Pre- Versus Sub-pectoral Implant-based Breast Reconstruction After Skin-sparing Mastectomy or Nipple-sparing Mastectomy OPBC-02PREPEC

compare the Quality of Life (QoL) with respect to long-term physical well-being (chest) after pre-pectoral or sub-pectoral IBBR. The BREAST-Q module specific to breast reconstruction version 2.0 consists of 13 independent scales covering health-related QoL domains and satisfaction domains. Each scale is scored to generate a numerical score on a scale from 0 (worst) to 100 (best).

The 5-level version of the EQ-5D (EQ-5D-5L) consists of the EQ-5D descriptive system that comprises five dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/Depression (5 answer levels each: no problems, slight problems, moderate problems, severe problems and extreme problems), resulting in a 1-digit number that expresses the level for that dimension. The digits for each dimension are combined into a 5-digit number that describes the patient's health state and is subsequently converted into a preference-based quality of life weight (utility) using an algorithm derived from population-based studies. In addition, patients are asked to rate their health on a vertical visual analogue scale (EQ VAS), where the anchors are labelled with 'The best health you can imagine' and 'The worst health you can imagine'.

compare the safety of pre-pectoral and sub-pectoral IBBR, in terms of loss of expander or implant. Loss of expander or implant is defined as an unplanned surgical removal of expander/implant with or without immediate replacement.

compare the safety of pre-pectoral and sub-pectoral IBBR, in terms of surgical complications. The complications include: Wound dehiscence, Haematoma, Seroma, Implant/expander exposure/Extrusion, Implant/Expander rotation/malpositioning, Infection, Mastectomy skin flap necrosis, Capsular contraction, Lymphedema

compare the safety of pre-pectoral and sub-pectoral IBBR, in terms of thromboembolic events according to Common Terminology Criteria for Adverse Events (CTCAE) v5.0

compare patient satisfaction after pre-pectoral or sub-pectoral IBBR

compare animation deformity after pre-pectoral or sub-pectoral IBBR by using pictures from before and 24 months after the mastectomy

compare capsular contracture after pre-pectoral or sub-pectoral IBBR by using pictures from before and 24 months after the mastectomy

compare aesthetic results after pre-pectoral or sub-pectoral IBBR assessed by photographs of the breast taken in a standardized way. They will be evaluated by an experienced investigator who is blinded for group assignment. The blinded outcome assessment team will be trained to enter data for the two most widely used semi-automatic software for objective aesthetic evaluation, the 'Breast Cancer Conservative Treatment cosmetic results' (BCCT.core)

RFS is defined as the time from randomization until the first documentation of any of the following events: local-regional occurrence or recurrence of invasive disease or ductal carcinoma in situ (DCIS), distant breast cancer metastasis, or death from any cause.

evaluated by patients using a four point scale: excellent, good, regular, bad.

assess the burden on patients by total number of operative procedures

length of hospital stay (index hospitalization and overall) following randomization until discharge and the cumulative number of days the patient was hospitalized

assess the burden on patients by total number of outpatient visits at the trial site and the emergency department

evaluated by local physicians using a four point scale: excellent, good, regular, bad.