New clinical and biological insights from the international TARGIT-A randomised trial of targeted intraoperative radiotherapy during lumpectomy for breast cancer

Vaidya, Jayant S.; Bulsara, Max; Baum, Michael; Wenz, Frederik; Massarut, Samuele; Pigorsch, Steffi; Alvarado, Michael; Douek, Michael; Saunders, Christobel; Flyger, Henrik; Eiermann, Wolfgang; Brew-Graves, Chris; Williams, Norman R.; Potyka, Ingrid; Roberts, Nicholas; Bernstein, Marcelle; Brown, Douglas; Sperk, Elena; Laws, Siobhan; Suetterlin, Marc; Corica, Tammy; Lundgren, Steinar; Holmes, Dennis; Vinante, Lorenzo; Bozza, Fernando; Pazos, Montserrat; Le Blanc-Onfroy, Magali; Gruber, Guenther; Polkowski, Wojciech; Dedes, Konstantin J.; Niewald, Marcus; Blohmer, Jens; McReady, David; Hoefer, Richard; Kelemen, Pond; Petralia, Gloria; Falzon, Mary; Joseph, David and Tobias, Jeffrey S. (2021): New clinical and biological insights from the international TARGIT-A randomised trial of targeted intraoperative radiotherapy during lumpectomy for breast cancer. In: British Journal of Cancer, Vol. 125, No. 3: pp. 380-389

Abstract

BACKGROUND: The TARGIT-A trial reported risk-adapted targeted intraoperative radiotherapy (TARGIT-IORT) during lumpectomy for breast cancer to be as effective as whole-breast external beam radiotherapy (EBRT). Here, we present further detailed analyses. METHODS: In total, 2298 women (>= 45 years, invasive ductal carcinoma <= 3.5 cm, cN0-N1) were randomised. We investigated the impact of tumour size, grade, ER, PgR, HER2 and lymph node status on local recurrence-free survival, and of local recurrence on distant relapse and mortality. We analysed the predictive factors for recommending supplemental EBRT after TARGIT-IORT as part of the risk-adapted approach, using regression modelling. Non-breast cancer mortality was compared between TARGIT-IORT plus EBRT vs. EBRT. RESULTS: Local recurrence-free survival was no different between TARGIT-IORT and EBRT, in every tumour subgroup. Unlike in the EBRT arm, local recurrence in the TARGIT-IORT arm was not a predictor of a higher risk of distant relapse or death. Our new predictive tool for recommending supplemental EBRT after TARGIT-IORT is at . Non-breast cancer mortality was significantly lower in the TARGIT-IORT arm, even when patients received supplemental EBRT, HR 0.38 (95% CI 0.17-0.88) P = 0.0091. CONCLUSION: TARGIT-IORT is as effective as EBRT in all subgroups. Local recurrence after TARGIT-IORT, unlike after EBRT, has a good prognosis. TARGIT-IORT might have a beneficial abscopal effect.

• Item Type: Journal article
• Faculties: Medicine
• Subjects: 600 Technology > 610 Medicine and health
• ISSN: 0007-0920
• Language: English