SHAPE study
Standardization of Oncoplastic Breast-Conserving Surgery in the Netherlands
– The Fourteenth Dutch Snapshot Study –
participating centers
patients
publications
Background
Oncoplastic breast-conserving surgery (OPBCS) enables wider tumor excision while preserving breast aesthetics and may reduce the need for mastectomy. With increasing emphasis on quality of life and cosmetic outcomes, the use of OPBCS is becoming increasingly relevant in breast cancer surgery. However, a wide variety of oncoplastic techniques and terminology has resulted in substantial variation in clinical practice and a lack of standardized registration. To address this heterogeneity, the NVCO recently developed a consensus document defining and classifying oncoplastic breast-conserving procedures and their indications. However, the extent to which these definitions are applied in current clinical practice, and whether OPBCS use varies between hospitals, remains unknown. This study will provide a nationwide overview of OPBCS use, and the findings will support standardization, quality improvement, and improved registration to facilitate future OPBCS research.
Objectives
The primary objective are to determine:
1. The incidence of standard wild local excision (WLE), level I
OPBCS, and level II OPBCS
2. Inter-hospital variation in the use of OPBCS
The main secondary objectives are to identify:
1. Factors influencing the decision-making process for choosing
standard WLE, level I or level II OPBCS
2. The frequency of the involvement of a plastic surgeon for level
I and level II OPBCS
3. The incidence of different OPBCS techniques
Other secondary factors are analyzing irradicality, re-excision rates, conversion-to-mastectomy rates, adherence to the NVCO registry codes, and different operative and postoperative outcomes, including complication rates.
Study design
This nationwide Snapshot study will collect real-time data on patients undergoing BCS to assess current OPBCS practice, surgical decision-making, techniques used, and adherence to national guidelines.
Study population
All patients undergoing breast conserving surgery (BCS) for primary DCIS or non-metastatic invasive breast cancer.
Main outcomes
The hypothesis of this study is that there is substantial (inter-hospital) variation in the use of OPBCS in the Netherlands, resulting in both misuse (application of complex techniques when not necessary) and underuse (missed opportunities to avoid mastectomy or improve cosmetic outcomes). Together with a possible inter-hospital variation in the use of OBCS, a difference in frequency in involvement of a plastic surgeon and a large heterogeneity in techniques used.
Planning
All breast cancer care-providing hospitals in the Netherlands will be invited to participate from September 2026. Participating hospitals will include patients during a 4-month period between January and December 2027.