51. New clinical and biological insights from the international TARGIT-A randomised trial of targeted intraoperative radiotherapy during lumpectomy for breast cancer
- Author
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Vaidya, JS, Bulsara, M, Baum, M, Wenz, F, Massarut, S, Pigorsch, S, Alvarado, M, Douek, M, Saunders, C, Flyger, H, Eiermann, W, Brew-Graves, C, Williams, NR, Potyka, I, Roberts, N, Bernstein, M, Brown, D, Sperk, E, Laws, S, Suetterlin, M, Corica, T, Lundgren, S, Holmes, D, Vinante, L, Bozza, F, Pazos, M, Le Blanc-Onfroy, M, Gruber, G, Polkowski, W, Dedes, KJ, Niewald, M, Blohmer, J, McReady, D, Hoefer, R, Kelemen, P, Petralia, G, Falzon, M, Joseph, D, Tobias, JS, Vaidya, JS, Bulsara, M, Baum, M, Wenz, F, Massarut, S, Pigorsch, S, Alvarado, M, Douek, M, Saunders, C, Flyger, H, Eiermann, W, Brew-Graves, C, Williams, NR, Potyka, I, Roberts, N, Bernstein, M, Brown, D, Sperk, E, Laws, S, Suetterlin, M, Corica, T, Lundgren, S, Holmes, D, Vinante, L, Bozza, F, Pazos, M, Le Blanc-Onfroy, M, Gruber, G, Polkowski, W, Dedes, KJ, Niewald, M, Blohmer, J, McReady, D, Hoefer, R, Kelemen, P, Petralia, G, Falzon, M, Joseph, D, and Tobias, JS
- 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 https://targit.org.uk/addrt . 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. TRIAL REGISTRATION: ISRCTN34086741 (21/7/2004), NCT00983684 (24/9/2009).
- Published
- 2021