A Phase 4 interventional study of Aspirin 325mg and Enoxaparin 40Mg/0.4mL Prefilled Syringe in Sarcoma, Soft Tissue Sarcoma and Bone Sarcoma, sponsored by Massachusetts General Hospital. Enrolling by invitation at 10 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-09.
Sponsored by Massachusetts General Hospital · Phase 4, Interventional, and Prevention
Aspirin and low molecular weight heparin (LMWH) are both commonly employed pharmacologic methods of venous thromboembolism (VTE) prophylaxis after orthopaedic surgery. Data comparing these two methods of VTE prophylaxis in patients undergoing pelvic/lower extremity orthopaedic surgery for malignancy are lacking, however, as compared to the data and guidelines present for VTE chemoprophylaxis after joint arthroplasty and hip fracture surgery. In this clinical trial, our specific aim is to compare the post operative incidence of VTE between patients receiving aspirin and LMWH after pelvic/lower extremity orthopaedic oncology procedures.
Lower extremity orthopaedic surgery and malignancy are both known major risk factors for venous thromboembolism (VTE). Guidelines from high quality data exist with regards to VTE prophylaxis in patients undergoing orthopaedic surgery, particularly joint arthroplasty. Far fewer data are available regarding the efficacy of various methods of pharmacologic VTE prophylaxis in patients undergoing surgery for primary or metastatic musculoskeletal malignancies as malignancy itself is known to confer a hypercoagulable state. The existing data, including published data from our institution, are almost exclusively from retrospective studies. Given the limited external validity of existing guidelines and limitations inherent in applying data from retrospective studies, a randomized, prospective study comparing two of the most common methods of pharmacologic VTE prophylaxis would help to guide clinical care of this patient population. In addition, large dead spaces susceptible to hematoma formation are often created from tumor resections in orthopaedic oncology. Our retrospective data suggest that hematoma formation may be an independent predictor of infection. An important risk of chemical VTE prophylaxis is an increased incidence of bleeding into these dead spaces, leading to hematomas. This illustrates the complexity of selecting a method of VTE prophylaxis in patients at both high risk of VTE and hematoma formation and the need for high quality data to guide clinical decision-making in this patient population.
The specific aim of this study is to compare the post operative incidence of symptomatic deep vein thrombosis (DVT) and pulmonary embolus (PE) between patients who receive low molecular weight heparin (LMWH) versus aspirin for prophylaxis after having undergone pelvic or lower extremity orthopaedic oncology surgery (primary bone sarcomas, soft tissue sarcomas, and metastatic osseous disease).
Our secondary aim is to compare the incidence of hematoma formation and wound complications between these methods of pharmacologic prophylaxis in the aforementioned patient population.
Our hypothesis is that there is no significant difference in the incidence rate of symptomatic DVT/PE in patients administered LMWH versus aspirin for prophylaxis; however there may exist a difference in the rate of wound complications between these prophylaxis methods.
1,607 studies on the registry are indexed under Sarcoma; 366 are open to participants now.
This study's planned enrollment of 2,868 is above the median of 40 across 1,255 interventional studies indexed under Sarcoma.
Browse Sarcoma studies →Massachusetts General Hospital is the lead sponsor of 2,586 studies on the registry; 447 are open to participants now.
Of its 222 completed or terminated interventional studies of FDA-regulated products, 168 (76%) have results posted.
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Patients will first be evaluated for inclusion in a master observational study with the following inclusion criteria:
Fulfills one of the following:
a. Cohort A: osseous disease, undergoing: i. Endoprosthetic reconstruction ii. Curettage, cement packing, and fixation with nails, plates, and/or screws iii. Intramedullary nail fixation only b. Cohort B: Primary bone sarcoma, undergoing wide resection, amputation, or reconstruction with endoprosthesis, allograft, or allograft-prosthesis composite (APC).
c. Cohort C: Primary soft tissue sarcoma ≥5 cm in diameter, undergoing wide resection
In addition to fulfilling all the inclusion criteria in Part 1 of this study, participants must also not meet any of the below exclusion criteria in order to be eligible for randomization to either aspirin or LMWH.
Exclusion Criteria:
Pregnancy testing, via a urine or blood test, is a routine part of pre-operative laboratory testing in patients scheduled to undergo orthopaedic surgeries. Attending surgeons may also choose to exclude any patient from randomization at their discretion.
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Metastases
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients undergoing surgery for pelvic/lower extremity soft tissue sarcomas and are randomized to Enoxaparin 40Mg/0.4mL prefilled syringe subcutaneous injection daily for VTE prophylaxis
Drug: Enoxaparin 40Mg/0.4mL Prefilled Syringe
Patients undergoing surgery for pelvic/lower extremity soft tissue sarcomas and are randomized to aspirin 325 mg po daily for VTE prophylaxis
Drug: Aspirin 325mg
Patients undergoing surgery for pelvic/lower extremity primary bone tumor and are randomized to Enoxaparin 40Mg/0.4mL prefilled syringe subcutaneous injection daily for VTE prophylaxis
Drug: Enoxaparin 40Mg/0.4mL Prefilled Syringe
Patients undergoing surgery for pelvic/lower extremity primary bone tumor and are randomized to aspirin 325 mg po daily for VTE prophylaxis
Drug: Aspirin 325mg
Patients undergoing surgery for pelvic/lower extremity metastatic bone disease and are randomized to Enoxaparin 40Mg/0.4mL prefilled syringe subcutaneous injection daily for VTE prophylaxis
Drug: Enoxaparin 40Mg/0.4mL Prefilled Syringe
Patients undergoing surgery for pelvic/lower extremity metastatic bone disease and are randomized to aspirin 325 mg po daily for VTE prophylaxis
Drug: Aspirin 325mg
Aspirin 325 mg by mouth once daily
Also known as: ASA
Drug page: Enoxaparin
Enoxaparin 40 mg subcutaneous injection once daily
Also known as: Lovenox
Venous thromboembolism
Deep venous thrombosis; pulmonary embolus
Time frame: Up to 3 or 6 months post operatively for bone/soft tissue sarcomas and metastatic osseous disease, respectively
Hematoma formation
Time frame: Up to 3 or 6 months post operatively for bone/soft tissue sarcomas and metastatic osseous disease, respectively
Complication requiring return to operating room
Return to operating room for any reason related to the original surgery
Time frame: Up to 3 or 6 months post operatively for bone/soft tissue sarcomas and metastatic osseous disease, respectively
Early chemoprophylaxis stop
ASA or LMWH stopped prior to 4 weeks post operatively by surgeon for any reason
Time frame: Up to 4 weeks post operatively
Infection
Infection requiring any sort of treatment (antibiotics alone, return to operating room)
Time frame: Up to 3 or 6 months post operatively for bone/soft tissue sarcomas and metastatic osseous disease, respectively
Plan to share: No
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Studies of the drugs tested here: Aspirin · Enoxaparin
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