Preoperative Radiation Therapy and Immediate Breast Reconstruction

The goal of this phase III randomized controlled trial (PRADAIIBE) is to assess if preoperative radiation therapy (Preop-RT) combined with immediate breast reconstruction (IBR) can safely improve both aesthetic and quality of life outcomes in breast cancer patients, compared to the standard of care (SoC) therapy consisting of post-mastectomy radiation therapy (PMRT) and delayed/immediate breast reconstruction, in a population of breast cancer patients with an indication of mastectomy and PMRT. The following hypotheses and outcomes will be assessed at the primary endpoint of 1 year of follow-up: * Efficacy: Does Preop-RT+IBR lead to a higher BREAST-Q satisfaction with breasts score (primary endpoint), EQ-5D-5L VAS score , EQ-5D-5L Index score, AIS-Total Aesthetic Score, or a shorter treatment duration compared to SoC? * Safety: Does Preop-RT+IBR lead to an increase in adverse events (general or surgical), a lower rate of pathologic Complete Response (pCR), or worse survival outcomes compared to SoC? \[Note: this study was not powered as a non-inferiority trial, all outcomes will be pooled internationally with parallel studies\] Eligible and consenting participants will undergo screening and baseline assessments. They will then be randomised between experimental (Preop-RT+IBR) and control (SoC) groups, in a 1:1 stratified variable block size design. Follow-up will take place at 3 months, 1, 2, 5, and 10 years after the last study treatment. At baseline and during each follow-up visit each participant will complete the Breast Q 'satisfaction with breasts' and EQ-5D-5L scales, photographs will be taken. During follow-up pCR will be assessed if applicable, adverse events will be registered, and oncological follow-up will be recorded.

Sex

Female

Minimum age

18 Years

Screening assessments, including review of all study eligibility criteria must be completed before enrolment and randomisation.

Inclusion criteria:

In order to be eligible to participate in this study, a participant must meet all of the following criteria:

1\. Women ≥18 years with histopathologically confirmed breast cancer who:

1.a. require SSM/NSM for any reason (e.g. extensive disease)

1.b. require postoperative radiation therapy of at least the chest wall

1. c. have a wish for a breast reconstruction
2. An Eastern Cooperative Oncology Group (ECOG) performance status grade ≤ 2
3. Participant is able and willing to provide written informed consent, which includes compliance with and ability to undergo all study procedures, and attend the scheduled follow-up visit(s) per protocol.

Exclusion criteria:

A potential participant who meets any of the following criteria will be excluded from participation in this study:

1. A previous history of breast cancer or irradiation of the chest wall for any other indication, on the other side (ipsilateral). A bilateral SSM/NSM + reconstruction (e.g. in case of a contralateral prophylactic SSM/NSM), or previous contralateral breast cancer disease/treatment, do not fall under this criterium and are thus allowed.
2. Collagen synthesis disease
3. Ongoing pregnancy
4. Actively breastfeeding
5. Smoking at time of inclusion (a history of smoking is allowed but needs to be registered in the eCRF). No interval between smoking cessation and study inclusion is defined, but the reconstructive surgeon needs to be willing to operate the patient using autologous tissue transfer. This generally translates to a smoking cessation of \>3months preoperatively.
6. BMI \> 35 kg/m2
7. cT4d tumour, metastatic disease or any reason making SSM/NSM not indicated

• DERIVEDQuisenaerts T, Van Der Auwera I, Poortmans P, Reynders D, Van Dieren L, Thiessen F, Amajoud Z, Tondu T, Punie K, Tjalma W, Van Berckelaer C, Kindts I, Remouchamps V, Depypere B, Machiels M. Preoperative Radiation Therapy and Immediate Breast Reconstruction, a phase 3 randomized controlled trial in the Belgian population (PRADAIIBE): a study protocol. BMC Cancer. 2026 Apr 27;26(1):743. doi: 10.1186/s12885-026-16071-6. PMID 42046025