Breast CancerPhase 3PRATONCT06960707
Two Versus One Week Breast Radiotherapy (RT)
A Phase 3 study testing Radiation therapy - 1 week and Radiation therapy - 2 weeks in people with Breast Cancer, run by Weill Medical College of Cornell University at 3 sites in United States.
Trial summary
This study is comparing two different radiation therapy approaches for early breast cancer to see which one is better for patients. One group will receive radiation over one week (based on the FAST-FORWARD trial), and the other group will receive radiation over two weeks with an extra focused dose (called a… Read more about this study
- Who is it for?
- Any age, women only
- Conditions the study is for
- Breast Cancer
- What is being tested?
- Radiation therapy - 1 week and Radiation therapy - 2 weeks
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 400 participants
- Where
- 3 sitesUnited States
- Study dates
- 29 Apr 2025to 31 Dec 2040
- Phase
- Phase 3
- 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 Any age
- Women only
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- Women status post segmental mastectomy.
- If unilateral, pT1-2 breast cancer excised with negative margins.
- If bilateral, pT1-2 breast cancer excised with negative margins AND/OR pTis excised with negative margins.
- Clinically N0 (cN0 as determined by ultrasound/SOUND criteria) or pN0-1 or Nx or sentinel node negative.
- Ductal carcinoma in situ DCIS with negative margins (no DCIS on inked margins).
- Women with previous contralateral treated breast cancer can be enrolled in the trial.
Who cannot join
- Previous radiation therapy to the ipsilateral breast.
- >90 days from last surgery, unless s/p adjuvant chemotherapy.
- >60 days from last chemotherapy.
- Male breast cancer.
- Ongoing treatment for severe autoimmune disease.
Trial locations and contacts
3 sites in 1 country. Contact the study team or a site near you to ask about taking part.
United States3 sites, 3 recruiting
- Recruiting
Brooklyn Methodist Hospital
New York, New York, 11215
Izael Nino, (929) 470-9426, izn4001@med.cornell.edu
Hani Ashamalla, MD
- Recruiting
New York Presbyterian Hospital
New York, New York, 11355
Krystalle Lyons, 718-670-1541, krl4003@med.cornell.edu
Steven DiBiase, MD
- Recruiting
New York-Presbyterian Weill Cornell Medical College
New York, New York, 11355
Maahi Patel, Bachelors of Science, BS, 9784025630, map4044@med.cornell.edu
Fabiana Gregucci, MD
About this study
Official title: Prospective Randomized Trial of Two Versus One Week Accelerated Radiotherapy (PRATO)
This study is comparing two different radiation therapy approaches for early breast cancer to see which one is better for patients. One group will receive radiation over one week (based on the FAST-FORWARD trial), and the other group will receive radiation over two weeks with an extra focused dose (called a "concomitant boost"). The study will look at how the treatments affect side effects, breast appearance, and cancer control in the breast. It also aims to find out if the two-week treatment does a better job at preventing cancer from coming back in the breast over the long term.
Read the detailed description
Radiotherapy: one week (Arm 1) 2600 cGy in 5 fractions whole breast radiotherapy over one week versus 2 weeks (Arm 2), 3200 cGy in 10 fractions with a concomitant tumor bed boost to 3600 cGy. In Arm 2, if no cavity is visible due to oncoplastic surgery, we will deliver 32 Gy to the whole breast only, without a boost.
Hypothesis: A regimen of whole breast radiotherapy to 2600 in five fractions, the current UK standard for early breast cancer (Arm 2), is not inferior to 3200cGy with a concomitant tumor bed boost to 3600 cGy in 10 fractions (Arm 1), in terms of acute toxicity and long-term fibrosis, breast cosmesis and local control at 2 and 5 years. It will also test the hypothesis of superior local control at 10 years in Arm 2 compared to Arm 1.
- Conditions
- Breast Cancer
- Being tested
- Radiation therapy - 1 week, Radiation therapy - 2 weeks
- Keywords
- Accelerated Radiotherapy, Prone Position, Adjuvant Setting, Non-Inferiority, Concomitant Boost
- Medical subject headings
- Breast Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Radiation therapy - 1 weekRadiation
2600 cGy whole breast radiotherapy in five fractions (Arm 1) over 1 week
Radiation therapy - 2 weeksRadiation
3200 cGy whole breast radiotherapy with a concomitant tumor bed boost to 3600 cGy in 10 fractions (Arm 2) over 2 weeks. In Arm 2, if no cavity is visible due to oncoplastic surgery, we will deliver 32 Gy to the whole breast only, without a boost.
| Study group | Role | What they receive |
|---|---|---|
| ARM 1-2600 cGy in 5 fractions whole breast radiotherapy | Experimental | Patients randomized to ARM 1 will receive 2600 cGy in 5 fractions whole breast radiotherapy over one week Receives: Radiation: Radiation therapy - 1 week |
| ARM 2- 3200 cGy in 10 fractions with a concomitant tumor bed boost to 3600 cGy | Experimental | Patients randomized to ARM 2 will receive 3200 cGy in 10 fractions with a concomitant tumor bed boost to 3600 cGy. Receives: Radiation: Radiation therapy - 2 weeks |
What is being measured
The primary outcome is the main question the study is designed to answer.
Rate of RT-related acute toxicity
The rate of RT-related acute toxicity is defined as cumulative acute toxicity events from the start of radiation treatment to 1 month follow up post RT. The toxicities will be graded by the research nurses assigned to the study according to Common Terminology Criteria for Adverse Events, version 5.0.
Measured: 1 month
Secondary outcomes (7)
The long-term evaluations at 2 years of fibrosis based on LENT/SOMA
The number of subjects scoring Grades 1 through 4 using the LENT/SOMA (Late Effects Normal Tissues (LENT)-Subjective, Objective, Management, Analytic (SOMA)) system will be reported.
The patients will grade the following items based on the following scale:
- Mild
- Moderate
- Severe
- Life-threatening
Measured: 24 months
The long-term evaluations at 2 years of breast cosmesis
Patient self-reported breast cosmesis will be assessed using the BCTOS questionnaire (Breast Cancer Treatment Outcome Scale).The number of subjects scoring Grades 1 through 4 will be reported. The patients will grade the following items based on the following scale:
- = No difference between treated and untreated breast/area
- = Slight difference
- = Moderate difference
- = Large difference
Measured: 24 months
The long-term evaluations at 2 years of local control
Number of subjects with Local control at 2 years will be extracted from the medical record, and can be derived from clinical reports from medical, surgical or radiation oncologists as well as from the primary care doctor who is following the patient.
Measured: 24 months
The long-term evaluations at 5 years OF fibrosis based on LENT/SOMA
The number of subjects scoring Grades 1 through 4 using the LENT/SOMA (Late Effects Normal Tissues (LENT)-Subjective, Objective, Management, Analytic (SOMA)) system will be reported.
The patients will grade the following items based on the following scale:
- Mild
- Moderate
- Severe
- Life-threatening
Measured: 60 months
The long-term evaluations at 5 years of breast cosmesis
Patient self-reported breast cosmesis will be assessed using the BCTOS questionnaire (Breast Cancer Treatment Outcome Scale). The number of subjects scoring Grades 1 through 4 will be reported. The patients will grade the following items based on the following scale:
- = No difference between treated and untreated breast/area
- = Slight difference
- = Moderate difference
- = Large difference
Measured: 60 months
The long-term evaluations at 5 years of local control.
Number of subjects with Local control at 5 years will be extracted from the medical record, and can be derived from clinical reports from medical, surgical or radiation oncologists as well as from the primary care doctor who is following the patient.
Measured: 60 months
Superior local control at 10 years
Number of subjects with Local control at 10 years will be extracted from the medical record, and can be derived from clinical reports from medical, surgical or radiation oncologists as well as from the primary care doctor who is following the patient.
Measured: 120 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 May 2025
- Study start29 Apr 2025
- Primary completion31 Dec 2030 (estimated)
- Study completion31 Dec 2040 (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.
- 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 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 400 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Weill Medical College of Cornell University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Silvia C. Formenti, MD, Principal investigator, Weill Medical College of Cornell University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06960707
- Sponsor's protocol ID
- 25-01028391
- Acronym
- PRATO
- Status last verified
- Jun 2026
- First submitted
- 28 Apr 2025
- Last updated
- 15 Jun 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 15 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Prospective Randomized Trial of Two Versus One Week Accelerated Radiotherapy (PRATO)
- ClinicalTrials.gov ID
- NCT06960707
- Acronym / sponsor ID
- PRATO / 25-01028391
- Conditions
- Breast Cancer
- Keywords
- Accelerated Radiotherapy, Prone Position, Adjuvant Setting, Non-Inferiority, Concomitant Boost
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 400 participants (estimated)
- Lead sponsor
- Weill Medical College of Cornell UniversityUniversity, hospital or other
- Study start
- 29 Apr 2025 (actual)
- Primary completion
- 31 Dec 2030 (estimated)
- Study completion
- 31 Dec 2040 (estimated)
- First posted
- 7 May 2025 (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 study is comparing two different radiation therapy approaches for early breast cancer to see which one is better for patients. One group will receive radiation over one week (based on the FAST-FORWARD trial), and the other group will receive radiation over two weeks with an extra focused dose (called a "concomitant boost"). The study will look at how the treatments affect side effects, breast appearance, and cancer control in the breast. It also aims to find out if the two-week treatment does a better job at preventing cancer from coming back in the breast over the long term.
Detailed description
Radiotherapy: one week (Arm 1) 2600 cGy in 5 fractions whole breast radiotherapy over one week versus 2 weeks (Arm 2), 3200 cGy in 10 fractions with a concomitant tumor bed boost to 3600 cGy. In Arm 2, if no cavity is visible due to oncoplastic surgery, we will deliver 32 Gy to the whole breast only, without a boost.
Hypothesis: A regimen of whole breast radiotherapy to 2600 in five fractions, the current UK standard for early breast cancer (Arm 2), is not inferior to 3200cGy with a concomitant tumor bed boost to 3600 cGy in 10 fractions (Arm 1), in terms of acute toxicity and long-term fibrosis, breast cosmesis and local control at 2 and 5 years. It will also test the hypothesis of superior local control at 10 years in Arm 2 compared to Arm 1.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| ARM 1-2600 cGy in 5 fractions whole breast radiotherapy | Experimental | Radiation: Radiation therapy - 1 weekPatients randomized to ARM 1 will receive 2600 cGy in 5 fractions whole breast radiotherapy over one week |
| ARM 2- 3200 cGy in 10 fractions with a concomitant tumor bed boost to 3600 cGy | Experimental | Radiation: Radiation therapy - 2 weeksPatients randomized to ARM 2 will receive 3200 cGy in 10 fractions with a concomitant tumor bed boost to 3600 cGy. |
Who may qualify
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (6 listed)
- Women status post segmental mastectomy.
- If unilateral, pT1-2 breast cancer excised with negative margins.
- If bilateral, pT1-2 breast cancer excised with negative margins AND/OR pTis excised with negative margins.
- Clinically N0 (cN0 as determined by ultrasound/SOUND criteria) or pN0-1 or Nx or sentinel node negative.
- Ductal carcinoma in situ DCIS with negative margins (no DCIS on inked margins).
Key exclusion criteria (5 listed)
- Previous radiation therapy to the ipsilateral breast.
- >90 days from last surgery, unless s/p adjuvant chemotherapy.
- >60 days from last chemotherapy.
- Male breast cancer.
- Ongoing treatment for severe autoimmune disease.
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 |
|---|---|---|
| Radiation therapy - 1 week2600 cGy whole breast radiotherapy in five fractions (Arm 1) over 1 week | Radiation | ARM 1-2600 cGy in 5 fractions whole breast radiotherapy |
| Radiation therapy - 2 weeks3200 cGy whole breast radiotherapy with a concomitant tumor bed boost to 3600 cGy in 10 fractions (Arm 2) over 2 weeks. In Arm 2, if no cavity is visible due to oncoplastic surgery, we will deliver 32 Gy to the whole breast only, without a boost. | Radiation | ARM 2- 3200 cGy in 10 fractions with a concomitant tumor bed boost to 3600 cGy |
Primary outcome
Rate of RT-related acute toxicity
Time frame: 1 month
The rate of RT-related acute toxicity is defined as cumulative acute toxicity events from the start of radiation treatment to 1 month follow up post RT. The toxicities will be graded by the research nurses assigned to the study according to Common Terminology Criteria for Adverse Events, version 5.0.
7 secondary outcomes
The long-term evaluations at 2 years of fibrosis based on LENT/SOMA
Time frame: 24 months
The long-term evaluations at 2 years of breast cosmesis
Time frame: 24 months
The long-term evaluations at 2 years of local control
Time frame: 24 months
The long-term evaluations at 5 years OF fibrosis based on LENT/SOMA
Time frame: 60 months
The long-term evaluations at 5 years of breast cosmesis
Time frame: 60 months
The long-term evaluations at 5 years of local control.
Time frame: 60 months
Superior local control at 10 years
Time frame: 120 months
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 15 Jun 2026.
- Individual participant dataSharing planned: No
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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.
Silvia C. Formenti, MD principal investigator
Weill Medical College of Cornell University
3 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing Radiation therapy - 1 week and Radiation therapy - 2 weeks in people with Breast Cancer, run by Weill Medical College of Cornell University at 3 sites 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 5 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 15 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 sites 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.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
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 Fabiana Gregucci, MD (6469623110, fgr4002@med.cornell.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Rate of RT-related acute toxicity (time frame: 1 month). 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 15 Jun 2026.