Pragmatic, Prospective Comparative Effectiveness Trial of Carbon Ion Therapy, Surgery, and Proton Therapy for the Management of Pelvic Sarcomas (Soft Tissue/Bone) Involving the Bone: The PROSPER Study Rationale and Design

Surgical treatment of pelvic sarcoma involving the bone is the standard of care but is associated with several sequelae and reduced functional quality of life (QOL). Treatment with photon and proton radiotherapy is associated with relapse. Carbon ion radiotherapy (CIRT) may reduce both relapse rates and treatment sequelae. The PROSPER study is a tricontinental, nonrandomized, prospective, three-arm, pragmatic trial evaluating treatments of pelvic sarcoma involving the bone. Patients aged at least 15 years are eligible for inclusion. Participants must have an Eastern Cooperative Oncology Group Performance Status score of two or less, newly diagnosed disease, and histopathologic confirmation of pelvic chordoma, chondrosarcoma, osteosarcoma, Ewing sarcoma with bone involvement, rhabdomyosarcoma (RMS) with bone involvement, or non-RMS soft tissue sarcoma with bone involvement. Treatment arms include (1) CIRT (n = 30) delivered in Europe and Asia, (2) surgical treatment with or without adjuvant radiotherapy (n = 30), and (3) proton therapy (n = 30). Arms two and three will be conducted at Mayo Clinic campuses in Arizona, Florida, and Minnesota. The primary end point is to compare the 1-year change in functional QOL between CIRT and surgical treatment. Additional comparisons among the three arms will be made between treatment sequelae, local control, and other QOL measures.

Prophylactic lymphaticovenous anastomosis (LVA) for preventing lymphedema after sarcoma resection in the lower limb: A report of three cases and literature review

Patients with soft tissue tumors of the lower extremities are at greater risk to develop postoperative disruption of lymphatic vessels. Currently, there is no widely effective cure for lymphatic dysfunction. Therefore, the best strategy is to prevent it and reconstruct efficient drainage as soon as the original pathway is damaged. We present a report of three prophylactic LVA cases after sarcoma resection in the lower limb, and a literature review to show the feasibility of prophylactic LVAs. The patients were 35, 73, and 77 years old, respectively, at the time of the procedure. All three patients had sarcoma in the medial thigh and underwent radiation therapy before the surgery. The locations of the LVAs include the medial thigh and medial and lateral calf. During the surgery, methylene blue and/or indocyanine green were injected to identify lymphatic vessels. Postoperative recovery was uneventful immediately after the surgery. At follow-up visits, all three patients reported improved functions with no significant swelling in the lower limb. One patient experienced a surgical wound infection that resolved after antibiotic admission. Two patients had a history of cardiac diseases, a major risk factor for developing postoperative lymphedema, but these two patients did not develop lymphedema with the treatment of prophylactic LVAs. These results suggest that prophylactic LVA may be an effective strategy to prevent secondary lymphedema after sarcoma resection. Further investigation is warranted.

One-Stage Synovectomies Result in Improved Short-Term Outcomes Compared to Two-Stage Synovectomies of Diffuse-Type Tenosynovial Giant Cell Tumor (D-TGCT) of the Knee: A Multicenter, Retrospective, Cohort Study

Diffuse-type tenosynovial giant cell tumors' (D-TGCTs) intra- and extra-articular expansion about the knee often necessitates an anterior and posterior surgical approach to facilitate an extensive synovectomy. There is no consensus on whether two-sided synovectomies should be performed in one or two stages. This retrospective study included 191 D-TGCT patients from nine sarcoma centers worldwide to compare the postoperative short-term outcomes between both treatments. Secondary outcomes were rates of radiological progression and subsequent treatments. Between 2000 and 2020, 117 patients underwent one-stage and 74 patients underwent two-stage synovectomies. The maximum range of motion achieved within one year postoperatively was similar (flexion 123-120°, p = 0.109; extension 0°, p = 0.093). Patients undergoing two-stage synovectomies stayed longer in the hospital (6 vs. 4 days, p < 0.0001). Complications occurred more often after two-stage synovectomies, although this was not statistically different (36% vs. 24%, p = 0.095). Patients treated with two-stage synovectomies exhibited more radiological progression and required subsequent treatments more often than patients treated with one-stage synovectomies (52% vs. 37%, p = 0.036) (54% vs. 34%, p = 0.007). In conclusion, D-TGCT of the knee requiring two-side synovectomies should be treated by one-stage synovectomies if feasible, since patients achieve a similar range of motion, do not have more complications, but stay for a shorter time in the hospital.

Sentinel Lymph Node Biopsy for Extremity and Truncal Soft Tissue Sarcomas: A Systematic Review of the Literature

BACKGROUND

Regional lymph node metastasis (RLNM) occurs infrequently in patients with soft tissue sarcoma (STS), although certain STS subtypes have a higher propensity for RLNM. The identification of RLNM has significant implications for staging and prognosis; however, the precise impact of node-positive disease on patient survival remains a topic of controversy. Although the benefits of sentinel lymph node biopsy (SLNB) are well documented in patients with melanoma and breast cancer, whether this procedure offers a benefit in STS is controversial.

METHODS

A systematic literature search was performed and articles reviewed to determine if SLNB in patients with extremity/truncal STS impacts disease-free or overall survival.

RESULTS

Six studies were included. Rates of sentinel lymph node positivity were heterogeneous (range 4.3-50%). The impact of SLNB on patient outcomes remains unclear. The overall quality of available evidence was low, as assessed by the Grading of Recommendations, Assessment, Development, and Evaluation system.

CONCLUSIONS

The literature addressing the impact of nodal basin evaluation on the staging and management of patients with extremity/truncal STS is confounded by heterogeneous patient cohorts and clinical practices. Multicenter prospective studies are warranted to determine the true incidence of RLNM and whether SLNB could benefit patients with clinically occult RLNM at diagnosis.

Twenty-Year Experience With Primary Distal Radioulnar Joint Arthroplasty From a Single Institution

PURPOSE

The use of implant arthroplasty in the distal radioulnar joint is increasing. Two main types of implants are commonly used, ulnar head prosthesis (UHP) and hemi or semi-constrained total distal radioulnar joint arthroplasty. The literature consists mainly of small patient series. The purpose of this study was to examine our long-term outcomes of distal radioulnar joint arthroplasty.

METHODS

Patient data were collected in a patient registry from 2000 to 2019. The follow-up included radiographic examination, physical examination, Mayo Wrist Scores, pain level, range of motion, and grip strength. Reoperations were recorded. The implants were a semi-constrained prosthesis and a metallic UHP. The mean age at surgery was 50 years. Patient demographics were similar, but the semi-constrained group had a higher preoperative percentage of instability (85 vs 52 percent). The median follow-up time was 30 months for the semi-constrained implants group and 102 months for the UHP group.

RESULTS

A total of 53 primary semi-constrained total joint arthroplasties and 102 UHPs were included. The grip strength and Mayo Wrist Score improved for both the implant groups. Pain reduced in 76% of the patients. Supination improved for the semi-constrained total joint arthroplasty group. Lifting capacity was better in the semi-constrained total joint arthroplasty patients. The unadjusted reoperation rate was 23% for the semi-constrained implants group and 34% for the UHP group. Twenty-two implants were bilateral; these had comparable results to unilateral implants. Kaplan-Meier survival curves demonstrated 94% survival rate for the semi-constrained implants group and 87% survival for the UHP group after 5 years. The risk factors associated with reoperation for the combined implant group included younger age at surgery, previous wrist surgery, ulnar shortening, and wrist fusion.

CONCLUSIONS

Distal radioulnar joint arthroplasty improved functional outcomes in both the implant groups, but reoperations were frequent. The semi-constrained implants group had better lifting capacity. The bilateral implants had comparable outcomes to the unilateral implants.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Management of Proximal Humeral Oncologic Lesions

The proximal humerus is a common location for primary tumors, benign lesions, and metastatic disease. Advances in neoadjuvant and adjuvant therapy have allowed for limb-salvage surgery in most of the cases. There are numerous of options for surgical management of proximal humerus lesions and the decision to pursue one over another depends on factors such as age, comorbidities, pathology, location within the proximal humerus, planned resection margins/size of defect, and bone quality. Long-term outcomes for these techniques tend to be retrospective comparative studies, with recent studies highlighting the improved outcomes of reverse total shoulders.

Management of Scapular Tumors

Scapular resections are large oncologic undertakings. Due to the soft tissue coverage of the scapula, tumors are often able to be resected with a negative margin. Involvement of the brachial plexus and axillary vessels is rare, allowing for a limb-salvage surgery in most cases. Functional outcomes are based on the magnitude of resection; patients undergoing a partial scapulectomy and those with glenoid preservation demonstrate improved outcomes compared to patients undergoing a total scapulectomy or glenoid resection. Although scapular endoprosthetics are available, there is limited data to support their routine use.

Restoration of hamstring function following sciatic nerve resection at the greater sciatic foramen with reconstruction involving acellular nerve allograft and vascularized sural nerve autograft: A case report

Segmental loss of the sciatic nerve secondary to oncologic resection or trauma is detrimental to hamstring and leg function. The diameter of this nerve and the length of its axons spanning the lower extremity create significant challenges in reconstruction and optimizing return of sensory or motor function. The purpose of this report is to describe outcomes of a free vascularized sural nerve graft to preserve hamstring function in a large proximal sciatic nerve defect beginning at the greater sciatic foramen. A 44-year-old female underwent neoadjuvant chemotherapy and radiation for treatment of a left sciatic nerve synovial cell sarcoma. The patient underwent R0 resection of the proximal left sciatic nerve resulting in a 15 cm defect. An ipsilateral vascularized sural nerve graft was used to reconstruct the medial aspect of the sciatic nerve, prioritizing the tibial division, in an effort to restore hamstring function and plantar sensation. A 5 cm allograft nerve was added to the cutaneous branches of the sural nerve graft to better span the large defect and reconstruct the lateral aspect of the nerve. The patient's postoperative course was uneventful. At 1-year follow-up, the patient showed MRC grade 4/5 strength with knee flexion and steady gait pattern with a left ankle-foot orthosis. Outcomes support the use of a single vascularized nerve graft alongside acellular nerve allograft to restore motor function in large diameter and large defect mixed nerve injuries.

Surgical Outcomes of Primary Dermatofibrosarcoma Protuberans: A Retrospective, Multicenter Study

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is a locally aggressive tumor with a low rate of metastatic disease. Previous series have shown a superiority of Mohs micrographic surgery (MMS) compared with wide local excision (WLE). Likewise, there is paucity of data examining the long-term follow-up of patients.

OBJECTIVE

The purpose of the current study was to examine the outcome of surgical treatment of primary DFSP of the trunk and extremities.

METHODS

We reviewed 236 patients (115 females, 121 males, mean age 41 ± 15 years) undergoing MMS (n = 81, 34%) or WLE (n = 155, 66%) to treat a primary DFSP. Mean tumor size and follow-up was 4 ± 2 cm and 7 years, respectively. Final margins were negative in 230 (97%) patients.

RESULTS

There was no difference (p > 0.05) in patient age, sex, tumor size, negative margin excision, or history of a previous inadvertent excision between patients who underwent WLE and those undergoing MMS. There were two cases of local recurrence and two cases of metastasis, with no difference in the 5-year local recurrence-free survival (98% vs. 99%, p = 0.69) or metastatic-free survival (98% vs. 100%, p= 0.27) between WLE and MMS.

CONCLUSION

There was no difference in oncologic outcome comparing MMS with WLE for DFSP outside the head and neck. The goal of treatment for DFSP is to achieve a negative margin, regardless of surgical treatment modalities. A 'less is more' approach to follow-up can likely be taken for patients with completely resected DFSP in easy-to-examine anatomical areas. In these patients, no formal follow-up should be required.

Outcome of Scapular Ewing Sarcoma

BACKGROUND/AIM

Ewing sarcoma is a common primary bone tumor, often located in the distal femur or pelvis. Although the scapula is a flat bone similar to the pelvis, scapular Ewing sarcoma is rare. The aim of this study was to review our institution's experience with the management of scapular Ewing sarcomas.

PATIENTS AND METHODS

We reviewed 9 patients with an Ewing sarcoma of the scapula, which included 5 males and 4 females with a mean age of 19±6 years. All patients were treated with chemotherapy and local control. Local control included surgical resection (n=7) and definitive radiotherapy (n=2). Mean follow-up was 6 years.

RESULTS

Prior to induction chemotherapy, the mean tumor size and volume were 10±2 cm and 181±112 cm3, respectively. Following induction chemotherapy, there was a reduction in the mean tumor size (6±3, p=0.02) and volume (20±12 cm3, p<0.01). The mean tumor necrosis in patients undergoing resection was 72±23%. The median survival was 30-months, and the 5-year disease specific survival was 38%. At most recent follow-up, the mean Musculoskeletal Tumor Society Score was 79±14%.

CONCLUSION

Scapular Ewing sarcoma is a rare, aggressive tumor. Even with chemotherapy and local control with surgery or definitive radiotherapy, patient survival is poor.

Merkel cell carcinoma of unknown primary: Clinical presentation and outcomes

BACKGROUND

Merkel cell carcinoma (MCC) is a rare, aggressive cutaneous malignancy that usually occurs in the head/neck or extremities. However, there are reports of MCC developing in the lymph nodes or parotid gland without evidence of a primary cutaneous lesion.

METHODS

We reviewed 415 patients with biopsy-proven MCC. Patients with MCC of unknown primary (n = 37, 9%, MCCUP) made up the study cohort. The primary endpoints of the study were rate of recurrence, disease-free survival, and overall survival.

RESULTS

Patients with MCCUP presented with tumors in lymph nodes (n = 34) or parotid gland (n = 3). Nodal disease was most commonly detected in the inguinal/external iliac (n = 15) or axillary (n = 14) regions. The mean age at diagnosis was 70 years and 24% were female. Patients presented with distant metastases in 24.3% of cases. Patients with stage IIIA disease treated with regional lymph node dissection (RLND) had a lower risk of disease recurrence (hazard ratio 0.26, p = 0.046). Recurrence-free survival was 59.3% at 5 years. Disease-specific survival was 63.3% at 5 years.

CONCLUSION

Patients with MCCUP have a high risk of recurrence and mortality. The optimal treatment for MCCUP has yet to be elucidated, although therapeutic RLND appears beneficial for these patients.

New school technology meets old school technique: Intensity modulated proton therapy and laparoscopic pelvic sling facilitate safe and efficacious treatment of pelvic sarcoma

Purpose

Small bowel tolerance may be dose-limiting in the management of some pelvic and abdominal malignancies with curative-intent radiation therapy. Multiple techniques previously have been attempted to exclude the small bowel from the radiation field, including the surgical insertion of an absorbable mesh to serve as a temporary pelvic sling. This case highlights a clinically meaningful application of this technique with modern radiation therapy.

Methods and Materials

A patient with locally invasive, unresectable high-grade sarcoma of the right pelvic vasculature was evaluated for definitive radiation therapy. The tumor immediately abutted the small bowel. The patient underwent laparoscopic placement of a mesh sling to retract the abutting small bowel and subsequently completed intensity modulated proton therapy.

Results

The patient tolerated the mesh insertion procedure and radiation therapy well with no significant toxic effects. The combination approach achieved excellent dose metrics, and the patient has no evidence of progression 14 months out from treatment.

Conclusions

The combination of mesh as a pelvic sling and proton radiation therapy enabled the application of a curative dose of radiation therapy and should be considered for patients in need of curative-intent radiation when the bowel is in close proximity to the target.

Treatment of giant cell tumors of the distal radius: A long-term patient-reported outcomes study

INTRODUCTION

The distal radius is a common location for giant cell tumors (GCTs) of bone. Management includes intralesional curettage or wide excision, however, long-term comparisons of treatment options are limited. The purpose of the current study was to evaluate our institutions' outcomes of treatment of these tumors.

METHODS

We reviewed 24 GCT of the distal radius in 23 patients (12 males: 11 females) with a mean age of 42 years at the time of surgery. Functional outcomes were collected including the Musculoskeletal Tumor Society Score (MSTS), QuickDash, the Visual Analog Scale (VAS), and the Patient Rated Wrist Evaluation (PRWE). The mean follow-up was 13 years.

RESULTS

Tumor grade included Campanacci Grade II (n = 14) and Grade III (n = 10). Treatment included extended intralesional curettage (n = 16) and wide excision (n = 8). Reconstruction mainly included bone grafting/cement (n = 16) or free vascularized fibula radiocarpal arthrodesis (n = 5). At most recent follow-up, there was no difference in MSTS, VAS, and PRWE (p > 0.05) between patients undergoing a joint sparing or arthrodesis. Patients undergoing arthrodesis had a lower QuickDASH score (13.7 vs. 20.8, p = 0.04) CONCLUSIONS: Treatment for GCT of the distal radius is individualized however in the setting of articular surface involvement, arthrodesis can lead to superior functional results at long-term follow-up.

Impact of racial disparities and insurance status in patients with bone sarcomas in the USA : a population-based cohort study

Aims

Socioeconomic and racial disparities have been recognized as impacting the care of patients with cancer, however there are a lack of data examining the impact of these disparities on patients with bone sarcoma. The purpose of this study was to examine socioeconomic and racial disparities that impact the oncological outcomes of patients with bone sarcoma.

Methods

We reviewed 4,739 patients diagnosed with primary bone sarcomas from the Surveillance, Epidemiology and End Results (SEER) registry between 2007 and 2015. We examined the impact of race and insurance status associated with the presence of metastatic disease at diagnosis, treatment outcome, and overall survival (OS).

Results

Patients with Medicaid (odds ratio (OR) 1.41; 95% confidence interval (CI) 1.15 to 1.72) and uninsured patients (OR 1.90; 95% CI 1.26 to 2.86) had higher risks of metastatic disease at diagnosis compared to patients with health insurance. Compared to White patients, Black (OR 0.63, 95% CI 0.47 to 0.85) and Asian/Pacific Islander (OR 0.65, 95% CI 0.46 to 0.91) were less likely to undergo surgery. In addition, Black patients were less likely to receive chemotherapy (OR 0.67, 95% CI 0.49 to 0.91) compared to White patients. In patients with chondrosarcoma, those with Medicaid had worse OS compared to patients with insurance (hazard ratio (HR) 1.65, 95% CI 1.06 to 2.56).

Conclusion

In patients with a bone sarcoma, the cancer stage at diagnosis varied based on insurance status, and racial disparities were identified in treatment. Further studies are needed to identify modifiable factors which can mitigate socioeconomic and racial disparities found in patients with bone sarcomas.

Cite this article: Bone Joint Res 2022;11(5):278–291.

How Do the Outcomes of Radiation-Associated Pelvic and Sacral Bone Sarcomas Compare to Primary Osteosarcomas following Surgical Resection?

Radiation-associated sarcoma of the pelvis and/or sacrum (RASB) is a rare but challenging disease process associated with a poor prognosis. We hypothesized that patients with RASB would have worse surgical and oncologic outcomes than patients diagnosed with primary pelvic or sacral bone sarcomas. This was a retrospective, multi-institution, comparative analysis. We reviewed surgically treated patients from multiple tertiary care centers who were diagnosed with a localized RASB. We also identified a comparison group including all patients diagnosed with a primary localized pelvic or sacral osteosarcoma/spindle cell sarcoma of bone (POPS). There were 35 patients with localized RASB and 73 patients with POPS treated with surgical resection. Patients with RASB were older than those with POPS (57 years vs. 38 years, p < 0.001). Patients with RASB were less likely to receive chemotherapy (71% for RASB vs. 90% for POPS, p = 0.01). Seventeen percent of patients with RASB died in the perioperative period (within 90 days of surgery) as compared to 4% with POPS (p = 0.03). Five-year disease-specific survival (DSS) (31% vs. 54% p = 0.02) was worse for patients with RASB vs. POPS. There was no difference in 5-year local recurrence free survival (LRFS) or metastasis free survival (MFS). RASB and POPS present challenging disease processes with poor oncologic outcomes. Rates of perioperative mortality and 5-year DSS are worse for RASB when compared to POPS.

Outcomes of Intramedullary Nail Fixation for Metastatic Disease: Impending and Pathologic Fractures

BACKGROUND/AIM

Intramedullary nail (IMN) fixation has become a treatment mean for impending and pathologic femur fractures. Currently there continues to be a lack of data examining functional outcomes, complications, and survivorship of patients treated with IMNs for metastatic disease of the femur.

PATIENTS AND METHODS

We retrospectively identified 183 IMNs placed for impending (n=145) or pathologic (n=38) metastatic fractures from 2010 to 2018. Functional outcomes and complications including blood transfusions, venous thromboembolisms (VTEs) and reoperations were studied.

RESULTS

Patients with impending lesions were more likely to be ambulatory at final follow-up (pathologic: 82%, impending: 99%, p<0.0001) and reported greater musculoskeletal tumor society scores (p<0.0001). Likewise, pathologic fractures were associated with greater discharge to non-home locations (p<0.0001) and were more likely to require a postoperative transfusion (pathologic: 66%, impending: 22%, p=0.0001). However, there was no difference in the incidence of VTEs (p=1.00) or reoperations (p=0.69) between cohorts. Patients treated for impending fractures had improved overall survival at 1 year (54% vs. 26%, p<0.0001).

CONCLUSION

IMN fixation was durable in impending and pathologic femoral fractures. Early identification of metastases remains critical as patients treated for impending lesions had greater functional outcomes, fewer complications and improved survivorship compared to patients treated for pathologic fractures.

Intrinsic Tendon Regeneration After Application of Purified Exosome Product: An In Vivo Study

Background:

Tendons are primarily acellular, limiting their intrinsic regenerative capabilities. This limited regenerative potential contributes to delayed healing, rupture, and adhesion formation after tendon injury.

Purpose:

To determine if a tendon’s intrinsic regenerative potential could be improved after the application of a purified exosome product (PEP) when loaded onto a collagen scaffold.

Study Design:

Controlled laboratory study.

Methods:

An in vivo rabbit Achilles tendon model was used and consisted of 3 groups: (1) Achilles tenotomy with suture repair, (2) Achilles tenotomy with suture repair and collagen scaffold, and (3) Achilles tenotomy with suture repair and collagen scaffold loaded with PEP at 1 × 10¹² exosomes/mL. Each group consisted of 15 rabbits for a total of 45 specimens. Mechanical and histologic analyses were performed at both 3 and 6 weeks.

Results:

The load to failure and ultimate tensile stress were found to be similar across all groups (P ≥ .15). The tendon cross-sectional area was significantly smaller for tendons treated with PEP compared with the control groups at 6 weeks, which was primarily related to an absence of external adhesions (P = .04). Histologic analysis confirmed these findings, demonstrating significantly lower adhesion grade both macroscopically (P = .0006) and microscopically (P = .0062) when tendons were treated with PEP. Immunohistochemical staining showed a greater intensity for type 1 collagen for PEP-treated tendons compared with collagen-only or control tendons.

Conclusion:

Mechanical and histologic results suggested that healing in the PEP-treated group favored intrinsic healing (absence of adhesions) while control animals and animals treated with collagen only healed primarily via extrinsic scar formation. Despite a smaller cross-sectional area, treated tendons had the same ultimate tensile stress. This pilot investigation shows promise for PEP as a means of effectively treating tendon injuries and enhancing intrinsic healing.

Clinical Relevance:

The production of a cell-free, off-the-shelf product that can promote tendon regeneration would provide a viable solution for physicians and patients to enhance tendon healing and decrease adhesions as well as shorten the time required to return to work or sports.

Lymphedema Is a Significant Risk Factor for Failure After Primary Total Hip Arthroplasty

BACKGROUND

Lymphedema is a chronic disease characterized by fluid buildup and swelling that can lead to skin and soft-tissue fibrosis and recurring soft-tissue infections. Literature with regard to the increased risk of complications following a surgical procedure in patients with lymphedema is emerging, but the impact of lymphedema in the setting of primary total hip arthroplasty (THA) remains unknown. The purpose of this study was to review outcomes following primary THA performed in patients with lymphedema compared with a matched cohort without lymphedema.

METHODS

Using our institutional total joint registry and medical records, we identified 83 patients (57 were female and 26 were male) who underwent THA with ipsilateral lymphedema. For comparison, these patients were matched 1:6 (based on sex, age, date of the surgical procedure, and body mass index [BMI]) to a group of 498 patients without lymphedema who underwent primary THA for osteoarthritis. Subsequently, postoperative complications and implant survivorship were evaluated for each group. The mean follow-up for each group was 6 years. Survivorship was compared between cohorts using Kaplan-Meier methodology and included both survivorship free of infection and survivorship free of reoperation or revision. Univariate Cox regression analysis was utilized to assess the association between patient factors for the time to event outcomes noted above.

RESULTS

In patients with a history of lymphedema, there was an increased risk of complications (hazard ratio [HR], 1.97; p < 0.01), including reoperation for any cause (HR, 3.16; p < 0.01) and postoperative infection (HR, 4.48; p < 0.01). The 5-year infection-free survival rate was 90.3% for patients with lymphedema compared with 97.7% for patients without lymphedema (p < 0.01).

CONCLUSIONS

Patients with lymphedema are at increased risk for complications, including reoperation and infection, following primary THA. These data emphasize the importance of appropriate preoperative counseling in this population and should encourage efforts to identify methods to improve outcomes, including further investigation of the effects of preoperative optimization of lymphedema prior to THA and methods for improved perioperative management.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Comparison of Oncologic Outcomes and Treatment-Related Toxicity of Carbon Ion Radiotherapy and En Bloc Resection for Sacral Chordoma

IMPORTANCE

Maximal resection is the preferred management for sacral chordomas but can be associated with unacceptable morbidity. Outcomes with radiotherapy are poor. Carbon ion radiotherapy (CIRT) is being explored as an alternative when surgery is not preferred.

OBJECTIVE

To compare oncologic outcomes and treatment-related toxicity of CIRT and en bloc resection for sacral chordoma.

DESIGN, SETTING, AND PARTICIPANTS

Univariable logistic regression was performed to evaluate the association between treatment type and oncologic and toxicity outcomes in this retrospective cohort study. Nearest-neighbor propensity score matching was used to match the CIRT cohort with the en bloc resection cohort and 10 National Cancer Database (NCDB) cohorts separately, with the objective of obtaining more homogeneous cohorts when comparing treatments. Patient- and tumor-related characteristics from 2 institutional cohorts were collected for patients diagnosed with sacral chordomas between April 1, 1994, and July 31, 2017. The NCDB was queried for data on patients with sacral chordoma from January 1, 2004, to December 31, 2016, as a comparator in overall survival (OS) analyses. Data analysis was conducted from February 24, 2020, to January 16, 2021.

EXPOSURES

En bloc resection, incomplete resection, photon radiotherapy, proton radiotherapy, and CIRT.

MAIN OUTCOMES AND MEASURES

Overall survival was estimated using the Kaplan-Meier method and compared using the Cox proportional hazards model. Peripheral motor nerve toxic effects were scored using Common Terminology Criteria for Adverse Events, version 4.03.

RESULTS

A total of 911 patients were included in the study (NCDB: n = 669; median age, 64 [IQR, 52-74] years; 410 [61.3%] men; CIRT: n = 188; median age, 66 [IQR, 58-71] years; 128 [68.1%] men; en bloc surgical resection: n = 54; median age, 53.5 [IQR 49-64] years, 36 [66.7%] men). Comparison of the propensity score-matched institutional en bloc resection and CIRT cohorts revealed no statistically significant difference in OS (CIRT: median OS, 68.1 [95% CI, 44.0-102.6] months; en bloc resection: median OS, 58.6 [95% CI, 25.6-123.5] months; P = .57; hazard ratio, 0.71 [95% CI, 0.25-2.06]; P = .53). The CIRT cohort experienced lower rates of peripheral motor neuropathy (odds ratio, 0.13 [95% CI, 0.04-0.40]; P < .001). On comparison of the propensity score-matched NCDB cohorts with the CIRT cohort, significantly higher OS was found for CIRT compared with margin-positive surgery without adjuvant radiotherapy (CIRT: median OS, 64.7 [95% CI, 57.8-69.7] months; margin-positive surgery without adjuvant radiotherapy: median OS, 60.6 [95% CI, 44.2-69.7] months, P = .03) and primary radiotherapy alone (CIRT: median OS, 64.9 [95% CI 57.0-70.5] months; primary radiotherapy alone: 31.8 [95% CI, 27.9-40.6] months; P < .001).

CONCLUSIONS AND RELEVANCE

These findings suggest that CIRT can be used as treatment for older patients with high performance status and sacral chordoma in whom surgery is not preferred. CIRT might provide additional benefit for patients who undergo margin-positive resection or who are candidates for primary photon radiotherapy.

Preoperative Risk Factors for Fibrosarcomatous Transformation in Dermatofibrosarcoma Protuberans

BACKGROUND/AIM

Dermat of ibrosarcoma protuberans (DFSP) is a soft-tissue sarcoma with a high risk of local recurrence, though typically never metastasizes. DFSP can transform into high-grade fibrosarcoma (DFSP-FS), which has a risk of metastasis. Currently, treatment for DFSP includes Moh's micrographic surgery (MMS); however, this is not recommended for DFSP-FS. Often, the transformation to DFSP-FS is not recognized until the final histological diagnosis. At that point, wide local excision (WLE) of a previous MMS site can be morbid. As such, we analyzed patient risk factors to allow identification of DFSP-FS transformation at presentation.

PATIENTS AND METHODS

We reviewed 368 (174 female, 194 male) patients with a mean age of 42 years from two sarcoma centers. A total of 319 (87%) patients had a history of DFSP and 49 (13%) had DFSP-FS.

RESULTS

When comparing patients with a DFSP to those with a DFSP-FS, patients with a DFSP-FS were more likely (p<0.05) to be older, female and with larger tumors. A painful mass and rapidly enlarging mass were associated with DFSP-FS.

CONCLUSION

Patients who presented with DFSP-FS were found to typically have a larger, painful, and growing mass. Patients with these features should be referred for WLE over MMS at presentation.