Variations in diagnostic and therapeutic procedures in a multicentre, randomized clinical trial (EORTC 10853) investigating breast-conserving treatment for DCIS

Aims: To evaluate the diagnostic and therapeutic procedures which were foll owed in a European Organization for Research and Treatment of Cancer (EORTC ) randomized clinical trial investigating the role of radiotherapy in breas t-conserving treatment (BCT) for ductal carcinoma in situ (DCIS) of the bre ast. Methods: The medical files of 824 of the 1010 randomized patients (82%) wer e reviewed during site visits to 30 participating institutes. Results: Large variations occurred, particularly in the surgical procedures and histopathological work-up which were performed. Important risk factors like tumour size and margin status were poorly quantified in the medical t iles. Conclusions: These findings emphasize the need for establishing uniform gui delines for diagnostic and therapeutic procedures for DCIS, and for clearly defined risk factors for recurrence after BCT for DCIS, Because of its ran domized nature, the main question of the trial, i.e. the effect of radiothe rapy on the risk of local recurrence, will not be influenced by variation. The risk of local recurrence in itself, and hence the success of BCT for DC IS, may however be influenced by the quality of the initial procedures that were conducted. (C) 2001 Harcourt Publishers Ltd.