Skeletal metastasis in renal cell carcinoma: A review

Implications of bone metastasis on response to systemic therapy in patients with advanced renal cell carcinoma: A systematic literature review

INTRODUCTION

Bone metastases negatively affect prognosis in patients with advanced renal cell carcinoma (aRCC). We conducted a systematic literature review to identify clinical trial publications including patients with aRCC with and without bone metastases.

METHODS

The review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta‑Analyses (PRISMA) guidelines and registered with PROSPERO (CRD42022355436). MEDLINE and Embase databases were searched (September 2, 2022) to identify publications reporting efficacy and safety outcomes for patients with/without bone metastasis from clinical trials of systemic RCC therapies. Risk of bias was assessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE).

RESULTS

Of 526 publications screened, 19 were eligible: seven (from five studies) reported phase 3 trials, six reported phase 2 trials, one reported phase 1b/2 trials, and five were pooled analyses. Five publications reported moderate-quality evidence, while 14 were graded as low- or very low-quality evidence, suggesting a high potential for uncertainty. Five studies reported benefits of investigational therapies versus comparators in patients with and without bone metastases; these studies included cabozantinib, nivolumab, cabozantinib plus nivolumab, and lenvatinib plus pembrolizumab treatment arms. Data were also available for nivolumab plus ipilimumab. Bone metastases were consistently associated with poor prognosis in patients with aRCC. Preliminary data support the hypothesis that therapies targeting pathways implicated in the development of bone metastases may be beneficial, and warrant further investigation. However, data to support treatment decision-making are lacking.

CONCLUSION

Our findings highlight the need for clinical data to assist in defining the optimal treatment for patients with aRCC and bone metastasis.

Practical management of renal cell carcinoma: integrating current approaches with advances in bone metastasis treatment

Renal cell carcinoma (RCC) is a common type of tumor that can develop in the kidney. It is responsible for around one-third of all cases of neoplasms. RCC manifests itself in a variety of distinct subtypes. The most frequent of which is clear cell RCC, followed by papillary and chromophobe RCC. RCC has the potential for metastasis to a variety of organs; nevertheless, bone metastases are one of the most common and potentially fatal complications. These bone metastases are characterized by osteolytic lesions that can result in pathological fractures, hypercalcemia, and other complications, which can ultimately lead to a deterioration in quality of life and an increase morbidity. While nephrectomy remains a foundational treatment for RCC, emerging evidence suggests that targeted therapies, including tyrosine kinase inhibitors and T cell checkpoint inhibitors, may offer effective alternatives, potentially obviating the need for adjuvant nephrectomy in certain cases of metastatic RCC Bone metastases continue to be a difficult complication of RCC, which is why more research is required to enhance patient outcome.

Mechanism and clinical progression of solid tumors bone marrow metastasis

The rich blood supply of the bone marrow provides favorable conditions for tumor cell proliferation and growth. In the disease's early stages, circulating tumor cells can escape to the bone marrow and form imperceptible micro metastases. These tumor cells may be reactivated to regain the ability to grow aggressively and eventually develop into visible metastases. Symptomatic bone marrow metastases with abnormal hematopoiesis solid tumor metastases are rare and have poor prognoses. Treatment options are carefully chosen because of the suppression of bone marrow function. In this review, we summarized the mechanisms involved in developing bone marrow metastases from tumor cells and the clinical features, treatment options, and prognosis of patients with symptomatic bone marrow metastases from different solid tumors reported in the literature.

Bone mimetic environments support engineering, propagation, and analysis of therapeutic response of patient-derived cells, ex vivo and in vivo

Bone metastases are the most common milestone in the lethal progression of prostate cancer and prominent in a substantial portion of renal malignancies. Interactions between cancer and bone host cells have emerged as drivers of both disease progression and therapeutic resistance. To best understand these central host-epithelial cell interactions, biologically relevant preclinical models are required. To achieve this goal, we here established and characterized tissue-engineered bone mimetic environments (BME) capable of supporting the growth of patient-derived xenograft (PDX) cells, ex vivo and in vivo. The BME consisted of a polycaprolactone (PCL) scaffold colonized by human mesenchymal stem cells (hMSCs) differentiated into osteoblasts. PDX-derived cells were isolated from bone metastatic prostate or renal tumors, engineered to express GFP or luciferase and seeded onto the BMEs. BMEs supported the growth and therapy response of PDX-derived cells, ex vivo. Additionally, BMEs survived after in vivo implantation and further sustained the growth of PDX-derived cells, their serial transplant, and their application to study the response to treatment. Taken together, this demonstrates the utility of BMEs in combination with patient-derived cells, both ex vivo and in vivo. STATEMENT OF SIGNIFICANCE: Our tissue-engineered BME supported the growth of patient-derived cells and proved useful to monitor the therapy response, both ex vivo and in vivo. This approach has the potential to enable co-clinical strategies to monitor bone metastatic tumor progression and therapy response, including identification and prioritization of new targets for patient treatment.

Cancer of unknown primary and the «seed and soil» hypothesis

The worldwide incidence rate of cancer of unknown primary (CUP) reaches 5% (Kang et al, 2021; Lee, Sanoff, 2020; Yang et al, 2022). CUP has an alarmingly high mortality rate, with 84% of patients succumbing within the first year following diagnosis (Registration and Service, 2018). Under normal circumstances, tumor cell metastasis follows the «seed and soil» hypothesis, displaying a tissue-specific pattern of cancer cell homing behavior based on the microenvironment composition of secondary organs. In this study, we questioned whether seed and soil concept applies to CUP, and whether the pattern of tumor and metastasis manifestations for cancer of known primary (CKP) can be used to inform diagnostic strategies for CUP. We compared data from metastatic and primary CUP foci to the metastasis patterns observed in CKP. Furthermore, we evaluated several techniques for identifying the tissue-of-origin (TOO) in CUP profiling, including DNA, RNA, and epigenetic TOO techniques.

TYROBP as a molecular target in cholangiocarcinoma, renal cancer and abdominal aortic aneurysm

Cholangiocarcinoma occurs when there is a malignant tumor in the bile duct system. Renal cancer originates from renal tubular epithelial cells. Abdominal aortic aneurysm (AAA) is a permanently localized dilation caused by a lesion or injury to abdominal aortic wall. However, the relationship between TYROBP and cholangiocarcinoma, renal cancer and AAA remains unclear. The profiles of cholangiocarcinoma dataset GSE107943, renal cell carcinoma dataset GSE213324, and AAA dataset GSE47472 were downloaded from the GEO database using the platforms GPL18573, GPL24676, and GPL10558. DEGs were screened, WGCNA was performed as well as construction and analysis of PPI network. Functional enrichment analysis, GSEA, heat map of gene expression, survival analysis, and immune infiltration analysis were performed. The most relevant diseases to core genes were found by CTD. The GSE107943 dataset identified 3383 DEGs for cholangiocarcinoma, GSE47472 identified 95 DEGs for abdominal aortic aneurysm, and GSE213324 identified 10245 DEGs for renal cell carcinoma. For the GSE107943 cholangiocarcinoma dataset, GO analysis revealed enrichment in immune response, cell adhesion, extracellular space, and oxidoreductase activity. KEGG analysis indicated enrichment in metabolic pathways, the PI3K-Akt signaling pathway, cell apoptosis, the cell cycle, and the NF-kappa B signaling pathway. In the GSE47472 AAA dataset, GO analysis showed enrichment in neuroblast differentiation, cardiac muscle myofilament complex, and alkaline binding. KEGG analysis indicated enrichment in mRNA surveillance pathway and purine metabolism. In the GSE213324 renal cell carcinoma dataset, GO analysis indicated enrichment in immune system processes, cell adhesion, and membrane parts. KEGG analysis showed enrichment in cytokine-cytokine receptor interaction, calcium signaling pathway, and hematopoietic cell lineage. Furthermore, for cholangiocarcinoma (GSE107943), enriched terms associated with DEGs were in metabolic pathways, cell apoptosis, and the cell cycle. For AAA (GSE47472), enriched terms were in alkaline binding and cellular redox homeostasis. For renal cell carcinoma (GSE213324), enriched terms were in biological adhesion, regulation of immune system processes, and cell surface. Common core genes (ADH6, AGXT, CYP3A43, TYROBP) were identified for cholangiocarcinoma, renal cell carcinoma, and AAA. ADH6 and TYROBP were associated with cholangiocarcinoma, AAA, renal tumors, kidney diseases, atherosclerosis, and inflammation. TYROBP is abnormally expressed in cholangiocarcinoma, renal cancer and abdominal aortic aneurysm.

Cuproptosis related gene PDHB is identified as a biomarker inversely associated with the progression of clear cell renal cell carcinoma

BACKGROUND

Cuproptosis is a newly discovered programmed cell death dependent on mitochondrial respiratory disorder induced by copper overload. Pyruvate dehydrogenase E1 subunit beta (PDHB) is one of the cuproptosis genesand is a nuclear-encoded pyruvate dehydrogenase, which catalyzes the conversion of pyruvate to acetyl coenzyme A. However, the mechanism of PDHB in clear cell renal cell carcinoma (ccRCC) remains unclear.

METHODS

We used data from TCGA and GEO to assess the expression of PDHB in normal and tumor tissues. We further analyzed the relationship between PDHB and somatic mutations and immune infiltration. Finally, we preliminarily explored the impact of PDHB on ccRCC.

RESULTS

The expression level of PDHB was lower in tumor tissue compared with normal tissue. Meanwhile, the expression level of PDHB was also lower in high-grade tumors than low-grade tumors. PDHB is positively correlated with prognosis in ccRCC. Furthermore, PDHB may be associated with decreased risk of VHL, PBRM1 and KDM5C mutations. In 786-O cells, copper chloride could promote the expression of cuproptosis genes (DLAT, PDHB and FDX1) and inhibit cell growth. Last but not least, we found that PDHB could inhibit the proliferation and migration of ccRCC cells.

CONCLUSION

Our results demonstrated that PDHB could inhibit the proliferation, migration and invasion in ccRCC cells, which might be a prognostic predictor of ccRCC. Targeting this molecular might provide a new therapeutic strategy for patients with advanced ccRCC.

Factors affecting local control of bone metastases from radioresistant tumors treated with palliative external beam radiotherapy

BACKGROUND

This study aimed to evaluate the factors that affect the local control (LC) of bone metastases from radioresistant carcinomas (renal cell carcinoma, hepatocellular carcinoma [HCC], and colorectal carcinoma [CRC]) treated with palliative external-beam radiotherapy (EBRT).

METHODS AND MATERIALS

Between January 2010 and December 2020, 211 bone metastases in 134 patients were treated with EBRT in two hospitals (a cancer center and university hospital). Based on follow-up CT, these cases were reviewed retrospectively to evaluate LC at the EBRT site.

RESULTS

The median EBRT dose (BED10) was 39.0 Gy (range, 14.4-66.3 Gy). The median follow-up time of the imaging studies was 6 months (range, 1-107 months). The 0.5-year overall survival and LC rates of the EBRT sites were 73% and 73%, respectively. Multivariate analysis revealed that the primary sites (HCC/CRC), low EBRT dose (BED10) (≤ 39.0 Gy), and non-administration of post-EBRT bone modifying agents (BMAs) and/or antineoplastic agents (ATs) were statistically significant factors that negatively affected the LC of EBRT sites. In the absence of BMAs or ATs, the EBRT dose (BED10) escalation from 39.0 Gy improved the LC of EBRT sites. Based on ATs administration, the LC of EBRT sites was significantly affected by tyrosine kinase inhibitors and/or immune checkpoint inhibitors.

CONCLUSIONS

Dose escalation improves LC in bone metastases from radioresistant carcinomas. Higher EBRT doses are needed to treat patients for whom few effective systemic therapies remain available.

A Review on the Usage of Bone Single-Photon Emission Computed Tomography/Computed Tomography in Detecting Skeletal Metastases in the Post-COVID-19 Era: Is it Time to Ditch Planar and Single-Photon Emission Computed Tomography only Gamma Camera Systems?

Planar whole-body bone scanning (WBS) is widely used to evaluate skeletal lesions seen in cancer and noncancer cases. Frequently, degenerative, or other benign bony changes may give rise to indeterminate lesions that mimic bone metastases. In the post-COVID-19 era, there is an evolutionary phase that puts importance on global development and adaptability, which encompasses to include nuclear medicine practices worldwide. Single-photon emission computed tomography/computed tomography (SPECT/CT) can be used to improve the characterization of these lesions and help to resolve the diagnostic conundrum while reducing the need for patients to undergo multiple different examinations at various imaging departments. The fusion of SPECT and CT allows morphological characterization of functional abnormality detected by focal tracer uptake on planar scintigraphy, which provides a one-stop center imaging in nuclear medicine departments. The objective of this study was to review the diagnostic accuracy of SPECT/CT in diagnosing bone metastases in a variety of oncology and nononcology cases and to determine the feasibility of performing bone SPECT/CT in all suspected cancer cases, including cases of bone infection instead of planar imaging alone. The utilization of hybrid SPECT/CT in indeterminate bone lesions detected on planar WBS can significantly increase the diagnostic confidence and accuracy of image interpretation. Recognition of patterns of disease identified using hybrid imaging can improve the management of patients with potentially lower costs in the long term. Currently, hybrid SPECT/CT machines are becoming a norm in nuclear medicine departments, thus potentially making single planar application machines obsolete in the near future. We hypothesize that in the interest of providing a meaningful interpretation of isotope bone scans, the default protocol should involve the option of acquiring SPECT/CT images rather than relying on whole-body scans only. Departments choosing to upgrade existing equipment or those choosing to invest in only one gamma camera should proactively opt for hybrid SPECT/CT systems.

Embolization of Renal Cell Carcinoma Skeletal Metastases Preceding Orthopedic Surgery

Renal cell carcinoma (RCC) is the most common type of renal malignancy in adults. Bone is a major site of metastatic disease from RCC. Osseous metastatic disease from RCC is often seen in the spine, pelvis, and femur, and is usually hypervascular in nature like its primary tumor source. This can cause significant pain, reduced function, pathological fracture, nerve compression, and decreased quality of life during cancer treatment and disease course. Surgical treatments for pathological fracture of the femur include resection, reconstruction, and stabilization with arthroplasty or placement of an intramedullary nail. This series looks at three cases of renal cell carcinoma metastases to the hip with pre-procedural embolization and orthopedic stabilization. Interventional radiology embolization of the arterial supply to the metastatic hypervascular bone lesions can reduce intraoperative blood loss and associated complications.

Clear Cell Renal Cell Carcinoma Spinal Metastases: Which Factors Matter to the Overall Survival? A 10-Year Experience of a High-Volume Tumor Spine Center

Clear cell renal cell carcinoma (ccRCC) usually spreads in the spinal region causing instability or spinal cord compression leading to neurological deficits. Therefore, surgical treatment is required for improving the outcome of patients. The aim of this study is to identify which prognostic factors could affect overall survival in patients affected by ccRCC. Methods: Retrospective cohort study of patients with ccRCC spinal metastases, surgically treated from November 2009 to April 2019. Demographic and clinical data were collected. The Kaplan−Meier method was used to estimate overall survival, and the log-rank test was used to evaluate differences in survival among potentially prognostic factors. Results: A total of 69 patients were surgically treated and followed up for a median period of 65 months. The average age at the time of surgery was 62.6 years old. The median overall survival (OS) was 34.7 months (95% CI 20.8−51.9) and 5-year OS was 31.2% (95% CI 19.2−44.1). A high Tokuhashi score (p = 0.0217), the presence of visceral metastases (p < 0.001), other bone metastases (p = 0.02012) and the kind of surgical treatment (p = 0.0395) are the main prognostic factors that influence the OS. Moreover, 3-year progression-free survival (PFS) was analyzed: the median PFS was 53.1 months and the % 3-year PFS was 62.9% (45.2−76.3). In the multivariate analysis, only pre-operative radiation therapy had a significant impact on 3-year PFS (95% CI 0.929−12.994, p = 0.0643). Conclusion: The results of this study suggest that the absence of visceral metastases and an aggressive surgery as en-bloc, when feasible, could prolong the survival rate and improve quality of life for patients.

Establishment and Validation of a Machine Learning Prediction Model Based on Big Data for Predicting the Risk of Bone Metastasis in Renal Cell Carcinoma Patients

Purpose

Since the prognosis of renal cell carcinoma (RCC) patients with bone metastasis (BM) is poor, this study is aimed at using big data to build a machine learning (ML) model to predict the risk of BM in RCC patients.

Methods

A retrospective study was conducted on 40,355 RCC patients in the SEER database from 2010 to 2017. LASSO regression and multivariate logistic regression analysis was performed to determine independent risk factors of RCC-BM. Six ML algorithm models, including LR, GBM, XGB, RF, DT, and NBC, were used to establish risk models for predicting RCC-BM. The prediction performance of ML models was weighed by 10-fold cross-validation.

Results

The study investigated 40,355 patients diagnosed with RCC in the SEER database, where 1,811 (4.5%) were BM patients. Independent risk factors for BM were tumor grade, T stage, N stage, liver metastasis, lung metastasis, and brain metastasis. Among the RCC-BM risk prediction models established by six ML algorithms, the XGB model showed the best prediction performance (AUC = 0.891). Therefore, a network calculator based on the XGB model was established to individually assess the risk of BM in patients with RCC.

Conclusion

The XGB risk prediction model based on the ML algorithm performed a good prediction effect on BM in RCC patients.

Socioeconomic and insurance-related disparities in disease-specific survival among patients with metastatic bone disease

BACKGROUND

Approximately 5% of cancer patients in the United States presented with metastatic bone disease (MBD) at diagnosis. Current study explores the disparities in survival for patients with MBD.

METHODS

Patients with the diagnosis of MBD at presentation for the five most common primary anatomical sites were extracted from Surveillance, Epidemiology, and End Results Census tract-level dataset (2010-2016). Kaplan-Meier and Cox Proportional Hazard models were used to evaluate survival, and prognostic factors for each cohort. Prognostic significance of socioeconomic status (SES) and insurance status were ascertained.

RESULTS

The five most common anatomical-sites with MBD at presentation included "lung" (n = 59 739), "prostate" (n = 19 732), "breast" (n = 16 244), "renal and urothelium" (n = 7718) and "colon" (n= 3068). Lower SES was an independent risk factor for worse disease-specific survival (DSS) for patients with MBD originating from lung, prostate, breast and colon. Lack of insurance was an independent risk factor for worse DSS for MBD patients with primary tumors in lung and breast.

CONCLUSIONS

MBD patients from the five most common primary sites demonstrated SES and insurance-related disparities in disease-specific survival. This is the first and largest study to explore SES and insurance-related disparities among patients specifically afflicted with MBD. Our findings highlight vulnerability of patients with MBD across multiple primary sites to financial toxicity.

Metastatic Renal Cell Cancer Instigating Paraplegia in a Male Patient

Renal cell carcinoma (RCC) constitutes about 2% of all adult malignancies and is the most common malignant renal neoplasm with bony metastases occurring in up to 50% of patients with RCC. In this case, we report a 42-year-old male who presented with chronic back pain and had a sudden episode of paraplegia. The patient was initially referred to the orthopedics service. He had a lumbar X-ray done followed by a CT of the spine that showed a burst fracture of the L1 vertebra with incidental finding of a right renal mass suspicious of RCC. Upon further investigations, the patient was found to have a large heterogeneous renal cortical mass with multiple cystic changes and necrosis invading the Gerota’s fascia as well as a tumor thrombus extending into the right renal vein and inferior vena cava.

Although it has been well established that RCC metastasizes to bones and it is not uncommon for vertebral column involvement, sudden paraplegia and incontinence resulting from lumbar fracture due to metastatic RCC has not been widely published. Conclusively, RCC is a common malignancy in which a significant number of patients have metastatic disease upon presentation and this can lead to initial confusion and delay in diagnosis, hence it should be part of the differential diagnosis when investigating chronic bony pain and pathological fractures.

The Urogenital System’s Role in Diseases: A Synopsis

Simple Summary

The urinary tract microbiome has come under a lot of scrutiny, and this has led to the rejection of the pre-established concept of sterility in the urinary bladder. Microbial communities in the urinary tract have been implicated in the maintenance of health. Thus, alterations in their composition have also been associated with different urinary pathologies, such as urinary tract infections. For that reason, tackling the urinary microbiome of healthy individuals, as well as its involvement in disease through the proliferation of opportunistic pathogens, could open a potential field of study, leading to new insights into prevention, diagnosis, and treatment strategies for different diseases.

Abstract

The human microbiota contains ten times more microbial cells than human cells contained by the human body, constituting a larger genetic material than the human genome itself. Emerging studies have shown that these microorganisms represent a critical determinant in human health and disease, and the use of probiotic products as potential therapeutic interventions to modulate homeostasis and treat disease is being explored. The gut is a niche for the largest proportion of the human microbiota with myriad studies suggesting a strong link between the gut microbiota composition and disease development throughout the body. More specifically, there is mounting evidence on the relevance of gut microbiota dysbiosis in the development of urinary tract disease including urinary tract infections (UTIs), chronic kidney disease, and kidney stones. Fewer emerging reports, however, are suggesting that the urinary tract, which has long been considered ‘sterile’, also houses its unique microbiota that might have an important role in urologic health and disease. The implications of this new paradigm could potentially change the therapeutic perspective in urological disease.

Wandering Cancer Cells: Metastatic Renal Cell Carcinoma Without Evidence of a Primary Tumor

Renal cell carcinoma (RCC) usually presents clinically in the advanced stage including bone metastasis. However metastatic RCC without evidence of a primary tumor in the kidney is extremely rare. We herein report a case of a 70-year-old male initially evaluated for bone lesion and diagnosed with biopsy-proven metastatic clear cell RCC without a renal primary. Given the rare nature of the disease, there is no standardized course of treatment that has yet been established. We believe that our case will add to the body of knowledge about uncommon oncologic instances and consolidate the information that has already been published.

What Factors Are Associated With Local Metastatic Lesion Progression After Intramedullary Nail Stabilization?

BACKGROUND

Pathologic fracture of the long bones is a common complication of bone metastases. Intramedullary nail stabilization can be used prophylactically (for impending fractures) or therapeutically (for completed fractures) to preserve mobility and quality of life. However, local disease progression may occur after such treatment, and there is concern that surgical instrumentation and the intramedullary nail itself may seed tumor cells along the intramedullary tract, ultimately leading to loss of structural integrity of the construct. Identifying factors associated with local disease progression after intramedullary nail stabilization would help surgeons predict which patients may benefit from alternative surgical strategies.

QUESTIONS/PURPOSES

(1) Among patients who underwent intramedullary nail stabilization for impending or completed pathologic fractures of the long bones, what is the risk of local progression, including progression of the existing lesion and development of a new lesion around the nail? (2) Among patients who experience local progression, what proportion undergo reoperation? (3) What patient characteristics and treatment factors are associated with postoperative local progression? (4) What is the difference in survival rates between patients who experienced local progression and those with stable local disease?

METHODS

Between January 2013 and December 2019, 177 patients at our institution were treated with an intramedullary nail for an impending or completed pathologic fracture. We excluded patients who did not have a pathologic diagnosis of metastasis before fixation, who were younger than 18 years of age, who presented with a primary soft tissue mass that eroded into bone, and who experienced nonunion from radiation osteitis or an avulsion fracture rather than from metastasis. Overall, 122 patients met the criteria for our study. Three fellowship-trained orthopaedic oncology surgeons involved in the care of these patients treated an impending or pathologic fracture with an intramedullary nail when a long bone lesion either fractured or was deemed to be of at least 35% risk of fracture within 3 months, and in patients with an anticipated duration of overall survival of at least 6 weeks (fractured) or 3 months (impending) to yield palliative benefit during their lifetime. The most common primary malignancy was multiple myeloma (25% [31 of 122]), followed by lung carcinoma (16% [20 of 122]), breast carcinoma (15% [18 of 122]), and renal cell carcinoma (12% [15 of 122]). The most commonly involved bone was the femur (68% [83 of 122]), followed by the humerus (27% [33 of 122]) and the tibia (5% [6 of 122]). A competing risk analysis was used to determine the risk of progression in our patients at 1 month, 3 months, 6 months, and 12 months after surgery. A proportion of patients who ultimately underwent reoperation due to progression was calculated. A univariate analysis was performed to determine whether lesion progression was associated with various factors, including the age and sex of the patient, use of adjuvant therapies (radiation therapy at the site of the lesion, systemic therapy, and antiresorptive therapy), histologic tumor type, location of the lesion, and fracture type (impending or complete). Patient survival was assessed with a Kaplan-Meier curve. A p value < 0.05 was considered significant.

RESULTS

The cumulative incidence of local tumor progression (with death as a competing risk) at 1 month, 3 months, 6 months, and 12 months after surgery was 1.9% (95% confidence interval 0.3% to 6.1%), 2.9% (95% CI 0.8% to 7.5%), 3.9% (95% CI 1.3% to 8.9%), and 4.9% (95% CI 1.8% to 10.3%), respectively. Of 122 patients, 6% (7) had disease progression around the intramedullary nail and 0.8% (1) had new lesions at the end of the intramedullary nail. Two percent (3 of 122) of patients ultimately underwent reoperation because of local progression. The only factors associated with progression were a primary tumor of renal cell carcinoma (odds ratio 5.1 [95% CI 0.69 to 29]; p = 0.03) and patient age (difference in mean age 7.7 years [95% CI 1.2 to 14]; p = 0.02). We found no associations between local disease progression and the presence of visceral metastases, other skeletal metastases, radiation therapy, systemic therapy, use of bisphosphonate or receptor activator of nuclear factor kappa-B ligand inhibitor, type of fracture, or the direction of nail insertion. There was no difference in survivorship curves between those with disease progression and those with stable local disease (= 0.36; p = 0.54).

CONCLUSION

Our analysis suggests that for this population of patients with metastatic bone disease who have a fracture or impeding fracture and an anticipated survival of at least 6 weeks (completed fracture) or 3 months (impending fracture), the risk of experiencing local progression of tumor growth and reoperations after intramedullary nail stabilization seems to be low. Lesion progression was not associated with the duration of survival, although this conclusion is limited by the small number of patients in the current study and the competing risks of survival and local progression. Based on our data, patients who present with renal cell carcinoma should be cautioned against undergoing intramedullary nailing because of the risk of postoperative lesion progression.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Tumor-to-Tumor Metastasis: Renal Cell Carcinoma Metastasizing to a Lipoma of the Thigh: A Case Report

CASE

A 73-year-old man with a medical history significant for renal cell carcinoma (RCC) presented with widespread osseous metastases and imaging suspicious for RCC metastasizing to a lipoma interdigitated within the right vastus lateralis. The patient's pathological fractures were surgically addressed, and the lipoma excised. Final histology revealed a thigh lipoma involved by metastatic RCC without direct extension.

CONCLUSION

Tumor-to-tumor metastasis is a rare occurrence, with RCC typically being the most common "recipient" tumor. This is the first case to the best of our knowledge of RCC metastasizing to a lipoma, highlighting a rare phenomena in a patient with metastatic disease.

A Tailored Approach for Appendicular Impending and Pathologic Fractures in Solid Cancer Metastases

Simple Summary

Patients with bone metastases often suffer with complications, such as bone fractures, which have a substantial negative impact on clinical outcomes. To optimize clinical results, a tailored approach should be defined for managing impending or pathologic fractures in each individual case. The ability to control systemic disease, the extent, location and nature of bone metastases, and the biology of the underlying tumor, are the main factors that will define the strategy to follow.

Abstract

Advances in medical and surgical treatment have played a major role in increasing the survival rates of cancer patients with metastatic bone disease. The clinical course of patients with bone metastases is often impaired by bone complications, such as bone fractures, which have a substantial negative impact on clinical outcomes. To optimize clinical results and prevent a detrimental impact on patients’ health, a tailored approach should be defined for any given patient. The optimal management of impending or pathologic fractures is unknown and relies on a multidisciplinary approach to tailor clinical decisions to each individual patient. The ability to control systemic disease, the extent, location and nature of bone metastases, and the biology of the underlying tumor, are the main factors that will define the strategy to follow. The present review covers the most recent data regarding impending and pathologic fractures in patients with bone metastases, and discusses the medical and surgical management of patients presenting with metastatic bone disease in different clinical settings.

The role of stereotactic body radiotherapy in switching systemic therapy for patients with extracranial oligometastatic renal cell carcinoma

BACKGROUND

Targeting oligometastatic lesions with metastasis-directed therapy (MDT) using stereotactic-body radiotherapy (SBRT) may improve treatment outcomes and postpone the need for second-line systemic therapy (NEST). We looked at the results of oligometastatic renal cell carcinoma (RCC) patients who had five or fewer lesions and were treated with SBRT.

METHODS

We examined the treatment outcomes of 70 extracranial metastatic RCC (mRCC) patients treated at two oncology centers between 2011 and 2020. The clinical parameters of patients with and without NEST changes were compared. The prognostic factors for overall survival (OS), progression-free survival (PFS), and NEST-free survival were evaluated.

RESULTS

Median age was 67 years (range 31-83 years). Lung and bone metastasis were found in 78.4% and 12.6% of patients, respectively. With a median follow-up of 21.1 months, median OS was 49.1 months and the median PFS was 18.3 months. Histology was a prognostic factor for OS, BED, and treatment switch for PFS in univariate analysis. In multivariate analysis, the significant predictor of poor OS was clear cell histology, and a lower BED for PFS. Following SBRT for oligometastatic lesions, 19 patients (27.2%) had a median NEST change of 15.2 months after MDT completion. There were no significant differences in median OS or PFS between patients who had NEST changes and those who did not. No patient experienced grade ≥ 3 acute and late toxicities.

CONCLUSIONS

The SBRT to oligometastatic sites is an effective and safe treatment option for ≤ 5 metastases in RCC patients by providing favorable survival and delaying NEST change.

A retrospective single-centered, comprehensive targeted genetic sequencing analysis of prognostic survival using tissues from Korean patients with metastatic renal cell carcinoma after targeted therapy

Purpose

To identify candidate gene mutations to significantly predict the risk of survival prognosis after treatment with systemic first-line targeted therapy (TT) in metastatic renal cell carcinoma (mRCC) patients.

Materials and Methods

Between 2005 and 2017, 168 triplet-tissue block samples from 56 mRCC patients were selected for targeted gene sequencing (TGS). Fifty-six patients’ medical records including overall survival (OS) and progression-free survival (PFS) at the time of mRCC diagnosis were evaluated. The patients were grouped into favorable (>12 months/>3 years), intermediate (3–12/12–36 months), and poor groups according to their PFS/OS (<3 months/<12 months). We identified any significant therapeutic targeted genes relating to the survival with a significance at p<0.050.

Results

The first line therapeutic response showed 1.8% complete remission, 14.2% partial response, 42.9% stable disease, and 41.1% progressive disease. Among the overall TGS results, the cumulative effect of CDH1, and/or PTK2 genes significantly reflected the therapeutic responses in terms of PFS/OS; CDH1 and PTK2 mutations were associated with poor prognostic outcomes (p<0.050). Among only triplet-quality check passed tissues, the SGO2, BRAF, URB1, and NEDD1 mutated genes significantly correlated with OS. Regarding metastasis, patients with liver metastasis had the worst OS (p=0.050). The combinational mutation number from these two candidate genes in the liver metastatic samples with mutated EGFR2 and FABP7 also showed a significantly worse OS than those with other metastatic lesions (p<0.050).

Conclusions

This study reports several significant mutated genes related to the survival prognosis in mRCC patients treated with first-line TT.

All bone metastases are not created equal: Revisiting treatment resistance in renal cell carcinoma

Renal cell carcinoma (RCC) is the most common malignancy of the kidney, representing 80-90% of renal neoplasms, and is associated with a five-year overall survival rate of approximately 74%. The second most common site of metastasis is bone. As patients are living longer due to new RCC targeting agents and immunotherapy, RCC bone metastases (RCCBM) treatment failure is more prevalent. Bone metastasis formation in RCC is indicative of a more aggressive disease and worse prognosis. Osteolysis is a prominent feature and causes SRE, including pathologic fractures. Bone metastasis from other tumors such as lung, breast, and prostate cancer, are more effectively treated with bisphosphonates and denosumab, thereby decreasing the need for palliative surgical intervention. Resistance to these antiresportives in RCCBM reflects unique cellular and molecular mechanisms in the bone microenvironment that promote progression via inhibition of the anabolic reparative response. Identification of critical mechanisms underlying RCCBM induced anabolic impairment could provide needed insight into how to improve treatment outcomes for patients with RCCBM, with the goals of minimizing progression that necessitates palliative surgery and improving survival.

Multimodal Imaging-Based Potential Visualization of the Tumor Microenvironment in Bone Metastasis

Bone metastasis (BM) is the most common malignant bone tumor and a significant cause of morbidity and mortality for patients with cancer. Compared to other metastatic organs, bone has unique characteristics in terms of the tumor microenvironment (TME). Precise assessments of the TME in BM could be an important step for developing an optimized management plan for patient care. Imaging approaches for BM have several advantages, such as biopsy not being required, multiple site evaluation, and serial assessment in the same sites. Owing to the developments of new imaging tracers or imaging modalities, bone TME could be visualized using multimodal imaging techniques. In this review, we describe the BM pathophysiology, diagnostic principles of major imaging modalities, and clinically available imaging modalities to visualize the TME in BM. We also discuss how the interactions between various factors affecting the TME could be visualized using multimodal imaging techniques.

Novel risk scoring system for metastatic renal cell carcinoma patients treated with cabozantinib

BACKGROUND

Cabozantinib is an effective treatment for metastatic renal cell carcinoma (mRCC). The international mRCC database consortium (IMDC) criteria is the gold standard for risk stratification in mRCC. We created a risk scoring system specific for mRCC patients treated with cabozantinib.

METHODS

We conducted a retrospective review of 87 patients with mRCC treated with cabozantinib at Winship Cancer Institute from 2015 to 2019. Overall survival (OS) and progression free survival (PFS) were used to measure clinical outcomes. Upon variable selection in multivariable analysis (MVA), elevated baseline monocyte-to-lymphocyte ratio (MLR), sarcomatoid histologic component, ECOG PS > 1, and absence of bone metastases were each assigned 1 point. A three-group risk scoring system was then created: low (score=0-1), intermediate (score=2), and high risk (score=3-4). The Cox proportional hazard model and Kaplan-Meier method were used for survival analyses.

RESULTS

The median age was 62 years-old and the majority were males (71%) with clear-cell RCC (75%). Most (67%) received at least 1 prior line of systemic therapy. High risk and intermediate risk pts had significantly shorter OS (high risk HR: 13.84, p<0.001; intermediate risk HR: 3.50, p = 0.004) and PFS (high risk HR: 7.31, p<0.001; intermediate risk HR: 1.87, p = 0.053) compared to low risk patients in MVA.

CONCLUSIONS

RCC patients treated with cabozantinib may benefit from specific risk stratification criteria using RCC histology, ECOG PS, sites of metastatic disease, and MLR. These variables are easily accessible in the clinical setting and may be helpful to determine which mRCC patients may benefit from treatment with cabozantinib.

Forkhead box F2 as a novel prognostic biomarker and potential therapeutic target in human cancers prone to bone metastasis: a meta-analysis

OBJECTIVE

To undertake a systematic review and meta-analysis to evaluate the prognostic value of Forkhead box F2 (FOXF2) levels in different types of cancers prone to bone metastasis.

METHODS

A systematic search of publications listed in electronic databases (The Web of Science, EMBASE®, PubMed®, PMC, Science Direct and CNKI) from inception to 5 November 2020 was conducted. The hazard ratios (HRs) and 95% confidence intervals (95% CIs) were used to assess the relationship between FOXF2 levels and patient prognosis including overall survival (OS) and disease-free survival (DFS).

RESULTS

Sixteen studies enrolling 8461 participants were included in the meta-analysis. High levels of FOXF2 were a predictor of OS (HR: 0.66; 95% CI 0.51, 0.86) and DFS (HR: 0.60; 95% CI 0.48, 0.76). The trim-and-fill analysis, sensitivity analysis and subgroup analyses stratified by the study characteristics confirmed the robustness of the results.

CONCLUSION

These current findings indicate that high FOXF2 levels could be an indicator of a good prognosis in cancer patients with tumours that are prone to bone metastasis. FOXF2 levels might be a clinically important prognostic biomarker.

State-of-the-art imaging for diagnosis of metastatic bone disease

Metastatic bone disease (MBD) is common—it is detected in up to 65–75% of patients with breast or prostate cancer, in over 35% of patients with lung cancer; and almost all patients with symptomatic multiple myeloma have focal lesions or a diffuse bone marrow infiltration. Metastatic bone disease can cause a variety of symptoms and is often associated with a poorer prognosis, with high social and health-care costs. Population-based cohort studies confirm significantly increased health-care utilization costs in patients presenting with cancer with MBD compared with those without MBD. The prolonged survival of patients with bone metastasis thanks to advances in therapy presents an opportunity for better treatments for this patient cohort. Early and accurate diagnosis of bone metastases is therefore crucial. The patterns and presentation of MBD are quite heterogeneous and necessitate good knowledge of the possibilities and limitations of each imaging modality. Here, we review the state-of-the-art imaging techniques, assess the need for evidence-based and cost-effective patient care pathways, and advocate multidisciplinary management based on collaborations between orthopedic surgeons, pathologists, oncologists, radiotherapists, and radiologists aimed at improving patient outcomes. Radiologists play a key role in this multidisciplinary approach to decision-making through correlating the tumor entity, the tumor biology, the impact on the surrounding tissues and progression, as well as the overall condition of the patient. This approach helps to choose the best patient-tailored imaging plan advocating a “choose wisely” strategy throughout the initial diagnosis, minimally invasive treatment procedures, as well as follow-up care plans.

Nomograms-based prediction of overall and cancer-specific survivals for patients with chromophobe renal cell carcinoma

This study built and tested two effective nomograms for the purpose of predicting cancer-specific survival and overall survival of chromophobe renal cell carcinoma (chRCC) patients. Multivariate Cox regression analysis was employed to filter independent prognostic factors predictive of cancer-specific survival and overall survival, and the nomograms were built based on a training set incorporating 2901 chRCC patients in a retrospective study (from 2004 to 2015) downloaded from the surveillance, epidemiology, and end results (SEER) database. The nomograms were verified on a validation cohort of 1934 patients, subsequently the performances of the nomograms were examined according to the receiver operating characteristic curve, calibration curves, the concordance (C-index), and decision curve analysis. The results showed that tumor grade, AJCC and N stages, race, marital status, age, histories of chemotherapy, radiotherapy and surgery were the individual prognostic factors for overall survival, and that AJCC, N and SEER stages, histories of surgery, radiotherapy and chemotherapy, age, tumor grade were individual prognostic factors for cancer-specific survival. According to C-indexes, receiver operating characteristic curves, and decision curve analysis outcomes, the nomograms showed a higher accuracy in predicting overall survival and OSS when compared with TNM stage and SEER stage. All the calibration curves were significantly consistent between predictive and validation sets. In this study, the nomograms, which were validated to be highly accurate and applicable, were built to facilitate individualized predictions of the cancer-specific survival and overall survival to patients diagnosed with chRCC between 2004 and 2015.

Radiographical efficacy of systemic treatment for bone metastasis from renal cell carcinoma

Enlarged bone metastasis from renal cell carcinoma (RCC) can cause skeletal-related events, and thus treatment to inhibit the growth of bone metastases is often required. Although radiotherapy for RCC bone metastases can achieve a certain degree of local control, evidence is lacking regarding the effects of systemic therapy to improve bone metastasis. The present study aimed to assess the treatment efficacy of targeted therapy and immune checkpoint inhibitors, and to determine whether systemic therapy without radiotherapy can shrink bone metastases of RCC. The present study retrospectively reviewed 44 patients with RCC with bone metastases treated via systemic therapy, including targeted therapy or immune checkpoint inhibitors. Patients were divided into two groups: Those who underwent systemic therapy with radiotherapy for bone lesions (n=29); and those who underwent systemic therapy without radiotherapy for bone lesions (n=15). The radiographical efficacy of systemic therapy and the time to progression of bone metastases were compared between groups. The overall response rate of systemic therapy with radiotherapy was 44%, and in total, 13 patients demonstrated a partial response. Only one patient (6%) had a partial response among those who were treated via systemic therapy without radiotherapy. The time to progression of bone metastasis was 9.5 and 2.1 months in patients treated with and without radiotherapy, respectively (P<0.0001). Collectively, the present results suggested that targeted therapy or immune checkpoint inhibitors without radiotherapy had only a slight effect on bone metastasis control.

A Case of a Missing Proximal Humerus

CASE PRESENTATION

In this case, we demonstrate how a small radiolucency in the proximal humerus can progress to an even larger problem within a few months in a patient without follow-up. Our patient's ultimate diagnosis was renal cell carcinoma with metastasis to the right proximal humerus, completely obliterating the affected bone.

DISCUSSION

In many underserved communities, patients have limited access to medical care, particularly specialty care. These patients often present to the emergency department and are unable to acquire appropriate follow-up. This situation illustrates the social issues that our patients face every day affecting their access to healthcare and ultimately necessary medical treatment.

Bone Metastases: Mechanisms of the Metastatic Process, Imaging and Therapy

The mechanisms by which tumors metastasize to bone are complex. Upon the successful establishment of metastatic deposits in the skeleton, detection of the disease becomes essential for therapeutic planning. The roles of CT, skeletal scintigraphy, SPECT/CT, MRI, PET/CT and PET/MRI will be reviewed. Therapeutic response criteria specifically designed to evaluate bone metastases (MD Anderson/MDA criteria) can guide image interpretation. Knowledge of therapeutic strategies such as systemic therapy with bisphosphonates or radiopharmaceuticals, radiation therapy, surgery, and percutaneous interventions such as vertebroplasty and radiofrequency ablation can help the radiologist produce reports that will provide maximum benefit to clinicians and patients.

Nationwide Patterns of Pathologic Fractures Among Patients Hospitalized With Bone Metastases

OBJECTIVES

Pathologic fractures from bone metastases can significantly affect quality-of-life, although it is unclear which patients may be at high risk of this outcome. We aim to determine risk factors for pathologic fracture among patients admitted with bone metastases and to evaluate the association of pathologic fracture with clinical and economic outcomes.

METHODS

The Healthcare Cost and Utilization Project National Inpatient Sample was queried for all patients hospitalized with bone metastases in 2016. Baseline differences between patients with and without pathologic fractures were assessed by χ and analysis of variance testing. Multivariable logistic regression was used to identify factors associated with fractures.

RESULTS

In 2016, 272,275 hospital admissions were associated with a diagnosis of bone metastases, of which 11,960 (4.4%) had a primary diagnosis of pathologic fracture. Patients with pathologic fractures had a longer length-of-hospital-stay (mean 7.5 vs. 6.4 d; P<0.001) and higher cost-of-hospital-stay (mean $23,611 vs. $15,942; P<0.001) compared to patients without pathologic fractures. Primary cancers associated with increased likelihood of pathologic fracture included liver and intrahepatic bile duct (odds ratio [OR] 2.34; 95% confidence interval [CI], 1.65-3.32), multiple myeloma (OR 1.94; 95% CI, 1.31-2.86), and kidney and renal pelvis cancer (OR 1.89; 95% CI, 1.50-2.37).

CONCLUSIONS

Nearly 5% of hospitalizations with bone metastases presented with a concomitant pathologic fracture, which was associated with longer inpatient stay and higher cost. Patients with hepatobiliary, renal cell carcinoma, or multiple myeloma, had a higher likelihood of pathologic fracture. These groups may benefit from increased outpatient monitoring, prophylactic stabilization, or early irradiation.

Survival After Surgery for Renal Cell Carcinoma Metastatic to the Spine: Impact of Modern Systemic Therapies on Outcomes

BACKGROUND

Modern medical management of metastatic renal cell carcinoma (RCC) includes therapies targeting tyrosine kinases, growth pathways (mammalian target of rapamycin (mTOR)), and immune checkpoints.

OBJECTIVE

To test our hypothesis that patients with spinal metastases would benefit from postoperative systemic therapy despite presenting with disease that, in many cases, was resistant to prior systemic therapy.

METHODS

This is an Institutional Review Board-approved clinical retrospective cohort analysis. A sample of adult patients with RCC metastatic to the spine who underwent operative intervention between January 2010 and December 2017 at 2 large academic medical centers was used in this study.

RESULTS

We identified 78 patients with metastatic RCC in whom instrumented stabilization was performed in 79% and postoperative stereotactic radiosurgery was performed in 41% of patients. Of patients presenting with weakness or myelopathy, 93% noted postoperative improvement and 78% reported improvement in radicular and axial paraspinal pain severity. Increased overall survival (OS) (913 d (95% CI: 633-1975 d, n = 49) vs 222 d (95% CI: 143-1005 d, n = 29), P = .003) following surgery was noted in patients who received postoperative systemic therapy a median of 80 d (interquartile range 48-227 d) following the surgical intervention.

CONCLUSION

Postoperative outcomes and palliation of symptoms for metastatic RCC without targeted therapies in this cohort are similar to those reported in earlier series prior to the adoption of these systemic therapies. We observed a significantly longer OS among patients who received modern systemic therapies postoperatively. These findings have implications for the preoperative evaluation of patients with systemic disease who may have been deemed poor surgical candidates prior to the availability of these systemic therapies.

Acute kidney injury after nephrectomy: a new nomogram to predict postoperative renal function

Background

We aimed to develop a nomogram based on preprocedural features for early prediction of acute kidney injury (AKI) and to assess the prognosis in patients after radical and partial nephrectomy.

Methods

The study included a development cohort of 1111 patients who were treated between June 2012 and June 2017 and an additional validation cohort of 356 patients who were treated between July 2017 and June 2018. Stepwise regression and logistic regression analyses were used to evaluate the association between predictors and AKI. Incorporating all independent predictors, a nomogram for postoperative AKI was developed and externally validated. Patients were followed up for 5 years to assess renal function, acute kidney disease (AKD), chronic kidney disease (CKD), hospital readmission and mortality were key prognosis we focused on.

Results

After multivariate logistic regression, radical nephrectomy (odds ratio (OR) = 3.57, p < 0.001), aspirin (OR = 1.79, p = 0.008), systolic blood pressure (OR = 1.41, p = 0.004), triglyceride (OR = 1.26, p = 0.024), and alkaline phosphatase (OR = 1.75, p = 0.034) were independent risk factors for postoperative AKI, while albumin (OR = 0.72, p = 0.031) was a protective factor for postoperative AKI. Patients with a higher estimated glomerular filtration rate (eGFR) (60–90 ml/min/1.73 m², OR = 0.41, p = 0.004; ≥ 90 ml/min/1.73 m², OR = 0.37, p < 0.001) were less prone to AKI than those with a lower eGFR (< 15 ml/min/1.73 m²). These predictors were all included in the final nomogram. The area under the receiver operating characteristics curve for the model were 0.77 (p < 0.001) in the development cohort and 0.72 (p < 0.001) in the validation cohort. The incidence of AKD and CKD were 27.12 and 18.64% in AKI group, which were much higher than those in no AKI group (p < 0.001).

Conclusions

The nomogram had excellent predictive ability and might have significant clinical implications for the early detection of AKI in patients undergoing nephrectomy.

Clinical outcomes of 168 Chinese patients after local surgery for bone metastases arising from advanced renal cell carcinoma

BACKGROUND

The effectiveness of local surgery for bone metastases (BM) arising from renal cell carcinoma (RCC) remains uncertain. Herein, the authors performed what to the best of their knowledge is the first investigation of the outcomes of Chinese patients with RCC and BM.

METHODS

Data were collected for 168 patients with RCC and BM who were treated at Changzheng Hospital in Shanghai, China, between March 2009 and December 2018. All patients underwent local surgery for BM arising from RCC. Overall survival (OS) was defined as the interval between the date of local surgery and death or last follow-up and was estimated using the Kaplan-Meier method. Univariate and multivariable Cox proportional hazards analyses were used to identify significant prognostic factors.

RESULTS

The median OS in the study cohort was 43 months (range, 0-113 months). The 1-year, 3-year, and 5-year survival rates after surgery were 77.4%, 55.9%, and 31.8%, respectively. Univariate analyses demonstrated significant survival differences associated with sex (P = .003), the number of preoperative metastatic sites (BM alone or BM with concomitant metastasis; P < .001), and the number of BM (single or multiple; P = .008). OS also did not appear to differ regardless of whether the patients received postsurgical targeted therapy. Multivariable Cox regression demonstrated that the following characteristics were independent predictors of OS: the number of preoperative metastatic sites, International Metastatic Renal Cell Carcinoma Database Consortium risk score, and Memorial Sloan Kettering Cancer Center score.

CONCLUSIONS

Careful patient selection for local surgery is of paramount importance. The prognoses of patients in the Memorial Sloan Kettering Cancer Center-based and International Metastatic Renal Cell Carcinoma Database Consortium-based poor-risk groups were much worse than those of the intermediate-risk groups. In current clinical practice, "stratified treatment" can be performed according to these criteria.

Next-generation RNA Sequencing-based Biomarker Characterization of Chromophobe Renal Cell Carcinoma and Related Oncocytic Neoplasms

BACKGROUND

Renal cell carcinomas (RCCs) are a heterogeneous group of neoplasms. Recent sequencing studies revealed various molecular features associated with histologic RCC subtypes, including chromophobe renal cell carcinoma (ChRCC).

OBJECTIVE

To characterize the gene expression and biomarker signatures associated with ChRCC.

DESIGN, SETTING, AND PARTICIPANTS

We performed integrative analysis on RNA sequencing data available from 1049 RCC specimens from The Cancer Genome Atlas and in-house studies. Our workflow identified genes relatively enriched in ChRCC, including Forkhead box I1 (FOXI1), Rh family C glycoprotein (RHCG), and LINC01187. We assessed the expression pattern of FOXI1 and RHCG protein by immunohistochemistry (IHC) and LINC01187 mRNA by RNA in situ hybridization (RNA-ISH) in whole tissue sections representing a cohort of 197 RCC cases, including both primary and metastatic tumors.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The FOXI1 and RHCG IHC staining, as well as the LINC01187 RNA-ISH staining, was evaluated in each case for intensity, pattern, and localization of expression.

RESULTS AND LIMITATIONS

All primary and metastatic classic ChRCCs demonstrated homogeneous positive labeling for FOXI1, RHCG proteins, and LINC01187 transcript. Unclassified RCC with oncocytic features, oncocytoma, and hybrid oncocytic tumor, as well as all but two cases of eosinophilic ChRCC also stained positive. Importantly, metastatic and primary RCC of all other subtypes did not demonstrate any unequivocal staining for FOXI1, RHCG, or LINC01187. In normal kidney, FOXI1, RHCG, and LINC01187 were detected in the distal nephron segment, specifically in intercalated cells. Two cases of eosinophilic ChRCC with focal expression of FOXI1 and LINC01187, and Golgi-like RHCG staining were found to contain MTOR gene mutations upon DNA sequencing.

CONCLUSIONS

We demonstrate a pipeline for the identification and validation of RCC subtype-specific biomarkers that can aid in the confirmation of cell of origin and may facilitate accurate classification and diagnosis of renal tumors.

PATIENT SUMMARY

FOXI1, RHCG, and LINC01187 are lineage-specific signature genes for chromophobe renal cell carcinoma.

Incidence of patients with bone metastases at diagnosis of solid tumors in adults: a large population-based study

Background

Bones are one of the most common metastatic sites for solid malignancies. Bone metastases can significantly increase mortality and decrease the quality of life of cancer patients. In the United States, around 350,000 people die each year from bone metastases. This study aimed to analyze and update the incidence and prognosis of bone metastases with solid tumors at the time of cancer diagnosis and its incidence rate for each solid cancer.

Methods

We used the Surveillance, Epidemiology, and End Results (SEER) database to find patients diagnosed with solid cancers originating from outside the bones and joints between 2010 and 2016. Data were stratified by age, sex, and race. Patients with a tumor in situ or with an unknown bone metastases stage were excluded. We then selected most of the sites where cancer often occurred, leaving 2,207,796 patients for the final incidence analysis. For the survival analysis, patients were excluded if they were diagnosed at their autopsy or on their death certificate, or had unknown follow-ups. The incidence of bone metastases and overall survival was compared between patients with different primary tumor sites.

Results

We identified 2,470,634 patients, including 426,594 patients with metastatic disease and 113,317 patients with bone metastases, for incidence analysis. The incidence of bone metastases among the metastatic subset was 88.74% in prostate cancer, 53.71% in breast cancer, and 38.65% in renal cancer. In descending order of incidence, there were patients with other cancers in the genitourinary system (except for renal, bladder, prostate, and testicular cancer) (37.91%), adenocarcinoma of the lung (ADC) (36.86%), other gynecologic cancers (36.02%), small-cell lung cancer (SCLC) (34.56%), non-small cell lung cancer not otherwise specified and others [NSCLC (NOS/others)] (33.55%), and bladder (31.08%) cancers. The rate of bone metastases is 23.19% in SCLC, 22.50% in NSCLC (NOS/others), 20.28% in ADC, 8.44% in squamous cell carcinoma of the lung (SCC), and 4.11% in bronchioloalveolar carcinoma [NSCLC (BAC)]. As for the digestive system, the overall bone metastases rate was 7.99% in the esophagus, 4.47% in the gastric cancer, 4.42% in the hepatobiliary cancer, 3.80% in the pancreas, 3.26% in other digestive organs, 1.24% in the colorectum, and 1.00% in the anus. Overall, the incidence rate of bone metastases among the entire cohort in breast and prostate cancer was 3.73% and 5.69%, respectively.

Conclusions

The results of this study provide population-based estimates for the incidence rates of patients with bone metastases at initial diagnosis of their solid tumor. The findings can help clinicians to early detect bone metastases by bone screening to anticipate the occurrence of symptoms and favorably improve the prognosis.

Low Dosed Curcumin Combined with Visible Light Exposure Inhibits Renal Cell Carcinoma Metastatic Behavior In Vitro

Recent documentation shows that a curcumin-induced growth arrest of renal cell carcinoma (RCC) cells can be amplified by visible light. This study was designed to investigate whether this strategy may also contribute to blocking metastatic progression of RCC. Low dosed curcumin (0.2 µg/mL; 0.54 µM) was applied to A498, Caki1, or KTCTL-26 cells for 1 h, followed by exposure to visible light for 5 min (400–550 nm, 5500 lx). Adhesion to human vascular endothelial cells or immobilized collagen was then evaluated. The influence of curcumin on chemotaxis and migration was also investigated, as well as curcumin induced alterations of α and β integrin expression. Curcumin without light exposure or light exposure without curcumin induced no alterations, whereas curcumin plus light significantly inhibited RCC adhesion, migration, and chemotaxis. This was associated with a distinct reduction of α3, α5, β1, and β3 integrins in all cell lines. Separate blocking of each of these integrin subtypes led to significant modification of tumor cell adhesion and chemotactic behavior. Combining low dosed curcumin with light considerably suppressed RCC binding activity and chemotactic movement and was associated with lowered integrin α and β subtypes. Therefore, curcumin combined with visible light holds promise for inhibiting metastatic processes in RCC.

Systemic Treatment of Bone Disease in Metastatic Urinary Malignancies

CONTEXT

Bone metastasis is a common site of metastatic disease in patients with genitourinary malignancies. Given that the presence of bone metastasis decreases survival and has a negative impact on quality of life impact, it is critical to optimize management of this patient population.

OBJECTIVE

To systematically review literature on the systemic treatment of bone metastasis in prostate cancer, renal cell carcinoma, urothelial carcinoma, and germ cell tumors.

EVIDENCE ACQUISITION

We performed a nonsystematic critical review of PubMed/Medline, clinicaltrials.gov, and the Cochrane Library from January 2001 to February 2019. Identified reports were reviewed according to the Consolidated Standards of Reporting Trials, and selected based on reporting skeletal related events and symptomatic skeletal events for patients with urologic malignancies.

EVIDENCE SYNTHESIS

Skeletal metastases occur frequently in genitourinary malignancies, at rates around 80% for patients with metastatic prostate cancer and 30% for patients with metastatic renal cell and urothelial carcinoma, and are uncommon in patients with germ cell tumors. Skeletal related events and symptomatic skeletal events can occur in these patients. Optimization of bone health involves dietary and lifestyle modifications, and use of osteoclast-targeted agents in select individuals. Additionally, disease-modifying agents, such as radiopharmaceutical, immunotherapy, and cMET inhibitors, which have activity in the bone, have improved outcomes for patients, including skeletal-related events and symptomatic skeletal events.

CONCLUSIONS

While the presence of bone metastases is associated with increased mortality and worse outcomes in patients with genitourinary malignancies, strategies have been developed to improve quality of life and survival for patients with skeletal metastases. Future studies investigating novel therapeutic options and bone supporting agents are warranted to target this patient population.

PATIENT SUMMARY

In this report, we reviewed the current literature and recent clinical trials involving treatment of bone metastases in urinary cancers. The use of bone-targeting agents can improve outcomes for patients, and additional lifestyle modification can optimize bone health in this population.

Management of bone complications in patients with genitourinary malignancies

Skeletal metastases are common in genitourinary malignancies-including prostate cancer, renal cell carcinoma, and urothelial cancer-and portend significant morbidity and poor prognosis. The presence of skeletal metastases can result in decreased quality of life and increased morbidity. Strategies can be employed to prevent bone-related complications including lifestyle modifications and dietary supplementation. Additionally, pharmacologic agents exist to prevent bone loss and may be appropriate for patients at high risk of fragility-related or skeletal complications, such as pathologic fracture related to bone metastases. Finally, advancement in effective systemic treatments, particularly novel hormone-targeted agents and immunotherapies, may limit the morbidity of advanced disease and delay the onset of skeletal-related complications.

Can surgery relieve pain and act as first-line treatment for a large metastasis of the sternum?

BACKGROUND

There are few papers published on sternal metastasis from renal cell carcinoma. The unifying element is the operability of the sternal metastasis if it is the only site of metastasis, on the operability of the primary site of the tumor and on the patient's health conditions.

PRESENTATION OF THE CASE

We present a case of a 66-years-old man undergone sternal resection for a large painful metastasis. He was previously undergone left nephrectomy for clear cells carcinoma. En bloc resection of the sternal manubrium and right clavicle was performed, a Gore-Tex mesh was placed. Histology confirmed metastasis of kidney clear cells carcinoma. Patient was discharged with no complications and no pain. Chest CT at six months follow up was negative for recurrence.

DISCUSSION AND CONCLUSION

We highlighted the importance of surgery as possible first-line treatment in symptomatic large sternum metastasis. Therefore, prospective studies should be considered to confirm our strategy.

Xanthogranulomatous Osteomyelitis of the Tibia

Background: Xanthogranulomatous osteomyelitis (XO) is a rare chronic inflammatory process that is histologically characterized by the presence of foamy macrophages, histiocytes, and plasma cells. Radiologic and gross examinations can mimic malignancy, so definitive diagnosis should be made by histopathologic evaluation. Case Report: A 15-year-old male presented with pain in the proximal right leg for 2 weeks prior to admission. The patient had a history of leg trauma 3 years prior that was responsive to as-needed analgesics. Laboratory data revealed increased erythrocyte sedimentation rate and C-reactive protein. X-ray of the right tibia showed a periosteal reaction and bulging of bone with a questionable destruction of the cortex. Magnetic resonance imaging demonstrated an expansile bony lesion in the proximal metaphysis of the tibia. Histopathologic examination showed the bone trabecula surrounded by chronic inflammatory cells and a fragment of dead bone surrounded by histiocytes, foamy macrophages, and plasma cells. The pathologist confirmed the diagnosis of XO. Wound culture proved moderate growth of Staphylococcus aureus, and treatment with cefazolin and cephalexin was successful. Conclusion: The patient was not treated with the routine therapy used in previously reported cases (curettage), suggesting that antibiotic therapy should be considered before employing surgical interventions for XO.

Bone Marrow Metastasis in Clear Cell Renal Cell Carcinoma: A Case Study

Clear cell renal cell carcinoma (RCC) is the most frequently reported renal cell neoplasm, which commonly metastasizes to the lungs, bones, lymph nodes, liver, adrenal gland and/or brain. It is usually diagnosed as an incidental finding on radiological imaging, which can further be confirmed by histological examination of the neoplastic tissue. Bone marrow metastasis of renal cell tumors is a rare event and very few cases have been reported. Here we report an unusual case of a 68-year-male who presented with lytic bone lesions on imaging. This raised the suspicion of a bone marrow involvement by a hematolymphoid malignancy or metastatic disease and a bone marrow biopsy was performed. Incidentally, the biopsy revealed infiltration of bone marrow by clear cell RCC. The patient was referred to the oncology clinic where further workup was done which revealed a primary renal tumor.

Extraosseous Colonic Uptake of 99mTc-MDP Associated With Iodinated Contrast CT

Extraosseous Tc-MDP uptake on bone scans is frequently encountered and has a broad differential diagnosis. A small subset of such patients can present with intestinal Tc-MDP uptake. We present the case of a 35-year-old woman with status after right nephrectomy for renal cell carcinoma, being followed with bone scan for osseous metastases. Follow-up imaging revealed new faint Tc-MDP uptake in the right hemiabdomen. Correlation with contrast-enhanced CT localized this uptake to the ascending colon. Enteric Tc-MDP uptake and its association with iodinated contrast should be considered in the differential diagnosis of extraosseous enteric Tc-MDP uptake.

mTOR inhibitor and bone-targeted drugs break the vicious cycle between clear-cell renal carcinoma and osteoclasts in an in vitro co-culture model

The skeleton is one of the most common sites of metastatic spread from advanced clear-cell renal carcinoma (ccRCC). Most of the bone lesions observed in RCC patients are classified as osteolytic, causing severe pain and morbidity due to pathological bone destruction. Nowadays, it is well known that cancer induced bone loss in lytic metastasis is caused by the triggering of a vicious cycle between cancer and bone resident cells that leads to an imbalance between bone formation and degradation. Targeting the mammalian target of rapamycin (mTOR) is an efficient treatment option for metastatic renal carcinoma patients. Moreover, bone targeted therapy could benefit bone metastatic cancer patients caused by advanced RCC. However, more data is needed to support the hypothesis of the beneficial effect of a combined therapy. The aim of this work is to investigate the effect of targeting mTOR and the sequential combination with bone targeted therapy as a strategy to break the vicious cycle between ccRCC cells and osteoclasts. A previously optimized fully human co-culture model is used to mimic the crosstalk between Caki-2 cells (ccRCC) and osteoclasts. Cells are treated at fixed timing with everolimus, zoledronic acid and denosumab as single or sequential combined treatment. We show that Caki-2 cells can induce osteoclast cells differentiation from isolated human monocytes, as demonstrated by specific tartrate-resistant acid phosphatase (TRAP) staining and f-actin ring formation, in a statistically significant manner. Moreover, differentiated osteoclasts proved to be functionally active by pit formation assay. Caki-2 cells co-cultured with osteoclasts acquire a more aggressive phenotype based on gene expression analysis. Interestingly, the sequential combined treatment of everolimus and zoledronic acid is the most effective in the inhibition of both Caki-2 cells survival and osteoclastogenic potential, making it an effective strategy to inhibit the vicious cycle of bone metastasis. At preclinical level, this observation confirms the value of our co-culture model as a useful tool to mimic the bone microenvironment and to assess drug sensitivity in vitro. A better understanding of the molecular mechanisms involved in tumor-bone cells crosstalk will be investigated next.

Solitary Metastatic Lesion of the Tibia from Clear Cell Renal Carcinoma: A Case Report of Segmental Skeletal Resection, Intercalary Allograft Over Reamed Nailing and Soleus Flap Interposition

BACKGROUND Renal cell carcinoma (RCC) is the most common malignancy of the kidney, with clear cell (ccRCC) subtype identified in 85% of the cases; one-third of these patients experience synchronous metastatic disease, while 20-30% of the remaining patients develop metachronous metastatic RCC. The axial skeleton (pelvis and sacrum) is the second most common location (following the lungs), with a reported incidence of 35%. Diaphysis of the long bones is rarely involved, with the tibia being an even rarer site of metastasis. CASE REPORT We present a rare case of solitary diaphyseal tibial metachronous metastasis from RCC in a 54-year-old male that appeared 8 years after nephrectomy without any previous evidence of disease. He underwent segmental skeletal resection, intercalary allograft over locked reamed intramedullary nailing, and soleus flap coverage. Thirty months later he presented with hardware failure and nonunion at the distal part of the allograft site. He was successfully treated with exchange nailing, fibular osteotomy, and bone grafting, showing excellent clinical and radiological outcome without any evidence of recurrence 5 years after the index operation. CONCLUSIONS Wide resection and biological reconstruction using intramedullary nailing and incorporated allograft is a good option for metachronous solitary RCC tumors.

Incidence of bone metastasis and factors contributing to its development and prognosis in newly diagnosed renal cell carcinoma: a population-based study

Purpose

The purpose of this study was to assess the incidence of and the risk factors and prognostic factors for bone metastasis (BM) in initial metastatic renal cell carcinoma (RCC) based on a large population analysis.

Patients and methods

Data were obtained for a total of 45,824 RCC patients recorded in the database of the Surveillance, Epidemiology, and End Results program of the National Cancer Institute between 2010 and 2014. Multivariate logistic and Cox regression analyses were used to identify the risk factors and prognostic factors associated with BM in RCC patients. Kaplan-Meier analysis was used to estimate the overall survival of RCC patients, and the difference between the survival curves was tested by log-rank tests.

Results

A total of 1,509 (3.29%) patients were diagnosed with bone metastases at initial diagnosis. Male gender, higher T stage, lymph node involvement, poor tumor grade, presence of lung, liver, and brain metastases, and the collecting duct type of RCC were positively associated with BM occurrence. The median survival time for RCC patients with bone metastases was 12.0 (95% confidence interval [CI]: 10.69-13.31) months, and the survival time for those with collecting duct, clear-cell, papillary, and chromophobe subtypes of RCC were 3 (95% CI: 0.23-5.77), 13 (95% CI: 11.60-14.40), 8 (95% CI: 5.09-10.91), and 11 (95% CI: 5.02-16.98) months; these differences were significantly different (P<0.01). Older age, higher T stage, lymph node involvement, poor tumor grade, the presence of lung, liver, and brain metastases, collecting duct RCC, and the absence of surgical treatments were the factors associated with worse prognoses.

Conclusion

BM was highly prevalent and significantly decreased the survival rate of RCC patients. A number of factors associated with the development and prognosis of BM were identified, and these insights provide preventive guidelines for screening and treatment of BM in RCC patients.