clinical trials of denosumab vs ZA in patients with MBD showed overall cumulative ONJ incidences to be 3.8% to 4.7% at approximately 5 years of treatment with denosumab across blinded and open-label extension phases. ONJ associated with ZA was only assessed in the blinded treatment phases, as patients switched to denosumab once superior efficacy was demonstrated. Here we report incidence rates of ONJ by first vs subsequent years of exposure for the blinded treatment phase of all three phase III clinical trials. Methods: Patients (n = 5,677) with bone metastases from solid tumors or multiple myeloma received either SC denosumab 120 mg and IV placebo or IV ZA 4 mg (adjusted for renal function) and SC placebo Q4W in the double-blinded treatment phase of each trial. Patients who received ≥ 1 active dose during the blinded treatment phase were included in this analysis for up to 44.5 months of denosumab exposure and 41.3 months of ZA exposure. Oral assessments were conducted at baseline and every 6 months thereafter by the investigator or other qualified examiner. Potential ONJ events were independently adjudicated by a blinded committee of experts. Results: The median (Q1, Q3) time to onset of ONJ was similar in both treatment groups (15.6 [9.5, 20.0] months for denosumab, 15.8 [11.0, 23.6] months for ZA). Cumulative incidence rates of ONJ during the blinded treatment phases for all three trials by patient-years of follow-up are shown below (Table). Conclusions: The incidence of ONJ increased with longer duration of antiresorptive exposure. There were no significant differences between treatment groups in ONJ incidence at year 1 or beyond. Clinical trial information: NCT00321464; NCT00330759; NCT00321620. [Table: see text]

Parametric response mapping of CT images provides early detection of local bone loss in a rat model of osteoporosis

Loss of bone mass due to disease, such as osteoporosis and metastatic cancer to the bone, is a leading cause of orthopedic complications and hospitalization. Onset of bone loss resulting from disease increases the risk of incurring fractures and subsequent pain, increasing medical expenses while reducing quality of life. Although current standard CT-based protocols provide adequate prognostic information for assessing bone loss, many of the techniques for evaluating CT scans rely on measures based on whole-bone summary statistics. This reduces the sensitivity at identifying local regions of bone resorption, as well as formation. In this study, we evaluate the effectiveness of a voxel-based image post-processing technique, called the Parametric Response Map (PRM), for identifying local changes in bone mass in weight-bearing bones on CT scans using an established animal model of osteoporosis. Serial CT scans were evaluated weekly using PRM subsequent to ovariectomy or sham surgeries over the period of one month. For comparison, bone volume fraction and mineral density measurements were acquired and found to significantly differ between groups starting 3 weeks post-surgery. High resolution ex vivo measurements acquired four weeks post-surgery validated the extent of bone loss in the surgical groups. In contrast to standard methodologies for assessing bone loss, PRM results were capable of identifying local decreases in bone mineral by week 2, which were found to be significant between groups. This study concludes that PRM is able to detect changes in bone mineral with higher sensitivity and spatial differentiation than conventional techniques for evaluating CT scans, which may aid in clinical decision making for patients suffering from bone loss.

American Society of Clinical Oncology Executive Summary of the Clinical Practice Guideline Update on the Role of Bone-Modifying Agents in Metastatic Breast Cancer

Purpose

To update the recommendations on the role of bone-modifying agents in the prevention and treatment of skeletal-related events (SREs) for patients with metastatic breast cancer with bone metastases.

Methods

A literature search using MEDLINE and the Cochrane Collaboration Library identified relevant studies published between January 2003 and November 2010. The primary outcomes of interest were SREs and time to SRE. Secondary outcomes included adverse events and pain. An Update Committee reviewed the literature and re-evaluated previous recommendations.

Results

Recommendations were modified to include a new agent. A recommendation regarding osteonecrosis of the jaw was added.

Recommendations

Bone-modifying agent therapy is only recommended for patients with breast cancer with evidence of bone metastases; denosumab 120 mg subcutaneously every 4 weeks, intravenous pamidronate 90 mg over no less than 2 hours, or zoledronic acid 4 mg over no less than 15 minutes every 3 to 4 weeks is recommended. There is insufficient evidence to demonstrate greater efficacy of one bone-modifying agent over another. In patients with a calculated serum creatinine clearance of more than 60 mg/min, no change in dosage, infusion time, or interval of bisphosphonate administration is required. Serum creatinine should be monitored before each dose. All patients should receive a dental examination and appropriate preventive dentistry before bone-modifying agent therapy and maintain optimal oral health. Current standards of care for cancer bone pain management should be applied at the onset of pain, in concert with the initiation of bone-modifying agent therapy. The use of biochemical markers to monitor bone-modifying agent use is not recommended.

American society of clinical oncology clinical practice guideline update: recommendations on the role of bone-modifying agents in metastatic breast cancer

Journal of Clinical Oncology recently published ASCO's update to its guideline on the use of bone-modifying agents for patients with bone metastases, the scope of which was narrowed to the use of bone-modifying agents for patients with evidence of bone metastases.

NCCN Task Force Report: Bone Health in Cancer Care

Bone health and maintenance of bone integrity are important components of comprehensive cancer care in both early and late stages of disease. Risk factors for osteoporosis are increased in patients with cancer, including women with chemotherapy-induced ovarian failure, those treated with aromatase inhibitors for breast cancer, men receiving androgen-deprivation therapy for prostate cancer, and patients undergoing glucocorticoid therapy. The skeleton is a common site of metastatic cancer recurrence, and skeletal-related events are the cause of significant morbidity. The National Comprehensive Cancer Network (NCCN) convened a multidisciplinary task force on Bone Health in Cancer Care to discuss the progress made in identifying effective screening and therapeutic options for management of treatment-related bone loss; understanding the factors that result in bone metastases; managing skeletal metastases; and evolving strategies to reduce bone recurrences. This report summarizes presentations made at the meeting.

Bisphosphonate-associated osteonecrosis of the jaw: report of a task force of the American Society for Bone and Mineral Research

ONJ has been increasingly suspected to be a potential complication of bisphosphonate therapy in recent years. Thus, the ASBMR leadership appointed a multidisciplinary task force to address key questions related to case definition, epidemiology, risk factors, diagnostic imaging, clinical management, and future areas for research related to the disorder. This report summarizes the findings and recommendations of the task force.

INTRODUCTION

The increasing recognition that use of bisphosphonates may be associated with osteonecrosis of the jaw (ONJ) led the leadership of the American Society for Bone and Mineral Research (ASBMR) to appoint a task force to address a number of key questions related to this disorder.

MATERIALS AND METHODS

A multidisciplinary expert group reviewed all pertinent published data on bisphosphonate-associated ONJ. Food and Drug Administration drug adverse event reports were also reviewed.

RESULTS AND CONCLUSIONS

A case definition was developed so that subsequent studies could report on the same condition. The task force defined ONJ as the presence of exposed bone in the maxillofacial region that did not heal within 8 wk after identification by a health care provider. Based on review of both published and unpublished data, the risk of ONJ associated with oral bisphosphonate therapy for osteoporosis seems to be low, estimated between 1 in 10,000 and <1 in 100,000 patient-treatment years. However, the task force recognized that information on incidence of ONJ is rapidly evolving and that the true incidence may be higher. The risk of ONJ in patients with cancer treated with high doses of intravenous bisphosphonates is clearly higher, in the range of 1-10 per 100 patients (depending on duration of therapy). In the future, improved diagnostic imaging modalities, such as optical coherence tomography or MRI combined with contrast agents and the manipulation of image planes, may identify patients at preclinical or early stages of the disease. Management is largely supportive. A research agenda aimed at filling the considerable gaps in knowledge regarding this disorder was also outlined.