Breast CancerCOOL-ITNCT05505643
Cryoablation vs Lumpectomy in T1 Breast Cancers
A study testing Endocare SlimLine Cryoprobe and Lumpectomy in people with Breast Cancer and Breast Neoplasm, run by Washington University School of Medicine at 1 site in United States.
Trial summary
This trial studies the efficacy and safety of cryoablation in patients with low risk, early stage breast cancer. Cryoablation is a method of killing a tumor by freezing it. The standard approach for patients with this kind of cancer is a lumpectomy. Read more about this study
- Who is it for?
- Ages 50 years and older, women only
- Conditions the study is for
- Breast Cancer, Breast Neoplasm
- What is being tested?
- Endocare SlimLine Cryoprobe and Lumpectomy
- Type of treatment
- Medical device, Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 120 participants
- Where
- 1 siteUnited States
- Study dates
- 3 Apr 2024to 30 Apr 2033
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 50 years and older
- Women only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Diagnosis of invasive ductal carcinoma of the breast (ER , Her-2 negative) that is grade 1 or 2 with intraductal component <25%. Must be T1N0M0 (2 cm or less).
- If DCIS is present in the biopsy specimen it should be <25% of the tumor and should be contiguous with the IDC. (i.e. DCIS should not be a separate tumor from the IDC).
- Oncotyping will be performed on T1b+Allred<6/8 and T1c tumors. Oncotype score in this subset of patients must be <26 to be included in the trial.
- At least 50 years of age.
- Negative ipsilateral axillary assessment as determined either by (1) negative axillary ultrasound (2) negative sentinel lymph node biopsy or (3) negative percutaneous axillary node biopsy with no further clinical or imaging concern for nodal metastatic disease.
- Able to understand and willing to sign an IRB-approved written informed consent document.
Who cannot join
- Indication for neoadjuvant chemotherapy.
- Prior history of breast cancer.
- Breast augmentation.
- Allergy to local anesthetics.
- Pregnant or lactating. Women of childbearing potential must have a negative pregnancy test within 14 days of study entry.
- Tumoral involvement of skin or chest wall.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Washington University School of Medicine
St Louis, Missouri, 63110
Heather Garrett, M.D., 636-916-9662, hvgarrett@wustl.edu
Heather Garrett, M.D.
About this study
Official title: COOL-IT: Cryoablation vs Lumpectomy in T1 Breast Cancers: A Randomized Controlled Trial With Safety Lead-in
This trial studies the efficacy and safety of cryoablation in patients with low risk, early stage breast cancer. Cryoablation is a method of killing a tumor by freezing it. The standard approach for patients with this kind of cancer is a lumpectomy. This study will review the safety of the cryoablation procedure initially, followed by comparing cryoablation to lumpectomy in order to see if the cryoablation results in better disease control, complication rates, and quality of life.
- Conditions
- Breast Cancer, Breast Neoplasm
- Being tested
- Endocare SlimLine Cryoprobe, Lumpectomy
- Keywords
- breast cancer, cryoablation, lumpectomy
- Medical subject headings
- Breast Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Endocare SlimLine CryoprobeDevice
The Endocare(TM) SlimLine (TM) Cryoprobe is a single use, disposable device designed for use with Endocare Cryocare Surgical Systems. Endocare cryoprobes are designed to deliver cold temperatures for cryoablation using high-pressure argon gas circulated through the cryoprobe, followed by active thawing using helium gas.
The Cryocare CS Surgical System is intended for use in open, minimally invasive, or endoscopic surgical procedures in the areas of general surgery, urology, gynecology, oncology, neurology, dermatology, ENT, proctology, pulmonary surgery, and thoracic surgery. The system is designed to freeze/ablate tissue by the application of extreme cold temperatures.
LumpectomyProcedure or surgery
Patients randomized to cryoablation who experience disease recurrence may undergo crossover to lumpectomy.
| Study group | Role | What they receive |
|---|---|---|
| Cryoablation | Experimental | Patients will be treated with cryoablation using the Endocare SlimLine Cyroprobe under real time ultrasound guidance and local anesthesia. The cryoablation consists of a 10 minute freeze phase followed by a 10 minute passive thaw, and ends with a second 10 minute freeze cycle. The freeze-thaw-freeze times may be adjusted at the physician's discretion depending on tumor size. Receives: Device: Endocare SlimLine Cryoprobe |
| Lumpectomy | Active comparator | Lumpectomy will be performed under general anesthesia as per standard operative procedures at Washington University and Siteman Cancer Center. Receives: Procedure: Lumpectomy |
| Rescue Arm: Lumpectomy | Other | If there is evidence of residual or recurrent tumor on follow-up imaging evaluation (6 month MRI (if can tolerate) and yearly MRI/mammography), patients in the cryoablation safety lead-in and who were randomized to receive cryoablation only will be crossed over to receive a rescue lumpectomy followed by adjuvant treatment based on standard of care. Receives: Procedure: Lumpectomy |
| Cryoablation - Safety Lead In | Experimental | Patients will be treated with cryoablation (Day 1) using the Endocare SlimLine Cyroprobe followed by adjuvant treatment. Receives: Device: Endocare SlimLine Cryoprobe |
What is being measured
The primary outcome is the main question the study is designed to answer.
Safety Lead-In: Number of treatment-related complications
Excessive adverse events will be graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) v5.0. They are defined as toxicities occurring within 30 days after the cryoablation procedure and are at least possibly related to the cryoablation. These include death, life-threatening adverse events, inpatient hospitalization or prolongation of existing hospitalization, a persistent or significant disability/incapacity, or complications related to cryoablation which interfere with adjuvant therapy such that the adjuvant therapy cannot be performed at all or delayed for a period longer than 6 months or which result in unplanned mastectomy.
Measured: Assessed from start of treatment through 30 days after cryoablation treatment (estimated to be 31 days)
Randomized Controlled Trial: Ipsilateral breast cancer recurrence (IBTR) in the treated breast.
IBTR defined from date of procedure to date of ipsilateral breast cancer recurrence, with the occurrence of ipsilateral breast tumor recurrence as the event and patients will be censored at the last follow-up.
Measured: At 5 years.
Secondary outcomes (3)
Proportion of patients who are free of serious treatment-related complications
Excessive adverse events will be graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) v5.0. They are defined as toxicities occurring within 30 days after the cryoablation procedure and are at least possibly related to the cryoablation. These include death, life-threatening adverse events, inpatient hospitalization or prolongation of existing hospitalization, a persistent or significant disability/incapacity, or complications related to cryoablation which interfere with adjuvant therapy such that the adjuvant therapy cannot be performed at all or delayed for a period longer than 6 months or which result in unplanned mastectomy.
Measured: Assessed from start of treatment through 30 days after cryoablation treatment (estimated to be 31 days)
Proportion of patients who demonstrate disease-free survival (DFS)
DFS is defined as the time from procedure to time of ipsilateral recurrence, contralateral recurrence, regional recurrence or distant metastasis, or date of last follow-up if none of the recurrence events occur.
Measured: Through 5 years.
Overall survival (OS)
OS is defined from date of procedure to date of death or date of last follow up if none of the recurrence events occur.
Measured: Through 5 years.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Aug 2022
- Study start3 Apr 2024
- Primary completion30 Apr 2033 (estimated)
- Study completion30 Apr 2033 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Breast CancerStudies of the same condition, open and under way.
- More trials run by Washington University School of MedicineThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- The initial 20 participants will be enrolled to a safety lead-in arm receiving cryoablation. The next 100 participants will be randomized in a 1:1 manner to either cryoablation or lumpectomy. Patients initially treated with cryoablation who have evidence of residual or recurrent tumor on follow-up imaging will be crossed over to receive a rescue lumpectomy.
- Masking
- None (open label)
- Enrolment
- 120 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Washington University School of Medicine
- Sponsor type
- University, hospital or other
- Collaborators
- The Foundation for Barnes-Jewish Hospital, Varian Medical Systems
- Responsible party
- Sponsor
- Investigators
- Heather Garrett, M.D., Principal investigator, Washington University School of Medicine
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05505643
- Sponsor's protocol ID
- 202302017
- Acronym
- COOL-IT
- Status last verified
- Feb 2026
- First submitted
- 15 Aug 2022
- Last updated
- 27 Feb 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- Yes: All of the de-identified individual participant data and the study protocol will be made available to investigators who provide a methodologically sound proposal. Proposals should be directed to hvgarrett@wustl.edu. De- identified individual participant data will also be made available to Varian.
Study at a glance
From the registry record, last updated by the sponsor on 27 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- COOL-IT: Cryoablation vs Lumpectomy in T1 Breast Cancers: A Randomized Controlled Trial With Safety Lead-in
- ClinicalTrials.gov ID
- NCT05505643
- Acronym / sponsor ID
- COOL-IT / 202302017
- Conditions
- Breast Cancer, Breast Neoplasm
- Keywords
- breast cancer, cryoablation, lumpectomy
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 120 participants (estimated)
- Lead sponsor
- Washington University School of MedicineUniversity, hospital or other
- Collaborators
- The Foundation for Barnes-Jewish Hospital, Varian Medical Systems
- Study start
- 3 Apr 2024 (actual)
- Primary completion
- 30 Apr 2033 (estimated)
- Study completion
- 30 Apr 2033 (estimated)
- First posted
- 18 Aug 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This trial studies the efficacy and safety of cryoablation in patients with low risk, early stage breast cancer. Cryoablation is a method of killing a tumor by freezing it. The standard approach for patients with this kind of cancer is a lumpectomy. This study will review the safety of the cryoablation procedure initially, followed by comparing cryoablation to lumpectomy in order to see if the cryoablation results in better disease control, complication rates, and quality of life.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 4
- Model description
- The initial 20 participants will be enrolled to a safety lead-in arm receiving cryoablation. The next 100 participants will be randomized in a 1:1 manner to either cryoablation or lumpectomy. Patients initially treated with cryoablation who have evidence of residual or recurrent tumor on follow-up imaging will be crossed over to receive a rescue lumpectomy.
| Arm | Type | Receives |
|---|---|---|
| Cryoablation | Experimental | Device: Endocare SlimLine CryoprobePatients will be treated with cryoablation using the Endocare SlimLine Cyroprobe under real time ultrasound guidance and local anesthesia. The cryoablation consists of a 10 minute freeze phase followed by a 10 minute passive thaw, and ends with a second 10 minute freeze cycle. The freeze-thaw-freeze times may be adjusted at the physician's discretion depending on tumor size. |
| Lumpectomy | Active comparator | Procedure: LumpectomyLumpectomy will be performed under general anesthesia as per standard operative procedures at Washington University and Siteman Cancer Center. |
| Rescue Arm: Lumpectomy | Other | Procedure: LumpectomyIf there is evidence of residual or recurrent tumor on follow-up imaging evaluation (6 month MRI (if can tolerate) and yearly MRI/mammography), patients in the cryoablation safety lead-in and who were randomized to receive cryoablation only will be crossed over to receive a rescue lumpectomy followed by adjuvant treatment based on standard of care. |
| Cryoablation - Safety Lead In | Experimental | Device: Endocare SlimLine CryoprobePatients will be treated with cryoablation (Day 1) using the Endocare SlimLine Cyroprobe followed by adjuvant treatment. |
Who may qualify
- Ages
- 50 years and older
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Diagnosis of invasive ductal carcinoma of the breast (ER , Her-2 negative) that is grade 1 or 2 with intraductal component <25%. Must be T1N0M0 (2 cm or less).
- If DCIS is present in the biopsy specimen it should be <25% of the tumor and should be contiguous with the IDC. (i.e. DCIS should not be a separate tumor from the IDC).
- Oncotyping will be performed on T1b+Allred<6/8 and T1c tumors. Oncotype score in this subset of patients must be <26 to be included in the trial.
- At least 50 years of age.
- Negative ipsilateral axillary assessment as determined either by (1) negative axillary ultrasound (2) negative sentinel lymph node biopsy or (3) negative percutaneous axillary node biopsy with no further clinical or imaging concern for nodal metastatic disease.
Key exclusion criteria (6 listed)
- Indication for neoadjuvant chemotherapy.
- Prior history of breast cancer.
- Breast augmentation.
- Allergy to local anesthetics.
- Pregnant or lactating. Women of childbearing potential must have a negative pregnancy test within 14 days of study entry.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Endocare SlimLine CryoprobeThe Endocare(TM) SlimLine (TM) Cryoprobe is a single use, disposable device designed for use with Endocare Cryocare Surgical Systems. Endocare cryoprobes are designed to deliver cold temperatures for cryoablation using high-pressure argon gas circulated through the cryoprobe, followed by active thawing using helium gas. The Cryocare CS Surgical System is intended for use in open, minimally invasive, or endoscopic surgical procedures in the areas of general surgery, urology, gynecology, oncology, neurology, dermatology, ENT, proctology, pulmonary surgery, and thoracic surgery. The system is designed to freeze/ablate tissue by the application of extreme cold temperatures. | Device | Cryoablation, Cryoablation - Safety Lead In |
| LumpectomyPatients randomized to cryoablation who experience disease recurrence may undergo crossover to lumpectomy. | Procedure or surgery | Lumpectomy, Rescue Arm: Lumpectomy |
Primary outcome
Safety Lead-In: Number of treatment-related complications
Time frame: Assessed from start of treatment through 30 days after cryoablation treatment (estimated to be 31 days)
Excessive adverse events will be graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) v5.0. They are defined as toxicities occurring within 30 days after the cryoablation procedure and are at least possibly related to the cryoablation. These include death, life-threatening adverse events, inpatient hospitalization or prolongation of existing hospitalization, a persistent or significant disability/incapacity, or complications related to cryoablation which interfere with adjuvant therapy such that the adjuvant therapy cannot be performed at all or delayed for a period longer than 6 months or which result in unplanned mastectomy.
Randomized Controlled Trial: Ipsilateral breast cancer recurrence (IBTR) in the treated breast.
Time frame: At 5 years.
IBTR defined from date of procedure to date of ipsilateral breast cancer recurrence, with the occurrence of ipsilateral breast tumor recurrence as the event and patients will be censored at the last follow-up.
3 secondary outcomes
Proportion of patients who are free of serious treatment-related complications
Time frame: Assessed from start of treatment through 30 days after cryoablation treatment (estimated to be 31 days)
Proportion of patients who demonstrate disease-free survival (DFS)
Time frame: Through 5 years.
Overall survival (OS)
Time frame: Through 5 years.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Feb 2026.
- Alvin J. Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of MedicineLink provided by the sponsor.
- Individual participant dataSharing planned: Yes. All of the de-identified individual participant data and the study protocol will be made available to investigators who provide a methodologically sound proposal. Proposals should be directed to hvgarrett@wustl.edu. De- identified individual participant data will also be made available to Varian.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Heather Garrett, M.D. principal investigator
Washington University School of Medicine
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Endocare SlimLine Cryoprobe and Lumpectomy in people with Breast Cancer and Breast Neoplasm, run by Washington University School of Medicine at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 27 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Heather Garrett, M.D. (636-916-9662, hvgarrett@wustl.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Safety Lead-In: Number of treatment-related complications (time frame: Assessed from start of treatment through 30 days after cryoablation treatment (estimated to be 31 days)). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 27 Feb 2026.