International multidisciplinary expert panel consensus on breast reconstruction and radiotherapy.

Background Conflicting evidence challenges clinical decision-making when breast reconstruction is considered in the context of radiotherapy. Current literature was evaluated and key statements on topical issues were generated and discussed by an expert panel at the International Oncoplastic Breast Surgery Meeting in Milan 2017. Methods Studies on radiotherapy and breast reconstruction (1985 to September 2017) were screened using MEDLINE, Embase and CENTRAL. The literature review yielded 30 controversial key questions. A set of key statements was derived and the highest levels of clinical evidence (LoE) for each of these were summarized. Nineteen panellists convened for dedicated discussions at the International Oncoplastic Breast Surgery Meeting to express agreement, disagreement or abstention for the generated key statements. Results The literature review identified 1522 peer-reviewed publications. A list of 22 key statements was produced, with the highest LoE recorded for each statement. These ranged from II to IV, with most statements (11 of 22, 50 per cent) supported by LoE III. There was full consensus for nine (41 per cent) of the 22 key statements, and more than 75 per cent agreement was reached for half (11 of 22). Conclusion Poor evidence exists on which to base patient-informed consent. Low-quality studies are conflicting with wide-ranging treatment options, precluding expert consensus regarding optimal type and timing of breast reconstruction in the context of radiotherapy. There is a need for high-quality evidence from prospective registries and randomized trials in this field.