In the Era After the European Organisation for Research and Treatment of Cancer ‘Boost’ Study, is the Additional Radiotherapy to the Breast Tumour Bed Still Beneficial for Young Women?

• Published in: Clinical oncology (Royal College of Radiologists (Great Britain)) 2020-06, Vol.32 (6), p.373-381
• Main Authors: Beaton, L., Chan, E.K., Tyldesley, S., Gondara, L., Speers, C., Nichol, A.
• Format: Article
• Language: English
• Subjects: Adult; Brachytherapy - methods; Breast cancer; Breast Neoplasms - pathology; Breast Neoplasms - radiotherapy; breast-conserving therapy; Female; hormone therapy; Humans; local recurrence; Neoplasm Recurrence, Local - pathology; Neoplasm Recurrence, Local - radiotherapy; Prognosis; Prospective Studies; radiotherapy tumour bed boost; Radiotherapy, Adjuvant - methods; Young Adult
• ISSN: 0936-6555; 1433-2981
• DOI: 10.1016/j.clon.2020.01.025

The European Organisation for Research and Treatment of Cancer (EORTC) 22,881–10,882 trial showed significant benefit of a radiotherapy boost (RTB) in women ≤40 years in a pre-hormone therapy (HT) era. We determined how the use of HT and RTB changed in response to clinical guidelines and whether the benefit of routine RTB was still observed in the HT era. Between 1996 and 2004, a provincial database identified all women ≤40 years with breast cancer who met the inclusion criteria of the EORTC trial. In total, 411 patients were classified into three eras defined by the guidelines: era 1 (discretionary HT, discretionary RTB); era 2 (routine HT, discretionary RTB); era 3 (routine HT, routine RTB). HT use, RTB use and cumulative incidence of local recurrence were calculated and compared across eras. HT use increased after the first policy change from 13% to 75% for oestrogen receptor-positive patients (P