Chemotherapy decreases epiphyseal strength and increases bone fracture risk

Treating Multilevel Cervical Degenerative Disk Disease in a Patient With Stage IV Lung Cancer With Notable Comorbidities Using a Drug Eluting Biomaterial: A Case Report

A 64-year-old patient with stage IV non-small-cell lung carcinoma and several comorbidities, which include obesity and long-term smoking, was treated with N-allyl noroxymorphone eluting osteoinductive bone graft biomaterial. The patient had multilevel degenerative disk disease (DDD), which has a high rate of failure when osteoinductive bone grafts are not used. Infuse, the most widely administered osteoinductive bone graft, is contraindicated in the spine for patients with active tumor. As such, a novel drug eluting osteoinductive biomaterial was administered to this patient, for whom no other therapeutic options were available, to promote bone fusion in a three-level anterior cervical diskectomy and fusion as part of the Food and Drug Administration Expanded Access program. Despite patient comorbidities that are associated with poor bone physiology, confirmed radiographic fusion was achieved in all three cervical levels at 8 months.

Regulation of base excision repair during adipogenesis and osteogenesis of bone marrow-derived mesenchymal stem cells

Bone marrow-derived human mesenchymal stem cells (hMSCs) can differentiate into various lineages, such as chondrocytes, adipocytes, osteoblasts, and neuronal lineages. It has been shown that the high-efficiency DNA-repair capacity of hMSCs is decreased during their differentiation. However, the underlying its mechanism during adipogenesis and osteogenesis is unknown. Herein, we investigated how alkyl-damage repair is modulated during adipogenic and osteogenic differentiation, especially focusing on the base excision repair (BER) pathway. Response to an alkylation agent was assessed via quantification of the double-strand break (DSB) foci and activities of BER-related enzymes during differentiation in hMSCs. Adipocytes showed high resistance against methyl methanesulfonate (MMS)-induced alkyl damage, whereas osteoblasts were more sensitive than hMSCs. During the differentiation, activities, and protein levels of uracil-DNA glycosylase were found to be regulated. In addition, ligation-related proteins, such as X-ray repair cross-complementing protein 1 (XRCC1) and DNA polymerase β, were upregulated in adipocytes, whereas their levels and recruitment declined during osteogenesis. These modulations of BER enzyme activity during differentiation influenced DNA repair efficiency and the accumulation of DSBs as repair intermediates in the nucleus. Taken together, we suggest that BER enzymatic activity is regulated in adipogenic and osteogenic differentiation and these alterations in the BER pathway led to different responses to alkyl damage from those in hMSCs.

Translational Strategies to Target Metastatic Bone Disease

Metastatic bone disease is a common and devastating complication to cancer, confounding treatments and recovery efforts and presenting a significant barrier to de-escalating the adverse outcomes associated with disease progression. Despite significant advances in the field, bone metastases remain presently incurable and contribute heavily to cancer-associated morbidity and mortality. Mechanisms associated with metastatic bone disease perpetuation and paralleled disruption of bone remodeling are highlighted to convey how they provide the foundation for therapeutic targets to stem disease escalation. The focus of this review aims to describe the preclinical modeling and diagnostic evaluation of metastatic bone disease as well as discuss the range of therapeutic modalities used clinically and how they may impact skeletal tissue.

Retracted: Icariin attenuates methotrexate chemotherapy-induced bone marrow microvascular damage and bone loss in rats

Methotrexate (MTX), a widely used antimetabolite in paediatric cancer to treatment, has been widely reported to cause bone loss and bone marrow (BM) microvascular (particularly sinusoids) damage. Investigations must now investigate how MTX-induced bone loss and microvasculature damage can be attenuated/prevented. In the present study, we examined the potency of icariin, an herbal flavonoid, in reducing bone loss and the dilation/damage of BM sinusoids in rats caused by MTX treatment. Groups of young rats were treated with five daily MTX injections (0.75 mg/kg) with and without icariin oral supplementation until Day 9 after the first MTX injection. Histological analyses showed a significant reduction in the bone volume/tissue volume (BV/TV) fraction (%) and trabecular number in the metaphysis trabecular bone of MTX-treated rats, but no significant changes in trabecular thickness and trabecular spacing. However, the BV/TV (%) and trabecular number were found to be significantly higher in MTX + icariin-treated rats than those of MTX alone-treated rats. Gene expression analyses showed that icariin treatment maintained expression of osteogenesis-related genes but suppressed the induction of adipogenesis-related genes in bones of MTX-treated rats. In addition, icariin treatment attenuated MTX-induced dilation of BM sinusoids and upregulated expression of endothelial cell marker CD31 in the metaphysis bone of icariin + MTX-treated rats. Furthermore, in vitro studies suggest that icariin treatment can potentially enhance the survival of cultured rat sinusoidal endothelial cells against cytotoxic effect of MTX and promote their migration and tube formation abilities, which is associated with enhanced production of nitric oxide.

The Epidemiology of Fracture in Patients with Acute Ischemic Stroke in Korea

BACKGROUND

Patients who survive an acute phase of stroke are at risk of falls and fractures afterwards. However, it is largely unknown how frequent fractures occur in the Asian stroke population.

METHODS

Patients with acute (< 7 days) ischemic stroke who were hospitalized between January 2011 and November 2013 were identified from a prospective multicenter stroke registry in Korea, and were linked to the National Health Insurance Service claim database. The incidences of fractures were investigated during the first 4 years after index stroke. The cumulative incidence functions (CIFs) were estimated by the Gray's test for competing risk data. Fine and Gray model for competing risk data was applied for exploring risk factors of post-stroke fractures.

RESULTS

Among a total of 11,522 patients, 1,616 fracture events were identified: 712 spine fractures, 397 hip fractures and 714 other fractures. The CIFs of any fractures were 2.63% at 6 months, 4.43% at 1 year, 8.09% at 2 years and 13.00% at 4 years. Those of spine/hip fractures were 1.11%/0.61%, 1.88%/1.03%, 3.28%/1.86% and 5.79%/3.15%, respectively. Age by a 10-year increment (hazard ratio [HR], 1.23; 95% confidence interval [CI], 1.17-1.30), women (HR, 1.74; 95% CI, 1.54-1.97), previous fracture (HR, 1.72; 95% CI, 1.54-1.92) and osteoporosis (HR, 1.44; 95% CI, 1.27-1.63) were independent risk factors of post-stroke fracture.

CONCLUSION

The CIFs of fractures are about 8% at 2 years and 13% at 4 years after acute ischemic stroke in Korea. Older age, women, pre-stroke fracture and osteoporosis raised the risk of post-stroke fractures.

Methotrexate chemotherapy triggers touch-evoked pain and increased CGRP-positive sensory fibres in the tibial periosteum of young rats

Although bone pain caused by cancer chemotherapy is a well-recognized and significant problem, with approximately 1 in 10 childhood cancer patients being reported to experience isolated bone pain along with other skeletal complications, the underlying mechanisms are poorly understood and there is no specific treatment. In this study, effects of methotrexate (MTX) treatment on pain in the hind legs and the extent of sensory innervation of the tibial bone were examined through a 20-day time course in young rats after 5 daily 0.75 mg/kg MTX injections. MTX treatment increased von-Frey filament stimulation-induced mechanical allodynia and palpation nocifensive score in the tibia. MTX-treated rats showed trends in reduced loading (numbers of stands) on hind limbs after palpation, commencing early during treatment and 2 weeks after the end of treatment despite no signs of ongoing pain during normal locomotion. Immunohistochemical analyses showed an increase in innervation of calcitonin gene-related peptide (CGRP)-positive sensory nerve fibres in tibial periosteum on days preceding and overlapping with those rats with touch-evoked pain responses and the bone repair phase. These data suggest that methotrexate chemotherapy triggers touch-evoked pain involving enhanced sensory nerve innervation of the bone.

No deleterious effect of low dose methotrexate on titanium implant osseointegration in a rabbit model

OBJECTIVE

To evaluate the effect of low dose methotrexate alone or in combination with glucocorticoid treatment on titanium implant osseointegration.

METHODS

Groups of 6-8 adult New Zealand White rabbits were treated for 18 weeks with saline (control), methotrexate, glucocorticoid, or methotrexate plus glucocorticoid. The animals received a titanium implant in the tibia at week 6. Lumbar spine and tibia bone mineral densities were analyzed before and after treatment. Histomorphometric analysis of bone cortical thickness, total bone area around the implant, and % of bone to implant contact was performed.

RESULTS

After 18 weeks, the change in the bone mineral density in the lumbar spines and tibias in the methotrexate group was comparable to the control group (0.035 vs. 0.055 g/cm² and 0.021 vs. 0.041 g/cm², respectively). In contrast, both the glucocorticoid group and glucocorticoid plus methotrexate group had significant reductions at both sites. Histomorphometric analysis of the tibia in the control and methotrexate groups revealed no significant changes in cortical thickness (133 vs. 126 μm), total bone area around the implant (33 vs. 30%), or bone to implant contact (40 vs. 38%). In contrast, glucocorticoid group had significant reductions compared to controls in tibia cortical thickness (99 vs. 133 μm), total bone area around the implant (24 vs. 33%), and bone to implant contact (27 vs. 40%). Similar reductions were observed in the glucocorticoid plus methotrexate group.

CONCLUSIONS

Our results demonstrate that low dose methotrexate treatment does not affect titanium implant osseointegration, suggesting that this therapy is safe for surgical procedures requiring a titanium implant.

Bone mineral density loss during adjuvant chemotherapy in pre-menopausal women with early breast cancer: is it dependent on oestrogen deficiency?

Pre-menopausal women given adjuvant chemotherapy for breast cancer experience both premature ovarian failure and loss of bone mineral density (BMD), and this study was designed to see if these observations are causally linked. Chemotherapy was administered to 41 pre-menopausal women with early breast cancer enrolled prospectively in a study of ovarian function and BMD in such women given systemic therapy. After giving written informed consent, all patients underwent baseline and regular on-treatment measurements of BMD by dual-energy X-ray absorptiometry (DXA) scan, bone turnover and ovarian function by analysis of serum hormone levels and self-reported menstrual diaries. Baseline lumbar spine BMD in the 41 women given chemotherapy was higher than the normal population (Z score 0.28 ± 0.14 (mean ± SEM), P = 0.047), and fell significantly over the first 6 months from a mean of 1.05-1.01 g/m(2), P < 0.0001, and similar but smaller changes were demonstrated in hip BMD. This fall was independent of age at diagnosis, type of chemotherapy, development of amenorrhoea or either baseline or on-treatment estradiol concentration. During the 6 months after completion of adjuvant chemotherapy, BMD fell further only in those women with low estradiol or experiencing amenorrhoea during the first 6 months, although all groups showed evidence of increased bone turnover. This study demonstrates loss of both spine and hip BMD in pre-menopausal women during 6 months' adjuvant systemic chemotherapy to be independent of changes in ovarian function. Ovarian function was, however, related to BMD changes after chemotherapy ceased.

Skeletal sequelae of cancer and cancer treatment

INTRODUCTION

Survivors of cancer may experience lingering adverse skeletal effects such as osteoporosis and osteomalacia. Skeletal disorders are often associated with advancing age, but these effects can be exacerbated by exposure to cancer and its treatment. This review will explore the cancer and cancer treatment-related causes of skeletal disorders.

METHODS

We performed a comprehensive search, using various Internet-based medical search engines such as PubMed, Medline Plus, Scopus, and Google Scholar, for published articles on the skeletal effects of cancer and cancer therapies.

RESULTS

One-hundred-forty-two publications, including journal articles, books, and book chapters, met the inclusion criteria. They included case reports, literature reviews, systematic analyses, and cohort reports. Skeletal effects resulting from cancer and cancer therapies, including hypogonadism, androgen deprivation therapy, estrogen suppression, glucocorticoids/corticosteroids, methotrexate, megestrol acetate, platinum compounds, cyclophosphamide, doxorubicin, interferon-alpha, valproic acid, cyclosporine, vitamin A, NSAIDS, estramustine, ifosfamide, radiotherapy, and combined chemotherapeutic regimens, were identified and described. Skeletal effects of hyperparathyroidism, vitamin D deficiency, gastrectomy, hypophosphatemia, and hyperprolactinemia resulting from cancer therapies were also described.

DISCUSSION/CONCLUSIONS

The publications researched during this review both highlight and emphasize the association between cancer therapies, including chemotherapy and radiotherapy, and skeletal dysfunction.

IMPLICATIONS FOR CANCER SURVIVORS

These studies confirm that cancer survivors experience a more rapid acceleration of bone loss than their age-matched peers who were never diagnosed with cancer. Further studies are needed to better address the skeletal needs of cancer survivors.

Cellular mechanisms for methotrexate chemotherapy-induced bone growth defects

Methotrexate (MTX) is a commonly used anti-metabolite in childhood oncology and is known to cause bone growth arrest and osteoporosis; yet the underlying mechanisms for MTX-induced bone growth defects remain largely unclear. This study characterized damaging effects in young rats of acute chemotherapy with 5 once-daily doses of MTX (0.75 mg/kg) on the cellular activities in the growth plate in producing calcified cartilage and trabecular bone and on activities of osteoblastic cells in the metaphysis. MTX treatment significantly induced chondrocyte apoptosis. MTX also suppressed chondrocyte proliferation and reduced collagen-II mRNA expression and total thickness of the growth plate, with the damage being most obvious on day 9 after the first injection, and with the growth plate histological structure returning normal on day 14. In the adjacent metaphyseal bone, mirroring the decrease in the width of the growth plate, production of primary spongiosa bone was markedly reduced and bone volume of the secondary spongiosa was decreased. Furthermore, MTX treatment significantly induced osteocyte apoptosis in the primary spongiosa and reduced proliferation of osteoblasts and preosteoblasts particularly in the secondary spongiosa. These observations suggest that methotrexate chemotherapy may cause bone growth defects by arresting cellular activities in the growth plate in producing calcified cartilage and primary trabecular bone and by decreasing pools of metaphyseal osteoblastic cells. However, this short-term MTX treatment only caused transit suppressions on growth plate cartilage and trabecular bone, as most cellular and histological parameters had recovered by day 14 or 21.

Folinic acid attenuates methotrexate chemotherapy-induced damages on bone growth mechanisms and pools of bone marrow stromal cells

Chemotherapy often induces bone growth defects in pediatric cancer patients; yet the underlying cellular mechanisms remain unclear and currently no preventative treatments are available. Using an acute chemotherapy model in young rats with the commonly used antimetabolite methotrexate (MTX), this study investigated damaging effects of five once-daily MTX injections and potential protective effects of supplementary treatment with antidote folinic acid (FA) on cellular activities in the tibial growth plate, metaphysis, and bone marrow. MTX suppressed proliferation and induced apoptosis of chondrocytes, and reduced collagen-II expression and growth plate thickness. It reduced production of primary spongiosa bone, volume of secondary spongiosa bone, and proliferation of metaphyseal osteoblasts, preosteoblasts and bone marrow stromal cells, with the cellular activities being most severely damaged on day 9 and returning to or towards near normal levels by day 14. On the other hand, proliferation of marrow pericytes was increased early after MTX treatment and during repair. FA supplementation significantly suppressed chondrocyte apoptosis, preserved chondrocyte proliferation and expression of collagen-II, and attenuated damaging effects on production of calcified cartilage and primary bone. The supplementation also significantly reduced MTX effects on proliferation of metaphyseal osteoblastic cells and of bone marrow stromal cells, and enhanced pericyte proliferation. These observations suggest that FA supplementation effectively attenuates MTX damage on cellular activities in producing calcified cartilage and primary trabecular bone and on pools of osteoblastic cells and marrow stromal cells, and that it enhances proliferation of mesenchymal progenitor cells during bone/bone marrow recovery.

Methotrexate, azathioprine, cyclosporine, and risk of fracture

We studied the fracture risk associated with use of methotrexate, azathioprine, and cyclosporine. The study was designed as a case-control study. All patients with a fracture (n = 124,655) in the year 2000 in Denmark served as cases. Information on fractures and confounders was retrieved from the National Hospital Discharge Register and a number of other national registers. For each case, three age- and gender-matched controls were randomly drawn from the general population (n = 373,962). Exposure was use of the drugs and a number of covariates including other immunosuppressive drugs, corticosteroids, any cancer, Crohn's disease, ulcerative colitis, rheumatoid arthritis, psoriasis, liver and kidney disease, prior fracture, and alcoholism. Azathioprine was associated with an increase in overall fracture risk, but besides this, none of the drugs was significantly associated with overall fracture risk or risk of hip, spine, or forearm fracture. Liver [odds ratio (OR) = 1.55, 95% confidence interval (CI) 1.42-1.69] and kidney (OR = 1.26, 95% CI 1.16-1.37) diseases were significantly associated with increased risk of fractures. Azathioprine was associated with an increase in overall fracture risk but not in the risk of spine, hip, or forearm fractures. Methotrexate and cyclosporine were not associated with fracture risk. It thus seems that the underlying disease for which the treatment is administered may be responsible for much of the increase in fracture risk rather than the drugs used to treat the disorder in question.

Density and structural changes in the bone of growing rats after weekly alendronate administration with and without a methotrexate challenge

Alendronate (ALN) and other bisphosphonates have been used successfully in pediatric patients with osteopenia secondary to connective tissue diseases. Loss of growth in height has not been reported, but concerns remain regarding the effect of these potent antiresorptive agents when used in children and adolescents. High-dose methotrexate (MTX) and other chemotherapy drugs have been implicated in osteoporosis and a high fracture incidence in survivors of childhood cancers and are also associated with osteopenia in adult animals. The effect of high dose MTX on bone density during rapid skeletal growth, however, has not been widely studied, nor has the potentially therapeutic effect of bisphosphonates in this setting. We examined the effects of ALN and MTX administration, alone and in combination, on bone density, morphology, mechanical strength, and longitudinal growth in normal growing rats. Sprague-Dawley rats were given ALN once weekly (0.3 mg/kg) from 5 to 11 weeks of age, with and without a course of methotrexate (MTX) given daily in weeks 1 and 3 (0.75 mg/kg/day). Twenty-four animals were randomly divided into four groups: Control (vehicle), ALN alone, ALN + MTX, and MTX alone. After 6 weeks, the femora, tibiae, and lumbar spine were studied by dual-energy X-ray absorptiometry, peripheral quantitative computed tomography, mechanical strength testing, microradiography, light microscopy, and by determination of ash weights and bone lengths. ALN treatment increased bone mineral density (BMD) by 23% to 68%. The largest increases in the femur occurred in the distal third where endochondral bone growth was greatest and included large increases in trabecular bone and total cross-sectional area. ALN + MTX produced similar effects to ALN alone. MTX only reduced BMD by 8% in the vertebrae, but not significantly at other sites. MTX also led to femoral length reductions of 2.9%. The small reductions in BMD due to MTX were overwhelmed by the increases due to ALN, whereas the length loss was unaffected. Transverse density banding corresponding to weekly ALN administrations were clearly evident radiographically throughout the growing skeleton, likely due to decreased resorption and possibly increased mineralization in the bands. ALN or ALN + MTX treatment also led to increases in mechanical strength in the femora. Although MTX administration during growth leads to some BMD reduction, ALN given with MTX eliminates this reduction and in fact bone density and strength increase above control levels.

Chemotherapy affects the pattern of failure after shear loading of the proximal tibial growth plate

INTRODUCTION

Tibial bones are shorter and less resistant to shear forces after treatment with doxorubicin, methotrexate, or cisplatin. We investigated the pattern of failure after shear loading of the proximal tibial growth plate in rats treated with these chemotherapeutic agents.

MATERIALS AND METHODS

Male Wistar rats from the age of 4 weeks were given doxorubicin intravenously at 15 mg/m2 body surface area (BSA), methotrexate 60 mg/m2 BSA, or cisplatin 7.5 mg/m2 BSA. There was one nontreated control group fed ad libitum an d a diet control group for each drug-treated group. At the age of 13 weeks the tibial bones were dissected. The proximal growth plate was shear loaded to failure in the posteroanterior direction. The pattern of failure through the growth plate was examined.

RESULTS

In rats fed ad libitum the failure pattern ran mainly through the transitional zone between proliferating and hypertrophic chondrocytes, but the pattern of failure showed considerable variability. The pattern in rats treated with methotrexate or cisplatin and that in their diet controls were comparable. In rats treated with doxorubicin the fracture ran mainly through the trabecular zone.

CONCLUSIONS

Doxorubicin affects the pattern of failure after shear loading of the proximal tibial growth plate, but methotrexate and cisplatin do not. Special attention should be paid to epiphyseal injuries in children treated with doxorubicin.