Bisphosphonate treatment and risk of esophageal cancer: a meta-analysis of observational studies

Bisphosphonates and risk of cancers: a systematic review and meta-analysis

Background

It is unclear whether bisphosphonates are associated with risk of cancers. Therefore, this meta-analysis aimed to evaluate the effect of bisphosphonates on overall cancers.

Methods

A search in Pubmed, Embase, Cochrane Library and Web of Science databases was conducted, from the inception date of each resource to September 26, 2019. The summarised effect estimates with 95% CIs were calculated using a random-effect model. Heterogeneity and publication bias were explored.

Results

Thirty-four articles were included in this study (4,508,261 participants; 403,196 cases). The results revealed that bisphosphonates significantly decreased the risk of colorectal cancer (RR = 0.89, 95% CI: 0.81–0.98), breast cancer (RR = 0.87, 95% CI: 0.82–0.93) and endometrial cancer (RR = 0.75, 95% CI: 0.61–0.94), but no significant association was observed in all-cause cancer. Furthermore, nitrogen-containing bisphosphonates only had protective effects both on breast cancer (RR = 0.94, 95% CI: 0.90–0.99) and endometrial cancer (RR = 0.70, 95% CI: 0.54–0.92). Non-nitrogen-containing bisphosphonates tended to increase the risk of liver cancer (RR = 2.14, 95% CI: 1.23–3.72) and pancreas cancer (RR = 1.75, 95% CI: 1.32–2.33).

Conclusion

Bisphosphonates are significantly associated with risk reduction of colorectal, breast and endometrial cancer, especially nitrogen-containing bisphosphonates. It should be noted that non-nitrogen-containing bisphosphonates might increase the risk of liver and pancreas cancer. Large prospective cohort studies are needed to find the causal association between bisphosphonates and risk of cancers.

Comparative safety and effectiveness of alendronate versus raloxifene in women with osteoporosis

Alendronate and raloxifene are among the most popular anti-osteoporosis medications. However, there is a lack of head-to-head comparative effectiveness studies comparing the two treatments. We conducted a retrospective large-scale multicenter study encompassing over 300 million patients across nine databases encoded in the Observational Medical Outcomes Partnership (OMOP) Common Data Model (CDM). The primary outcome was the incidence of osteoporotic hip fracture, while secondary outcomes were vertebral fracture, atypical femoral fracture (AFF), osteonecrosis of the jaw (ONJ), and esophageal cancer. We used propensity score trimming and stratification based on an expansive propensity score model with all pre-treatment patient characteritistcs. We accounted for unmeasured confounding using negative control outcomes to estimate and adjust for residual systematic bias in each data source. We identified 283,586 alendronate patients and 40,463 raloxifene patients. There were 7.48 hip fracture, 8.18 vertebral fracture, 1.14 AFF, 0.21 esophageal cancer and 0.09 ONJ events per 1,000 person-years in the alendronate cohort and 6.62, 7.36, 0.69, 0.22 and 0.06 events per 1,000 person-years, respectively, in the raloxifene cohort. Alendronate and raloxifene have a similar hip fracture risk (hazard ratio [HR] 1.03, 95% confidence interval [CI] 0.94–1.13), but alendronate users are more likely to have vertebral fractures (HR 1.07, 95% CI 1.01–1.14). Alendronate has higher risk for AFF (HR 1.51, 95% CI 1.23–1.84) but similar risk for esophageal cancer (HR 0.95, 95% CI 0.53–1.70), and ONJ (HR 1.62, 95% CI 0.78–3.34). We demonstrated substantial control of measured confounding by propensity score adjustment, and minimal residual systematic bias through negative control experiments, lending credibility to our effect estimates. Raloxifene is as effective as alendronate and may remain an option in the prevention of osteoporotic fracture.

The Belgian Bone Club 2020 guidelines for the management of osteoporosis in postmenopausal women

PURPOSE

To provide updated evidence-based guidelines for the management of osteoporosis in postmenopausal women in Belgium.

METHODS

The Belgian Bone Club (BBC) gathered a guideline developer group. Nine "Population, Intervention, Comparator, Outcome" (PICO) questions covering screening, diagnosis, non-pharmacological and pharmacological treatments, and monitoring were formulated. A systematic search of MEDLINE, the Cochrane Database of Systematic Reviews, and Scopus was performed to find network meta-analyses, meta-analyses, systematic reviews, guidelines, and recommendations from scientific societies published in the last 10 years. Manual searches were also performed. Summaries of evidence were provided, and recommendations were further validated by the BBC board members and other national scientific societies' experts.

RESULTS

Of the 3840 references in the search, 333 full texts were assessed for eligibility, and 129 met the inclusion criteria. Osteoporosis screening using clinical risk factors should be considered. Patients with a recent (<2 years) major osteoporotic fracture were considered at very high and imminent risk of future fracture. The combination of bone mineral density measured by dual-energy X-ray absorptiometry and 10-year fracture risk was used to categorize patients as low or high risk. Patient education, the combination of weight-bearing and resistance training, and optimal calcium intake and vitamin D status were recommended. Antiresorptive and anabolic osteoporosis treatment should be considered for patients at high and very high fracture risk, respectively. Follow-up should focus on compliance, and patient-tailored monitoring should be considered.

CONCLUSION

BBC guidelines and 25 guideline recommendations bridge the gap between research and clinical practice for the screening, diagnosis, and management of osteoporosis.

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.

Risk reduction of endometrial and ovarian cancer after bisphosphonates use: A meta-analysis

OBJECTIVE

Recent epidemiological studies have investigated the associations between the use of bisphosphonates and the development of endometrial cancer and ovarian cancer; these studies have shown controversial results. Hence, this meta-analysis was conducted to evaluate the changes in the risks of developing endometrial and ovarian cancers after using bisphosphonates based on current evidence.

METHODS

A comprehensive search was performed in the MEDLINE, EMBASE, and Web of Science databases through January 2017. The summary relative risk (RR) estimates for the effects of the use of bisphosphonates on the risks of developing endometrial and ovarian cancers were calculated using a random-effects model.

RESULTS

Seven studies were included with a total of 6471 endometrial cancer cases (7 studies with 213,920 participants) and 6783 ovarian cancer cases (4 studies with 105,507 participants). This meta-analysis suggested that any use of bisphosphonates was associated with a significant 27% reduction in the risk of endometrial cancer (RR = 0.73, 95% CI: 0.58-0.93, P = 0.012), but the reduction in the risk of ovarian cancer (RR = 0.81, 95% CI: 0.58-1.14, P = 0.227) was not significant. The protective effects of the use of bisphosphonates against endometrial cancer are mainly found in postmenopausal women (RR = 0.53, 95% CI: 0.34-0.93, P = 0.012) or in those who have taken bisphosphonates for longer than 1 year (RR = 0.57, 95% CI: 0.35-0.93, P = 0.024).

CONCLUSION

This meta-analysis suggests that the use of bisphosphonates is associated with a reduction in the risk of endometrial cancer but not ovarian cancer.

Bisphosphonate-induced osteonecrosis of the ear canal: our experience and a review of the literature

BACKGROUND

Oesophageal disorders and osteonecrosis of the jaw are recognised complications of the commonly prescribed medication bisphosphonate. Despite these diagnoses being seen comparatively frequently within the ENT clinic, osteonecrosis of the external ear is a less well reported complication.

METHODS

The current literature is reviewed and our experience with six cases of bisphosphonate-related ear canal osteonecrosis is presented.

RESULTS

Six cases were identified as suffering from ear canal osteonecrosis as a result of bisphosphonate treatment. One of our cases suffered bilateral ear canal osteonecrosis after only 20 months of oral alendronic acid treatment. Management ranged from bisphosphonate cessation and topical treatment, to surgical debridement in the operating theatre.

CONCLUSION

Bisphosphonate-related ear canal osteonecrosis is undoubtedly under-diagnosed. For such a commonly prescribed medication, the risks and side effects of bisphosphonate should be better known and long-term treatment should be avoided if possible.

A systematic review and economic evaluation of bisphosphonates for the prevention of fragility fractures

BACKGROUND

Fragility fractures are fractures that result from mechanical forces that would not ordinarily result in fracture.

OBJECTIVES

To evaluate the clinical effectiveness and safety of bisphosphonates [alendronic acid (Fosamax^® and Fosamax^® Once Weekly, Merck Sharp & Dohme Ltd), risedronic acid (Actonel^® and Actonel Once a Week^®, Warner Chilcott UK Ltd), ibandronic acid (Bonviva^®, Roche Products Ltd) and zoledronic acid (Aclasta^®, Novartis Pharmaceuticals UK Ltd)] for the prevention of fragility fracture and to assess their cost-effectiveness at varying levels of fracture risk.

DATA SOURCES

For the clinical effectiveness review, six electronic databases and two trial registries were searched: MEDLINE, EMBASE, The Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, Web of Science and BIOSIS Previews, Clinicaltrials.gov and World Health Organization International Clinical Trials Registry Platform. Searches were limited by date from 2008 until September 2014.

REVIEW METHODS

A systematic review and network meta-analysis (NMA) of effectiveness studies were conducted. A review of published economic analyses was undertaken and a de novo health economic model was constructed. Discrete event simulation was used to estimate lifetime costs and quality-adjusted life-years (QALYs) for each bisphosphonate treatment strategy and a strategy of no treatment for a simulated cohort of patients with heterogeneous characteristics. The model was populated with effectiveness evidence from the systematic review and NMA. All other parameters were estimated from published sources. A NHS and Personal Social Services perspective was taken, and costs and benefits were discounted at 3.5% per annum. Fracture risk was estimated from patient characteristics using the QFracture^® (QFracture-2012 open source revision 38, Clinrisk Ltd, Leeds, UK) and FRAX^® (web version 3.9, University of Sheffield, Sheffield, UK) tools. The relationship between fracture risk and incremental net benefit (INB) was estimated using non-parametric regression. Probabilistic sensitivity analysis (PSA) and scenario analyses were used to assess uncertainty.

RESULTS

Forty-six randomised controlled trials (RCTs) were included in the clinical effectiveness systematic review, with 27 RCTs providing data for the fracture NMA and 35 RCTs providing data for the femoral neck bone mineral density (BMD) NMA. All treatments had beneficial effects on fractures versus placebo, with hazard ratios varying from 0.41 to 0.92 depending on treatment and fracture type. The effects on vertebral fractures and percentage change in BMD were statistically significant for all treatments. There was no evidence of a difference in effect on fractures between bisphosphonates. A statistically significant difference in the incidence of influenza-like symptoms was identified from the RCTs for zoledronic acid compared with placebo. Reviews of observational studies suggest that upper gastrointestinal symptoms are frequently reported in the first month of oral bisphosphonate treatment, but pooled analyses of placebo-controlled trials found no statistically significant difference. A strategy of no treatment was estimated to have the maximum INB for patients with a 10-year QFracture risk under 1.5%, whereas oral bisphosphonates provided maximum INB at higher levels of risk. However, the PSA suggested that there is considerable uncertainty regarding whether or not no treatment is the optimal strategy until the QFracture score is around 5.5%. In the model using FRAX, the mean INBs were positive for all oral bisphosphonate treatments across all risk categories. Intravenous bisphosphonates were estimated to have lower INBs than oral bisphosphonates across all levels of fracture risk when estimated using either QFracture or FRAX.

LIMITATIONS

We assumed that all treatment strategies are viable alternatives across the whole population.

CONCLUSIONS

Bisphosphonates are effective in preventing fragility fractures. However, the benefit-to-risk ratio in the lowest-risk patients may be debatable given the low absolute QALY gains and the potential for adverse events. We plan to extend the analysis to include non-bisphosphonate therapies.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013006883.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Long-Term Bisphosphonate Therapy in Osteogenesis Imperfecta

PURPOSE OF REVIEW

Osteogenesis imperfecta (OI) is a genetic bone disorder resulting in bone fragility. It has a heterogeneous phenotype which typically includes reduced bone mass, multiple fractures, deformity, and chronic disability. Bisphosphonate treatment remains the first-line medical management, but there is still debate on aspects of its effectiveness. This review summarizes current knowledge about long-term bisphosphonate use in OI with recommendations on clinical application.

RECENT FINDINGS

Bisphosphonates increase bone mineral density, most notably of the vertebrae, and reduce fracture risk in the pediatric OI population. Gains in strength and mobility, together with the permissive effect on orthopedic surgery (e.g., in combination with intramedullary rodding) and physiotherapy, have resulted in improved quality of life for those with OI. As experience in its use continues, the risks and benefits of long-term bisphosphonate treatment in OI are slowly emerging. Patient registries containing data on genotype, phenotype, fractures, bisphosphonate treatment, orthopedic intervention, and functional outcomes are essential for systematic evaluation given the lack of large multi-centered randomized control trials.

Physicians’ knowledge and attitude regarding bisphosphonates-related adverse events: An observational study

AIM

To assess the knowledge and attitude of Lebanese physicians regarding bisphosphonates (BPs)-related complications.

METHODS

An observational cross-sectional study was conducted at a major tertiary teaching hospital in Beirut city, and its affiliated primary health care center. Data were collected through a new self-administered questionnaire distributed via a delegated secretary to physicians expected to regularly prescribe BPs (n = 215). It assessed participants’ knowledge, fear and experience regarding BPs-reported complications.

RESULTS

One hundred and fifty-seven physicians fulfilled the questionnaire (response rate: 73.0%): 77.7% and 75.2% considered that gastrointestinal intolerance and osteonecrosis of the jaw are linked to BPs, respectively. Conversely, the least recognised complications are ocular inflammation (7.6%) and severe musculoskeletal pain (37.6%). The association of BPs with oesophageal cancer, atrial fibrillation and hepatotoxicity was reported by 11.5%, 13.4% and 24.8% of respondents, respectively. The multivariate analysis showed a significant association between level of knowledge and physicians’ department affiliation (P-value = 0.043), their gender (P-value = 0.044), whether or not they prescribe a BP (P-value = 0.012), and the number of BP prescriptions delivered monthly (P-value = 0.012). Physicians are mainly concerned about osteonecrosis of the jaw and nephrotoxicity when prescribing a BP. Yet, the complications commonly met in their practice are gastrointestinal intolerance (44.6%) and acute phase reactions (26.7%).

CONCLUSION

This study revealed the presence of a deficient knowledge regarding BPs-related adverse events among our physicians. Professional training proposals are needed to increase their knowledge and improve their practices. Pharmaceutical industries should reconsider the instructions they provide to physicians regarding the complications of medications they promote. Moreover, they must actively collaborate with education providers and institutions in educational interventions.

Bisphosphonate-related osteonecrosis of the jaw: from the sine qua non condition of bone exposure to a non-exposed BRONJ entity

The present work aimed to review the literature focusing on the diagnostic criteria for bisphosphonate-related osteonecrosis of the jaw (BRONJ) and its implications regarding the management of the disease. Since the report of the first cases, BRONJ concepts, diagnostic criteria and guidelines have been changed. The presence of bone exposure in the oral cavity was at first a sine qua non condition for diagnosis. However, it seems that the great concern now is the possibility of occurrence of BRONJ without this feature. Some authors warn that the bone exposure criterion leads to late diagnosis and poor response to treatment. Meanwhile, some radiographic features, such as bone sclerosis, have been postulated as early signs of the disease. Criticisms have also been raised about the clinical staging system of BRONJ. While there is no consensus on the subject, common sense recommends treating symptomatic patients taking bisphosphonate as having BRONJ despite the absence of bone exposure; and asymptomatic patients must be kept under dental follow-up, since all of them are at risk for BRONJ.

Oral Bisphosphonates and Upper Gastrointestinal Cancer Risks in Asians with Osteoporosis: A Nested Case-Control Study Using National Retrospective Cohort Sample Data from Korea

Background

Bisphosphonate can irritate the gastrointestinal mucosa and increase the risk of esophageal or gastric cancer. The relatively high prevalence of upper gastrointestinal cancers and the widespread use of bisphosphonate in Korea call for further investigation. We conducted a case-control study to evaluate the risk of esophageal or gastric cancer after exposure to oral bisphosphonates in Korean patients with osteoporosis.

Methods

We used the National Health Insurance Service-National Sample Cohort database of Korea from 2002 to 2013. Among osteoporotic patients (>40 years), cases were defined as incident diagnosis of esophageal or gastric cancer between 2006 and 2013. For each case, four controls were matched for age, sex, and income level by type of insurance. We categorized bisphosphonate use as non-user, recent user, past user, and past and recent user, depending on prescription in two periods (1 to 2 years and 2 to 4 years prior to the index date). We also assessed the duration of bisphosphonate use by measuring cumulative duration of exposure (CDE). To examine the association between oral bisphosphonates and esophageal or gastric cancer, we estimated adjusted odds ratios (aORs) and 95% confidence intervals (CIs) using conditional logistic regression analysis, adjusting for concomitant diseases.

Results

A total of 1,708 cases and 6,832 controls were identified. The aORs (95% CIs) of recent, past, and continuous bisphosphonate use compared to non-users were 1.18 (0.93–1.51), 1.04 (0.83–1.29), and 1.25 (0.95–1.58)), respectively. In addition, no significant association was observed by CDE, even when different outcome definitions were applied.

Conclusions

This study did not prove an increased risk of esophageal or gastric cancer risk associated with bisphosphonate use, with respect to both risk windows and duration of exposure, in an Asian population-based, real-world setting.

Bisphosphonates as potential adjuvants for patients with cancers of the digestive system

Best known for their anti-resorptive activity in bone, bisphosphonates (BPs) have generated interest as potential antineoplastic agents given their pleiotropic biological effects which include antiproliferative, antiangiogenic and immune-modulating properties. Clinical studies in multiple malignancies suggest that BPs may be active in the prevention or treatment of cancer. Digestive tract malignancies represent a large and heterogeneous disease group, and the activity of BPs in these cancers has not been extensively studied. Recent data showing that some BPs inhibit human epidermal growth factor receptor (HER) signaling highlight a potential therapeutic opportunity in digestive cancers, many of which have alterations in the HER axis. Herein, we review the available evidence providing a rationale for the repurposing of BPs as a therapeutic adjunct in the treatment of digestive malignancies, especially in HER-driven subgroups.

Carpal Tunnel Syndrome Associated with Oral Bisphosphonates. A Population-Based Cohort Study

BACKGROUND

Bisphosphonates are widely used to prevent osteoporotic fractures. Some severe musculoskeletal reactions have been described with this medication; among them, some cases of carpal tunnel syndrome. Thus, the aim of this study was to explore whether bisphosphonates may be associated with this syndrome.

METHODS

A cohort study was conducted to compare exposed to unexposed women; the exposed group was that composed of women having received at least one prescription of an oral bisphosphonate. For the purpose, we used information from The Health Improvement Network (THIN) database. The outcome of interest was defined as those women diagnosed with carpal tunnel syndrome. A survival analysis was performed; the Cox proportional hazard model was used to calculate hazard ratios and 95% confidence intervals, and to adjust for identified confounding variables.

RESULTS

Out of a sample of 59,475 women older than 51 years, 19,825 were treated with bisphosphonates during the period studied. No differences in age distribution or mean follow-up time were observed between the two groups in comparison. Overall, there were 572 women diagnosed with carpal tunnel syndrome, 242 (1.2%) in the group exposed to bisphosphonates, and 330 (0.8%) in the unexposed. An adjusted hazard ratio of developing carpal tunnel syndrome of 1.38 (95%CI, 1.15-1.64) was found for women exposed to bisphosphonates; no significant changes in the hazard ratios were found when considering different levels of bisphosphonate exposure.

CONCLUSIONS

An increased risk of carpal tunnel syndrome is associated with the use of bisphosphonates in postmenopausal women.

Bisphosphonates and evidence for association with esophageal and gastric cancer: a systematic review and meta-analysis

OBJECTIVES

Concerns have been raised about a possible link between bisphosphonate use, and in particular alendronate, and upper gastrointestinal (UGI) cancer. A number of epidemiological studies have been published with conflicting results. We conducted a systematic review and meta-analysis of observational studies, to determine the risk of esophageal and gastric cancer in users of bisphosphonates compared with non-users.

DESIGN

We searched PubMed, MEDLINE, EMBASE, Web of Knowledge and Cochrane Database of Systematic Reviews for studies investigating bisphosphonates and esophageal or gastric cancer. We calculated pooled ORs and 95% CIs for the risk of esophageal or gastric cancer in bisphosphonate users compared with non-users. We performed a sensitivity analysis of alendronate as this was the most common single drug studied and is also the most widely used in clinical practice.

RESULTS

11 studies (from 10 papers) examining bisphosphonate exposure and UGI cancer (gastric and esophageal), met our inclusion criteria. All studies were retrospective, 6/11 (55%) case-control and 5/11(45%) cohort, and carried out using data from 5 longitudinal clinical databases. Combining 5 studies (1 from each database), we found no increased risk, OR 1.11 (95% CI 0.97 to 1.27) of esophageal cancer in bisphosphonate users compared with non-users and no increased risk of gastric cancer in bisphosphonate users, OR 0.96 (95% CI 0.82 to 1.12).

CONCLUSION

This is the fourth and most detailed meta-analysis on this topic. We have not identified any compelling evidence for a significantly raised risk of esophageal cancer or gastric cancer in male and female patients prescribed bisphosphonates.

The use of bisphosphonates in women: when to use and when to stop

INTRODUCTION

Bisphosphonates (BPs) are the most commonly used drugs in osteoporosis.

AREAS COVERED

This review focuses on the criteria for identifying patients who should be treated with BPs and also the rational for the duration of treatment.

EXPERT OPINION

BPs remain the mainstay for the treatment of osteoporosis. For their low cost, the treatment threshold is related exclusively to the ratio between expected benefits and the risk of side effects. This is the case of patients with prior fragility fracture or with low bone density and the presence of other relevant risk factors. The treatment should continue for 3 - 5 years or until fracture risk is no longer high. Afterward a treatment holiday should be considered on the light of the increasing risk of side effects but its duration is still controversial. The duration of this treatment holiday depends on the drug used. Discontinuation of risedronate and ibandronate is associated with the quick loss of the acquired benefits and with these two BPs discontinuation should not exceed 6 months. Alendronate and zoledronate are characterized by a persistent effect after discontinuing treatment and this would allow a more prolonged drug holiday.

Oral Bisphosphonate and Risk of Esophageal Cancer: A Nationwide Claim Study

Background

Epidemiology studies suggest that oral bisphosphonate may increase the risk of esophageal cancer. The present study aimed to investigate the association between exposure of oral bisphosphonate and risk of esophageal cancer.

Methods

Using the nationwide medical claim database in South Korea, 2,167,955 subjects, who initiated osteoporosis treatment (oral bisphosphonate, intravenous bisphosphonate or raloxifene) or performed dual energy X-ray absorptiometry (DXA) between 2008 and 2012, were analyzed. Diagnosis of esophageal cancer was estimated from medical claim database. Standardized incidence ratio (SIR) was estimated by comparing with incidence in the general population. Cox proportional hazards modeling was used to investigate age-adjusted hazard ratio (aHR) of esophageal cancer.

Results

The present study included oral bisphosphonate group (N=1,435,846), comparator group 1 (intravenous bisphosphonate or raloxifene, N=78,363) and comparator group 2 (DXA, N=653,746). Mean age was 65.6±8.8 years and mean observation duration was 30.9±17.7 months. During 5,503,688 patient-years, 205 esophageal cancer incidences were observed. The annual incidence of esophageal cancer was 3.88, 4.21, and 3.30 for oral bisphosphonate group, comparator group 1 and comparator group 2, respectively. SIR of esophageal cancer was 1.24, 1.38, and 1.40 for oral bisphosphonate group, comparator group 1 and comparator group 2, respectively. Esophageal cancer risk of oral bisphosphonate group was not significantly different from comparator group 1 and comparator group 2 (aHR 0.87; 95% confidence interval [CI] 0.39-1.98 and aHR 0.94; 95% CI 0.68-1.30, respectively).

Conclusions

The use of oral bisphosphonate was not associated with increased risk of esophageal cancer in real clinical practice using large scale nationwide database.

The carcinogenicity of alendronate in patients with osteoporosis: evidence from cohort studies

Context

Alendronate may relate to the incidence of cancers, especially esophageal and colon cancer. But the results are inconsistent in different studies.

Objective

To quantify the association between the use of alendronate and the occurrence of different types of cancer.

Data Sources

We searched Embase, Pubmed, CENTRAL, SIGLE and clinicaltrials.gov, up to 2014 June.

Study Selection

Cohort studies reporting association between alendronate or bisphosphonate therapy including alendronate in patients with osteoporosis and risk of cancer were selected by two authors.

Data Extraction

Two authors independently extracted the data. The Chi-square test and the I-square test were used for testing heterogeneity between studies.

Data Synthesis

Eight cohort studies were included in the meta-analysis. Meta-analysis result manifested that alendronate significantly increased the incidence of lung cancer (HR 1.23, 95%CI 1.03 to 1.47, P value = 0.03), nevertheless, there was no significant difference after we excluded either Lee’s 2012 study (HR 1.17, 95%CI 0.95 to 1.44, P value = 0.13) or Chiang’s 2012 study (HR 1.47, 95%CI 1 to 2.17, P value = 0.05). For the incidence of colorectal cancer, no significant difference occurred (HR 0.91, 95%CI 0.74 to 1.13, P value = 0.39), but there was a positive relationship when we used fixed model (HR 0.85, 95%CI 0.78 to 0.93, P value = 0.004). For the incidence of liver cancer, there was no significant difference (HR 1.36, 95%CI 0.9 to 2.04, P value = 0.14), however, the result changed after we excluded Chiang’s 2012 study (HR 1.69, 95%CI 1.03 to 2.77, P value = 0.04). There was no significant difference in other types of cancer.

Conclusion

Based on current evidences, alendronate therapy may be associated with a high risk of lung cancer, may with an excess risk of liver cancer, a low risk of colorectal and no related risk of other cancers.

Oral bisphosphonates and upper gastrointestinal toxicity: a study of cancer and early signals of esophageal injury

SUMMARY

We evaluated the association between bisphosphonate use and (1) upper gastrointestinal cancer, (2) upper endoscopy, (3) incident Barrett's esophagus, and (4) prescription antacid initiation among Medicare beneficiaries. We found no bisphosphonate-cancer association and negative bisphosphonate-Barrett's association.

INTRODUCTION

Bisphosphonates can irritate the esophagus; a cancer association has been suggested. Widespread bisphosphonates use compels continued investigation of upper gastrointestinal toxicity.

METHODS

Using a 40% Medicare random sample denominator, inpatient, outpatient (2003-2011), and prescription (2006-2011) claims, we studied patients age 68 and older with osteoporosis and/or oral bisphosphonate use. Inverse propensity weighting estimated marginal structural models for the effect of bisphosphonate intensity (pills per month) and cumulative bisphosphonate pills received on upper gastrointestinal cancer risk. Secondary analyses of sub-cohorts without past bisphosphonates or upper endoscopy assessed bisphosphonate initiation and risk of (1) upper endoscopy, (2) incident Barrett's esophagus, and (3) prescription antacid initiation.

RESULTS

The cohort included 1.64 million beneficiaries: 87.9% women, mean age, 76.8 (standard deviation (SD) 9.3); mean follow-up, 39.6 months; 38.1% received oral bisphosphonates. Cumulative bisphosphonate receipt, among users, ranged from 4 to 252 pills (5th to 95th percentile). We identified 2,308 upper gastrointestinal cancers (0.43/1000 person years). We found no association between cumulative bisphosphonate pills and cancer, odds ratio (OR) for each additional pill 1.00 (95% confidence interval (CI) 1.00, 1.00). In sub-cohorts, compared to none, lowest cumulative bisphosphonate use (one to nine pills) was associated with higher risk of endoscopy (OR 1.11, 95% CI 1.08-1.14) and antacid initiation (OR 1.13, 95% CI 1.10-1.16); higher intensity conferred no increased risk. Higher intensity and higher cumulative bisphosphonate category were associated with lower Barrett's risk.

CONCLUSIONS

We found no bisphosphonate-cancer association and negative bisphosphonate-Barrett's association. Bisphosphonate initiation appears to identify patients susceptible to early irritating effects; clinicians might offer alternatives and delay endoscopy or antacids.

New strategies for osteoporosis patients previously managed with strontium ranelate

The aim of this article is to describe potential alternatives to patients no longer eligible for management with strontium ranelate for osteoporosis according to the recommendations by the European Medicines Agency. A systematic search of Pubmed was done for papers on fracture efficacy of various treatments for osteoporosis, and potential harms especially in terms of cardiovascular events and stroke. The results showed that drugs more efficacious in terms of relative risk reduction of fractures than strontium ranelate were alendronate, risedronate, zoledronate, and denosumab. Raloxifene, as for strontium, may be associated with an increased risk of deep venous thromboembolism and fatal stroke. In terms of cardiovascular events special attention may be given to calcium supplements. Thus, patients at risk of stroke and ischemic cardiac events such as acute myocardial infarction should not use strontium ranelate. Ideally more efficacious drugs in terms of fracture reduction should be used such as alendronate, risedronate, zoledronate or denosumab. Raloxifene may pose a special problem as this too may be associated with an increased risk of fatal strokes. Other less-potent drugs in terms of fracture reduction should only be used if no alternatives are available (ibandronate, pamidronate, clodronate). Parathyroid hormone or analogs may be used for a limited time interval in specially selected patients and needs to be followed up with antiresorptive treatment to prevent loss of the bone gained. However, it should be remembered that no head-to-head comparison studies exist.

How long should we treat?

Osteoporosis is a chronic disease, for which effective drugs are available. These drugs have reduced the risk of osteoporosis-related fractures in robust trials of 3-5 years duration. There is no evidence of anti-fracture efficacy for treatments of longer duration. The consequences of stopping treatments are very different for the different molecules. Bisphosphonates can be safely discontinued after 3-5 years of treatment if there was optimal adherence and if patients are no longer osteoporotic. This discontinuation cannot be applied in patients with recent fractures or for other treatments. Safety of prolonged treatment is a huge concern which must be managed appropriately. The decision of a prolonged treatment is driven by the underlying risk of fracture. This risk must be assessed regularly in order to share with the patient the benefit-risk ratio of prolonged treatment.

Safety issues with bisphosphonate therapy for osteoporosis

Randomized controlled trials have demonstrated the efficacy of bisphosphonates (BP) in improving BMD and reducing fracture risk. Various safety issues that were not noted in clinical trials have, however, now emerged with post-marketing surveillance and increasing clinical experience. The risk of atypical femoral fracture could increase with long-term use of BP, although absolute risk is very small, particularly when balanced against benefits. A drug holiday should be considered after 5 years of treatment for patients at low risk of fracture, although there is no official recommendation regarding this to guide clinicians. Osteonecrosis of the jaw from low-dose BP used for osteoporosis is very rare, and mainly a complication with high-dose i.v. BP used in oncology. The risk of atrial fibrillation too is negligible, and a definite link cannot be established between BP and oesophageal cancer. BP should be avoided in patients with severe renal impairment and during pregnancy and lactation because of limited safety data. Further epidemiological and clinical data are required to establish safety of BP in long-term users (>5 years) and provide evidence-based management.