Maastricht Delphi Consensus on Event Definitions for Classification of Recurrence in Breast Cancer Research

• Published in: JNCI : Journal of the National Cancer Institute Vol. 106; no. 12; p. 1
• Main Authors: MOOSSDORFF, Martine, VAN ROOZENDAAL, Lori M, KLIMBERG, V. Suzanne, KOCZWARA, Bogda, KÜHN, Thorsten, LIPPMAN, Marc E, LUCCI, Anthony, PICCART, Martine, SMITH, Benjamin D, TJAN-HEIJNEN, Vivianne C. G, VAN DE VELDE, Cornelis J. H, VAN ZEE, Kimberly J, STROBBE, Luc J. A, VERMORKEN, Jan B, VIALE, Giuseppe, VOOGD, Adri C, WAPNIR, Irene L, WHITE, Julia R, SMIDT, Marjolein L, AEBI, Stefan, CAMERON, David A, DIXON, J. Michael, GIULIANO, Armando E, HAFFTY, Bruce G, HICKEY, Brigid E, HUDIS, Clifford A
• Format: Journal Article
• Language: English
• Published: Cary, NC Oxford University Press 01.12.2014; Oxford Publishing Limited (England)
• Subjects: Biological and medical sciences; Breast cancer; Breast Neoplasms - diagnosis; Breast Neoplasms - pathology; Carcinoma, Intraductal, Noninfiltrating - diagnosis; Comparative analysis; Delphi Technique; Female; Gynecology. Andrology. Obstetrics; Humans; International Cooperation; Lymphatic Metastasis; Mammary gland diseases; Medical sciences; Metastasis; Multiple tumors. Solid tumors. Tumors in childhood (general aspects); Neoplasm Recurrence, Local - diagnosis; Neoplasm Recurrence, Local - pathology; Neoplasms, Second Primary - diagnosis; Neoplasms, Second Primary - pathology; Oncology; Skin Neoplasms - secondary; Surveys and Questionnaires; Thoracic Wall - pathology; Tissues; Tumors; Mammary gland diseases; Relapse; Breast disease; Cancerology; Classification; Definition; Breast cancer; Malignant tumor; Research; Consensus; Cancer
• ISSN: 0027-8874; 1460-2105
• DOI: 10.1093/jnci/dju288

In breast cancer studies, many different endpoints are used. Definitions are often not provided or vary between studies. For instance, "local recurrence" may include different components in similar studies. This limits transparency and comparability of results. This project aimed to reach consensus on the definitions of local event, second primary breast cancer, regional and distant event for breast cancer studies. The RAND-UCLA Appropriateness method (modified Delphi method) was used. A Consensus Group of international breast cancer experts was formed, including representatives of all involved clinical disciplines. Consensus was reached in two rounds of online questionnaires and one meeting. Twenty-four international breast cancer experts participated. Consensus was reached on 134 items in four categories. Local event is defined as any epithelial breast cancer or ductal carcinoma in situ (DCIS) in the ipsilateral breast, or skin and subcutaneous tissue on the ipsilateral thoracic wall. Second primary breast cancer is defined as epithelial breast cancer in the contralateral breast. Regional events are breast cancer in ipsilateral lymph nodes. A distant event is breast cancer in any other location. Therefore, this includes metastasis in contralateral lymph nodes and breast cancer involving the sternal bone. If feasible, tissue sampling of a first, solitary, lesion suspected for metastasis is highly recommended. This project resulted in consensus-based event definitions for classification of recurrence in breast cancer research. Future breast cancer research projects should adopt these definitions to increase transparency. This should facilitate comparison of results and conducting reviews as well as meta-analysis.