Effectiveness of bisphosphonate use and risk of contralateral breast cancer and recurrence in women with early-stage breast cancer treated with tamoxifen

PdpaMn inhibits fatty acid synthase-mediated glycolysis by down-regulating PI3K/Akt signaling pathway in breast cancer

Novel manganese complex, PdpaMn ([(Pdpa)MnCl2]), was developed to induce apoptosis in breast cancer cells. The impact of phosphoinositide-(3)-kinase pathway onto fatty acid synthase (FASN) has an effect on cellular metabolism in breast cancer. However, reverse actions from FASN towards PI3K/Akt are still indefinable. Perhaps, loss of FASN could regulate glycolysis. Previously we established that PdpaMn inhibits FASN and involve in mitochondrial function. This study investigated the activity of PdpaMn on glycolysis and its mechanism. PdpaMn was used to suppress FASN expression in tumor. Expression of ATP and lactic acid level was measured to investigate the glycolysis variance in cells and animals. MCF-7 and 4T1 cells were treated with G28UCM, an inhibitor of FASN and PdpaMn, western blotting to detect PI3K/Akt signaling pathway. The capacity of proliferation was investigated by western blotting and immunohistochemistry. PdpaMn selectively inhibits cancer cells and tumor growth but also block FASN expression and suppresses the content of free fatty acid. Lactate dehydrogenase (LDHA) protein level was down-regulated as G28UCM and PdpaMn inhibited FASN, glucose transporter (Glut1), and pyruvate kinase (PKM2) proteins level were not affected. PI3K, p-Akt in the experimental group evidently declined compared to the control group. Proliferation was suppressed in FASN-arbitrated glycolysis. Our study supports the hypothesis that loss of FASN by PdpaMn suppressed glycolysis via down-regulating PI3K/Akt signaling pathway revealing the direct link between FASN and glycolysis. The results have paved the way to unravel the mechanisms of FASN and mitochondrial will be useful for designing novel co-targeting strategies for breast cancer.

Benefits of Bisphosphonate Therapy: Beyond the Skeleton

PURPOSE OF REVIEW

Recent evidence from clinical trials and observational studies raises the possibility that bisphosphonate use might confer a lower risk of cardiovascular disease and cancer, resulting in a mortality benefit. This review summarizes clinical and preclinical studies examining the non-skeletal effects of bisphosphonates.

RECENT FINDINGS

Data from clinical trials are conflicting regarding whether or not bisphosphonates have beneficial effects on mortality, cardiovascular events, or cancer incidence. No clinical trials have assessed these outcomes as primary endpoints, and most trials were shorter than 4 years. Observational data suggest that bisphosphonate users may have lower mortality, delayed progression of vascular calcification and atherosclerotic burden, and reduced incidence of breast and colorectal cancer compared to non-users. Preclinical studies confirm that bisphosphonates can be taken up by macrophages and monocytes, and nitrogen-containing bisphosphonates have the ability to disrupt the mevalonate pathway within these cells. In this manner, bisphosphonates exert anti-atherogenic and anti-cancer effects. Bisphosphonates also appear to exert protective effects on vascular smooth muscle cells and endothelial cells and may have direct cytotoxic effects on cancer cells. The balance of evidence does not support bisphosphonate treatment for the primary purpose of improving non-skeletal outcomes, although appropriately designed controlled trials that further explore this possibility are both justified and required. Patients with skeletal indications for bisphosphonate therapy can be reassured that these agents are not associated with increased mortality, cardiovascular disease, or cancer incidence.

Effects of Zoledronate on Cancer, Cardiac Events, and Mortality in Osteopenic Older Women

We recently showed that zoledronate prevented fractures in older women with osteopenia (hip T-scores between -1.0 and -2.5). In addition to fewer fractures, this study also suggested that women randomized to zoledronate had fewer vascular events, a lower incidence of cancer, and a trend to lower mortality. The present analysis provides a more detailed presentation of the adverse event data from that study, a 6-year, double-blind trial of 2000 women aged >65 years recruited using electoral rolls. They were randomly assigned to receive four infusions of either zoledronate 5 mg or normal saline at 18-month intervals. Supplements of vitamin D, but not calcium, were provided. There were 1017 serious adverse events in 443 participants in the placebo group, and 820 events in 400 participants in those randomized to zoledronate (relative risk = 0.90; 95% CI, 0.81 to 1.00). These events included fractures resulting in hospital admission. Myocardial infarction occurred in 39 women (43 events) in the placebo group and in 24 women (25 events) in the zoledronate group (hazard ratio 0.60 [95% CI, 0.36 to 1.00]; rate ratio 0.58 [95% CI, 0.35 to 0.94]). For a prespecified composite cardiovascular endpoint (sudden death, myocardial infarction, coronary artery revascularization, or stroke) 69 women had 98 events in the placebo group, and 53 women had 71 events in the zoledronate group (hazard ratio 0.76 [95% CI, 0.53 to 1.08]; rate ratio 0.72 [95% CI, 0.53 to 0.98]). Total cancers were significantly reduced with zoledronate (hazard ratio 0.67 [95% CI, 0.51 to 0.89]; rate ratio 0.68 [95% CI, 0.52 to 0.89]), and this was significant for both breast cancers and for non-breast cancers. Eleven women had recurrent or second breast cancers during the study, all in the placebo group. The hazard ratio for death was 0.65 (95% CI, 0.40 to 1.06; p = 0.08), and 0.51 (95% CI, 0.30 to 0.87) in those without incident fragility fracture. These apparent beneficial effects justify further appropriately powered trials of zoledronate with these nonskeletal conditions as primary endpoints. © 2019 American Society for Bone and Mineral Research.

Preventive drug therapy and contralateral breast cancer: summary of the evidence of clinical trials and observational studies

Background: Breast cancer patients have a lifelong 2-4-fold increased risk of developing a second primary tumor in the contralateral breast compared with the risk for a first primary breast cancer in the general female population. Prevention of contralateral breast cancer (CBC) has received increased attention during recent decades. Here, we summarize and discuss the available literature on drug preventive therapy and CBC.Results: The endocrine-targetting drugs, tamoxifen and aromatase inhibitors are used as standard adjuvant treatment for estrogen receptor (ER)-positive breast cancer. Both are associated with relative risk reductions of CBC of up to 50%, but incur serious side effects. Several prescription drugs originally developed for other purposes, including bisphosphonates, statins, non-steroidal anti-inflammatory drugs, metformin, anti-hypertensives and retinoids, have shown anti-cancer activity in preclinical models. However, results of observational studies on CBC are sparse and inconsistent, with only statins demonstrating promise as preventive agents and a potential treatment option for ER-negative breast cancer patients.Conclusion: Future studies are needed to assess the effect of statins in risk reduction and to identify other drugs with chemopreventive potential against CBC. Eventually, efforts must be directed towards identifying those breast cancer patients likely to benefit most from specific preventive therapies.

Bisphosphonates and primary breast cancer risk: an updated systematic review and meta-analysis involving 963,995 women

Importance

Prevention of primary breast cancer (BCa) in women is of great public health importance. The existing results from observational epidemiologic studies focused on the association between bisphosphonates and primary BCa risk have been inconsistent.

Objective

To update this systematic review and meta-analysis to assess the effect of bisphosphonates on primary BCa risk.

Data sources

We comprehensively searched MEDLINE, EMBASE, Cochrane libraries, ProQuest, and Web of Science through June 25, 2018 for relevant studies.

Study selection

Epidemiological studies that assessed the effect of bisphosphonates on the risk of primary BCa in women.

Data extraction and synthesis

We reported this meta-analysis according to the PRISMA guidelines. Available multivariable-adjusted effect estimates and corresponding 95% CIs were pooled with a random-effects model.

Main outcomes and measures

The prespecified main outcome was the risk of primary BCa.

Results

In total, five cohort studies involving 657,558 women and 12,991 primary BCa patients, three population-based case-control studies involving 54,701 primary BCa cases and 237,962 healthy controls and two randomized controlled trials (RCTs) involving 13,774 women and 165 primary BCa patients were included in this meta-analysis. Bisphosphonates were associated with a 12% decreased risk of primary BCa (RR, 0.88; 95% CI, 0.83–0.94). However, when we analyzed study designs separately, the pooled results from observational studies were inconsistent with that from RCTs. The observed association of primary BCa risk with long-term use (≥1 year) of bisphosphonates seemed to be more robust and stronger than that of short-term use (<1 year) (RR, 0.75; 95% CI, 0.66–0.84; and 0.90; 95% CI, 0.84–0.97; respectively).

Conclusion

This meta-analysis adds to the body of evidence for an association between bisphosphonates and a significantly decreased risk of primary BCa. However, future large-scale RCTs are required to validate this concern.

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

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

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

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

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

Bisphosphonate Use and Risk of Recurrence, Second Primary Breast Cancer, and Breast Cancer Mortality in a Population-Based Cohort of Breast Cancer Patients

Background: Studies of bisphosphonate use and breast cancer recurrence have produced conflicting results. Analyses of large adjuvant trials suggest that bisphosphonates reduce recurrence risk only in postmenopausal women.Methods: We assessed the effect of noncancer treatment-related bisphosphonate use on breast cancer outcomes in a population-based prognostic cohort of women with early-stage invasive breast cancer (n = 1,813; median follow-up = 11.8 years). Using medical record, interview, and cancer registry data, information was assembled on risk factors, cancer treatment, medication use, and outcomes. Statistical analyses used Cox proportional hazards regression models.Results: Bisphosphonate use was associated with a significantly decreased risk of a breast cancer event [locoregional/distant recurrence or second primary breast cancer; HR ever use, 0.65; 95% confidence interval (CI), 0.47-0.90]. Reduced risks were observed in both pre/peri and postmenopausal women, in both ER-negative and ER-positive breast cancers, and for both earlier and later recurrences. Bisphosphonate use was also associated with a significantly decreased risk of breast cancer mortality (HR, 0.40; 95% CI, 0.23-0.69).Conclusions: Bisphosphonate use was associated with a reduction in risk of breast cancer events and improved breast cancer-specific survival in women with early-stage breast cancer. We hypothesize that the benefit of bisphosphonates on breast cancer outcomes may be present primarily in women with low bone density and regardless of menopausal status.Impact: Our findings suggest further consideration of bone density status as a modifier of bisphosphonate's potential beneficial benefits on breast cancer outcomes is warranted. Cancer Epidemiol Biomarkers Prev; 27(2); 165-73. ©2017 AACR.