Cancer treatment-induced bone loss (CTIBL): pathogenesis and clinical implications

Sexual and reproductive complications and concerns of survivors of childhood, adolescent and adult cancer

PURPOSE

Cancer survivors may experience infertility and sexual dysfunction following cancer treatment. Survivors report significant gaps in oncofertility care and consider these issues important, yet they are rarely discussed. The aims of this study were to evaluate survivors' sexual and reproductive complications across age groups and to identify specific groups of survivors at risk for sexual and reproductive complications.

METHOD

We report data collected from survivors of cancers diagnosed in childhood, adolescence and adulthood following the development and piloting of a reproductive survivorship patient reported outcome measure (RS-PROM).

RESULTS

One hundred and fifty survivors participated in the study (mean age at cancer diagnosis was 23.2 years [SD, 10.3 years]). About 68% of participants expressed concerns about their sexual health and function. Survivors (50%) expressed at least one body image concern, with the female gender the most common risk factor for all subgroups. A total of 36% of participants reported at least one concern regarding their fertility, with more male than female survivors reporting fertility preservation prior to treatment. Females compared with male participants were more likely to feel less physically attractive after treatment (OR = 3.83, 95% CI = 1.84-7.95, p < 0.001). More females than males were also more likely to feel dissatisfied with the appearance of a scar(s) after treatment (OR = 2.36, 95% CI = 1.13-4.91, p = 0.02).

CONCLUSION

The RS-PROM identified multiple reproductive complications and concerns for cancer survivors in the survivorship period.

IMPLICATIONS FOR CANCER SURVIVORS

Utilising the RS-PROM in conjunction with a clinic appointment could help identify and address cancer patients' concerns and symptoms.

M2 macrophage-derived exosomes carry miR-142-3p to restore the differentiation balance of irradiated BMMSCs by targeting TGF-β1

Radiotherapy is essential to cancer treatment, while it inevitably injures surrounding normal tissues, and bone tissue is one of the most common sites prone to irradiation. Bone marrow mesenchymal stem cells (BMMSCs) are sensitive to irradiation and the irradiated dysfunction of BMMSCs may be closely related to irradiation-induced bone damage. Macropahges play important role in regulating stem cell function, bone metabolic balance and irradiation response, but the effects of macrophages on irradiated BMMSCs are still unclear. This study aimed to investigate the role of macrophages and macrophage-derived exosomes in restoring irradiated BMMSCs function. The effects of macrophage conditioned medium (CM) and macrophage-derived exosomes on osteogenic and fibrogenic differentiation capacities of irradiated BMMSCs were detected. The key microribonucleic acids (miRNAs) and targeted proteins in exosomes were also determined. The results showed that irradiation significantly inhibited the proliferation of BMMSCs, and caused differentiation imbalance of BMMSCs, with decreased osteogenic differentiation and increased fibrogenic differentiation. M2 macrophage-derived exosomes (M2D-exos) inhibited the fibrogenic differentiation and promoted the osteogenic differentiation of irradiated BMMSCs. We identified that miR-142-3p was significantly overexpressed in M2D-exos and irradiated BMMSCs treated with M2D-exos. After inhibition of miR-142-3p in M2 macrophage, the effects of M2D-exos on irradiated BMMSCs differentiation were eliminated. Furthermore, transforming growth factor beta 1 (TGF-β1), as a direct target of miR-142-3p, was significantly decreased in irradiated BMMSCs treated with M2D-exos. This study indicated that M2D-exos could carry miR-142-3p to restore the differentiation balance of irradiated BMMSCs by targeting TGF-β1. These findings pave a new way for promising and cell-free method to treat irradiation-induced bone damage.

Hormone Replacement Therapy in Post-Menopause Hormone-Dependent Gynecological Cancer Patients: A Narrative Review

BACKGROUND

Advances in the treatment of gynecological cancer have led to improvements in survival but also an increase in menopausal symptoms, especially in young women with premature iatrogenic menopause.

METHODS

A narrative review was performed to clarify the possibility of prescribing hormone replacement therapy (HRT) after hormone-dependent gynecological cancers (ovarian cancer [OC], cervical adenocarcinoma [AC], and endometrial cancer [EC]).

RESULTS

HRT can be prescribed to patients with early-stage, grade I-II OC who experience bothersome menopausal symptoms non-responsive to alternative non-hormone therapy after optimal surgery. Caution should be exercised in administering HRT after serous borderline tumors and endometrioid OC, and HRT is not recommended in low-grade serous OC. HRT is not contraindicated in AC survivors. After surgery for EC, HRT can be prescribed in women with early-stage low-grade EC. There is not enough data to give indications to patients with advanced EC.

CONCLUSIONS

HRT can be discussed with patients, evaluating the risks and benefits of hormone-dependent gynecological cancer. Counseling should be performed by gynecologic oncologists experienced in the management of these patients.

Neodymium and manganese ions co-doped whitlockite for temperature monitoring, photothermal therapy, and bone tissue repair in osteosarcoma

Osteosarcoma is one of the most dangerous forms of tumors, leading to death in >90% of patients. The surgical treatment of osteosarcoma results in significant bone defects and risks of tumor recurrence. Using neodymium (Nd) and manganese (Mn) ions co-doped with whitlockite nanoparticle (Nd10%Mn10%WH NPs) and sodium alginate (SA), we designed and synthesized an organic-inorganic composite hydrogel (Nd10%Mn10%WH-SA) that displayed the excellent fluorescence and photothermal properties. Furthermore, the maximum fluorescence emission intensity of Nd10%Mn10%WH-SA at 1062 nm was linear with temperature. The optimal temperature for the treatment of tumors was determined by considering the changes in fluorescence intensity that led to a reduction in tissue damage around the tumors. Nd10%Mn10%WH NPs demonstrated a significant function in promoting human bone marrow mesenchymal stem cells (hBMSCs) proliferation. Furthermore, Nd10%Mn10%WH-SA could almost kill tumors when the photothermal temperature was raised to 50 °C, with a minimal leftover scar after photothermal therapy (PTT). Nd10%Mn10%WH-SA had a better promotion effect on the growth of the new bone. These results suggested that Nd10%Mn10%WH-SA offers a new PTT method for the "integrated treatment and repair" of osteosarcoma.

Total Hip Arthroplasty Outcomes in Patients Who Have a History of Prior Radiation

BACKGROUND

The purpose of this study was to assess the odds of developing medical and surgical adverse events following total hip arthroplasty (THA) in patients who have a history of radiation therapy (RT) for cancer.

METHODS

A retrospective cohort study was conducted using a national database to identify patients who underwent primary THA (Current Procedural Terminology code 27130) from 2002 to 2022. Patients who had a prior RT were identified by International Classification of Diseases, Tenth Revision, Clinical Modification codes Z51.0 (encounter for antineoplastic RT), Z92.3 (personal history of irradiation), or Current Procedural Terminology code 101843 (radiation oncology treatment). One-to-one propensity score matching was conducted to generate 3 pairs of cohorts: 1) THA with/without a history of RT; 2) THA with/without a history of cancer; and 3) THA patients who have a history of cancer treated with/without RT. Surgical and medical complications were assessed at the 30-day, 90-day, and 1-year postoperative periods.

RESULTS

Patients who have a history of RT had higher odds of developing anemia, deep vein thrombosis, pneumonia, pulmonary embolism, and prosthetic joint infection at all intervals. When controlling for a history of cancer, RT was associated with an increased risk of pulmonary embolism, heterotrophic ossification, prosthetic joint infection, and periprosthetic fracture at all postoperative time points. There was additionally an increased risk of aseptic loosening at 1 year (odds ratio: 2.0, 95% confidence interval: 1.2 to 3.1).

CONCLUSION

These findings suggest that patients who have a history of antineoplastic RT are at an increased risk of developing various surgical and medical complications following THA.

CT-based body composition in diffuse large B cell lymphoma patients: changes after treatment and association with survival

PURPOSE

Primary purpose was to assess changes of bone mineral density (BMD) in diffuse large B cell lymphoma (DLBCL) patients treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone R-CHOP (like) chemotherapy regimen. Secondary purposes were to assess other body composition features changes and to assess the association of pre-therapy values and their changes over time with survival.

MATERIAL AND METHODS

Patients selected underwent R-CHOP(like) regimen for DLBCL, and underwent PET-CT before and after treatment. Main clinical data collected included body mass index, date of last follow-up, date of progression, and date of death. From the low-dose CT images, BMD was assessed at the L1 level; the other body composition values, including muscle and fat distribution, were assessed at the L3 level by using a dedicated software. Descriptive statistics were reported as median and interquartile range, or frequencies and percentages. Statistical comparisons of body composition variables between pre- and post-treatment assessments were performed using the Wilcoxon matched pairs signed rank test. Non-normal distribution of variables was tested with the Shapiro-Wilk test. For qualitative variables, the Fisher exact test was used. Log rank test was used to compare survival between different subgroups of the study population defined by specific body composition cutoffs. The significance level was set at p < 0.05.

RESULTS

Eighty-two patients were included. The mean follow-up was 37.5 ± 21.4 months. A significant difference was found in mean BMD before and after R-CHOP(like) treatment (p < 0.0001). The same trend was observed for mean skeletal muscle area (SMA) (p = 0.004) and mean skeletal muscle index (SMI) (p = 0.006). No significant association was demonstrated between body composition variables, PFS and OS.

CONCLUSION

R-CHOP(like) treatment in DLBCL patients was associated with significant reduction of BMD, SMA and SMI.

Development and validation of a nomogram for predicting osteoporosis in prostate cancer patients: A cross-sectional study from China

BACKGROUND

The specific risk factors contributing to the development of osteoporosis and the appropriate timing of treatment in Chinese prostate cancer (PCa) patients remain unclear. Our objective was to develop and validate a nomogram capable of predicting the occurrence of osteoporosis in PCa patients.

METHODS

We conducted a cross-sectional study with PCa patients attending the Second Hospital of Tianjin Medical University, collecting data from June 2021 to February 2023. The patients were divided into training and validation sets in a 7:3 ratio. The LASSO regression was used to identify the most relevant predictive variables, and the multivariable logistic regression was used to construct the nomogram. The nomogram's performance was validated through receiver operating characteristic (ROC) curves, C-index, calibration curves, and decision curve analysis (DCA) in both the training and validation sets.

RESULTS

We collected data from a total of 596 patients and then constructed the nomogram using age, body mass index, hemoglobin, vitamin D3, testosterone, and androgen deprivation therapy duration. The C-index of the nomogram was 0.923 in the training set and 0.859 in the validation set. The nomogram showed good consistency in both sets. DCA demonstrated the clinical benefit of the nomogram across various prediction thresholds. Furthermore, a separate nomogram was constructed to predict bone loss in patients undergoing ADT, exhibiting equally favorable diagnostic performance and clinical benefit.

CONCLUSION

This study constructed two reliable nomograms to predict osteoporosis and bone loss, integrating personal health information and PCa-specific treatment data. These nomograms offer an easy and individualized approach to predict the occurrence of osteoporosis and bone loss in PCa patients.

CR6-Interacting Factor-1 Promotes Osteoclastogenesis Through the NF-κB Signaling Pathway after Irradiation

Radiation exposure arising from radiotherapy may induce rapid bone loss and an increase in the extent of bone resorption. Reactive oxygen species (ROS) caused by radiation exposure play a crucial role during the process of osteoclastogenesis. However, the pathological mechanisms underlying radiation-induced osteoclastogenesis have yet to be fully elucidated. CR6-interacting factor-1 (Crif1) as a multifunctional protein is involved in regulating multiple biological functions in cells. Here, we investigated the role of Crif1 in radiation-induced osteoclastogenesis and found that radiation exposure induced an increase in the expression level of Crif1 and enhanced osteoclastogenesis in osteoclast progenitors. Crif1 and NF-κB p65 co-localized in the cytoplasm after radiation exposure. Crif1 knockdown did not affect the phosphorylation and total protein levels of extracellular signal-regulated kinases (ERK), c-Jun amino (N)-terminal kinases (JNK), p38, and IκB-α before and after irradiation. However, Crif1 knockdown did lead to the reduced phosphorylation and nuclear translocation of NF-κB p65 after irradiation and resulted in a reduced level of osteoclastogenesis in RAW264.7 cells after irradiation. In vivo studies involving Lyz2Cre;Crif1fl/fl mice possessing the myeloid-specific deletion of Crif1 demonstrated the alleviation of bone loss after irradiation when compared with Crif1fl/fl mice. Our findings demonstrate that Crif1 mediated the phosphorylation and nuclear translocation of NF-κB p65 and promoted osteoclastogenesis via the NF-κB signaling pathway after radiation exposure. Thus, our analysis revealed a specific role for Crif1 in the mediation of radiation-induced bone loss and may provide new insight into potential therapeutic strategies for radiation-induced bone loss.

A cross-sectional study on Chinese oncology nurses' knowledge of bone health among cancer patients

OBJECTIVE

To understand the knowledge status, obstacle factors, and management confidence of oncology nurses on the bone health of cancer patients, and in addition to provide reference for establishing bone health knowledge training system for oncology nurses and guiding them to manage bone health of cancer patients.

METHODS

A total of 602 nurses engaged in oncology nursing in 6 hospitals in Hebei Province were selected by cluster sampling, and an online anonymous survey was conducted by sending questionnaires to oncology nurses from the Hebei Cancer Prevention and Control Association. The questionnaire was developed by the study team. There are 4 parts, namely general information, nurses' role and job responsibilities, knowledge of skeletal-related events (SREs) and cancer treatment-induced bone loss (CTIBL), and understanding and confidence in bone health management, for a total of 33 questions.

RESULTS

Thirty-seven percent of oncology nurses received training on bone health and other related contents; 40.48% of oncology nurses used domestic and foreign guidelines when managing patients with bone metastases or CTIBL. Only approximately one-third of oncology nurses had confidence in managing the side effects of bone metastases and bone modification drugs and identifying patients at risk of CTIBL and fracture; only 33.04% of oncology nurses believed that weight-bearing exercise can prevent bone loss; less than 50% of oncology nurses believed that aromatase inhibitor therapy, ovarian suppression therapy, androgen deprivation therapy, and low body weight were risk factors for pathological fractures. The reasons that hindered oncology nurses from optimizing the management of patients with bone metastases and understanding the preventive measures and risk factors for bone loss mainly included lack of relevant knowledge training, lack of understanding of effective intervention measures, and lack of training and professionalism of specialized nurses, including insufficient development time and guidelines for clinical nursing practice.

CONCLUSION

Managers must continuously improve the training system of oncology nurses, enrich the content of training pertaining to bone health for cancer patients, formulate clinical nursing practice guidelines, and give oncology nurses more time for professional development.

Preserving bone in cancers of the elderly: A necessity

The occurrence of bone fractures is frequent in the elderly population, and in cancer patients, especially with bone metastases. The growing incidence of cancer associated with an aging population implies important health challenges, including bone health. Decisions on cancer care in older adults have to take into account older adults' specificities. Screening tools as G8 or VES 13 and evaluating tools as comprehensive geriatric assessment (CGA) do not include bone-related items. Bone risk assessment is indicated according to identification of geriatric syndromes such as falls, history, and the oncology treatment plan. Some cancer treatments disrupt bone turnover and decrease bone mineral density. This is mainly caused by hypogonadism, induced by hormonal treatments and some chemotherapies. Treatments can also cause direct (i.e., chemotherapy, radiotherapy or glucocorticoids) or indirect toxicity through electrolyte disorders (i.e., some chemotherapies or tyrosine kinase inhibitors) on bone turnover. Bone risk prevention is multidisciplinary. Certain interventions proposed in the CGA aim to improve bone health and reduce the risk of falling. It is also based on the drug management of osteoporosis, and the prevention of complications from bone metastases. Management of fractures, related or not to bone metastases relates to the concept of orthogeriatrics. It is also based on the benefit-risk ratio of the operation, access to minimally invasive techniques, prehabilitation or rehabilitation, but also the prognosis related to cancer and geriatric syndromes. Bone health is essential in older cancer patient's care. Bone risk assessment should be part of CGA in routine use and specific decision-making tools should be developed. Bone event management must be integrated throughout the patient's care pathway and oncogeriatrics multidisciplinarity should include rheumatological expertise.

Type H vessel/platelet-derived growth factor receptor β+ perivascular cell disintegration is involved in vascular injury and bone loss in radiation-induced bone damage

Collapse of the microvascular system is a prerequisite for radiation-induced bone loss. Since type H vessels, a specific bone vessel subtype surrounded by platelet-derived growth factor receptor β⁺ (PDGFRβ⁺ ) perivascular cells (PVCs), has been recently identified to couple angiogenesis and osteogenesis, we hypothesize that type H vessel injury initiates PDGFRβ⁺ PVC dysfunction, which contributes to the abnormal angiogenesis and osteogenesis after irradiation. In this study, we found that radiation led to the decrease of both type H endothelial cell (EC) and PDGFRβ⁺ PVC numbers. Remarkably, results from lineage tracing showed that PDGFRβ⁺ PVCs detached from microvessels and converted the lineage commitment from osteoblasts to adipocytes, leading to vascular injury and bone loss after irradiation. These phenotype transitions above were further verified to be associated with the decrease in hypoxia-inducible factor-1α (HIF-1α)/PDGF-BB/PDGFRβ signalling between type H ECs and PDGFRβ⁺ PVCs. Pharmacological blockade of HIF-1α/PDGF-BB/PDGFRβ signalling induced a phenotype similar to radiation-induced bone damage, while the rescue of this signalling significantly alleviated radiation-induced bone injury. Our findings show that the decrease in HIF-1α/PDGF-BB/PDGFRβ signalling between type H ECs and PDGFRβ⁺ PVCs after irradiation affects the homeostasis of EC-PVC coupling and plays a part in vascular damage and bone loss, which has broad implications for effective translational therapies.

Iodine-125 brachytherapy suppresses tumor growth and alters bone metabolism in a H1299 xenograft mouse model

The present study aimed to investigate the efficacy of Iodine-125 (I-125) brachytherapy in a mouse model of non-small cell lung cancer, to further explore the efficacy and appropriate method of implantation of the I-125 radioactive seed. This study also aimed to determine the impact of brachytherapy on bone metabolism. A total of 18 mice were used to establish H1299 xenograft models, and were randomly assigned to three groups. These included non-radioactive seed implantation (Sham IM), fractionated I-125 seed implantation (Fractionated IM) and single I-125 seed implantation (Single IM) groups. Mice were euthanized after 28 days of implantation. H&E staining, Ki67 immunohistochemistry, CD31 morphometric analysis and TUNEL immunofluorescence assays were respectively used to determine the histopathological changes, proliferation, micro-angiogenesis and apoptosis of tumors. In addition, bone volume and microstructure were evaluated using trabecular bone area (Tb.Ar), trabecular thickness (Tb.Th), trabecular number (Tb.N) and cortical thickness. Bone metabolic status was analyzed using histomorphometric staining of tartrate-resistant acid phosphate (TRAP) and alkaline phosphatase (ALP) expression in the femur, and using an ELISA assay to determine the expression of C-telopeptide of type 1 collagen (CTX-1) and procollagen type 1 n-terminal propeptide (P1NP) in the serum. Moreover, reverse transcription-quantitative PCR and western blotting were carried out for the analysis of bone remodeling-related gene expression in the bone tissue. Results of the present study demonstrated that compared with the Sham IM group, both the I-125 seed implantation groups, including Fractionated IM and Single IM, demonstrated significant therapeutic effects in both tumor volume and weight. More specifically, the most significant therapeutic effects on tumor inhibition were observed in the Fractionated IM group. Results of Ki67 and CD31 immunohistochemical staining suggested a notable reduction in tumor cell proliferation and micro-angiogenesis, and results of the TUNEL assay demonstrated an increase in tumor cell apoptosis. Although the cortical bone appeared thinner and more fragile in both I-125 seed implantation groups, no notable adverse changes in the morphology of the cancellous bone were observed, and the index of Tb.Ar, Tb.Th and Tb.n was not significantly different among Sham IM and I-125 implantation groups. However, alterations in bone metabolism were characterized by a decrease in CTX-1 and P1NP expression, accompanied by an increase in TRAP activity and a decrease in ALP activity. Results of the present study also demonstrated the notable suppression of osteocalcin and runt-related transcription factor 2. I-125 seed implantation may be an effective and safe antitumor strategy. Moreover, the use of fractionated implantation patterns based on tumor shape exhibited improved therapeutic effect on tumor suppression when the total number of I-125 seeds was equivalent along with reduced complications associated with bone loss.

Bone loss induced by cancer treatments in breast and prostate cancer patients

Cancer and cancer therapies are a major factor risk for osteoporosis due to bone loss and deterioration of bone microarchitecture. Both factors contribute to a decrease in bone strength and, consequently, increased bone fragility and risk of fracture. Cancer-associated bone loss is a multifactorial process, and optimal interdisciplinary management of skeletal health, accurate assessment of bone density, and early diagnosis are essential when making decisions aimed at reducing bone loss and fracture risk in patients who have received or are receiving treatment for cancer. In this document, a multidisciplinary group of experts collected the latest evidence on the pathophysiology of osteoporosis and its prevention, diagnosis, and treatment with the support of the Spanish scientific society SEOM. The aim was to provide an up-to-date and in-depth view of osteoporotic risk and its consequences, and to present a series of recommendations aimed at optimizing the management of bone health in the context of cancer.

The effect of breast cancer surgery on spine alignment: Whole-spine radiograph analysis

Breast cancer survivors may experience spinal deformity following breast cancer surgery. This study investigated the long-term effects of breast cancer surgery on whole-spine alignment. This retrospective study included 200 patients who underwent breast cancer surgery and ≥2 anteroposterior standing whole-spine X-rays. The curvature of the spine was measured using the Cobb angle; changes in Cobb angle between X-rays were compared among three groups according to breast cancer surgery type. The mean interval between initial and follow-up X-ray was 28.46 ± 13.39 months. The change in Cobb angle was 0.40 ± 1.65 degrees and the absolute value of that change was 1.25 ± 1.15 degrees in all patients with breast cancer. There were no significant differences in angular change among groups according to breast cancer surgery type. Most patients showed minimal changes in spinal alignment after breast cancer surgery. Our findings indicate that breast cancer surgery does not negatively affect spinal alignment.

High-specificity protection against radiation-induced bone loss by a pulsed electromagnetic field

Radiotherapy increases tumor cure and survival rates; however, radiotherapy-induced bone damage remains a common issue for which effective countermeasures are lacking, especially considering tumor recurrence risks. We report a high-specificity protection technique based on noninvasive electromagnetic field (EMF). A unique pulsed-burst EMF (PEMF) at 15 Hz and 2 mT induces notable Ca²⁺ oscillations with robust Ca²⁺ spikes in osteoblasts in contrast to other waveforms. This waveform parameter substantially inhibits radiotherapy-induced bone loss by specifically modulating osteoblasts without affecting other bone cell types or tumor cells. Mechanistically, primary cilia are identified as major PEMF sensors in osteoblasts, and the differentiated ciliary expression dominates distinct PEMF sensitivity between osteoblasts and tumor cells. PEMF-induced unique Ca²⁺ oscillations depend on interactions between ciliary polycystins-1/2 and endoplasmic reticulum, which activates the Ras/MAPK/AP-1 axis and subsequent DNA repair Ku70 transcription. Our study introduces a previously unidentified method against radiation-induced bone damage in a noninvasive, cost-effective, and highly specific manner.

Modulation of Differentiation and Bone Resorbing Activity of Human (Pre-) Osteoclasts After X-Ray Exposure

Low-dose radiotherapy (LD-RT) is a local treatment option for patients with chronic degenerative and inflammatory diseases, in particular musculoskeletal diseases. Despite reported analgesic and anti-inflammatory effects, cellular and molecular mechanisms related to osteoimmunological effects are still elusive. Here we test the hypothesis that X-irradiation inhibits the differentiation of precursor osteoclasts into mature osteoclasts (mOC) and their bone resorbing activity. Circulating monocytes from healthy donors were isolated and irradiated after attachment with single or fractionated X-ray doses, comparable to an LD-RT treatment scheme. Then monocytes underwent ex vivo differentiation into OC during cultivation up to 21 days, under conditions mimicking the physiological microenvironment of OC on bone. After irradiation, apoptotic frequencies were low, but the total number of OC precursors and mOC decreased up to the end of the cultivation period. On top, we observed an impairment of terminal differentiation, i.e. a smaller fraction of mOC, reduced resorbing activity on bone, and release of collagen fragments. We further analyzed the effect of X-irradiation on multinucleation, resulting from the fusion of precursor OC, which occurs late during OC differentiation. At 21 days after exposure, the observation of smaller cellular areas and a reduced number of nuclei per mOC suggest an impaired fusion of OC precursors to form mOC. Before, at 14 days, the nuclear translocation of Nuclear Factor Of Activated T Cells 1 (NFATc1), a master regulator of osteoclast differentiation and fusion, was decreased. In first results, obtained in the frame of a longitudinal LD-RT study, we previously reported a pain-relieving effect in patients. However, in a subgroup of patients suffering from Calcaneodynia or Achillodynia, we did not observe a consistent decrease of established blood markers for resorption and formation of bone, or modified T cell subtypes involved in regulating these processes. To assess the relevance of changes in bone metabolism for other diseases treated with LD-RT will be subject of further studies. Taken together, we observed that in vitro X-irradiation of monocytes results in an inhibition of the differentiation into bone-resorbing OC and a concomitant reduction of resorbing activity. The detected reduced NFATc1 signaling could be one underlying mechanism.

Fertility preservation techniques in cervical carcinoma

The usefulness of this review is to highlight how a fertility preservation (FP) approach is currently feasible for patients diagnosed with uterine cervical cancer. To this regard, a fertility sparing surgery has just overcome its traditional limits, gained acceptance within the major gynecologic oncology societies thanks to the ability to identify the "ideal" candidates to this conservative treatment. On the other hand, the use of other FPs for oocyte and ovarian cortex cryopreservation is still extremely debated. In fact, the existing risk of tumor spreading during oocyte retrieval necessary for oocyte cryostorage for patients' candidates for neo-adjuvant therapy, as well as the potential hazard of cancer cell dissemination after ovarian tissue replacement in cases of non-squamous type cervical carcinomas should not be underestimated. Therefore, in consideration of the encountered limitations and the need to ensure adequate reproductive health for young uterine cervical cancer survivors, translational research regarding the FP has progressively collected innovative insights into the employment of stemness technology. In this context, the property of ovarian stem cells obtained from the ovarian cortex to generate functional oocytes in women could represent a promising therapeutic alternative to the current procedures for a novel and safer FP approach in cancer survivors.

Pharmacological Prevention and Management of Skeletal-Related Events and Bone Loss in Individuals with Cancer

OBJECTIVE

To provide a literature review of the clinical efficacy and safety data of various pharmacological agents used to manage bone health in people affected by cancer.

DATA SOURCES

Peer-reviewed articles and research publications identified from PubMed and relevant clinical guidelines were used in this evidence synthesis.

CONCLUSION

Individuals with cancers such as breast and prostate cancers, multiple myeloma, and other malignancies are at a high risk of developing skeletal-related events such as bone fracture, bone metastasis, and osteoporosis. Pharmacologic agents such as bisphosphonates and RANK-L inhibitor (denosumab) are the mainstay therapy options for managing bone health in this population.

IMPLICATIONS FOR NURSING PRACTICE

Nurses and nurse practitioners should be aware of the efficacy data of bisphosphonates and denosumab but also should be well-versed in the appropriate administration of these agents, potential side effect profiles, timely assessment, and interventions to optimize quality of life.

Longitudinal Changes in Bone Mineral Measurements Inside and Outside Radiation Fields Used for Cervical Cancer Treatment

PURPOSE

We compared the magnitude of changes in bone mineral density (BMD), within and outside the radiation field, among women who received pelvic radiotherapy (RT) with or without chemotherapy for cervical cancer.

PATIENTS & METHODS

In this secondary analysis of a prospective study, we analyzed serial CT scans and dual-energy X-ray absorptiometry (DXA) scans from 78 patients who received definitive RT or chemoradiation (CRT) for cervical cancer at a single institution from 2008 to 2015. BMD values at L1, L2, L3 and L4 were measured. We compared changes in BMD within the radiation field (i.e., at L4) with those outside the field (i.e., at L1). Linear mixed models were also used to examine the effect of RT on changes in BMD over time and covariate adjustment.

RESULTS

The median age of the 78 patients was 45.5 years (range 23-88); all received RT and 76 (97%) received concurrent CRT. Treatment was associated with significant declines in BMD in all 4 lumbar vertebral bodies over time (P<0.05), with nadir at 3 months for L4 and at 1 year for L1. Pairwise comparisons at 3 months and 2 years after treatment indicated that BMD in L4 (within the RT field) had improved (P=0.037), but BMD in L1 (outside the RT field) was no different at 3 months and 2 years.

CONCLUSIONS

Significant BMD declines were observed in all lumbar vertebral bodies immediately following RT. However, in-field vertebral bodies reached nadir BMD earlier than those located outside the RT field. Our results suggest that treatment and patient-related factors other than RT may contribute to declines in BMD after treatment for cervical cancer. Routine bone density screening and post-RT therapy with hormones may be beneficial for selected patients who receive CRT for cervical cancer.

Therapy-induced bone changes in oncology imaging with 18F-sodium fluoride (NaF) PET-CT

¹⁸F-Sodium fluoride (¹⁸F-NaF) is a PET tracer that is mostly used in the evaluation of bone metastasis in oncology cases. Recently, ¹⁸F-NaF PET/CT is gaining wide popularity owing to its higher sensitivity over the other conventional bone tracer with higher and rapid single-pass extraction, negligible plasma protein binding, rapid blood, and renal clearance. In the era of constant evolution of cancer therapy regimens, considerable bone health impact is seen in the form of avascular necrosis, insufficiency fractures, among others. A significant number of these therapy-induced changes show high bone turnover and thereby ¹⁸F-NaF accumulation, mimicking metastatic lesions. This article summarizes and illustrates the pattern and morphological features of ¹⁸F-NaF PET/CT findings in these changes in the context of clinical and therapeutic history.

Attention to bone health in follow-up of gynaecological cancers in tertiary care

OBJECTIVE

Women with gynaecological cancers are at an increased risk of cancer treatment-induced bone loss, which impacts on their quality of life and overall survival. Clinical cancer follow-up reviews focus on cancer status and fail to attend to important health and quality-of-life issues. We questioned whether there was a care-gap between tertiary clinicians and primary care physicians in the management of bone health in this cohort. Significant care-gaps in relation to bone health have been demonstrated in other oncologic settings. The objective of this study was to determine the level of attention to bone health in the care of women living with and beyond gynaecological cancer at a tertiary referral centre for gynaecological oncology.

METHODS

Retrospective, observational cohort study of attention to bone health in the management and follow-up of gynaecological cancers.

RESULTS

This study shows that there has been suboptimal attention from the carers at a cancer centre to bone health during the oncological follow up of women undergoing treatment for gynaecological cancer. In those at particular risk of cancer treatment-induced bone loss (iatrogenic menopause and/or external beam pelvic radiotherapy), 52% of women had no reference to bone health in their notes, and 57% had no assessment of bone mineral density.

CONCLUSION

Tertiary cancer carers may underestimate the importance of bone health or believe that it falls outside the remit of their gynaecologic oncology service. Further research is needed to explore whether these findings are indicative of a true care gap and to gain insight into possible corrective measures.

Clinical, biochemical and genetic findings in adult patients with chronic hypophosphatasemia

PURPOSE

The study aimed to define the clinical, biochemical and genetic features of adult patients with osteopenia/osteoporosis and/or bone fragility and low serum alkaline phosphatase (sALP).

METHODS

Twenty-two patients with at least two sALP values below the reference range were retrospectively enrolled after exclusion of secondary causes. Data about clinical features, mineral and bone markers, serum pyridoxal-5'-phosphate (PLP), urine phosphoethanolamine (PEA), lumbar and femur bone densitometry, and column X-ray were collected. Peripheral blood DNA of each participant was analyzed to detect ALPL gene anomalies.

RESULTS

Pathogenic ALPL variants (pALPL) occurred in 23% and benign variants in 36% of patients (bALPL), while nine patients harbored wild-type alleles (wtALPL). Fragility fractures and dental anomalies were more frequent in patients harboring pALPL and bALPL than in wtALPL patients. Of note, wtALPL patients comprised women treated with tamoxifen for hormone-sensitive breast cancer. Mineral and bone markers were similar in the three groups. Mean urine PEA levels were significantly higher in patients harboring pALPL than those detected in patients harboring bALPL and wtALPL; by contrast, serum PLP levels were similar in the three groups. A 6-points score, considering clinical and biochemical features, was predictive of pALPL detection [P = 0.060, OR 1.92 (95% CI 0.972, 3.794)], and more significantly of pALPL or bALPL [P = 0.025, OR 14.33 (95% CI 1.401, 14.605)].

CONCLUSION

In osteopenic/osteoporotic patients, single clinical or biochemical factors did not distinguish hypophosphatasemic patients harboring pALPL or bALPL from those harboring wtALPL. Occurrence of multiple clinical and biochemical features is predictive of ALPL anomalies, and, therefore, they should be carefully identified. Tamoxifen emerged as a hypophosphatasemic drug.

Persistent Abnormal Immunocytes Induced Systemic Bone Loss in Locally Irradiated Rats

Chronic and systemic bone complications frequently occur in patients who undergo radiotherapy; however, the pathological mechanisms underlying these complications remain unclear. This study aimed to observe persistent and systemic changes in locally irradiated rats and to determine the systemic pathological changes that persistently affect bone metabolism. We examined the inflammatory and oxidative stress responses that occurred after local irradiation using enzyme immunoassays and biochemical analyses. Lymphocytes obtained from the blood, spleen, thymus, and bone marrow were evaluated using flow cytometry. The proliferation and apoptosis characteristics of co-cultured bone marrow-derived mesenchymal stem cells (BMSCs) were detected by MTT assay and PI/Annexin V-FITC staining, respectively, and the differentiation of BMSCs was measured according to alkaline phosphatase (ALP) staining, alizarin red staining, and Oil Red O staining and by evaluating the mRNA expression of ALP, osteocalcin (OCN), osteopontin (OPN), collagen I, Runx2, and PPARγ. Our results revealed that no significant or continuous differences were present in the inflammatory response or the oxidative stress response throughout the body after local irradiation. B lymphocyte levels increased continuously in the blood, spleen, and bone marrow after local irradiation. T lymphocyte levels were decreased at 2 weeks after local irradiation, and CD8⁺T lymphocyte levels were increased in the blood, thymus, and bone marrow at 12 weeks after local irradiation. The ratio of CD4⁺/CD8⁺T lymphocytes began to decrease during the early phase after local irradiation and became significantly decreased at 12 weeks after local irradiation. Normal BMSCs co-cultured with lymphocytes derived from irradiated rats exhibited decreased proliferation and increased apoptosis, and the ALP staining intensity, alizarin red staining intensity, and mRNA expression of related genes were all also decreased. Oil Red O staining intensity and mRNA expression of PPARγ were both increased. Lymphocyte levels contribute to chronic and systemic bone complications after radiotherapy by inhibiting the proliferation and osteoblastogenesis of BMSCs.

Construction of tellurium-doped mesoporous bioactive glass nanoparticles for bone cancer therapy by promoting ROS-mediated apoptosis and antibacterial activity

The commonly used treatment methods for bone cancer include chemotherapy, surgery and radiotherapy, but there are disadvantages such as nonspecific distribution, high toxicity of chemotherapy drugs, implantable infections and low monitoring. Nanoparticles are the new development direction of nanomedicine in cancer treatment. Structural characteristics of nanoparticles make it an excellent model for targeting and penetrating cancer-induced abnormal cell growth. In this study, a kind of novel and interesting tellurium ion doped mesoporous bioactive glasses (Te-MBG) nanoparticles were successfully synthesized by a simple sol-gel method, which had uniform spherical morphology (≈ 500 nm), high surface area (> 300 m²/g) and mesopore volume (> 0.30 cm³/g). Results found that Te doping does not affect the mineralization and degradation of the MBG nanoparticles. Meanwhile, compared to the undoped MBG, Te doped MBG not merely had the ability to promote MG63 cell apoptosis to inhibit bone cancer growth by ROS-mediated, but also had significant antibacterial activity. This all depends on the concentration of Te doping. It can be seen that Te-MBG nanoparticles can not only potentially fill bone defects caused by bone cancer removal, but also induce cancer cell apoptosis by tellurium release inducing reactive oxygen species (ROS) excessive production to inhibit bone cancer formation. This study provides a feasible strategy for the development of Te-MBG nanoparticles as well as their evaluation and basic research for bone cancer therapy.

Effects of I-125 seeds combined with anlotinib on tumor growth and bone metabolism in A549 tumor-bearing mice

PURPOSE

This study aimed to investigate the therapeutic potential of tumor suppression and mechanism for different implantation modes of iodine-125 (I-125) seeds irradiation in a mice xenograft model, and its skeletal complications.

MATERIALS AND METHODS

A total of 24 mice carrying A549 lung tumor-derived xenografts were randomly assigned to four groups, including non-radioactive (sham) seeds implantation, I-125 seeds fractional implantation, I-125 seeds single implantation and I-125 seeds single implantation combined with anlotinib. Ki67 immunohistochemistry, TUNEL immunofluorescence and CD31 morphometric analysis were used to determine the proliferation index, rate of apoptotic cells and microvessel density, respectively. Additionally, the side effects on the skeletal system in mice treated with I-125 seeds implantation were evaluated by histomorphometric staining with tartrate-resistant acid phosphate (TRAP) and alkaline phosphatase (ALP) expression in femur, tartrate-resistant acid phosphatase 5b (TRACP-5b) and procollagen type I N-terminal propeptide (PINP) levels in serum were evaluated by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The I-125 seeds single and fractionated implantation had similar therapeutic effects and complications when the total number of I-125 seeds was the same. A single implantation of I-125 seeds with or without anlotinib could analogously inhibit the tumor growth in xenografts mice, while the single implantation combined with anlotinib had more effective in tumor inhibition. The results of Ki67, TUNEL and CD31 staining confirmed an evident reduction in tumor cell proliferation and angiogenesis, as well as an increase in apoptosis. A relatively integrated bone metabolism was indicated after I-125 seeds single implantation with or without anlotinib, and the results were similar in I-125 seeds fractional implantation, including a reduction in the number of TRAP-positive cells and an increase in ALP expression level. Additionally, the serum TRACP-5b activity was decreased and the serum PINP concentration was increased following I-125 seeds implantation.

CONCLUSIONS

Single and fractionated implantation pattern of I-125 radioactive seeds had similar therapeutic efficacy against tumor growth, while brachytherapy with I-125 seeds implantation may be an effective and safe treatment strategy for its potential protection against cancer treatment-induced bone loss.

Prevalence of osteoporosis and osteopenia in a cohort of HIV positive women with a history of treated neoplasms

Introduction:

Higher prevalence of osteopenia and osteoporosis in HIV positive patients compared to non-infected population has been recognized. However, cancer patients have a higher risk of bone loss and fractures that is multifactorial. The aim of the study was to describe the prevalence of osteopenia and osteoporosis in HIV positive women with history of treated cancer.

Methods:

Between January 2018 and December 2019, women aged >40 years, HIV+ with a history of cancer diagnosis, who attended the AIDS Cancer Clinic at Instituto Nacional de Cancerología, Mexico City, and who had a dual X-ray absorptiometry performed during the study period were included. Two control groups (CG)—HIV negative women with history of cancer (CG1) and non-HIV, non-cancer women (CG2)—were matched by age 1:1.

Results:

Forty-eight patients in each group were included; the mean age was 51.1 ± 8.1 years. Osteopenia was found in femoral neck in 54.2% (HIV+), 37.5% (CG1), and 27.1% (CG2), p = 0.02; in spine was 35.7%, 47.9%, and 31.2%, respectively, p = 0.442. Osteoporosis in femoral neck was documented in 12.5%, 2.1%, and 0% in HIV+, CG1, and CG2 (p = 0.03), and in the spine was 47.9%, 16.7%, and 14.6%, respectively (p = 0.002).

Conclusion:

HIV patients with a history of treated cancer have a much higher prevalence of osteoporosis when compared with same-aged HIV-uninfected women with and without cancer. It is necessary to monitor Bone Mineral Density periodically, and all patients should be encouraged to make lifestyle changes, such as avoid tobacco and alcohol, and to increase exercising.

The pathophysiology of immunoporosis: innovative therapeutic targets

BACKGROUND

The physiological balance between bone resorption and bone formation is now known to be mediated by a cascade of events parallel to the classic osteoblast-osteoclast interaction. Thus, osteoimmunology now encompasses the role played by other cell types, such as cytokines, lymphocytes and chemokines, in immunological responses and how they help modulate bone metabolism. All these factors have an impact on the RANK/RANKL/OPG pathway, which is the major pathway for the maturation and resorption activity of osteoclast precursor cells, responsible for osteoporosis development. Recently, immunoporosis has emerged as a new research area in osteoimmunology dedicated to the immune system's role in osteoporosis.

METHODS

The first part of this review presents theoretical concepts on the factors involved in the skeletal system and osteoimmunology. Secondly, existing treatments and novel therapeutic approaches to treat osteoporosis are summarized. These were selected from to the most recent studies published on PubMed containing the term osteoporosis. All data relate to the results of in vitro and in vivo studies on the osteoimmunological system of humans, mice and rats.

FINDINGS

Treatments for osteoporosis can be classified into two categories. They either target osteoclastogenesis inhibition (denosumab, bisphosphonates), or they aim to restore the number and function of osteoblasts (romozumab, abaloparatide). Even novel therapies, such as resolvins, gene therapy, and mesenchymal stem cell transplantation, fall within this classification system.

CONCLUSION

This review presents alternative pathways in the pathophysiology of osteoporosis, along with some recent therapeutic breakthroughs to restore bone homeostasis.

Chemotherapy-induced peripheral neuropathy increases nontraumatic fracture risk in breast cancer survivors

Chemotherapy is a common treatment for breast cancer (BrCa) and can cause chemotherapy‐induced peripheral neuropathy (CIPN). CIPN contributes to falls, and is thus a potential risk factor for nontraumatic fractures (NTFx); yet, the effect of CIPN on NTFx risk has not been examined for BrCa survivors. We therefore investigated the association between CIPN and NTFx in BrCa survivors. Data were extracted from Optum's Deidentified Clinformatics® Data Mart Database years 2010–2015 in this retrospective cohort study. Among women, three groups were derived based on BrCa and CIPN status: BrCa+/CIPN+ (primary group of interest), BrCa+/CIPN− (first comparison group), and BrCa−/CIPN− (second comparison group). After propensity score matching the comparison groups to BrCa+/CIPN+ at a ratio of 1:11 (BrCa:control) for demographics, osteoporosis, glucocorticoid medication, comorbidities, and cancer‐related variables for BrCa+/CIPN−, 1‐year incidence rate (IR) of NTFx was determined for each group. The incident rate ratio (IRR) determined if the IR for NTFx was different for BrCa+/CIPN+ compared to BrCa+/CIPN− and BrCa−/CIPN−. Cox proportional hazards regression models estimated the hazard ratios (HRs) after adjusting for covariates that were unable to be matched for. The crude IR (95% confidence interval [CI]) of NTFx was 4.54 (2.32–6.77) for BrCa+/CIPN+ (n = 359), 2.53 (2.03–3.04) for BrCa+/CIPN− (n = 3949), and 1.76 (1.35–2.18) for BrCa−/CIPN− (n = 3949). The crude IRR of NTFx was significantly elevated for BrCa+/CIPN+ as compared to BrCa+/CIPN− (IRR = 1.80; 95% CI, 1.06–3.05) and BrCa−/CIPN− (IRR = 2.58; 95% CI, 1.50–4.44). The elevated rate of NTFx for BrCa+/CIPN+ remained unchanged after adjusting for aromatase inhibitors compared to BrCa+/CIPN− (HR = 1.79; 95% CI, 1.06–3.04). Female BrCa survivors have an increased 1‐year IR of NTFx after the onset of CIPN, suggesting that CIPN is an additive burden on NTFx risk among BrCa survivors. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Quality of Life Interventions in Breast Cancer Survivors: State of the Art in Targeted Rehabilitation Strategies

Breast cancer is the most common malignant tumor and the most prevalent cause of mortality in women. Advances in early diagnosis and more effective adjuvant therapies have improved the long-term survival of these patients. Pharmacotherapies and intrinsic tumor-related factors may lead to a wide spectrum of treatment-related disabling complications, such as breast cancer-related lymphedema, axillary web syndrome, persistent pain, bone loss, arthralgia, and fatigue. These conditions have a detrimental impact on the health-related quality of life of survivors. Here, we sought to provide a portrait of the role that rehabilitation plays in breast cancer survivors. Particular emphasis has been placed on recovering function, improving independence in activities of daily living, and reducing disability. This complex scenario requires a precision medicine approach to provide more effective decision-making and adequate treatment compliance.

Analyses of the association between cervical cancer and osteoporosis/osteoporotic fracture: a cross-sectional study using KoGES HEXA data

BACKGROUND

This study aimed to evaluate the association between cervical cancer and the occurrence of osteoporosis and osteoporotic fracture using data from the Korean Genome and Epidemiology Study (KoGES).

METHODS

In this national cohort study using KoGES health examination (HEXA) data, we extracted data for patients with cervical cancer (n = 493) and control participants (n = 77,571); we then analyzed the occurrence of osteoporosis and osteoporotic fracture at baseline from 2004 to 2013 and during follow-up from 2012 to 2016. A logistic regression model was used to analyze the odds ratios (ORs) and the 95% confidence intervals (CIs).

RESULTS

The ORs (95% CIs) for osteoporosis and osteoporotic fracture were 1.49 (95% CI 1.15-1.92, p = 0.03) and 1.06 (95% CI 0.82-1.38, p = 0.634), respectively, in the cervical cancer group. The ORs (95% CIs) for osteoporosis were 2.12 (95% CI 1.14-3.95, p = 0.018) in the ≤ 51-year-old group and 1.43 (95% CI 1.08-1.89, p = 0.011) in the ≥ 52-year-old group of cervical cancer patients.

CONCLUSION

We concluded that Korean women with cervical cancer had a higher risk of osteoporosis than healthy women, but the same finding was not observed for osteoporotic fracture.

An indispensable tool: Exosomes play a role in therapy for radiation damage

Radiotherapy is one of the three main treatments for tumors. Almost 70% of tumor patients undergo radiotherapy at different periods. Although radiotherapy can enhance the local control rate of tumors and patients' quality of life, normal tissues often show radiation damage following radiotherapy. In recent years, several studies have shown that exosomes could be biomarkers for diseases and be involved in the treatment of radiation damage. Exosomes are nanoscale vesicles containing complex miRNAs and proteins. They can regulate the inflammatory response, enhance the regeneration effect of damaged tissue, and promote the repair of damaged tissues and cells, extending their survival time. In addition, their functions are achieved by paracrine signaling. In this review, we discuss the potential of exosomes as biomarkers and introduce the impact of exosomes on radiation damage in different organs and the hematopoietic system in detail.

Identification of non-Hodgkin lymphoma patients at risk for treatment-related vertebral density loss and fractures

Information on bone loss in treated non-Hodgkin's lymphoma patients is limited. In this study, we used CT to analyze bone loss as well as prevalent and incident fractures. We found severe bone loss, a high rate of fractures, and a novel association between bone loss and the international prognostic index.

INTRODUCTION

To investigate bone loss and fracture risk in non-Hodgkin-lymphoma (NHL) patients by (i) comparing treatment-related vertebral density (VD) loss in NHL patients with control subjects and (ii) investigating associations of VD loss versus fracture risk. Further, associations of VD loss and clinical parameters were investigated.

METHODS

VD of 123 NHL patients was measured pre- and post-treatment in the L1, L2, and L3 vertebrae in routine computed tomography (CT) scans, performed between Jan 2016 and Mar 2017. Control measurements (n = 52) were obtained from CT colonographies between Sept 2003 and Sept 2017 and their subsequent follow-up-exams (10-137 months). Prevalent and incident (between baseline and follow-up) fractures were assessed in all subjects, and VD loss per year was calculated. Linear regression models were used to (i) compare VD loss between patients and controls and (ii) identify associations between VD loss and clinical parameters. Using logistic regression models, ORs for fractures per SD change in VD were assessed in patients. Analyses were adjusted for age, sex, and contrast application.

RESULTS

NHL patients experienced significantly greater VDL1-3 loss than controls (P = 0.003), and greater VDL1-3 loss was associated with a greater likelihood of incident fractures (OR, [95%-CI], P 1.90, [1.03, 3.51], 0.04). Patients with an initial international prognostic index (IPI) of 5 suffered significantly greater VD loss compared with an IPI of 0 (P = 0.01).

CONCLUSION

Using VD measurements in routine CT scans, substantial vertebral bone loss in NHL patients could be documented with a high incidence of fractures.

[Endocrine late-effects and bone mineral density after combined treatment of malignant brain tumors in childhood and adolescence]

Обоснование

Обоснование. Внедрение в клиническую практику стандартизированных протоколов комбинированного лечения онкологических заболеваний неизбежно приводит к развитию отдаленных последствий. Поскольку у лиц, излеченных в детском и подростковом возрасте, ожидаемая продолжительность жизни велика, своевременная диагностика и коррекция отдаленных последствий противоопухолевого лечения имеют даже большее значение, чем острые осложнения химиолучевой терапии.

Цель

Цель. Изучить распространенность эндокринных нарушений, оценить распространенность и степень снижения минеральной плотности костной ткани (МПК) у лиц, перенесших комбинированное лечение злокачественных опухолей головного мозга в детском и молодом возрасте.

Материалы и методы

Материалы и методы. Проведено ретроспективное исследование с участием 59 пациентов (31 мужчина; 28 женщин), перенесших в детском и молодом возрасте оперативное лечение злокачественной опухоли головного мозга с последующей лучевой терапией в объеме краниоспинального облучения в сочетании с полихимиотерапией или без нее. I группу составили 37 пациентов, которым комбинированное лечение проводилось в возрасте от 3 до 16 лет. Во II группу были включены 22 пациента, получившие лечение в возрасте от 16 до 38 лет.

Результаты

Результаты. Недостаточность соматотропного гормона по результатам пробы с инсулиновой гипогликемией выявлена у 48 пациентов (81%), вторичная надпочечниковая недостаточность — у 22 (37%). Большая часть обследованных (33 пациента (56%)) не достигли целевого роста. Лечение рекомбинантным гормоном роста (рГР) получили только 5 человек из I группы. Проведенный корреляционный анализ показал, что возраст на момент лечения — основной фактор, влияющий на конечный рост (r=0,619; p<0,001). Выявлена высокая частота развития гипотиреоза (n=39 (66%)), гипогонадизма (19 женщин; 17 мужчин). По результатам DXA снижение МПК ≤-2,0 SD по Z-критерию в поясничном отделе позвоночника выявлено у 35 из 59 обследованных (59%). МПК у пациентов I группы была значимо ниже по сравнению с пациентами, получившими лечение в более старшем возрасте (p<0,001). Обнаружена умеренная корреляция между МПК в поясничном отделе позвоночника на момент обследования и уровнем эстрадиола в крови у женщин (r=0,596; p<0,05) и тестостерона у мужчин (r=0,472; p<0,05). Выявлена прямая зависимость МПК от возраста на момент заболевания (r=0,781; p<0,01).

Заключение

Заключение. Полученные результаты свидетельствуют о необходимости ежегодного и пожизненного наблюдения пациентов после комбинированного лечения злокачественных опухолей головного мозга на предмет выявления отдаленных последствий лечения. Высокая распространенность остеопенических состояний определяет актуальность и необходимость проведения ранней диагностики для предотвращения дальнейшей потери костной массы, снижения прочности кости и риска переломов.

Computed tomography-measured bone mineral density as a surrogate marker of survival after resection of colorectal liver metastases

Background

Osteopenia/osteoporosis, characterized by low bone mineral density (BMD), is a potential prognostic factor in cancer patients. We conducted a retrospective single-institution study to evaluate the prognostic impact of preoperative low BMD on colorectal liver metastases (CRLM) in patients undergoing liver resection.

Methods

BMD was assessed in 281 patients undergoing initial liver resection for CRLM by analyzing the preoperative computed tomography (CT) images at the level of the eleventh thoracic vertebra as the region of interest. Survival outcomes were compared between the two groups divided by the median BMD value and prognostic factors after surgery were assessed. Propensity score-based inverse probability weighting (IPW) was applied to adjust for between-group differences in baseline characteristics.

Results

The low BMD group had significantly more older patients (≥75 years) (P=0.01) and a higher incidence of bilobar metastases (P=0.005) than the normal BMD group. After IPW adjustment, overall survival (OS) was significantly poorer (P=0.02) and recurrence-free survival was slightly poorer (P=0.05) in the low BMD group than in the normal BMD group. IPW-adjusted regression analysis revealed that low BMD was independently associated with an adverse OS (hazard ratio, 1.42; 95% CI, 1.04–1.93; P=0.03), in addition to other factors such as tumor number, extrahepatic disease, preoperative carcinoembryonic antigen level (≥5 ng/mL), and right-sided primary tumor location.

Conclusions

Preoperative CT-measured low BMD can serve as a surrogate marker of adverse OS in CRLM patients undergoing liver resection. Prevention and early intervention for osteopenia/osteoporosis may be suggested for these patients.

An Italian Retrospective Survey on Bone Metastasis in Melanoma: Impact of Immunotherapy and Radiotherapy on Survival

Background

We performed a multicenter retrospective observational study to investigate the impact of clinical–pathological features and therapeutic strategies on both the complications and survival of patients with bone metastases (BMs) from malignant melanoma.

Patients and Methods

A total of 305 patients with melanoma and radiological evidence of BMs were retrospectively enrolled from 19 Italian centers. All patients received conventional treatments in accordance with each own treating physician’s practice. Both univariate and multivariate models were used to explore the impact of melanoma features, including skeletal-related events (SREs), and different treatments on both overall survival (OS) and time-to-SREs. The chi-squared test evaluated the suitability of several parameters to predict the occurrence of SREs.

Results

Eighty-three percent of patients had metachronous BMs. The prevalent (90%) bone metastatic site was the spine, while 45% had involvement of the appendicular skeleton. Forty-seven percent experienced at least one SRE, including palliative radiotherapy (RT) in 37% of cases. No melanoma-associated factor was predictive of the development of SREs, although patients receiving early treatment with bone-targeted agents showed 62% lower risk and delayed time of SRE occurrence. Median OS from the diagnosis of bone metastasis was 10.7 months. The multivariate analysis revealed as independent prognostic factors the number of BMs, number of metastatic organs, baseline lactate dehydrogenase levels, and treatment with targeted therapy or immunotherapy. Subgroup analyses showed the best OS (median = 16.5 months) in the subset of patients receiving both immunotherapy and palliative RT.

Conclusion

Based on our results, patients undergoing immunotherapy and palliative RT showed an OS benefit suggestive of a possible additive effect. The apparent protective role of bone targeting agent use on SREs observed in our analysis should deserve prospective evaluation.

Denosumab for cancer-related bone loss

INTRODUCTION

Prolonged use of anti-cancer treatments in breast and prostate tumors alters physiological bone turnover leading to adverse skeletal related events, such as osteoporosis, loss of bone mass, and increased risk of fractures. These complications known as cancer treatment-induced bone loss (CTIBL) should be managed with bone targeting agents such as the bisphosphonates and denosumab. The latter is a monoclonal antibody against the receptor activator of nuclear factor-kB ligand (RANKL) that suppresses osteoclasts function and survival increasing bone mass.

AREAS COVERED

This review will focus on the mechanisms associated with bone loss induced by cancer treatments and the most recent evidence about the use of denosumab as preventive and therapeutic strategy to protect bone health. Moreover, we will discuss several key aspects regarding the clinical practical use of denosumab to optimize the management of CTLIB in breast and prostate cancer.

EXPERT OPINION

Denosumab treatment strongly prevents cancer therapies-related skeletal issues in breast and prostate cancer with a good safety profile. Adjuvant six-monthly denosumab delays the time to first fracture onset in early stage breast cancer patients with normal or altered bone mineral density (BMD). Similarly, denosumab treatment is able to prevent fractures and BMD loss in nonmetastatic prostate cancer patients.

Association of Chemoradiotherapy With Thoracic Vertebral Fractures in Patients With Esophageal Cancer

IMPORTANCE

The association of chemoradiotherapy (CRT) with a thoracic vertebral fracture in patients with esophageal cancer is unknown.

OBJECTIVE

To determine whether CRT is associated with thoracic vertebral fractures in patients with esophageal cancer.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study included patients with clinical stages I to III thoracic esophageal cancer who visited the Kyoto University Hospital, Kyoto, Japan, from January 1, 2007, to December 31, 2013. Data were analyzed from April 6, 2018, to June 4, 2020.

EXPOSURES

Chemoradiotherapy (CRT group) or surgery or endoscopic treatment (non-CRT group).

MAIN OUTCOMES AND MEASURES

The main outcome of this study was the cumulative incidence rate of thoracic vertebral fractures in 36 months. The incidence rate was calculated taking censoring into account. Possible risk factors, including CRT, were explored in the multivariable analysis. The association of irradiated doses with fractured vertebrae was also evaluated.

RESULTS

A total of 315 patients (119 for the CRT group and 196 for the non-CRT group) were included. The median age of patients was 65 (range, 32-85) years. Fifty-six patients (17.8%) were female and 259 (82.2%) were male. The median observation time was 40.4 (range, 0.7-124.1) months. Thoracic vertebral fractures were observed in 20 patients (16.8%) in the CRT group and 8 patients (4.1%) in the non-CRT group. The 36-month incidence rate of thoracic vertebral fractures was 12.3% (95% CI, 7.0%-19.1%) in the CRT group and 3.5% (95% CI, 1.3%-7.5%) in the non-CRT group (hazard ratio [HR], 3.41 [95% CI, 1.50-7.73]; P = .003). The multivariable analysis showed that the HR of the thoracic vertebral fracture in the CRT group to non-CRT group was 3.91 (95% CI, 1.66-9.23; P = .002) with adjusting for sex, 3.14 (95% CI, 1.37-7.19; P = .007) with adjusting for age, and 3.10 (95% CI, 1.33-7.24; P = .009) with adjusting for the history of vertebral or hip fractures. The HR of the thoracic vertebral fracture for a 5-Gy increase in the mean radiation dose to the single vertebra was 1.19 (95% CI, 1.04-1.36; P = .009).

CONCLUSIONS AND RELEVANCE

This study found that chemoradiotherapy was associated with thoracic vertebral fractures in patients with esophageal cancers. A reduced radiation dose to thoracic vertebrae may decrease the incidence of fractures.

Radiation alters osteoclastogenesis by regulating the cytoskeleton and lytic enzymes in RAW 264.7 cells and mouse bone marrow-derived macrophages

PURPOSE

The aim of the present study was to investigate the duality of irradiation effect on osteoclastogenesis, particularly on the cytoskeleton and expression of lytic enzymes in osteoclast precursors. Therefore, the present study may serve as a useful reference for the prevention and treatment of radiation-induced bone loss in the clinic.

MATERIALS AND METHODS

Two typical osteoclast precursors, murine RAW 264.7 macrophage cells and mouse bone marrow-derived macrophages (BMMs), were exposed to radiation in the order of 0.25-8 Gy, and the effects on cell viability, TRAP activity and bone resorption were subsequently investigated. Furthermore, changes in the cytoskeleton, cell apoptosis, and expression of lytic enzymes in osteoclasts were examined to elucidate the molecular mechanism of the duality of irradiation on osteoclastogenesis.

RESULTS

Morphological changes and impaired viability were observed in RAW 264.7 cells and BMMs treated with 1-8 Gy irradiation with or without RANKL. However, the cell fusion tendency of osteoclasts was enhanced after 2 Gy irradiation, and an increased number of fused giant osteoclasts and enhanced F-actin ring formation were observed. Consistently, the bone resorption activity and the enzyme expression of TRAP, cathepsin K, matrix metalloproteinase 9, activator protein 1, and Caspase 9 were increased following irradiation with 2 Gy. Furthermore, intracellular ROS production and apoptosis of osteoclast precursors were increased.

CONCLUSIONS

Irradiation with 2 Gy inhibited the viability of osteoclast precursors, but increased osteoclastogenesis by enhancing cell fusion and increasing the secretion of lytic enzymes, which may be an important mechanism of radiation-induced bone loss.

Establishment of a serological molecular model for the early diagnosis and progression monitoring of bone metastasis in lung cancer

Background

The prognosis is very poor for lung cancer patients with bone metastasis. Unfortunately, a suitable method has yet to become available for the early diagnosis of bone metastasis in lung cancer patients. The present work describes an attempt to develop a novel model for the early identification of lung cancer patients with bone metastasis risk.

Methods

As the test group, 205 primary lung cancer patients were recruited, of which 127 patients had bone metastasis; the other 78 patients without bone metastasis were set as the negative control. Additionally, 106 healthy volunteers were enrolled as the normal control. Serum levels of several cytokines in the bone microenvironment (CaN, OPG, PTHrP, and IL-6) and bone turnover markers (tP1NP, β-CTx) were detected in all samples by ECLIA or ELISA assay. Receiver operating characteristic (ROC) curves and multivariate analyses were performed to evaluate diagnostic abilities and to assess the attributable risk of bone metastasis for each of these indicators; the diagnostic model was established via logistic regression analysis. The prospective validation group consisted of 44 patients with stage IV primary lung cancer on whom a follow-up of at least 2 years was conducted, during which serum bone biochemical marker concentrations were monitored.

Results

The serological molecular model for the diagnosis of bone metastasis was logit (p). ROC analysis showed that when logit (p) > 0.452, the area under curve of the model was 0.939 (sensitivity: 85.8%, specificity: 89.7%). Model validation demonstrated accuracy with a high degree of consistency (specificity: 85.7%, specificity: 87.5%, Kappa: 0.770). The average predictive time for bone metastasis occurrence of the model was 9.46 months earlier than that of the bone scan diagnosis. Serum OPG, PTHrP, tP1NP, β-CTx, and the diagnostic model logit (p) were all positively correlated with bone metastasis progression (P < 0.05).

Conclusions

This diagnostic model has the potential to be a simple, non-invasive, and sensitive tool for diagnosing the occurrence and monitoring the progression of bone metastasis in patients with lung cancer.

FGF23-related hypophosphatemia in patients with low bone mineral density and fragility fractures: challenges in diagnosis and management

PURPOSE

Hypophosphatemia (HP) can be observed in patients evaluated for skeletal fragility. We investigated prevalence of HP among outpatients referred for low bone density or fragility fractures, HP-associated clinical and biochemical features and outcomes of recommended diagnostic algorithm in our cohort.

METHODS

Chronic HP (phosphate ≤ 2.7 mg/dL over 6 months or longer) was retrospectively investigated among 2319 patients. In renal wasting-related HP, intact FGF23 was assessed; non-suppressed FGF23 prompted the performance of ⁶⁸Ga-DOTATOC PET/CT in the suspicion of tumor-induced steomalacia (TIO).

RESULTS

Renal wasting-related HP (median 2.2, range 1.6-2.6 mg/dL) was observed in 19 patients (0.82%). FGF23 levels were suppressed in two patients diagnosed with renal tubular disease, increased in one and within normal range in most patients. X-linked hypophosphatemic rickets was diagnosed in one woman. In the remaining 16 patients, highly prevalent fragility fractures (50%) and severely reduced bone mineral density were detected, though diagnostic criteria for osteomalacia were not fulfilled. ⁶⁸Ga-PET was performed in nine patients and was positive in four. While intact FGF23 levels alone failed to differentiate PET's outcomes (positive: FGF23 median 70.5 pg/mL; negative: 52 pg/mL, P = 0.462), the coexistence of multiple biochemical and radiologic alterations performed better in prediction of PET's positivity.

CONCLUSION

Mild, apparently unexplained HP is observed in 0.82% of patients with low bone density or fragility fractures. In asymptomatic patients with isolated mild hypophosphatemia, the probability of finding an underlying tumor disease is very low, and utility of extensive and expensive diagnostic workup should be carefully considered in this setting.

Role of Bone Targeting Agents in the Prevention of Bone Metastases from Breast Cancer

Breast cancer (BC) is the most common malignancy in women worldwide and leads, in more than 70% of patients with advanced disease, to skeleton colonization and formation of bone metastases (BM). This condition implies a severe disability and deterioration of the quality of life, with consequent additional social costs. In recent decades, several studies explored the role of agents acting within the bone microenvironment to counteract BM development, and several bone-targeting agents (BTAs) have been introduced in the clinical practice to manage bone lesions and reduce the risk of skeletal complications. However, long-term exposure to these agents is not free from potential toxicities and needs careful monitoring. In this context, the potential capability to prevent BM onset in selected BC patients, through the early administration of BTAs, has been explored by several researchers, with the belief that “prevention is better than cure” and that, ultimately, metastatic BC is an incurable condition. Here, we revised the mechanisms of BM development in BC as well as the strategies for selecting high-risk patients suitable for early BTA treatment.

The Roles of ROS Generation in RANKL-Induced Osteoclastogenesis: Suppressive Effects of Febuxostat

Receptor activator of NF-κB ligand (RANKL), a critical mediator of osteoclastogenesis, is upregulated in multiple myeloma (MM). The xanthine oxidase inhibitor febuxostat, clinically used for prevention of tumor lysis syndrome, has been demonstrated to effectively inhibit not only the generation of uric acid but also the formation of reactive oxygen species (ROS). ROS has been demonstrated to mediate RANKL-mediated osteoclastogenesis. In the present study, we therefore explored the role of cancer-treatment-induced ROS in RANKL-mediated osteoclastogenesis and the suppressive effects of febuxostat on ROS generation and osteoclastogenesis. RANKL dose-dependently induced ROS production in RAW264.7 preosteoclastic cells; however, febuxostat inhibited the RANKL-induced ROS production and osteoclast (OC) formation. Interestingly, doxorubicin (Dox) further enhanced RANKL-induced osteoclastogenesis through upregulation of ROS production, which was mostly abolished by addition of febuxostat. Febuxostat also inhibited osteoclastogenesis enhanced in cocultures of bone marrow cells with MM cells. Importantly, febuxostat rather suppressed MM cell viability and did not compromise Dox's anti-MM activity. In addition, febuxostat was able to alleviate pathological osteoclastic activity and bone loss in ovariectomized mice. Collectively, these results suggest that excessive ROS production by aberrant RANKL overexpression and/or anticancer treatment disadvantageously impacts bone, and that febuxostat can prevent the ROS-mediated osteoclastic bone damage.

Irradiation-induced senescence of bone marrow mesenchymal stem cells aggravates osteogenic differentiation dysfunction via paracrine signaling

The role of cellular senescence induced by radiation in bone loss has attracted much attention. As one of the common complications of anticancer radiotherapy, irradiation-induced bone deterioration is common and clinically significant, but the pathological mechanism has not been elucidated. This study was performed to explore the cellular senescence and senescence-associated secretory phenotype (SASP) induction of bone marrow-derived mesenchymal stem cells (BMSCs) by irradiation and its role in osteogenic differentiation dysfunction. It was observed that irradiated BMSCs lost typical fibroblast-like morphology, exhibited suppressed viability and differentiation potential accompanied with senescence phenotypes, including an increase in senescence-associated β-galactosidase (SA-β-gal) staining-positive cells, and upregulated senescence-related genes p53/p21, whereas no changes happened to p16. Additionally, DNA damage γ-H2AX foci, G0/G1 phase of cell cycle arrest, and cellular and mitochondrial reactive oxygen species (ROS) increased in an irradiation dose-dependent manner. Meanwhile, the JAK1/STAT3 pathway was activated and accompanied by an increase in SASP secretion, such as IL-6, IL-8, and matrix metalloproteinase-9 (MMP9), whereas 0.8 μM JAK1 inhibitor (JAKi) treatment effectively inhibited the JAK pathway and SASP production. Furthermore, conditioned medium (CM) from irradiation-induced senescent (IRIS) BMSCs exhibited a markedly reduced ability in osteogenic differentiation and marker gene expression of osteoblasts, whereas CM with JAKi intervention may effectively improve these deterioration effects. In conclusion, irradiation could provoke BMSC senescence and SASP secretion and further aggravate osteogenic differentiation dysfunction via paracrine signaling, whereas SASP targeting may be a possible intervention strategy for alleviating irradiation-induced bone loss.

CR6-interacting factor-1 contributes to osteoclastogenesis by inducing receptor activator of nuclear factor κB ligand after radiation

BACKGROUND

Radiation induces rapid bone loss and enhances bone resorption and adipogenesis, leading to an increased risk of bone fracture. There is still a lack of effective preventive or therapeutic method for irradiation-induced bone injury. Receptor activator of nuclear factor κB ligand (RANKL) provides the crucial signal to induce osteoclast differentiation and plays an important role in bone resorption. However, the mechanisms of radiation-induced osteoporosis are not fully understood.

AIM

To investigate the role of CR6-interacting factor-1 (Crif1) in osteoclastogenesis after radiation and its possible mechanism.

METHODS

C57BL/6 mice were exposed to Co-60 gamma rays and received 5 Gy of whole-body sublethal irradiation at a rate of 0.69 Gy/min. For in vitro study, mouse bone marrow mesenchymal stem/stromal cells (BM-MSCs) were irradiated with Co-60 at a single dose of 9 Gy. For osteoclast induction, monocyte-macrophage RAW264.7 cells were cocultured with mouse BM-MSCs for 7 d. ClusPro and InterProSurf were used to investigate the interaction interface in Crif1 and protein kinase cyclic adenosine monophosphate (cAMP)-activited catalytic subunit alpha complex. Virtual screening using 462608 compounds from the Life Chemicals database around His120 of Crif1 was carried out using the program Autodock_vina. A tetrazolium salt (WST-8) assay was carried out to study the toxicity of compounds to different cells, including human BM-MSCs, mouse BM-MSCs, and Vero cells.

RESULTS

Crif1 expression increased in bone marrow cells after radiation in mice. Overexpression of Crif1 in mouse BM-MSCs and radiation exposure could increase RANKL secretion and promote osteoclastogenesis in vitro. Deletion of Crif1 in BM-MSCs could reduce both adipogenesis and RANKL expression, resulting in the inhibition of osteoclastogenesis. Deletion of Crif1 in RAW264.7 cells did not affect the receptor activator of nuclear factor κB expression or osteoclast differentiation. Following treatment with protein kinase A (PKA) agonist (forskolin) and inhibitor (H-89) in mouse BM-MSCs, Crif1 induced RANKL secretion via the cAMP/PKA pathway. Moreover, we identified the Crif1-protein kinase cyclic adenosine monophosphate-activited catalytic subunit alpha interaction interface by in silico studies and shortlisted interface inhibitors through virtual screening on Crif1. Five compounds dramatically suppressed RANKL secretion and adipogenesis by inhibiting the cAMP/PKA pathway.

CONCLUSION

Crif1 promotes RANKL expression via the cAMP/PKA pathway, which induces osteoclastogenesis by binding to receptor activator of nuclear factor κB on monocytes-macrophages in the mouse model. These results suggest a role for Crif1 in modulating osteoclastogenesis and provide insights into potential therapeutic strategies targeting the balance between osteogenesis and adipogenesis for radiation-induced bone injury.

The versatile biomedical applications of bismuth-based nanoparticles and composites: therapeutic, diagnostic, biosensing, and regenerative properties

Studies of nanosized forms of bismuth (Bi)-containing materials have recently expanded from optical, chemical, electronic, and engineering fields towards biomedicine, as a result of their safety, cost-effective fabrication processes, large surface area, high stability, and high versatility in terms of shape, size, and porosity. Bi, as a nontoxic and inexpensive diamagnetic heavy metal, has been used for the fabrication of various nanoparticles (NPs) with unique structural, physicochemical, and compositional features to combine various properties, such as a favourably high X-ray attenuation coefficient and near-infrared (NIR) absorbance, excellent light-to-heat conversion efficiency, and a long circulation half-life. These features have rendered bismuth-containing nanoparticles (BiNPs) with desirable performance for combined cancer therapy, photothermal and radiation therapy (RT), multimodal imaging, theranostics, drug delivery, biosensing, and tissue engineering. Bismuth oxyhalides (BiO_x, where X is Cl, Br or I) and bismuth chalcogenides, including bismuth oxide, bismuth sulfide, bismuth selenide, and bismuth telluride, have been heavily investigated for therapeutic purposes. The pharmacokinetics of these BiNPs can be easily improved via the facile modification of their surfaces with biocompatible polymers and proteins, resulting in enhanced colloidal stability, extended blood circulation, and reduced toxicity. Desirable antibacterial effects, bone regeneration potential, and tumor growth suppression under NIR laser radiation are the main biomedical research areas involving BiNPs that have opened up a new paradigm for their future clinical translation. This review emphasizes the synthesis and state-of-the-art progress related to the biomedical applications of BiNPs with different structures, sizes, and compositions. Furthermore, a comprehensive discussion focusing on challenges and future opportunities is presented.

Influence of radiation exposure pattern on the bone injury and osteoclastogenesis in a rat model

Radiotherapy, one of the clinical treatments of cancer, is accompanied by a high risk of damage to healthy tissues, such as bone loss and increased risk of fractures. The aim of the present study was to establish a rat model of local and systemic bone injury by focal irradiation, in order to study the etiological mechanism and intervention. The proximal metaphyseal region of the left hindlimb of male Sprague-Dawley rats were exposed to a single 2 Gy or three 8 Gy doses delivered on days 1, 3 and 5 using a small animal irradiator, the changes in bone volume and microarchitecture were evaluated, and the mineral apposition rate (MAR) was assessed. Furthermore, bone marrow-derived macrophages (BMMs) were isolated and induced to osteoclasts. It has been demonstrated that a single dose of 2 Gy may result in a significant loss of lumbar bone density at 3 days post-irradiation, however this is restored at 30 days post-irradiation. In the 3x8 Gy irradiation rat model, there was a rapid decrease in the aBMD of lumbar spine at 3 days and at 7 days post-irradiation, and the aBMD decline persisted even at 60 days post-irradiation. In addition, microCT analysis revealed a persistent decline in bone volume and damage in microarchitecture in the 3x8 Gy irradiation model, accompanied by a decrease in MAR, index of the decline in bone-forming ability. In the cellular mechanism, a single 2 Gy local irradiation mainly manifested as an enhancement of the BMMs osteoclastogenesis potential, which was different from the osteoclastogenesis inhibition after high-dose focal irradiation (3x8 Gy). In summary, the irradiation with simulated clinical focal fractionated radiotherapy exerts short- and long-term systemic injury on bone tissue, characterized by different osteoclastogenesis potential between the high dose mode and a single 2 Gy focal irradiation. Physicians must consider the irreversibility of bone damage in clinical radiotherapy.

Clinical and translational pharmacology of drugs for the prevention and treatment of bone metastases and cancer-induced bone loss

Bone disease is a frequent event in cancer patients, both due to cancer spread to bone and to cancer therapies. Bone is the organ most frequently affected by metastatic disease when considering the two most frequent cancers in the Western world (breast and prostate cancers). Bone metastases can have a substantial detrimental effect on patients' quality of life, as well as significant morbidity due to complications collectively known as skeletal-related events (SREs), which include hypercalcaemia, pathological fractures, spinal cord compression, and need of radiotherapy or surgery to the bone. These have been successfully mitigated with the development of bone-targeted agents (BTAs; bisphosphonates and denosumab), focused on inhibiting osteoclast activity. The potential direct antitumour effect of bisphosphonates, as well as the impact of osteoclast inhibition with subsequent decrease in bone metabolism, have also propelled investigation on the role of BTAs in preventing cancer relapse in bone. In this review, the authors aimed to discuss the role of BTAs in the treatment and prevention of bone metastases, as well as their potential value in preventing cancer treatment-induced bone loss (CTIBL). The review will focus on breast and prostate cancers, with the aim of providing the most relevant clinical data emerging from bench to bedside translational research in the field of cancer-induced bone disease.

Osteopenia and fractures associated with long-term therapy with MEK inhibitors

Targeted therapies have markedly improved the survival of patients with melanoma. We report the case of two patients with advanced melanoma controlled by long-term MEK inhibitor or combination of BRAF and MEK inhibitors, who developed fractures related to severe osteopenia. A 48-year-old woman was treated by pimasertib after the failure of two lines of chemotherapy, and a 42-year-old man was treated by an association of BRAFi (dabrafenib) and MEKi (trametinib) after the failure of one line of chemotherapy. During follow-up, both complained of buttock pain, revealing primary fractures of the pelvis and lumbar vertebra. In both patients, none had osteoporosis risk factors; DEXA scan revealed osteopenia, and analysis ruled out metastatic bone lesion or secondary osteoporosis. Zoledronic acid, cholecalciferol (vitamin D3), oral calcium, and pain killers were introduced, leading to no further bone event. Numerous pathways are involved in the homeostasis of bone turnover, and the effect of tyrosine kinase inhibitors on those pathways is not well known yet. The absence of usual causes of osteoporosis or metastatic bone lesion and kinetics of symptoms lead us to suggest that MEK inhibitors were responsible for the development of osteoporosis. To the best of our knowledge, this is the first report of fractures associated with osteopenia in patients treated with MEKi. Long-term survival owing to new targeted treatment could be associated with yet underestimated adverse effects such as osteopenia/osteoporosis that could impair patient's quality of life and should be investigated.