ClinicalTrials.gg
RecruitingNCT04031677STRASS2Updated Oct 7, 2026

Surgery With or Without Neoadjuvant Chemotherapy in High Risk RetroPeritoneal Sarcoma

A Phase 3 interventional study of Surgery and Preoperative chemotherapy in Retroperitoneal Sarcoma, Liposarcoma and Leiomyosarcoma, sponsored by European Organisation for Research and Treatment of Cancer - EORTC. Recruiting at 176 sites in 15 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-07.

Sponsored by European Organisation for Research and Treatment of Cancer - EORTC · Phase 3, Interventional, and Treatment

From the registry’s dates

  • Started Jan 2021; still recruiting 5 years 9 months later.
Updated Oct 7, 20261 site addedGo to Updates ↓
Phase
Phase 3
Study type
Interventional
Enrollment
250
Allocation
Randomized
Ages
18 Years and older
Sex
All
01

Study summary

This is a multicenter, randomized, open label phase lll trial to assess whether preoperative chemotherapy, as an adjunct to curative-intent surgery, improves the prognosis of high risk DDLPS (dedifferentiated Liposarcoma) and LMS (Leiomyosarcoma) patients as measured by disease free survival.

After confirmation of eligibility criteria, patients will be randomized to either the standard arm or experimental arm.

Read the detailed description

Standard arm:

  • Large en-bloc curative-intent surgery within 4 weeks following randomization- Experimental arm

Experimental arm:

  • 3 cycles of neoadjuvant chemotherapy starting within 2 weeks following randomization:

    • High grade LPS: ADM (doxorubicin) 75 mg/m2 (or the equivalent EpiADM 120 mg/m2) + ifosfamide 9 g/m3 Q3 weeks.
    • LMS: ADM 75 mg/m2 + DTIC (dacarbazine) 1 g/m2 Q3 weeks
  • re-assessment of operability
  • curative-intent surgery within 3-6 weeks of last cycle of chemotherapy
02

Conditions studied

  • Retroperitoneal Sarcoma
  • Liposarcoma
  • Leiomyosarcoma
03

In context

Liposarcoma

160 studies on the registry are indexed under Liposarcoma; 36 are open to participants now.

This study's planned enrollment of 250 is above the median of 52 across 136 interventional studies indexed under Liposarcoma.

Browse Liposarcoma studies →

Lead sponsor

European Organisation for Research and Treatment of Cancer - EORTC is the lead sponsor of 352 studies on the registry; 23 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

  1. STRASS 2

Inclusion criteria

Inclusion Criteria:

  • proven primary high risk leiomyosarcoma (LMS) or Liposarcoma (LPS) of retroperitoneal space or infra-peritoneal spaces of pelvis.
  • LMS:

    • Any grade LMS can be included
    • Minimum size of LMS tumor should be 5 cm
  • LPS:

    • Diagnosis should be confirmed based on MDM2 (Mouse double minute 2 homolog) and CDK4 (Cyclin-dependent kinase 4) expression on IHC (immunohistochemistry), while proof of MDM2 amplification is highly recommended.
    • All grade 3 DDLPS can be included.
    • DDLPS with confirmed grade 2 on can be included when:

      • The grade 2 DDLPS has an FNCLCC score=5 (Fédération Nationale des Centres de Lutte Contre Le Cancer), and clear necrosis on imaging (whether or not present on the biopsy).
      • The tumors carry a high risk gene profile as determined by the Complexity INdex in SARComas (CINSARC-high)
    • Unifocal tumour
    • Resectable tumour: resectability is based on pre-operative imaging (CT-abdomen, potentially also with MRI) and has to be defined by the local treating sarcoma team. A patient is not considered resectable when the expectation is that only an R2 resection is feasible.
    • Criteria for non-resectability are:
    • Involvement of the superior mesenteric artery, aorta, coeliac trunk and/or portal vein
    • Involvement of bone
    • Growth into the spinal canal
    • Progression of retro-hepatic inferior vena cava leiomyosarcoma towards the right atrium
    • Infiltration of multiple major organs like liver, pancreas and or major vessels
    • Patient must have radiologically ( 1.1), as confirmed by imaging. CT thorax abdomen pelvis with IV contrast is the preferred imaging modality. In case of any (medical or regulatory), it is allowed to perform a non-contrast CT thorax + MRI abdomen \& pelvis
    • Collection of tumour tissue for central pathology review is mandatory.
    • For patients with LMS: if there is not enough tissue for assessing the grading, this is acceptable.
    • If tumour tissue is not available for the central pathology review, patient will not be eligible.
    • If the biopsy was not done or the FFPE of the biopsy not available but at least 10 unstained slides or one pathological block are available for the central review, that will be considered as acceptable.
    • For the biopsy if fine needle aspiration (FNA) is performed instead of core needle biopsy (CNB) recommended by the standard guidelines, please contact the EORTC medical monitors for further evaluation.
    • Collection of tumour tissue and blood samples for translational research is mandatory.
    • In case there is not enough tissue for TR, a new biopsy is not required and if the patient fulfils all other eligibility criteria, he/she will be eligible.
    • If the blood samples are not collected, patient will not be eligible.
    • If the patient refuses the collection of biomaterial for TR, patient will not be eligible even if he/she fulfils all other eligibility criteria
    • ≥ 18 years old (no upper age limit)
    • ≤ 2
    • Adequate haematological and organ function
    • American Society of Anaesthesiologist (ASA) score \< 3
    • Women of (WOCBP) must have a negative serum pregnancy test within 3 days prior to randomization.

Note: a woman is considered of childbearing potential, i.e., fertile, if she is following menarche. She remains of childbearing potential until she becomes or permanently sterile.Permanent sterilisation methods include hysterectomy, bilateral salpingectomy and bilateral oophorectomy.

A postmenopausal state is defined as no menses for 12 months without an alternative medical cause. A high follicle stimulating hormone (FSH) level in the postmenopausal range may be used to confirm a post-menopausal state in women not using hormonal or hormonal replacement therapy. However, in the absence of 12 consecutive months without menses, a single FSH measurement is insufficient.

  • WOCBP in both arms should use highly effective birth control measures, during the study treatment period and for at least 6 months after the last dose of chemotherapy or date of surgery (except for women receiving chemotherapy with ifosfamide who should continue contraception until 1 year after last day of treatment). A highly effective method of birth control is defined as a method which results in a low failure rate (i.e., less than 1% per year) when used consistently and correctly.
  • For men in the experimental arm: agreement to remain abstinent (refrain from heterosexual intercourse) or use contraceptive measures, and agreement to refrain from donating sperm.
  • Female subjects who are breast feeding should discontinue nursing prior to the first day of study treatment and until 6months after the last study treatment.
  • Before patient randomization, written must be given according to ICH/GCP, and national/local regulations.

Exclusion criteria

Exclusion criteria:

  • Sarcoma originating from bone structure, abdominal or gynecological viscera
  • Extension through the sciatic notch or across the diaphragm
  • disease
  • Any previous surgery (excluding diagnostic ), radiotherapy or systemic therapy for the present tumour
  • to doxorubicin, ifosfamide, dacarbazine or to any of their metabolites or to any of their
  • Congestive heart failure
  • Angina pectoris
  • Myocardial infarction within 1 year before randomization
  • Uncontrolled arterial hypertension defined as blood pressure ≥ 150/100 mm Hg despite optimal medical therapy.

Note: in case of high blood pressure: 1) initiation or adjustment of antihypertensive medication(s) is permitted prior to study entry; 2) blood pressure must be re-assessed on two occasions that are separated by a minimum of 1 hour. The mean SBP / DBP values from each blood pressure assessment must be ≤ 150/90mmHg in order for a patient to be eligible for the study.

  • Uncontrolled cardiac arrhythmia
  • Previous treatment with maximum cumulative doses (450mg/m² Doxorubicin or equivalent 900mg/m² Epirubicin) of doxorubicin, daunorubicin, epirubicin, idarubicin, and/or other anthracyclines and anthracenediones
  • Active and uncontrolled infections
  • Vaccination with within 30 days prior to study entry
  • Inflammation of the urinary bladder (interstitial cystitis) and/or obstructions of the urine flow.
  • Other invasive within 5 years, with the exception of adequately treated non-melanoma skin cancer, localized cervical cancer, localized and Gleason ≤ 6prostate cancer.
  • Uncontrolled severe illness, infection, medical condition (including uncontrolled diabetes), other than the primary LPS or LMS of the retroperitoneum.
  • Female patients who are pregnant or breastfeeding or female and male patients of who are not willing to employ effective method.
  • Any psychological, familial, sociological or geographical condition potentially hampering compliance with the study protocol and follow-up schedule; those conditions should be discussed with the patient before randomization in the trial
  • Known to imaging tracer and to MRI
  1. Selection criteria for STREXIT 2

    • Patients with proven primary resectable localized high-risk DDLPS or LMS of retroperitoneal space or infra-peritoneal spaces of pelvis (as described in the inclusion criteria of STRASS 2) and amenable to receive chemotherapy but for whom the list of eligibility criteria for the study is too restrictive (tumour grading not available, inadequate organ function, concomitant diseases)
    • Patients who meet all eligibility criteria of STRASS 2 but do not consent to randomization or are not enrolled for any other reason.
    • Patients enrolled in a Registry collecting data on primary RPS patients in the centres participating in STRASS 2 (e.g., RESAR) and who satisfy the above criteria.
  2. Selection criteria for preferences for chemotherapy in STRASS 2 substudy

All patients recruited to STRASS 2 in participating centres (Australia +/- international sites) that are able to read, comprehend and write in English at a sufficient level to complete study materials.

Terms in these criteria, in plain language(17)

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.

Histologically or cytologically confirmed

The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).

Your pathology report is the document that shows this.

Biopsy and archival tissue

A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.

Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.

Measurable disease

The amount of disease can be tracked with a defined measurement, so the study can see whether it shrinks or grows. It might be a tumour measured on a scan or, in some blood cancers such as myeloma, a marker measured in blood or urine.

The criteria or the study team say which measurement counts — having no tumour visible on a scan does not by itself rule you out.

RECIST

The standard rules for measuring tumours on CT or MRI scans, to tell whether a cancer is shrinking, stable or growing during treatment.

“Measurable disease per RECIST 1.1” usually means at least one tumour 10 mm or more at its longest on a CT scan, or a lymph node 15 mm or more across its short axis.

Contraindication

A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.

ECOG performance status

A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.

0
Fully active, no restrictions.
1
Limited in strenuous activity, but walking and able to do light work, such as housework or office work.
2
Walking and able to look after yourself, but unable to work; up and about more than half of waking hours.
3
Able to look after yourself only in part; in bed or a chair more than half of waking hours.
4
Unable to look after yourself at all; in bed or a chair all day.

Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.

Childbearing potential

Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).

Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.

Postmenopausal

Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

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.

Metastases

Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.

Hypersensitivity

An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.

Excipients

The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.

Live vaccines

Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.

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.

Reproductive potential

Able to have children. For women this usually means from the first period until menopause, unless permanently unable to through surgery; for men, unless permanently sterile. Read who the line is about — participants, women, men, or their partners.

Criteria about it usually ask for contraception during the study and for a time after it.

Adjuvant and neoadjuvant

Neoadjuvant treatment is given before the main treatment (usually surgery), often to shrink a tumour. Adjuvant treatment is given after it, to lower the chance of the cancer coming back.

05

Study design

Phase
Phase 3
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
250 participants (estimated)

Study arms

  • Other
    Standard arm

    Surgery alone

    Procedure: Surgery

  • Experimental
    Experimental arm

    Preoperative chemotherapy and surgery

    Drug: Preoperative chemotherapy

Interventions

  • ProcedureSurgery

    Large en-bloc curative-intent surgery

  • DrugPreoperative chemotherapy

    * High grade LPS: ADM 75 mg/m2 (or the equivalent EpiADM 120 mg/m2) + ifosfamide 9 g/m2 Q3 weeks * LMS: ADM 75 mg/m2 + DTIC 1g/m2 Q3 weeks Note: the recommended dose of Doxorubicin (or Epirubicin) can be modified according to national/institutional guidelines, given that the minimal threshold must be Doxorubicin 60 mg/m2 per cycle (or the equivalent Epirubicin 95 mg/m2 per cycle); the recommended dose of Ifosfamide can be modified according to national/institutional guidelines, given that the minimal threshold must be 7.5 g/m2 per cycle; the recommended dose of Dacarbazine can be modified according to national/institutional guidelines, given that the minimal threshold must be 900 mg/m2 per cycle. The schedule of administration of above chemotherapies can be modified according to national/institutional guidelines provided that the minimal threshold of doses, and the treatment periods with chemotherapies remain the same.

    Also known as: neoadjuvant chemotherapy

06

What researchers measure

Primary outcomes

  1. Disease free survival

    Disease free survival will be measured from the date of randomization (as reference) to the date of recurrence or death, whichever occurs first.

    Time frame: 7 years from first patient in

Secondary outcomes

  1. Overall survival (OS)

    OS will be measured from the date of randomization to the date of death, whatever the cause. Alive patients will be censored at the date of last follow-up.

    Time frame: 8 years from first patient in

  2. Recurrence free survival

    Recurrence free survival will be measured in patients who were successfully operated (R0/R1 resection) from the date of surgery (as reference) to the date of recurrence (local or distant) or death, whichever occurs first. Patients without one of these events will be censored at the date of last follow-up.

    Time frame: 8 years from first patient in

  3. Distant metastases free survival

    Distant metastases free survival will be from the date of randomization (as reference) to the date of distant metastases or death (whatever the cause), whichever occurs first. Patients without any of these events will be censored at the date of last follow-up.

    Time frame: 8 years from first patient in

  4. Cumulative incidence of local recurrences

    Cumulative incidence of local recurrences will be measured from the date of randomization (as reference) to the date of local recurrence.

    Time frame: 8 years from first patient in

  5. Cumulative incidence of distant metastases

    Cumulative incidence of distant metastases will be measured from the date of randomization to the date of occurrence of distant metastases.

    Time frame: 8 years from first patient in

  6. Radiological response to neoadjuvant chemotherapy according to RECIST

    For patients receiving neo-adjuvant chemotherapy, the radiological response will be assessed using RECIST 1.1 by comparison of the baseline and preoperative imaging.

    Time frame: 8 years from first patient in

  7. Radiological response to neoadjuvant chemotherapy according to CHOI

    For patients receiving neo-adjuvant chemotherapy, the radiological response will be also assessed using Choi criteria by comparison of the baseline and preoperative imaging.

    Time frame: 8 years from first patient in

  8. Pathological response

    Response evaluation will be done according to the EORTC response score.

    Time frame: 8 years from first patient in

  9. Safety and toxicity of neoadjuvant chemotherapy

    Safety and toxicity of neoadjuvant chemotherapy will be evaluated and graded using CTCAE V5.0.

    Time frame: 8 years from first patient in

  10. Perioperative complications

    Perioperative complications will be evaluated with the Dindo scale for the events related to the surgery and CTCAE V5.0 will be used for all other events.

    Time frame: 8 years from first patient in

  11. Late complications

    Late complications (after the 60th day following the surgery) will be evaluated and graded according to the CTCAE version 5.0.

    Time frame: 8 years from first patient in

  12. Health-Related Quality of life (EORTC QLQ-C30 + Item list from QLQ-STO22)

    Health-Related Quality of life assessment will be based on the EORTC QLQ C30 questionnaire version 3.0, with additional questions from the QLQ-STO22 module.

    Time frame: 8 years from first patient in

  13. Health utility, calculated from the collected patient-reported HRQoL data and patient demographics economics.

    he EORTC QLQ C30 data will be mapped to health utility values using an established indirect mapping approach.

    Time frame: 8 years from first patient in

07

Study locations

153 of 176 sites recruiting

Showing the first 100 of 176 sites across 15 countries. Choose a country and city above to see the rest.

08

References and documents

Publications

  • Nardi W, Nicolas N, El Zein S, Tzanis D, Bouhadiba T, Helfre S, Watson S, Brisse HJ, Servois V, Bonvalot S. Diagnostic accuracy and safety of percutaneous core needle biopsy of retroperitoneal tumours. Eur J Surg Oncol. 2024 Jan;50(1):107298. doi: 10.1016/j.ejso.2023.107298. Epub 2023 Nov 30. PubMed 38086314 ↗

Individual participant data

Plan to share: No

09

Timeline

1 registry update since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reached

Started Jan 2021 (actual). Primary completion is estimated for Apr 2027, 75 months after the start.

How these figures are worked out, and which studies are left out of them.

Registered
Jul 22, 2019
First posted
Jul 24, 2019
StartActual
Jan 20, 2021
Primary completionEst.
Apr 21, 2027
CompletionEst.
Apr 21, 2028
Last update
Oct 7, 2026
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
Sites
1 site added
Show site
  • Midwestern Regional Medical Center · Zion, United States
Oct 7, 2026
Show all 1 update
  1. Oct 7, 2026
    1 site added
    Show site
    • Midwestern Regional Medical Center · Zion, United States
    + 1 other change: verification date

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 ↗

10

Registry details

Key details

Study ID
NCT04031677
Collaborators
Canadian Cancer Trials Group, ECOG-ACRIN Cancer Research Group, Anticancer Fund, Belgium, Australia and New Zealand Sarcoma Association, Japan Clinical Oncology Group
Responsible party
Sponsor
First posted
Jul 24, 2019
Start date
Jan 20, 2021
Primary completion
Apr 21, 2027 (estimated)
Completion
Apr 21, 2028 (estimated)
Last update
Oct 7, 2026

Study contacts

EORTC HQ
Contact
1809@eortc.org
+3227741611

Oversight

Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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