Does the number of 6-monthly adjuvant zoledronate infusions received affect treatment efficacy for early breast cancer? A sub-study of ABCSG-12.

BACKGROUND: The widespread adoption of adjuvant bisphosphonate therapy for postmenopausal early breast cancer (EBC) patients was based on results of the Early Breast Cancer Trialist Group (EBCTCG) meta-analysis. Despite multiple regimens evaluated, there was no signal of varying efficacy with type, dose/dose intensity of bisphosphonate administration. We evaluated the effect of early treatment cessation using long-term outcome data from the ABCSG-12 trial. PATIENTS AND METHODS: ABCSG-12 randomized 1803 hormone-receptor positive EBC patients on ovarian suppression between 1999 and 2006 to receive 4 mg zoledronic acid 6-monthly or not (and tamoxifen or anastrozole, 2:2 factorial design). In the current study, we evaluated whether the number of zoledronate infusions had an impact on breast cancer-specific outcomes. We hypothesized that amongst patients who received at least one zoledronate infusion, the number of infusions had no effect on outcomes. Time-to-event endpoints were analysed with Cox models and Kaplan Meier curves starting from a 3-year landmark. BMD analysis was restricted to patients who participated in the BMD sub-study. RESULTS: 725 patients who received at least one zoledronate infusion were included in the time-to-event analysis. There was no statistically significant difference in disease-free or overall survival in the patients who received ≤6 zoledronate infusions (n = 170) compared to those who received ≥7 zoledronate infusions (n = 555). CONCLUSIONS: Comparable to efforts to de-escalate treatment duration in metastatic bone disease, there was no evidence to indicate that a reduced number of zoledronate infusions is associated with reduced adjuvant efficacy. Further studies to define optimal regimens of adjuvant bone-targeted therapies are required.

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.

Long-term impact of bone-modifying agents for the treatment of bone metastases: a systematic review.

PURPOSE: Bone-modifying agents (BMAs) for bone metastases are commonly prescribed for many years even though randomized clinical trials are only 1-2 years in duration. A systematic review on the risk-benefit of BMA use for > 2 years in breast cancer or castrate-resistant prostate cancer was conducted. METHODS: MEDLINE, Embase, and Cochrane databases were searched (1970-February 2019) for randomized and observational studies, and case series reporting on BMA efficacy (skeletal-related events and quality of life) and toxicity (osteonecrosis of the jaw, renal impairment, hypocalcemia, and atypical femoral fractures) beyond 2 years. RESULTS: Of 2107 citations, 64 studies were identified. Three prospective and 9 retrospective studies were eligible. Data beyond 2 years was limited to subgroup analyses in all studies. Only one study (n = 181) reported skeletal-related event rates based on bisphosphonate exposure, with decreased rates from 27.6% (0-24 months) to 15.5% (> 24 months). None reported on quality of life. All 12 studies (denosumab (n = 948), zoledronate (n = 1036), pamidronate (n = 163), pamidronate-zoledronate (n = 522), ibandronate (n = 118)) reported ≥ 1 toxicity outcome. Seven bisphosphonate studies (n = 1077) and one denosumab study (n = 948) reported on osteonecrosis of the jaw. Across three studies (n = 1236), osteonecrosis of the jaw incidence ranged from 1 to 4% in the first 2 years to 3.8-18% after 2 years. Clinically significant hypocalcemia ranged from 1 to 2%. Severe renal function decline was ≤ 3%. Atypical femoral fractures were rare. CONCLUSIONS: Evidence informing the use of BMA beyond 2 years is heterogeneous and based on retrospective analysis. Prospective randomized studies with greater emphasis on quality of life are needed. PROSPERO REGISTRATION NUMBER: CRD42019126813.

Effects of Celecoxib and Low-dose Aspirin on Outcomes in Adjuvant Aromatase Inhibitor-Treated Patients: CCTG MA.27.

Background: Celecoxib and low-dose aspirin might decrease risk of breast cancer recurrence. Methods: In the Canadian Cancer Trials Group MA.27, postmenopausal hormone receptor-positive breast cancer patients were randomly assigned (2 × 2) to adjuvant exemestane or anastrozole, and celecoxib or placebo. Low-dose aspirin of 81 mg or less was a stratification factor. Due to concerns about cardiac toxicity, celecoxib use was stopped in December 2004, while stratification by aspirin use was removed through protocol amendment. We examined the effects of celecoxib and low-dose aspirin on event-free survival (EFS), defined as time from random assignment to time of locoregional or distant disease recurrence, new primary breast cancer, or death from any cause; distant disease-free survival (DDFS); and overall survival (OS). All statistical tests were two-sided. Results: Random assignment to celecoxib (n = 811, 50.0%) or placebo (n = 811, 50.0%) was discontinued after 18 months (n = 1622). At a median of 4.1 years' follow-up, among 1622 patients, 186 (11.5%) patients had an EFS event: 80 (4.9%) had distant relapse, and 125 (7.7%) died from any cause. Celecoxib did not statistically significantly impact EFS, DDFS, or OS in univariate analysis (respectively, P = .92, P = .55, and P = .56) or multivariable analysis (respectively, P = .74, P = .60, and P = .76). Low-dose aspirin use (aspirin users n = 476, 21.5%; non-aspirin users n = 1733, 78.5%) was associated in univariate analyses with worse EFS (hazard ratio [HR] = 1.48, 95% confidence interval [CI] = 1.12 to 1.96, P = 0.006) and worse OS (HR = 1.87, 95% CI = 1.35 to 2.61, P < .001). After adjusting for baseline characteristics and treatment arm, aspirin use showed no statistical association with EFS (P = .08) and DDFS (P = .82), but was associated with statistically worse OS (HR = 1.67, 95% CI = 1.13 to 2.49, P = .01). Conclusion: Random assignment to short-term (≤18 months) celecoxib as well as use of low-dose aspirin showed no effect on DDFS and EFS in multivariable analysis. Low-dose aspirin increased "all-cause" mortality, presumably because of higher preexisting cardiovascular risks.

Role of Bone-Modifying Agents in Metastatic Breast Cancer: An American Society of Clinical Oncology-Cancer Care Ontario Focused Guideline Update.

Purpose To update, in collaboration with Cancer Care Ontario (CCO), key recommendations of the American Society of Clinical Oncology (ASCO) guideline on the role of bone-modifying agents (BMAs) in metastatic breast cancer. This focused update addressed the new data on intervals between dosing and the role of BMAs in control of bone pain. Methods A joint ASCO-CCO Update Committee conducted targeted systematic literature reviews to identify relevant studies. Results The Update Committee reviewed three phase III noninferiority trials of dosing intervals, one systematic review and meta-analysis of studies of de-escalation of BMAs, and two randomized trials of BMAs in control of pain secondary to bone metastases. Recommendations Patients with breast cancer who have evidence of bone metastases should be treated with BMAs. Options include denosumab, 120 mg subcutaneously, every 4 weeks; pamidronate, 90 mg intravenously, every 3 to 4 weeks; or zoledronic acid, 4 mg intravenously every 12 weeks or every 3 to 4 weeks. The analgesic effects of BMAs are modest, and they should not be used alone for bone pain. The Update Committee recommends that the current standard of care for supportive care and pain management-analgesia, adjunct therapies, radiotherapy, surgery, systemic anticancer therapy, and referral to supportive care and pain management-be applied. Evidence is insufficient to support the use of one BMA over another. Additional information is available at www.asco.org/breast-cancer-guidelines and www.asco.org/guidelineswiki .

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 .

A phase I/II trial of epirubicin and docetaxel in locally advanced breast cancer (LABC) on 2-weekly or 3-weekly schedules: NCIC CTG MA.22.

This phase I/II neoadjuvant trial (ClinicalTrials.gov identifier NCT00066443) determined maximally-tolerated doses (MTD), dose-limiting toxicities, response-to-therapy, and explored the role of novel response biomarkers. MA.22 accrued T3N0, any N2 or N3, and T4 breast cancer patients. Treatment was 6 cycles of 3-weekly (Schedule A; N = 47) or 8 cycles of 2-weekly (Schedule B; N = 46) epirubicin/docetaxel chemotherapy in sequential phase I/II studies, with growth factor support. In phase I of each schedule, MTDs were based on DLT. In phase II, clinical responses (CR/PR) and pathologic complete responses (pCR) were assessed. Tumor biopsy cores were obtained pre-, mid-, and post-treatment: 3 for pathologic assessment; 3 for microarray studies. DLT for Schedule A was febrile neutropenia at 105 mg/m(2) epirubicin and 75 mg/m(2) docetaxel; for schedule B, it was fatigue at 75 mg/m(2) for both agents. Phase II doses were 90 mg/m(2) epirubicin/75 mg/m(2) docetaxel for Schedule A and 60 mg/m(2) (both agents) for Schedule B. Schedule A CR/PR and pCR rates were 90 and 10 %, with large reductions in tumor RNA content and integrity following treatment; Schedule B results were 93 and 0 %, with smaller reductions in RNA quality. Pre-treatment expression of several genes was associated with clinical response, including those within a likely amplicon at 17q12 (ERBB2, TCAP, GSDMB, and PNMT). The combination regimens had acceptable toxicity, good clinical response, induction of changes in tumor RNA content and integrity. Pre-treatment expression of particular genes was associated with clinical responses, including several near 17q12, which with ERBB2, may better identify chemoresponsiveness.

Randomised, phase II, placebo-controlled, trial of fulvestrant plus vandetanib in postmenopausal women with bone only or bone predominant, hormone-receptor-positive metastatic breast cancer (MBC): the OCOG ZAMBONEY study.

Biomarkers of bone turnover, including urine N-telopeptide (uNTx), have been used as surrogate measures of response to bone-targeted therapies. Vascular endothelial growth factor (VEGF) levels correlate with extent of bone metastases. We assessed whether vandetanib, an inhibitor of VEGF, epidermal growth factor receptor and RET signalling, improved uNTx response when added to fulvestrant (F) in breast cancer patients with bone metastases. Postmenopausal patients with bone predominant, hormone-receptor-positive metastatic breast cancer were randomised to F (500 mg IM days 1, 15, 29, then monthly) with either vandetanib (100 mg PO OD) (FV) or placebo (FP). The primary objective was uNTx response. Secondary objectives included PFS, OS, RECIST response, pain scores and toxicity. Sixty-one patients were allocated to FV and 68 to FP. Out of 127 analyzable patients, an uNTx response occurred in 66 % for FV and 54 % for FP (p = 0.21). No difference was detected between groups for PFS; HR = 0.95 (95 % CI 0.65-1.38) or OS HR = 0.69 (95 % CI 0.37-1.31). For the 62 patients with measurable disease, clinical benefit rates were 41 and 43 %, respectively (p = 0.47). Serious adverse events were similar, 3.3 % for FV versus 5.9 % for FP. Elevated baseline uNTx (>65 nM BCE/mmol Cr) was prognostic for PFS, HR = 1.55 (95 % CI 1.04-2.30) and for OS, HR = 2.32 (95 % CI 1.25-4.33). The addition of vandetanib to fulvestrant did not improve biomarker response, PFS or OS in patients with bone metastases. Baseline bone turnover was prognostic for PFS and OS.

Bevacizumab for advanced breast cancer: hope, hype, and hundreds of headlines.

On February 22, 2008, the Food and Drug Administration granted accelerated approval for the use of bevacizumab (Avastin) in metastatic breast cancer. Based on subsequent clinical trials, this approval was revoked on November 18, 2011. In this study, we categorize and analyze the newspaper reports related to bevacizumab's use in advanced breast cancer. Methods. Using the Factiva media database, we reviewed all newspaper reports published in North America from January 4, 2002, to January 4, 2013, containing the words "breast cancer" and "Avastin," or "bevacizumab." Articles were classified as pre-approval (January 4, 2002-February 21, 2008), approval (February 22, 2008-November 17, 2011), or post-approval loss (November 18, 2011-January 4, 2013). Information regarding benefits, side effects, costs, interviewees, and article tone and theme were abstracted from each article by two independent reviewers. Differences among the three study phases were compared using the chi square analysis. Results. A total of 359 articles met study inclusion criteria. The number of reports having a positive headline tone and/or positive article tone declined with each study period. The proportion of articles discussing side effects and financial costs increased, whereas those discussing efficacy decreased with each study period. Drug representatives were most likely to be quoted in newspaper articles prior to bevacizumab's approval. Conclusion. Media reports are a common source of medical information for patients, practitioners, and policy makers. We observed substantial fluidity of media reports over time.

Bone-targeted agents in the treatment of bone metastases: RANK outsider or new kid on the block?

Stopeck AT, Lipton A, Body JJ et al.: Denosumab compared with zoledronic acid for the treatment of bone metastases in patients with advanced breast cancer: a randomized, double-blind study. Clin. Oncol. 28(35), 5132-5139 (2010). Bone is the most common site of recurrence in patients with advanced breast cancer. Bisphosphonates have revolutionized the care for patients with bone metastases by delaying and reducing skeletal complications. The RANK ligand inhibitor denosumab has been developed as a result of our enhanced understanding of bone physiology. In a recent randomized, double-blind trial, denosumab has been shown to be superior to zoledronic acid in delaying the onset of skeletal complications in advanced breast cancer patients. While these results are exciting, the absence of any survival benefit and the considerable cost of this agent mean that further quality-of-life data are needed before it becomes widely used as a new standard of care.

Phase II multicenter trial of anthracycline rechallenge with pegylated liposomal doxorubicin plus cyclophosphamide for first-line therapy of metastatic breast cancer previously treated with adjuvant anthracyclines.

PURPOSE: Anthracyclines are a component of breast cancer chemotherapy regimens in both adjuvant and metastatic settings. Anthracycline rechallenge for metastatic disease, for those previously exposed to adjuvant anthracyclines, may not be considered because of concerns about efficacy, tolerability, and cumulative cardiotoxicity. PATIENTS AND METHODS: This prospective, multicenter, single-arm, phase II trial examined the efficacy and safety of pegylated liposomal doxorubicin (PLD) 35 mg/m(2) plus cyclophosphamide 600 mg/m(2) as first-line therapy, delivered every 3 weeks, in 70 patients who developed metastatic disease more than 12 months after completion of an adjuvant anthracycline-containing regimen. Seven patients discontinued treatment early and were excluded from the efficacy analysis. RESULTS: After a median of six cycles, the objective response rate was 38%. An additional 33% of patients achieved stable disease lasting more than 6 months, for an overall clinical benefit rate of 71%. The estimated median time to progression was 12.2 months. Median overall survival time was 16.5 months. Clinical response was equally robust in patients with and without prior taxane exposure. Treatment was well tolerated. The most common grade 3 to 4 toxicities were palmar-plantar erythrodysesthesia (PPE; 10%), dyspnea (9%), and neutropenia (9%). One (1.4%) of 70 patients discontinued treatment as a result of PPE. One patient (1.4%) experienced an infusion reaction requiring discontinuation. No symptomatic cardiac events were observed. CONCLUSION: PLD plus cyclophosphamide is effective and well tolerated in patients with metastatic breast cancer who have received prior adjuvant anthracycline-containing chemotherapy. The majority of patients experienced a clinical benefit without any significant impact on cardiac function.

Changes in estrogen receptor, progesterone receptor and Her-2/neu status with time: discordance rates between primary and metastatic breast cancer.

BACKGROUND: Changes in the receptor profile between primary and metastatic breast cancer tissue have been suggested. The degree of hormone receptor discordance in archival paired pathological samples was evaluated. MATERIALS AND METHODS: Archival data were collected on 100 patients for whom tissue from primary and metastatic sites was available. Estrogen receptor (ER), progesterone receptor (PR) and Her-2/neu status in the primary and metastasis were compared. RESULTS: The discordance rate for ER was 17.7% (2-sided p=0.0039) with 9.7% of tumours changing from ER-positive to ER-negative and 8.0% changing from ER-negative to ER-positive. The discordance rate for PR was 37.3% (2-sided p<0.0001), with all of these tumours changing from PR-positive to PR-negative. No significant discordance for Her-2/neu was found. CONCLUSIONS: This series suggests that significant discordance exists for hormone receptor status between primary and metastatic breast cancer samples. Loss of PR was particularly frequent.

Adjuvant bisphosphonate therapy for breast cancer patients: Standard of care or future direction?

Bone is the most common site of metastatic spread in breast cancer patients. The use of bisphosphonates (BPs) in women with bone metastases from breast cancer has been shown to reduce the incidence, and delay the onset of, skeletal-related events. Indeed, BPs are now an established standard of care in treating patients with bone metastases. As with many new therapies, once efficacy in the metastatic setting is demonstrated, therapies are tested in the adjuvant setting. There are a number of trials that have tested the hypothesis that BP therapy in women with early breast cancer may not only reduce the development of skeletal metastases but also improve both disease-free and overall survival; recent randomized trials have demonstrated intriguing results regarding the possible anticancer effects of adjuvant BP therapy. Furthermore, interesting signals are filtering through from trials evaluating the role of BPs to prevent cancer-treatment induced bone loss. Many of these trials will be reported in the near future. In this article we review possible subgroups that may benefit from adjuvant treatment with BPs, and ongoing trials that may offer more definitive answers.

A randomized clinical trial of adjuvant chemotherapy for radically resected locoregional relapse of breast cancer: IBCSG 27-02, BIG 1-02, and NSABP B-37.

In this phase III, multinational, randomized trial, the International Breast Cancer Study Group, Breast International Group, and the National Surgical Adjuvant Breast and Bowel Project will attempt to define the effectiveness of cytotoxic therapy for patients with locoregional recurrence of breast cancer. We will evaluate whether chemotherapy prolongs disease-free survival and, secondarily, whether its use improves overall survival and systemic disease-free survival. Quality of life measurements will be monitored during the first 12 months of the study. Women who have had a previous diagnosis of invasive breast cancer treated by mastectomy or breast-conserving surgery and who have undergone complete surgical excision of all macroscopic disease but who subsequently develop isolated local and/or regional ipsilateral invasive recurrence are eligible. Patients are randomized to observation/no adjuvant chemotherapy or to adjuvant chemotherapy; all suitable patients receive radiation, hormonal, and trastuzumab therapy. Radiation therapy is recommended for patients who have not received previous adjuvant radiation therapy but is required for those with microscopically positive margins. The radiation field must encompass the tumor bed plus a surrounding margin to a dose of >or= 40 Gy. Radiation therapy will be administered before, during, or after chemotherapy. All women with estrogen receptor-positive and/or progesterone receptor-positive recurrence must receive hormonal therapy, with the agent and duration to be determined by the patient's investigator. Adjuvant trastuzumab therapy is permitted for those with HER2- positive tumors, provided that intent to treat is declared before randomization. Although multidrug regimens are preferred, the agents, doses, and use of supportive therapy are at the discretion of the investigator.

Phase II trial evaluating the palliative benefit of second-line zoledronic acid in breast cancer patients with either a skeletal-related event or progressive bone metastases despite first-line bisphosphonate therapy.

PURPOSE: This study evaluated whether additional palliative benefits could be derived from the second-line use of the more potent bisphosphonate zoledronic acid in metastatic breast cancer patients with either progressive bone metastases or skeletal-related events (SRE), despite first-line therapy with either pamidronate or clodronate. PATIENTS AND METHODS: This prospective study evaluated the impact of second-line zoledronic acid on pain, quality of life, and markers of bone turnover (for example, urinary N-telopeptide [NTX]). Patients received monthly zoledronic acid (4 mg) for 3 months. Study evaluations were made weekly during the first month and again at week 8. No changes in chemotherapy or endocrine therapy were allowed in the month before or after commencing study treatment. RESULTS: Thirty-one women completed this study. By week 8, patients had experienced significant improvements in pain control (P < .001). There was a downward trend in urinary NTX levels over the same time period (P = .008). Overall, there was a trend towards a positive correlation between improvement in pain control and reduction in week one urinary NTX relative to baseline (Spearman's rho r = 0.27; P = .15). CONCLUSION: This is the first study to demonstrate that patients with either progressive bone metastases or SREs while on clodronate or pamidronate can have relevant palliative benefits with a switch to the more potent bisphosphonate zoledronic acid. This is reflected by significant improvements in pain control and bone turnover markers. If confirmed in randomized trials, these findings have major implications to the use of bisphosphonates in both the metastatic and adjuvant settings.