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Background: While sustainable long-term function has been established for biological reconstruction with distraction osteogenesis (DO) following osseous resections, there is a paucity of published data informing surgeons and patients on important milestones in the reconstructive process. The objectives of this study were to determine when to expect complete bone healing and full weight-bearing as well as to quantify the influence of chemotherapy on the osseous regeneration process. Methods: Prospectively, pathological and clinical data were collected for 30 consecutive patients who underwent primary or secondary DO-based reconstruction following osseous resection from 2018 to 2021. Serial radiographs indicated the times to cortex formation and full union. An unpaired t test was used to compare the time required for full bone remodeling of segments transported with and without concurrent chemotherapy. Results: The average resection length was 13.6 cm (range, 4 to 22 cm). Patients underwent an average of 6.1 procedures (range, 1 to 14 procedures). Half (50%) of all procedures were planned, while half were unplanned procedures. All patients achieved full, independent weight-bearing at a median of 12 months (interquartile range [IQR], 9 to 16 months). For the 34 segments transported concurrently with chemotherapy, the mean bone healing index (BHI) was 2.3 ± 0.7, and the mean BHI was 1.2 ± 0.4 for the 25 segments without chemotherapy at any point during their transport (p < 0.0001). Conclusions: All 30 patients achieved full bone healing and independent weight-bearing at a median of 1 year postoperatively and continued to show functional improvement afterward. Surgeons and patients can expect bone healing to be nearly twice as fast for segments transported after completion of systemic chemotherapy compared with segments transported concurrently with adjuvant chemotherapy. [ABSTRACT FROM AUTHOR]

Background: Femoral diaphyseal reconstructions with metal prostheses have mediocre results because of high mechanical forces that result in eventual implant failure. Biological alternatives require prolonged restrictions on weightbearing and have high rates of infection, nonunion, and fracture. A novel method of utilizing a vascularized fibula in combination with an intercalary prosthesis was developed to complement the immediate stability of the prosthesis with the long-term biological fixation of a vascularized fibular graft. Methods: A prospectively maintained database was retrospectively reviewed to identify patients who underwent reconstruction of an oncological intercalary femoral defect using an intercalary prosthesis and an inline fibular free flap (FFF). They were compared with patients who underwent femoral reconstruction using an intercalary allograft and an FFF. Results: Femoral reconstruction with an intercalary metal prosthesis and an FFF was performed in 8 patients, and reconstruction with an allograft and an FFF was performed in 16 patients. The mean follow-up was 5.3 years and 8.5 years, respectively (p = 0.02). In the bioprosthetic group, radiographic union of the fibula occurred in 7 (88%) of 8 patients, whereas in the allograft group, 13 (81%) of 16 patients had allograft union (p = 1.00) and all 16 patients had fibular union (p = 0.33). The mean time to fibular union in the bioprosthetic group was 9.0 months, whereas in the allograft group, the mean time to allograft union was 15.3 months (p = 0.03) and the mean time to fibular union was 12.5 months (p = 0.42). Unrestricted weight-bearing occurred at a mean of 3.7 months in the prosthesis group and 16.5 months in the allograft group (p < 0.01). Complications were observed in 2 (25%) of 8 patients in the prosthesis group and in 13 (81%) of 16 patients in the allograft group (p = 0.02). Neither chemotherapy nor radiation affected fibular or allograft union rates. Musculoskeletal Tumor Society scores did not differ significantly between the groups (mean, 26 versus 28; p = 0.10). Conclusions: Bioprosthetic intercalary femoral reconstruction with a metal prosthesis and an FFF resulted in earlier weight-bearing, a shorter time to union, fewer operations needed for union, and lower complication rates than reconstruction with an allograft and an FFF. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Giant cell tumor of bone (GCTB) is a locally aggressive tumor that shows predilection for the metaphysis/epiphysis of long bones, with an incidence of 4–5% of primary bone tumors. GCTB shows two main populations of cells: mononuclear cells and non-neoplastic multi-nucleated giant cells, with or without fibrous background. On the other hand, giant-cell-poor GCTB are rare with only few reports in the literature. These cases offer a diagnostic challenge, given the absence of giant cells and such cases have consistently been shown to harbor the H3F3A gene mutation by sequencing. The H3.3 G34W mutation-specific monoclonal antibody has shown high specificity in the diagnosis of GCTB. Two cases of giant-cell-poor GCTB are presented in this study, in which giant cells were absent or sparse and the diagnosis of GCTB was confirmed by the expression of H3.3 G34W monoclonal antibody in the mononuclear cells by immunohistochemistry. Whether this represents a histologic variant of GCTB or partial involution of GCTB is not yet fully understood; however, an immune response, infectious/inflammatory reaction, and/or anti-tumor cytokine production have been purported to be factors inciting disease regression in GCTB. [ABSTRACT FROM AUTHOR]

Background: Osteosarcoma and Ewing sarcoma are the 2 most common primary bone sarcomas, occurring predominantly in pediatric patients, with the incidence of osteosarcoma correlating with periods of peak bone-growth velocity. Although survival outcomes have plateaued over the past several decades, ongoing treatment advances have improved function, decreased infection rates, and improved other clinical outcomes in patients with bone tumors. Recently, the Prophylactic Antibiotic Regimens in Tumor Surgery (PARITY) trial addressed the serious problem of surgical site infection (SSI) and the lack of consensus regarding the appropriate prophylactic postoperative antibiotic regimen. The objective of the present secondary analysis of the PARITY trial was to characterize the modern treatment and surgical and oncologic outcomes of pediatric patients with bone tumors at 1 year postoperatively. Methods: The PARITY trial included patients ‡12 years old with a bone tumor or soft-tissue sarcoma that was invading the femur or tibia, necessitating osseous resection and endoprosthetic reconstruction. This pediatric subanalysis of the PARITY trial data included all PARITY patients £18 years old. As in the main PARITY study, patients were randomized to either a 5-day or 1-day course of postoperative antibiotic prophylaxis. The primary outcome measure was the development of an SSI within 1 year, and secondary outcomes included antibiotic-related adverse events, unplanned additional operations, local recurrence, metastasis, and death. Results: A total of 151 patients were included. An adjudicated SSI occurred in 27 patients (17.9%). There was no difference in the rate of any SSI between the 5-day and 1-day antibiotic groups (hazard ratio [HR], 0.92; 95% confidence interval [CI], 0.4 to 1.9; p = 0.82). Antibiotic-related complications occurred in 13 patients (8.6%), with no difference noted between groups (HR, 0.46; 95% CI, 0.2 to 1.4; p = 0.18). A total of 45 patients (29.8%) required a return to the operating room within the first postoperative year, which corresponded with a 68.8% reoperation-free rate of survival at 1 year when accounting for competing risks. The most common reason for reoperation was infection (29 of 45; 64.4%). A total of 7 patients (4.6%) required subsequent amputation of the operative extremity, and an additional 6 patients (4.0%) required implant revision within 12 months. A total of 36 patients (23.8%) developed metastases, and 6 patients (4.0%) developed a local recurrence during the first postoperative year. A total of 11 patients (7.3%) died during the study period. There were no significant differences in oncologic outcomes between the 5-day and 1-day antibiotic groups (HR, 0.97; 95% CI, 0.5-1.8; p = 0.92). Conclusions: There were no significant differences in surgical or oncologic outcomes between pediatric patients who underwent a 1-day versus 5-day antibiotic regimen following endoprosthetic reconstruction in the PARITY trial. Surgeons should be aware of and counsel patients and caregivers regarding the 30% rate of reoperation and the risks of infection (17.9%), death (7.3%), amputation (4.6%), and implant revision (4%) within the first postoperative year. [ABSTRACT FROM AUTHOR]

Background The Tenosynovial giant cell tumor Observational Platform Project (TOPP) registry is an international prospective study that -previously described the impact of diffuse-type tenosynovial giant cell tumour (D-TGCT) on patient-reported outcomes (PROs) from a baseline snapshot. This analysis describes the impact of D-TGCT at 2-year follow-up based on treatment strategies. Material and Methods TOPP was conducted at 12 sites (EU: 10; US: 2). Captured PRO measurements assessed at baseline, 1-year, and 2-year follow-ups were Brief Pain Inventory (BPI), Pain Interference, BPI Pain Severity, Worst Pain, EQ-5D-5L, Worst Stiffness, and -Patient-Reported Outcomes Measurement Information System. Treatment interventions were no current/planned treatment (Off-Treatment) and systemic treatment/surgery (On-Treatment). Results A total of 176 patients (mean age: 43.5 years) were included in the full analysis set. For patients without active treatment strategy -(Off-Treatment) at baseline (n = 79), BPI Pain Interference (1.00 vs. 2.86) and BPI Pain Severity scores (1.50 vs. 3.00) were numerically favorable in patients remaining Off-Treatment compared with those who switched to an active treatment strategy at year 1. From 1-year to 2-year -follow-ups, patients who remained Off-Treatment had better BPI Pain Interference (0.57 vs. 2.57) and Worst Pain (2.0 vs. 4.5) scores compared with patients who switched to an alternative treatment strategy. In addition, EQ-5D VAS scores (80.0 vs. 65.0) were higher in patients who remained -Off-Treatment between 1-year and 2-year follow-ups compared with patients who changed treatment strategy. For patients receiving systemic treatment at baseline, numerically favorable scores were seen in patients remaining on systemic therapy at 1-year follow-up: BPI Pain Interference (2.79 vs. 5.93), BPI Pain Severity (3.63 vs. 6.38), Worst Pain (4.5 vs. 7.5), and Worst Stiffness (4.0 vs. 7.5). From 1-year to 2-year follow-up, EQ-5D VAS scores (77.5 vs. 65.0) were higher in patients who changed from systemic treatment to a different treatment strategy. Conclusion These findings highlight the impact D-TGCT has on patient quality of life, and how treatment strategies may be influenced by these outcome measures. (ClinicalTrials.gov number: NCT02948088) [ABSTRACT FROM AUTHOR]

Metastatic disease of the periacetabular region is a common problem in orthopaedic oncology, associated with severe pain, decreased mobility, and substantial decline of the quality of life. Conservative management includes optimisation of pain management, activity modification, and radiation therapy. However, patients with destructive lesions affecting the weight-bearing portion of the acetabulum often require reconstructive surgery to decrease pain and restore mobility. The goal of surgery is to provide an immediately stable and durable construct, allowing immediate postoperative weight-bearing and maintaining functional independence for the remaining lifetime of the patient. A variety of surgical techniques have been reported, most of which are based upon cemented total hip arthroplasty, but also include porous tantalum implants and percutaneous cementoplasty. This review discusses the various reconstructive concepts and options, including their respective indications and outcome. A reconstructive algorithm incorporating different techniques and strategies based upon location and quality of remaining bone is also presented. [ABSTRACT FROM AUTHOR]

Background: The double-blind, randomized, placebo-controlled phase 3 study of orally administered PLX3397 in patients with pigmented villonodular synovitis or giant cell tumor of the tendon sheath (ENLIVEN) showed that pexidartinib provides a robust objective tumor response in adults with tenosynovial giant cell tumors (TGCT) not amenable to improvement with surgery. Based on these results, in 2019, pexidartinib received accelerated approval in the United States in this population as a breakthrough therapy under an orphan drug designation. However, the ability of pexidartinib to relieve pain in ENLIVEN was not fully detailed, and the relationship between pain relief and objective tumor response was not described. Questions/purposes: (1) What level of pain relief was achieved by pexidartinib treatment in ENLIVEN? (2) How was pain relief related to objective tumor responses? (3) How durable was pain relief? Methods: The current study included planned primary and exploratory assessments of patient-assessed worst pain at the site of the tumor in the ENLIVEN trial. ENLIVEN was a phase 3 randomized, placebo-controlled clinical trial in which adults with TGCT not amenable to improvement with surgery received pexidartinib or placebo for 24 weeks, after which eligible patients could receive open-label pexidartinib. Of 174 patients assessed for eligibility, 121 were randomized (50% [60] to placebo, 50% [61] to pexidartinib), and 120 were given either placebo or pexidartinib (59 received placebo and 61 received pexidartinib) and were included in an intent-to-treat analysis. Fifty-nine percent (71 of 120) of the overall treated population was female, and 88% (106 of 120) were White. Mean age was 45 ± 13 years. Tumors were mostly in the lower extremities (92% [110 of 120]), most commonly in the knee (61% [73 of 120]) and ankle (18% [21 of 120]). As a secondary outcome, patients scored worst pain at the site of the tumor in the past 24 hours on an 11-point numeric rating scale (NRS). The primary definition of a pain response was a decrease of at least 30% in the weekly mean worst-pain NRS score and increase of less than 30% in narcotic analgesic use between baseline and week 25. Planned exploratory assessments of pain included the frequency of a pain response using alternative thresholds, including a decrease in worst-pain NRS score of 50% or more and a decrease of at least 2 points (minimum clinically important difference [MCID]), the magnitude of pain reduction between baseline and week 25, correlation between worst-pain NRS score and tumor shrinkage by RECIST 1.1 criteria, and the durability of the pain response during the open-label extension. Pain responses during the randomized portion of the trial were compared according to intention-to-treat analysis, with a one-sided threshold of p < 0.025 to reduce the risk of false-positive results. Pain assessment was complete for 59% (35 of 59) of patients in the placebo group and 54% (33 of 61) of patients in the pexidartinib group. Demographic and disease characteristics did not differ between the two treatment groups. Results: A difference in the primary assessment of a pain response was not detected between pexidartinib and placebo (response percentage 31% [19 of 61] [95% CI 21% to 44%] versus 15% [9 of 59] [95% CI 8% to 27%]; one-sided p = 0.03). In the exploratory analyses, pexidartinib provided a modest improvement in pain (response percentage 26% [16 of 61] [95% CI 17% to 38%] versus 10% [6 of 59] [95% CI 5% to 20%]; one-sided p = 0.02 using the 50% threshold and 31% [19 of 61] [95% CI 21% to 44%] versus 14% [8 of 59] [95% CI 7% to 25%]; one-sided p = 0.02 using the MCID threshold). The least-squares mean change in the weekly mean worst-pain NRS score between baseline and week 25 was larger in patients treated with pexidartinib than placebo (-2.5 [95% CI -3.0 to -1.9] versus -0.3 [95% CI -0.9 to 0.3]; p < 0.001), although the mean difference between the two groups (-2.2 [95% CI -3.0 to -1.4]) was just over the MCID. Improvement in the weekly mean worst-pain NRS score correlated with the reduction in tumor size (r = 0.44; p < 0.001) and tumor volume score (r = 0.61; p < 0.001). For patients in the open-label extension, the change in the worst-pain NRS score from baseline was similar to the change at the end of the randomized portion and just above the MCID (mean -2.7 ± 2.2 after 25 weeks and -3.3 ± 1.7 after 50 weeks of receiving pexidartinib). Conclusion: Based on the current study, a modest reduction in pain, just larger than the MCID, may be an added benefit of pexidartinib in these patients, although the findings are insufficient to justify the routine use of pexidartinib for pain relief. Level of Evidence: Level II, therapeutic study. [ABSTRACT FROM AUTHOR]

Tenosynovial giant cell tumor (TGCT) is a rare neoplasm of the joint synovium that has a wide clinical spectrum including pain and stiffness in the affected joint, joint swelling, periarticular erosions, and cartilage loss, which can severely impact quality of life. The mainstay treatment for TGCT has been surgery involving partial or total synovectomy using arthroscopic or open techniques. However, surgical resection alone is associated with high recurrence rates, particularly in diffuse-TGCT (D-TGCT) cases. The 3 cases presented here summarize a combination approach (surgery+pexidartinib [tyrosine kinase inhibitor]) in patients with previously unresectable or inoperable D-TGCT. Case 1-Hip. A 29-year-old male was treated with pexidartinib prior to surgery, resulting in tumor reduction. A left total hip arthroplasty (THA) was then performed with a lack of recurrence in 12 months postoperative, and the patient currently on pexidartinib treatment. Case 2-Foot. A 35-year-old female, nearly a decade following a left foot mass resection, was treated with pexidartinib following disease recurrence. A decrease in soft tissue lesions at the midfoot and decreased marrow enhancement at the first metatarsal head were seen within 4–5 months of pexidartinib treatment; the patient is currently on pexidartinib (400 mg/day) with improved symptom control. Case 3-Knee. A 55-year-old male patient received pexidartinib pre- and postoperatively. A reduction in swelling and the size of the popliteal cyst was significant and maintained, with the synovial disease growing when pexidartinib was discontinued. Surgery and adjuvant therapy eliminated the disease as of the last follow-up visit (11 months postoperative). These cases provide a unique perspective based on tumor location, type/timing of treatment strategy, and patient outcomes. Optimal treatment strategies for this debilitating disease may entail utilizing a combination approach (surgery+systemic treatment) to reduce surgical morbidity and the risk of postoperative disease recurrence. [ABSTRACT FROM AUTHOR]

Background: It is estimated that the 12-month prevalence of depression in the United States is 8.6%, and for anxiety it is 2.9%. Although prior studies have evaluated depression and anxiety in patients with carcinoma, few have specifically evaluated patients with sarcoma, who often have unique treatment considerations such as mobility changes after surgery.Questions/purposes: We evaluated patients with sarcoma seen in our orthopaedic oncology clinic to determine (1) the proportion of patients with depression symptoms, symptom severity, how many patients triggered a referral to mental health professionals based upon our prespecified cutoff scores on the nine-item Patient Health Questionnaire (PHQ-9), and if their symptoms varied by disease state; (2) the proportion of patients with anxiety symptoms, symptom severity, how many patients triggered a referral to mental health professionals based upon our prespecified cutoff scores on the seven-item Generalized Anxiety Disorder Scale (GAD-7), and if they symptoms varied by disease state; (3) whether other factors were associated with the proportion and severity of symptoms of anxiety or depression, such as tumor location in the body (axial skeleton, upper extremity, or lower extremity), general type of tumor (bone or soft tissue), specific diagnosis, use of chemotherapy, length of follow-up (less than 1 year or greater than 1 year), and gender; and (4) what proportion of patients accepted referrals to mental health professionals, when offered.Methods: This study was a cross-sectional survey study performed at a single urban National Cancer Institute-designated Comprehensive Cancer Center from April 2021 until July 2021. All patients seen in the orthopaedic clinic 18 years of age and older with a diagnosis/presumed diagnosis of sarcoma were provided the PHQ-9 as well as the GAD-7 in our clinic. We did not track those who elected not to complete the surveys. Surveys were scored per survey protocol (each question was scored from 0 to 3 and summed). Specifically, PHQ-9 scores the symptoms of depression as 5 to 9 (mild), 10 to 14 (moderate), 15 to 19 (moderately severe), and 20 to 27 (severe). The GAD-7 scores symptoms of anxiety as 5 to 9 (mild), 10 to 14 (moderate), and 15 to 21 (severe). Patients with PHQ-9 or GAD-7 scores of 10 to 14 were referred to social work and those with scores 15 or higher were referred to psychiatry. Patients with thoughts of self-harm were referred regardless of score. Patients were divided based on disease state: patients during their initial management; patients with active, locally recurrent disease; patients with active metastatic disease; patients with prior recurrence or metastatic lesions who were subsequently treated and now have no evidence of disease (considered to be patients with discontinuous no evidence of disease); patients with no evidence of disease; and patients with an active, noncancerous complication but otherwise no evidence of disease. We additionally looked at the association of gender, chemotherapy administration, and tumor location on survey responses. Data are summarized using descriptive statistics. Differences across categories of disease state were tested for statistical significance using Kruskal-Wallis tests for continuous variables and Fisher exact tests for categorical variables as well as pairwise Wilcoxon rank sum tests.Results: Overall, symptoms of depression were seen in 35% (67 of 190) of patients, at varying levels of severity: 19% (37 of 190) had mild symptoms, 9% (17 of 190) had moderate symptoms, 6% (12 of 190) had moderately severe symptoms, and 1% (1 of 190) had severe symptoms. Depresssion symptoms severe enough to trigger a referral were seen in 17% (32 of 190) of patients overall. Patients scored higher on the PHQ-9 during their initial treatment or when they had recurrent or metastatic disease, and they were more likely to trigger a referral during those timepoints as well. The mean PHQ-9 was 5.7 ± 5.8 during initial treatment, 6.1 ± 4.9 with metastatic disease, and 7.4 ± 5.2 with recurrent disease as compared with 3.2 ± 4.2 if there was no evidence of disease (p = 0.001). Anxiety symptoms were seen in 33% (61 of 185) of patients: 17% (32 of 185) had mild symptoms, 8% (14 of 185) had moderate symptoms, and 8% (15 of 185) had severe symptoms. Anxiety symptoms severe enough to trigger a referral were seen in 16% (29 of 185) of patients overall. Patients scored higher on the GAD-7 during initial treatment and when they had recurrent disease or an active noncancerous complication. The mean GAD-7 was 6.3 ± 3.2 in patients with active noncancerous complications, 6.8 ± 5.8 in patients during initial treatment, and 8.4 ± 8.3 in patients with recurrent disease as compared with 3.1 ± 4.2 in patients with no evidence of disease (p = 0.002). Patients were more likely to trigger a referral during initial treatment (32% [9 of 28]) and with recurrent disease (43% [6 of 14]) compared with those with no evidence of disease (9% [9 of 97]) and those with discontinuous no evidence of disease (6% [1 of 16]; p = 0.004). There was an increase in both PHQ-9 and GAD-7 scores among patients who had chemotherapy. Other factors that were associated with higher PHQ-9 scores were location of tumor (upper extremity versus lower extremity or axial skeleton) and gender. Another factor that was associated with higher GAD-7 scores included general category of diagnosis (bone versus soft tissue sarcoma). Specific diagnosis and length of follow-up had no association with symptoms of depression or anxiety. Overall, 22% (41 of 190) of patients were offered referrals to mental health professionals; 73% (30 of 41) accepted the referral.Conclusion: When treating patients with sarcoma, consideration should be given to potential concomitant psychiatric symptoms. Screening, especially at the highest-risk timepoints such as at the initial diagnosis and the time of recurrence, should be considered. Further work should be done to determine the effect of early psychiatric referral on patient-related outcomes and healthcare costs.Level Of Evidence: Level III, therapeutic study. [ABSTRACT FROM AUTHOR]

Background: Clinical practice guidelines recommend centralized care for patients with bone sarcoma. However, the relationship between the distance that patients travel to obtain care, institutional treatment volume, and survival is unknown.Methods: We used the National Cancer Database to examine associations between travel distance and survival among 8,432 patients with bone sarcoma diagnosed from 2004 to 2015. Associations were identified using multivariable Cox regression analyses that controlled for sociodemographic, clinical, and hospital-level factors; subgroup analyses stratified patients by histological diagnosis, tumor stage, and pediatric or adult status.Results: Mortality risk was lower among patients who traveled ≥50 miles (≥80.5 km) than among patients who traveled ≤10 miles (≤16.1 km) (hazard ratio [HR], 0.69 [95% confidence interval (CI), 0.63 to 0.76]). Among hospital-level factors, facility volume independently affected survival: mortality risk was lower among patients at high-volume facilities (≥20 cases per year) than at low-volume facilities (≤5 cases per year), with an HR of 0.72 (95% CI, 0.66 to 0.80). The proportion of patients who received care at high-volume facilities varied by distance traveled (p < 0.001); it was highest among patients who traveled ≥50 miles (53%) and lower among those who traveled 11 to 49 miles (17.7 to 78.9 km) (32%) or ≤10 miles (18%). Patients who traveled ≥50 miles to a high-volume facility had a lower risk of mortality (HR, 0.65 [95% CI, 0.56 to 0.77]) than those who traveled ≤10 miles to a low-volume facility. In subgroup analyses, this association was evident among patients with all 3 major histological subtypes; those with stage-I, II, and IV tumors; and adults.Conclusions: This national study showed that greater travel burden was associated with higher survival rates in adults, a finding attributable to patients traveling to receive care at high-volume facilities. Despite the burdens associated with travel, modification of referral pathways to specialized centers may improve survival for patients with bone sarcoma.Level Of Evidence: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

PURPOSE: Ewing sarcoma (ES) is a primitive sarcoma defined by EWSR1-ETS fusions as the primary driver alteration. To better define the landscape of cooperating secondary genetic alterations in ES, we analyzed clinical genomic profiling data of 113 patients with ES, a cohort including more adult patients (> 18 years) and more patients with advanced stage at presentation than previous genomic cohorts. METHODS: The data set consisted of patients with ES prospectively tested with the US Food and Drug Administration–cleared Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets large panel, hybrid capture-based next-generation sequencing assay. To assess the functional significance of ERF loss, we generated ES cell lines with increased expression of ERF and lines with knockdown of ERF. We assessed cell viability, clonogenic growth, and motility in these ES lines and performed transcriptomic and epigenetic analyses. Finally, we validated our findings in vivo using cell line xenografts. RESULTS: Novel subsets were defined by recurrent secondary alterations in ERF , which encodes an ETS domain transcriptional repressor, in 7% of patients (five truncating mutations, one deep deletion, and two missense mutations) and in FGFR1 in another 2.7% (one amplification and two known activating mutations). ERF alterations were nonoverlapping with STAG2 alterations. In vitro , increased expression of ERF decreased tumor cell growth, colony formation, and motility in two ES cell lines, whereas ERF loss induced cellular proliferation and clonogenic growth. Transcriptomic analysis of cell lines with ERF loss revealed an increased expression of genes and pathways associated with aggressive tumor biology, and epigenetic, chromatin-based studies revealed that ERF competes with EWSR1-FLI1 at ETS-binding sites. CONCLUSION: Our findings open avenues to new insights into ES pathobiology and to novel therapeutic approaches in a subset of patients with ES. [ABSTRACT FROM AUTHOR]

Pexidartinib is a novel oral small‐molecule tyrosine kinase inhibitor targeting the colony‐stimulating factor 1 receptor. Pexidartinib undergoes extensive hepatic metabolism via multiple cytochrome P450 and uridine 5'‐diphospho‐glucuronosyl transferase enzymes, with ZAAD‐1006a as the only major metabolite in human plasma. As pexidartinib is extensively metabolized, hepatic impairment (HI) could lead to increased exposure to pexidartinib. The objective of the two phase 1, open‐label studies was to determine the pharmacokinetics of pexidartinib after a single 200‐mg dose in subjects with mild and moderate HI, based on Child–Pugh classification (PL3397‐A‐U123: 8 mild HI and 8 moderate HI vs 16 matched healthy controls) and National Cancer Institute Organ Dysfunction Working Group (NCI‐ODWG) criteria (PL3397‐A‐U129: 8 moderate HI versus 8 matched healthy controls [NCT04223635]). Based on Child–Pugh classification, exposure to pexidartinib (maximum observed concentration [Cmax], area under the plasma concentration–time curve up to the last measurable concentration [AUClast], and extrapolated to infinity [AUCinf]) was similar in subjects with mild and moderate HI and in respective matched healthy controls, whereas ZAAD‐1006a exposure (AUC) was approximately 27% to 28% and 41% to 48% higher in mild and moderate HI, respectively. According to NCI‐ODWG criteria, total pexidartinib exposure was 42% to 46% higher in subjects with moderate HI, compared with healthy controls, and total ZAAD‐1006a exposure was 70% to 79% higher for subjects with moderate HI, compared with matched healthy controls with normal hepatic function. These findings were used to develop appropriate dose recommendations in patients with hepatic impairment. [ABSTRACT FROM AUTHOR]

Tenosynovial giant cell tumor (TCGT) is a rare neoplasm affecting the synovium of joints, bursae, and tendon sheaths. The overproduction of colony‐stimulating factor‐1 (CSF‐1) by a minority of the tumor population works in a paracrine fashion to drive tumor growth. Pathology of the reactive, monocytic component has been well elucidated, whereas the populations of neoplastic cells and all the sources of CSF‐1 overproduction are incompletely characterized. Podoplanin (PDPN), or gp38, is a cell surface glycoprotein that is expressed on fibroblast‐like synovial cells and upregulated in rheumatoid arthritis and many cancers; it governs cell mobility, epithelial–mesenchymal transition, and other functions and is associated with lymphangiogenesis and poor prognosis in many solid tumors, which underscores its local and possible systemic effects. We found higher PDPN expression in TGCT than in internal controls of patients' healthy synovium. Flow cytometry partitioned PDPNhigh cells into PDPNhighCD90+ and PDPNhighCD14+ populations. Quantitative real‐time polymerase chain reaction analysis of the PDPNhighCD90+ cells revealed that CSF‐1 expression was 10‐fold higher than in PDPNhighCD14+ cells. Therefore, we conclude that the lining fibroblast‐like synovial cells, which express PDPNhighCD90+, are responsible for the overproduction of CSF‐1 and for driving tumor growth. [ABSTRACT FROM AUTHOR]

Targeted imaging and therapy for triple-negative breast cancer (TNBC) in the perioperative period are imperative for better disease management and improved life expectancy. Still, they are not available in clinical settings, and only a few nanoparticle-based theranostic agents potentially offer these capabilities. Herein, we develop an innovative class of biocompatible triple-modality nanoprobes (TMNPs) that offer optical imaging using optoacoustic, fluorescence, and surface-enhanced Raman scattering (SERS), as well as photothermal therapy (PTT) with near-infrared (NIR) light. The TMNPs are fabricated by immobilizing positively charged NIR fluorophores on negatively charged DNA-coated gold nanorods (AuNRs), followed by silica encapsulation. The DNA-based design allows the screening of commercially available positively charged NIR fluorophores for the optimum fluorescence emission and SERS. After design optimization, we functionalize TMNPs with folate groups to target folate receptor1 (FOLR1)-overexpressing TNBC in vitro and in vivo. Our results reveal that TMNPs preferentially accumulate in FOLR1 positive tumors in TNBC patient-derived xenograft mouse models and show excellent imaging capabilities with all three imaging modalities. Selective exposure of the tumor to a NIR laser shows efficient thermal tissue ablation without causing systemic toxicity. Collectively, TMNPs hold great promise for real-time multiplexed imaging of cancer biomarkers and therapeutic capability. [ABSTRACT FROM AUTHOR]

Aim: Monitoring treatment of tenosynovial giant cell tumor (TGCT) is complicated by the irregular shape and asymmetrical growth of the tumor. We compared responses to pexidartinib by Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 with those by tumor volume score (TVS) and modified RECIST (m-RECIST). Materials & methods: MRIs acquired every two cycles were assessed centrally using RECIST 1.1, m-RECIST and TVS and tissue damage score (TDS). Results: Thirty-one evaluable TGCT patients were treated with pexidartinib. From baseline to last visit, 94% of patients (29/31) showed a decrease in tumor size (median change: -60% [RECIST], -66% [m-RECIST], -79% [TVS]). All methods showed 100% disease control rate. For TDS, improvements were seen in bone erosion (32%), bone marrow edema (58%) and knee effusion (46%). Conclusion: TVS and m-RECIST offer potentially superior alternatives to conventional RECIST for monitoring disease progression and treatment response in TGCT. TDS adds important information about joint damage associated with TGCT. [ABSTRACT FROM AUTHOR]

Currently, the cell of origin for osteosarcoma or other primary skeletal tumors is largely unknown. Recent reports identifying specific cell types comprising bone now newly enable investigation of this topic. Specifically, CXC motif chemokine 12 (CXCL12)‐abundant reticular (CAR) cells are a specific skeletal stromal cell type that orchestrate the bone marrow microenvironment through cross‐talk with hematopoietic and endothelial cells and a likely candidate cell of origin for at least a subset of primary skeletal tumors. Here, we analyze osteosarcomas via immunohistochemistry for known markers of CAR cells such as leptin receptor (LEPR), B‐cell factor 3 (EBF3), CXCL12, and platelet‐derived growth factor receptor alpha (PDGFRA). A large proportion of high‐grade tumors expressed LEPR, PDGFRA, and EBF3 but not CXCL12. These data raise the hypothesis that CAR cells are the cell of origin of this osteoblastic osteosarcoma subset, a finding with implications for the cellular oncogenesis of primary osteosarcoma and the development of effective targeted therapies. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research. [ABSTRACT FROM AUTHOR]

Tenosynovial giant cell tumor (TGCT) is a neoplasm of the joint synovium that can have severe impacts on joint mobility, function, and quality of life. Traditionally, treatment modalities included partial or complete surgical synovectomy, radiotherapy (typically as an adjunct to surgery), and watchful monitoring (no medical or surgical intervention). However, these approaches have been met with varying degrees of success and high recurrence rates, as well as onerous complications and clinical sequelae. Pexidartinib, a colony-stimulating factor 1 receptor (CSF1R) inhibitor, presents a promising molecular approach that targets a neoplastic driver of TGCT. While the introduction of pexidartinib allows clinicians to avoid the significant morbidity associated with traditional treatment options, there are also defined risks associated with pexidartinib treatment. Therefore, patient selection is critical in optimizing treatment modalities in TGCT. The purpose of this literature review is to identify the TGCT patient population that would derive maximal benefit with minimal risk from pexidartinib, and to determine the specific indications and contraindications for selecting pexidartinib over other therapeutic approaches. Specifically, this paper compares the efficacy and safety profile of pexidartinib across clinical and preclinical studies to that of surgery, radiotherapy, and watchful monitoring. Rates of improvement in joint mobility, pain, and recurrence-free survival across studies of pexidartinib have been encouraging. The most common adverse events are mild (hypopigmentation of the hair) or reversible (transient aminotransferase elevation). Severe or permanent adverse events (notably cholestatic hepatotoxicity) are rare. While the optimal treatment strategy remains highly dependent on a patient's clinical circumstances and treatment goals, pexidartinib has surfaced as a promising therapeutic in cases where the morbidity of surgery or radiotherapy outweighs the benefits. [ABSTRACT FROM AUTHOR]

This analysis was conducted to assess exposure–response relationships for efficacy and safety of pexidartinib in patients with tenosynovial giant cell tumor. Efficacy was assessed categorically by overall response rate (ORR) with Response Evaluation Criteria in Solid Tumors version 1.1 and longitudinally (changes in tumor size and volume). Safety included hepatic parameters (i.e., alanine aminotransferase [ALT], aspartate aminotransferase [AST], and total bilirubin). Average pexidartinib concentration (Cavg) was identified as the primary exposure parameter correlated with response. In categorical and longitudinal analyses, higher Cavg coincided with greater ORR and tumor size reduction, respectively, with smaller joint size having a greater impact. For safety, a significant relationship was observed between Cavg and incidence of ALT‐related and AST‐related adverse events (AEs). With increased exposure, an increase in efficacy was predicted with near maximum effect at 800 mg/day. Higher initial dose (1000 mg/day) during the first 2 weeks did not improve efficacy. Higher doses were associated with an increased risk of ALT‐related and AST‐related AEs. These results support the US Food and Drug Administration–approved dose (400 mg two times/day without initial loading dose). [ABSTRACT FROM AUTHOR]

The SF‐36 is widely used to evaluate the health‐related quality of life (HRQoL) of patients with musculoskeletal tumors. Instead of typical methods, calculating the SF‐36 Global Score has recently become an increasingly common reporting approach. However, numerical changes lack clear clinical relevance. The minimal clinically important difference (MCID) is useful for interpreting changes in functional scores by defining the smallest change patients may perceive as clinically meaningful. The aim of this study is to determine the MCID of the SF‐36 Global Score in orthopedic oncology patients, which has not been reported to date. Three‐hundred ten patients who underwent surgery and completed two surveys during postoperative follow‐up were reviewed. The two most common methods for calculating the SF‐36 Global Score were used: (1) anchor‐based methods and receiver operating characteristic analysis based on one‐half of the SD of change score and standard error of measurement at baseline and; (2) distribution‐based methods. Using anchor‐based methods, the MCIDs of SF‐36 Global Scores #1 and #2 were 2.7 (area under the curve [AUC] = 0.85) and 2.5 (AUC = 0.79) for improvement, and −1.5 (AUC = 0.81) and −0.6 (AUC = 0.83) for deterioration, respectively. Using distribution‐based methods, the MCIDs of SF‐36 Global Scores #1 and #2 were 4.1 and 4.4 by half SD, and 4.1 and 4.5 by standard error of measurement, respectively. Our findings provide benchmark values, which can serve as a reference for future studies in musculoskeletal tumor patients using the SF‐36 Global Score as a single measure for HRQoL. [ABSTRACT FROM AUTHOR]

Computer-assisted navigation and robotic surgery have gained popularity in the treatment of pelvic bone malignancies, given the complexity of the bony pelvis, the proximity of numerous vital structures, and the historical challenges of pelvic bone tumor surgery. Initial interest was on enhancing the accuracy in sarcoma resection by improving the quality of surgical margins and decreasing the incidence of local recurrences. Several studies have shown an association between intraoperative navigation and increased incidence of negative margin bone resection, but long-term outcomes of navigation in pelvic bone tumor resection have yet to be established. Historically, mechanical stabilization of pelvic bone metastases has been limited to Harrington-type total hip arthroplasty for disabling periacetabular disease, but more recently, computer-assisted surgery has been employed for minimally invasive percutaneous fixation and stabilization; although still in its incipient stages, this procedure is potentially appealing for treating patients with bone metastases to the pelvis. The authors review the literature on navigation for the treatment of primary and metastatic tumors of the pelvic bone and discuss the best practices and limitations of these techniques. [ABSTRACT FROM AUTHOR]

Background and purpose — The ENLIVEN trial showed that, after 25 weeks, pexidartinib statistically significantly reduced tumor size more than placebo in patients with symptomatic, advanced tenosynovial giant cell tumor (TGCT) for whom surgery was not recommended. Here, we detail the effect of pexidartinib on patient-reported physical function and stiffness in ENLIVEN. Patients and methods — This was a planned analysis of patient-reported outcome data from ENLIVEN, a double-blinded, randomized phase 3 trial of adults with symptomatic, advanced TGCT treated with pexidartinib or placebo. Physical function was assessed using the Patient-Reported Outcomes Measurement Information System (PROMIS)-physical function (PF), and worst stiffness was assessed using a numerical rating scale (NRS). A mixed model for repeated measures was used to compare changes in PROMIS-PF and worst stiffness NRS scores from baseline to week 25 between treatment groups. Response rates for the PROMIS-PF and worst stiffness NRS at week 25 were calculated based on threshold estimates from reliable change index and anchor-based methods. Results — Between baseline and week 25, greater improvements in physical function and stiffness were experienced by patients receiving pexidartinib than patients receiving placebo (change in PROMIS-PF = 4.1 [95% confidence interval (CI) 1.8–6.3] vs. –0.9 [CI −3.0 to 1.2]; change in worst stiffness NRS = –2.5 [CI −3.0 to −1.9] vs. –0.3 [CI −0.9 to 0.3]). Patients receiving pexidartinib had higher response rates than patients receiving placebo for meaningful improvements in physical function and stiffness. Improvements were sustained after 50 weeks of pexidartinib treatment. Interpretation — Pexidartinib treatment provided sustained, meaningful improvements in physical function and stiffness for patients with symptomatic, advanced TGCT. [ABSTRACT FROM AUTHOR]

Background: Compliant compression fixation was developed to promote permanent bone-prosthesis osteointegration while preserving bone stock in patients needing endoprosthetic reconstructions. This has demonstrated durability in the distal femur, with reliable cortical hypertrophy adjacent to the implant. However, the extent of bone formation and prosthetic survivorship of proximal femoral replacements with compliant compression fixation has not been established.Questions/purposes: (1) How much bone formation occurs across the compression segment in patients treated with a proximal femoral replacement implant using compliant compression fixation? (2) What were the Musculoskeletal Tumor Society (MSTS) scores at minimum 24-month follow-up of patients who received this reconstruction? (3) What is the implant survivorship free from implant removal or revision for any reason at final follow-up?Methods: From 2006 to 2018, we performed 213 proximal femoral replacements in patients with oncologic conditions of the proximal femur where the trochanters could not be preserved. Of these, 6% (12 of 213) were performed with an implant that used compliant compression fixation. We used this device in primary oncologic reconstructions in patients younger than 65 years of age without metastases who had nonirradiated bone with the requisite ≥ 2.5 mm of cortical thickness in the hope that it would provide more durable fixation and bone stock preservation than conventional reconstructions. All patients were followed for longer than 2 years except one who died in that interval. Median (range) follow-up was 6 years (2 to 10 years). Seven patients received diagnosis-specific chemotherapy in a consistent manner based on Children's Oncology Group chemotherapy protocols. Using the NIH-developed ImageJ open-access software, we measured the area of bone under compression on 3-, 6-, 9-, 12-, 18-, and 24-month radiographs and the length of the traction bar potential-compression distance, reconciling independent measures from two investigators using the identical method as published for the distal femur with compression fixation. The duration of prosthesis retention was evaluated using a competing risk analysis for the 11 surviving patients.Results: Bone hypertrophy in the compression segment was scant. At the final analysis, cortical bone formation was a median (range) of 4 (-7 to 14) above baseline. The median (range) MSTS score was 27 (19 to 30). One implant failed after trauma, and the patient underwent revision of the implant.Conclusion: Despite scant bone formation across the compression segment and drastically less formation than reported for distal femoral replacements, compliant compression fixation of the proximal femur demonstrated good survivorship in patients 65 years or younger with localized sarcoma and nonirradiated, adequate bone stock in this small, retrospective series. Patients achieved good functional outcomes at final follow-up. The potential benefit of this reconstruction method should be weighed against the initial period of limited weightbearing and the life expectancy of the patient.Level Of Evidence: Level IV, cohort study. [ABSTRACT FROM AUTHOR]

Background: Pexidartinib is approved in the U.S. for tenosynovial giant cell tumors (TGCTs). Herein, we assessed the hepatic safety profile of pexidartinib across patients with TGCTs receiving pexidartinib. Materials, and Methods: Hepatic adverse reactions (ARs) were assessed by type and magnitude of liver test abnormalities, classified as (a) isolated aminotransferase elevations (alanine [ALT] or aspartate [AST], without significant alkaline phosphatase [ALP] or bilirubin elevations), or (b) mixed or cholestatic hepatotoxicity (increase in ALP with or without ALT/AST and bilirubin elevations, based on adjudication). Median follow‐up from initial pexidartinib treatment was 39 months (range, 32–82) in 140 patients with TGCTs across clinical studies NCT01004861, NCT02371369, NCT02734433, and NCT03291288. Results: In total, 95% of patients with TGCTs (133/140) treated with pexidartinib (median duration of exposure, 19 months [range, 1–76]), experienced a hepatic AR. A total of 128 patients (91%) had reversible, low‐grade dose‐dependent isolated AST/ALT elevations without significant ALP elevations. Five patients (4%) experienced serious mixed or cholestatic injury. No case met Hy's law criteria. Onset of hepatic ARs was predominantly in the first 2 months. All five serious hepatic AR cases recovered 1–7 months following pexidartinib discontinuation. Five patients from the non‐TGCT population (N = 658) experienced serious hepatic ARs, two irreversible cases. Conclusion: This pooled analysis provides information to help form the basis for the treating physician's risk assessment for patients with TCGTs, a locally aggressive but typically nonmetastatic tumor. In particular, long‐term treatment with pexidartinib has a predictable effect on hepatic aminotransferases and unpredictable risk of serious cholestatic or mixed liver injury. Implications for Practice: This is the first long‐term pooled analysis to report on the long‐term hepatic safety of pexidartinib in patients with tenosynovial giant cell tumors associated with severe morbidity or functional limitations and not amenable to improvement with surgery. These findings extend beyond what has been previously published, describing the observed instances of hepatic toxicity following pexidartinib treatment across the clinical development program. This information is highly relevant for medical oncologists and orthopedic oncologists and provides guidance for its proper use for appropriate patients within the Pexidartinib Risk Evaluation and Mitigation Safety program. Pexidartinib is approved in the U.S. for treatment of tenosynovial giant cell tumors (TGCT). This article assesses the hepatic safety profile of pexidartinib in TGCT cases and describes risk mitigation procedures designed to identify any instances of serious liver injury as early as possible to better inform prescribers and patients about this drug. [ABSTRACT FROM AUTHOR]

Background: Tenosynovial giant cell tumor (TGCT) is a rare, locally aggressive neoplasm arising from the synovium of joints, bursae, and tendon sheaths affecting small and large joints. It represents a wide spectrum ranging from minimally symptomatic to massively debilitating. Most findings to date are mainly from small, retrospective case series, and thus the morbidity and actual impact of this rare disease remain to be elucidated. This study prospectively explores the management of TGCT in tertiary sarcoma centers.Methods: The TGCT Observational Platform Project registry was a multinational, multicenter, prospective observational study involving 12 tertiary sarcoma centers in 7 European countries, and 2 US sites. This study enrolled for 2 years all consecutive ≥ 18 years old patients, with histologically diagnosed primary or recurrent cases of diffuse-type TGCT. Patient demographic and clinical characteristics were collected at baseline and every 6 months for 24 months. Quality of life questionnaires (PROMIS-PF and EQ-5D) were also administered at the same time-points. Here we report baseline patient characteristics.Results: 166 patients were enrolled between November 2016 and March 2019. Baseline characteristics were: mean age 44 years (mean age at disease onset: 39 years), 139/166 (83.7%) had prior treatment, 71/166 patients (42.8%) had ≥ 1 recurrence after treatment of their primary tumor, 76/136 (55.9%) visited a medical specialist ≥ 5 times, 66/116 (56.9%) missed work in the 24 months prior to baseline, and 17/166 (11.6%) changed employment status or retired prematurely due to disease burden. Prior treatment consisted of surgery (i.e., arthroscopic, open synovectomy) (128/166; 77.1%) and systemic treatments (52/166; 31.3%) with imatinib (19/52; 36.5%) or pexidartinib (27/52; 51.9%). Treatment strategies at baseline visits consisted mainly of watchful waiting (81/166; 48.8%), surgery (41/166; 24.7%), or targeted systemic therapy (37/166; 22.3%). Patients indicated for treatment reported more impairment compared to patients indicated for watchful waiting: worst stiffness NRS 5.16/3.44, worst pain NRS 6.13/5.03, PROMIS-PF 39.48/43.85, and EQ-5D VAS 66.54/71.85.Conclusion: This study confirms that diffuse-type TGCT can highly impact quality of life. A prospective observational registry in rare disease is feasible and can be a tool to collect curated-population reflective data in orphan diseases. Name of registry: Tenosynovial Giant Cell Tumors (TGCT) Observational Platform Project (TOPP).Trial Registration Number: NCT02948088. Date of registration: 10 October 2016. URL of Trial registry record: https://clinicaltrials.gov/ct2/show/NCT02948088?term=NCT02948088&draw=2 . [ABSTRACT FROM AUTHOR]

Background: There is a lack of evidence regarding long-term outcomes of rotating-hinge knee prostheses with distal femoral replacement in a large oncologic patient series. In this study, we investigated the proportion of patients experiencing complications requiring surgery in the long term, as well as the cumulative incidence of implant removal/revision and amputation at 5, 10, 15, and 20 years through competing risk analyses.Methods: We retrospectively studied 214 patients treated with a Finn/Orthopaedic Salvage System (OSS) knee prosthesis (Zimmer Biomet) after distal femoral resection from 1991 to 2017. The study end points were postoperative complications requiring surgery. Reoperations were classified as major when there was (1) removal of the metal-body femoral component, the tibial component, or the bone-implant fixation; (2) major revision (exchange of the metal-body femoral component, the tibial component, or the bone-implant fixation); or (3) amputation. Minor reoperations were defined as all other reoperations. Competing risk analysis was used to estimate the cumulative incidence of implant removal/revision or amputation.Results: There were 312 reoperations in 113 patients (98 major reoperations in 68 patients and 214 minor reoperations). Seventeen patients (8%) required ≥5 additional operations, and 21 patients (10%) required >1 major reoperation. Although the number of reoperations decreased over time, major and minor reoperations continuously accrued after 10 years. The cumulative incidences of implant removal or revision for any reason at 5, 10, 15, and 20 years were 22.6%, 30.1%, 34.3%, and 42.5%, respectively. Although most implant removals/revisions occurred in the first 10 years, the risk persisted after 10 years, at a mean of 1.24%/year, mainly due to deep infection (1.06%/year).Conclusions: The long-term outcomes of treatment with a Finn/OSS distal femoral rotating-hinge knee prosthesis showed it to be a durable reconstruction technique. The rate of implant removal/revisions after 10 years was gradual (1.24%/year). Deep infection remains a major late-failure mechanism, and lifetime surveillance for prosthetic problems is needed.Level Of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Pexidartinib is a kinase inhibitor that induces tumor response and improvements in symptoms and functional outcomes in adult patients with symptomatic tenosynovial giant cell tumor (TGCT). A population pharmacokinetic (PK) model for pexidartinib and its metabolite, ZAAD, was developed, and effects of demographic and clinical factors on the PK of pexidartinib and ZAAD were estimated. The analysis included pooled data from 7 studies in healthy volunteers (N = 159) and 2 studies in patients with TGCT or other solid tumors (N = 216). A structural 2‐compartment model with sequential zero‐ and first‐order absorption and lag time, and linear elimination from the central compartment adequately described pexidartinib and ZAAD PKs. Clearance of pexidartinib was estimated at 5.83 L/h in a typical patient with reference covariates (male, non‐Asian, weight = 80 kg, creatinine clearance ≥90 mL/min, aspartate aminotransferase ≤80 U/L, and total bilirubin ≤20.5 μmol/L). In the covariate analysis, Asians and healthy subjects had modestly lower pexidartinib exposure (21% decrease each) in terms of steady‐state area under the curve values from 0 to 24 hours (AUC0‐24,ss). Effects of body weight, sex, and hepatic function parameters on pexidartinib AUC0‐24,ss were generally <20%. Patients with TGCT with mild renal impairment were predicted to have approximately 23% higher AUC0‐24,ss than those with normal renal function. The effects of covariates on ZAAD exposure were similar to those on pexidartinib. These results indicate small and generally clinically nonmeaningful effects of patient demographic and clinical characteristics on pexidartinib and ZAAD PK profiles. [ABSTRACT FROM AUTHOR]

Background: Giant cell tumor of bone is a benign, locally aggressive neoplasm. Surgical resection is the preferred treatment method. However, for cases in which resection poses an increased risk to the patient, denosumab (anti-RANKL monoclonal antibody) is considered. Secukinumab is an anti-IL-17 antibody that is used in psoriatic arthritis to reduce bone resorption and articular damage.Case Presentation: One case of giant cell tumor of bone (GCTB) in a patient treated with secukinumab for psoriatic arthritis demonstrated findings significant for intra-lesional calcifications. Histologic examination showed ossification, new bone formation, and remodeling. A paucity of osteoclast type giant cells was noted. Real-time quantitative polymerase-chain-reaction (qRT-PCR) analysis revealed decreased osteoclast function compared to treatment-naive GCTB.Conclusions: Secukinumab may play a role in bone remodeling for GCTB. Radiologists, surgeons, and pathologists should be aware of this interaction, which can cause lesional ossification. Further research is required to define the therapeutic potential of this drug for GCTB and osteolytic disease. [ABSTRACT FROM AUTHOR]

Soft tissue sarcoma (STS) of the extremities is typically treated with limb-sparing surgery and radiation therapy; with this treatment approach, high local control rates can be achieved. However, postradiation bone fractures, fractures occurring in the prior radiation field with minimal or no trauma, are a serious late complication that occurs in 2–22% of patients who receive surgery and radiation for STS. Multiple risk factors for sustaining a postradiation fracture exist, including high radiation dose, female sex, periosteal stripping, older age, femur location, and chemotherapy administration. The treatment of these pathological fractures can be difficult, with complications including delayed union, nonunion, and infection posing particular challenges. Here, we review the mechanisms, risk factors, and treatment challenges associated with postradiation fractures in STS patients. [ABSTRACT FROM AUTHOR]

Background: The objective of this study was to report on the long-term effects of pexidartinib on tenosynovial giant cell tumor (TGCT).Methods: This was a pooled analysis encompassing 3 pexidartinib-treated TGCT cohorts: 1) a phase 1 extension study (NCT01004861; 1000 mg/d; n = 39), 2) ENLIVEN patients randomized to pexidartinib (1000 mg/d for 2 weeks and then 800 mg/d; n = 61), and 3) ENLIVEN crossover patients (NCT02371369; 800 mg/d; n = 30). Eligible patients were 18 years old or older and had a histologically confirmed TGCT that was unresectable and symptomatic. Efficacy endpoints included the best overall response (complete or partial response) and the duration of response (DOR) by the Response Evaluation Criteria in Solid Tumors (RECIST) and the tumor volume score (TVS). The safety assessment included the frequency of treatment-emergent adverse events (TEAEs) and hepatic laboratory abnormalities (aminotransferase elevations and mixed/cholestatic hepatotoxicity). The data cutoff was May 31, 2019.Results: One hundred thirty patients with TGCT received pexidartinib (median treatment duration, 19 months; range, 1 to 76+ months); 54 (42%) remained on treatment at the end of the analysis (26 months after initial data cut of March 2017). The RECIST overall response rate (ORR) was 60%; the TVS ORR was 65%. The median times to response were 3.4 (RECIST) and 2.8 months (TVS), with 48 of the responding patients (62%) achieving a RECIST partial response by 6 months and with 72 (92%) doing so by 18 months. The median DOR was reached for TVS (46.8 months). Reported TEAEs were mostly low-grade, with hair color changes being most frequent (75%). Most liver abnormalities (92%) were aminotransferase elevations; 4 patients (3%) experienced mixed/cholestatic hepatotoxicity (all within the first 2 months of treatment), which was reversible in all cases (recovery spanned 1-7 months).Conclusions: This study demonstrates the prolonged efficacy and tolerability of long-term pexidartinib treatment for TGCT. [ABSTRACT FROM AUTHOR]

Palmar and plantar fibromatosis are benign proliferative processes which present as a diffuse thickening or nodules of the hands and/or feet and may lead to flexion contractures, pain, and functional impairment known as Dupuytren and Ledderhose diseases, respectively. Current treatments are noncurative and associated with significant morbidity. Here, we report on the outcomes of 5 patients with advanced disease, no longer surgical candidates, treated with sorafenib. Sorafenib exhibited an expected safety profile. All 5 patients demonstrated objective responses as evaluated by a decrease in tumor size and/or tumor cellularity from baseline and all 5 patients reported subjective pain relief and/or functional improvement. Mechanistically, immunohistochemistry revealed patchy positivity for PDGFRβ, a known target of sorafenib. The outcomes of these 5 patients suggest the safety and efficacy of a relatively well-tolerated oral agent in the treatment of Dupuytren and Ledderhose diseases and suggest the need for future controlled studies. [ABSTRACT FROM AUTHOR]

Background: Megaprostheses are commonly used for reconstruction after distal femoral resection in orthopaedic oncology. The polyethylene bearings in these reconstructions experience wear and wear-related complications that may result in revision surgery. Improved manufacturing and processing of polyethylene has increased the durability of components commonly used for routine arthroplasty. Alterations in the manufacture of polyethylene is expected to reduce the revision risk of oncologic megaprostheses, resulting in fewer revision procedures, but this has not been proven.Questions/purposes: Is there a difference in the hazard of polyethylene wear or breakage leading to prosthetic revision between differences in polyethylene manufacture and processing based on a competing risk analysis?Methods: This was a single-center, observational, retrospective comparative study of 224 patients who had distal femur megaprostheses with identical rotating hinge articulations and knee kinematics after oncologic surgery from 1993 to 2015. No differences in surgical indications, joint articular components and kinematics, age, sex, diagnosis, BMI, use of chemotherapy, or tumor stage were seen with the patient numbers available. Prosthetic survivorship free from prosthetic revision surgery because of polyethylene wear-related revisions, defined as breakage, increased excursion on varus-valgus stress, or new locking or giving way was compared between two groups of patients: group 1 polyethylene (P1) (66 patients) who had air-sterilized machined ram-extruded bar stock or group 2 polyethylene (P2) (158 patients) molded gamma-radiated argon-processed polyethylene components. The mean follow-up duration for the P1 group (89 ± 55 months) was not different from that of patients with P2 polyethylene (79 ± 63 months; p = 0.24) including 27% (18 of 66) of patients in the P1 group and 25% (40 of 158) of patients in the P2 group followed for more than 10 years. More patients in the P2 group were lost to follow-up (9.2%, 16 of 174) than in the P1 group (5.7%, 4 of 70) but this was not statistically different (chi square; p = 0.37). The hazard of revision because of polyethylene wear or breakage was calculated with a competing risk analysis using the Fine-Gray subdistribution hazard model.Results: The P1 implants had a higher hazard ratio for revision caused by polyethylene damage at 120 months than did the P2 polyethylene implants (P1 HR 0.24 [95% CI 0.13 to 0.36] versus HR 0.07 [95% CI 0.03 to 0.12]), which represents an estimated absolute risk reduction of 17% (95% CI 6.15 to 27.9).Conclusion: Polyethylene damage can result in megaprosthetic revisions in patients undergoing oncologic procedures. The hazard of polyethylene failure resulting in revision surgery was lower in patients who received recent polyethylene than in patients with polyethylene produced by previous methods, enhancing the durability of distal femoral megaprosthetic reconstructions. Despite improvements in polyethylene manufacture and clinical results, revision solely because of polyethylene damage still occurs in 7% of patients by the 10-year timepoint; thus, more improvement is needed. Patients who receive these implants should be monitored for signs and symptoms of polyethylene damage.Level Of Evidence: Level III, therapeutic study. [ABSTRACT FROM AUTHOR]

Background: The SF-36 is widely used to evaluate the health-related quality of life of patients with musculoskeletal tumors. The minimum clinically important difference (MCID) is useful for interpreting changes in functional scores because it defines the smallest change each patient may perceive. Since the MCID is influenced by the population characteristics, MCIDs of the SF-36 should be defined to reflect the specific conditions of orthopaedic oncology patients.Questions/purposes: (1) What is the MCID of SF-36 physical component summary (PCS) and mental component summary (MCS) scores in patients with orthopaedic oncologic conditions when calculated with distribution-based methods? (2) What is the MCID of SF-36 PCS and MCS scores in patients with orthopaedic oncologic conditions when calculated by anchor-based methods?Methods: Of all 960 patients who underwent surgery from 1999 to 2005, 32% (310) of patients who underwent musculoskeletal oncologic surgery and completed two surveys during postoperative follow-up were reviewed. We evaluated a dataset that ended in 2005, completing follow-up of data accrued as part of the cooperative effort between the American Academy of Orthopaedic Surgeons and the Council of Musculoskeletal Specialty Societies to create patient reported quality of life instruments for lower extremity conditions. This effort, started in 1994 was validated and widely accepted by its publication in 2004. We believe the findings from this period are still relevant today because (1) this critical information has never been available for clinicians and researchers to distinguish real differences in outcome among orthopaedic oncology patients, (2) the SF-36 continues to be the best validated and widely used instrument to assess health-related quality of life, and unfortunately (3) there has been no significant change in outcome for oncology patients over the intervening years. SF-36 PCS and MCS are aggregates of the eight scale scores specific to physical and mental dimension (scores range from 0 to 100, with higher scores representing better health). Their responsiveness has been shown postoperatively for several surgical procedures (such as, colorectal surgery). Two different methods were used to calculate the MCID: the distribution-based method, which was based on half the SD of the change in score and standard error of the measurement at baseline, and anchor-based, in which a receiver operating characteristic (ROC) curve analysis was performed. The anchor-based method uses a plain-language question to ask patients how their individual conditions changed when compared with the previous survey. Answer choices were "much better," "somewhat better," "about the same," "somewhat worse," or "much worse." The ROC curve-derived MCIDs were defined as the change in scores from baseline, with sensitivity and specificity to detect differences in patients who stated their outcome was, about the same and those who stated their status was somewhat better or somewhat worse. This approach is based on each patient's perception. It considers that the definition of MCID is the minimal difference each patient can perceive as meaningful.Results: Using the distribution-based method, we found that the MCIDs of the PCS and MCS were 5 and 5 by half the SD, and 6 and 5 by standard error of the measurement. In the anchor-based method, the MCIDs of the PCS and MCS for improvement/deterioration were 4 (area under the curve, 0.82)/-2 (area under the curve, 0.79) and 4 (area under the curve, 0.72)/ (area under the curve, 0.68), respectively.Conclusions: Since both anchor-based and distribution-based MCID estimates of the SF-36 in patients with musculoskeletal tumors were so similar, we have confidence in the estimates we made, which were about 5 points for both the PCS and the MCS subscales of the SF-36. This suggests that interventions improving SF-36 by less than that amount are unlikely to be perceived by patients as clinically important. Therefore, those interventions may not justify exposing patients to risk, cost, or inconvenience. When applying new interventions to orthopaedic oncology patients going forward, it will be important to consider these MCIDs for evaluation purposes.Level Of Evidence: Level III, diagnostic study. [ABSTRACT FROM AUTHOR]

Compliant self-adjusting compression implants are a novel approach to increase the durability of megaprosthesis fixation. However, there is no report of current implant designs that documents the bone-prosthetic interface of this implant. A well-fixed compliant, self-adjusting distal femoral replacement was retrieved from a patient undergoing revision unrelated to fixation. The prosthesis-bone interface was preserved, embedded in poly(methyl methacrylate), and sectioned into 2–4-mm slices. Slices were then imaged using backscatter electron microscopy, and ongrowth and ingrowth were quantified using imaging software. The average percentage of bony ongrowth from five successive sections was 52.5%, and the average percentage of ingrowth into the porous titanium surface was 13.5%. We found that bone ongrowth on the cortex between anchor plug and spindle averages more than 50% and up to 70% depending upon the slice examined with backscatter electron microscopy. Bone ingrowth was consistently around 13% on every slice examined. This is a new finding compared with prior spindle designs, likely due to the addition of hydroxyapatite-coated porous metal titanium surface on the spindle. This report is an important step in understanding the mechanism of bony fixation generated by this implant and supports its increased use in oncological and complex reconstructive situations. [ABSTRACT FROM AUTHOR]

Background: Biologic agents may prolong survival of patients with certain kidney and lung adenocarcinomas that have metastasized to bone, and patient response to these agents should be considered when choosing between an endoprosthesis and internal fixation for surgical treatment of femoral metastases.Questions/purposes: Among patients undergoing surgery for femoral metastases of lung or renal cell carcinoma, (1) Does survival differ between patients who receive only cytotoxic chemotherapy and those who either respond or do not respond to biologic therapy? (2) Does postsurgical incidence of local disease progression differ between groups stratified by systemic treatment and response? (3) Does implant survival differ among groups stratified by systemic treatment and response?Methods: From our institutional longitudinally maintained orthopaedic database, patients were identified by a query initially identifying all patients who carried a diagnosis of renal cell carcinoma or lung carcinoma. Patients who underwent internal fixation or prosthetic reconstruction between 2000 and 2016 for pathologic fracture of the femur and who survived ≥ 1 year after surgery were studied. Patients who received either traditional cytotoxic chemotherapy or a biologic agent were included. Patients were classified as responders or nonresponders to biologic agents based on whether they had clinical and imaging evidence of a response recorded on two consecutive office visits over ≥ 6 months. Endpoints were overall survival from the time of diagnosis, survival after the femoral operation, evidence of disease progression in the femoral operative site, and symptomatic local disease progression for which revision surgery was necessary. Our analysis included 148 patients with renal (n = 26) and lung (n = 122) adenocarcinoma. Fifty-one patients received traditional chemotherapy only. Of 97 patients who received a biologic agent, 41 achieved a response (stabilization/regression of visceral metastases), whereas 56 developed disease progression. We analyzed overall patient survival with the Kaplan-Meier method and used the log-rank test to identify significant differences (p < 0.05) between groups.Results: One-year survival after surgery among patients responsive to biologic therapy was 61% compared with 20% among patients nonresponsive to biologics (p < 0.001) and 10% among those who received chemotherapy only (p < 0.009). With the number of patients we had to study, we could not detect any difference in local progression of femoral disease associated with systemic treatment and response. Radiologic evidence of periimplant local disease progression developed in three (7%) of 41 patients who responded to biologic treatment, two (3%) of 56 patients nonresponsive to biologics, and one (2%) of 51 patients treated with traditional chemotherapy. With the numbers of patients we had, we could not detect a difference in patients who underwent revision. All three patients responsive to biologics who developed local recurrence underwent revision, whereas the two without a response to biologics did not.Conclusions: Biologic therapy improves the overall longevity of some patients with lung and renal metastases to the femur in whom a visceral disease response occurred. In our limited cohort, we could not demonstrate an implant survival difference between such patients and those with shorter survival who may have had more aggressive disease. However, an increased life expectancy beyond 1 year among patients responsive to biologics may increase risk of mechanical failure of fixation constructs.Level Of Evidence: Level III, therapeutic study. [ABSTRACT FROM AUTHOR]