Long-term risk of subsequent ipsilateral lesions after surgery with or without radiotherapy for ductal carcinoma in situ of the breast

TY - JOUR

T1 - Long-term risk of subsequent ipsilateral lesions after surgery with or without radiotherapy for ductal carcinoma in situ of the breast

AU - Grand Challenge PRECISION Consortium

AU - van Seijen, Maartje

AU - Lips, Esther H.

AU - Fu, Liping

AU - Giardiello, Daniele

AU - van Duijnhoven, Frederieke

AU - de Munck, Linda

AU - Elshof, Lotte E.

AU - Thompson, Alastair

AU - Sawyer, Elinor

AU - Ryser, Marc D.

AU - Hwang, E. Shelley

AU - Schmidt, Marjanka K.

AU - Elkhuizen, Paula H.M.

AU - Wesseling, Jelle

AU - Schaapveld, Michael

N1 - Funding Information: This work was supported by Cancer Research UK and by KWF Kankerbestrijding (ref. C38317/A24043). This content is solely the responsibility of the authors. The funder had no role in study design, data collection, analysis or interpretation or writing of the manuscript. Publisher Copyright: © 2021, The Author(s). Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2021/11/9

Y1 - 2021/11/9

N2 - Background: Radiotherapy (RT) following breast-conserving surgery (BCS) for ductal carcinoma in situ (DCIS) reduces ipsilateral breast event rates in clinical trials. This study assessed the impact of DCIS treatment on a 20-year risk of ipsilateral DCIS (iDCIS) and ipsilateral invasive breast cancer (iIBC) in a population-based cohort. Methods: The cohort comprised all women diagnosed with DCIS in the Netherlands during 1989–2004 with follow-up until 2017. Cumulative incidence of iDCIS and iIBC following BCS and BCS + RT were assessed. Associations of DCIS treatment with iDCIS and iIBC risk were estimated in multivariable Cox models. Results: The 20-year cumulative incidence of any ipsilateral breast event was 30.6% (95% confidence interval (CI): 28.9–32.6) after BCS compared to 18.2% (95% CI 16.3–20.3) following BCS + RT. Women treated with BCS compared to BCS + RT had higher risk of developing iDCIS and iIBC within 5 years after DCIS diagnosis (for iDCIS: hazard ratio (HR)age < 50 3.2 (95% CI 1.6–6.6); HRage ≥ 50 3.6 (95% CI 2.6–4.8) and for iIBC: HRage<50 2.1 (95% CI 1.4–3.2); HRage ≥ 50 4.3 (95% CI 3.0–6.0)). After 10 years, the risk of iDCIS and iIBC no longer differed for BCS versus BCS + RT (for iDCIS: HRage < 50 0.7 (95% CI 0.3–1.5); HRage ≥ 50 0.7 (95% CI 0.4–1.3) and for iIBC: HRage < 50 0.6 (95% CI 0.4–0.9); HRage ≥ 50 1.2 (95% CI 0.9–1.6)). Conclusion: RT is associated with lower iDCIS and iIBC risk up to 10 years after BCS, but this effect wanes thereafter.

AB - Background: Radiotherapy (RT) following breast-conserving surgery (BCS) for ductal carcinoma in situ (DCIS) reduces ipsilateral breast event rates in clinical trials. This study assessed the impact of DCIS treatment on a 20-year risk of ipsilateral DCIS (iDCIS) and ipsilateral invasive breast cancer (iIBC) in a population-based cohort. Methods: The cohort comprised all women diagnosed with DCIS in the Netherlands during 1989–2004 with follow-up until 2017. Cumulative incidence of iDCIS and iIBC following BCS and BCS + RT were assessed. Associations of DCIS treatment with iDCIS and iIBC risk were estimated in multivariable Cox models. Results: The 20-year cumulative incidence of any ipsilateral breast event was 30.6% (95% confidence interval (CI): 28.9–32.6) after BCS compared to 18.2% (95% CI 16.3–20.3) following BCS + RT. Women treated with BCS compared to BCS + RT had higher risk of developing iDCIS and iIBC within 5 years after DCIS diagnosis (for iDCIS: hazard ratio (HR)age < 50 3.2 (95% CI 1.6–6.6); HRage ≥ 50 3.6 (95% CI 2.6–4.8) and for iIBC: HRage<50 2.1 (95% CI 1.4–3.2); HRage ≥ 50 4.3 (95% CI 3.0–6.0)). After 10 years, the risk of iDCIS and iIBC no longer differed for BCS versus BCS + RT (for iDCIS: HRage < 50 0.7 (95% CI 0.3–1.5); HRage ≥ 50 0.7 (95% CI 0.4–1.3) and for iIBC: HRage < 50 0.6 (95% CI 0.4–0.9); HRage ≥ 50 1.2 (95% CI 0.9–1.6)). Conclusion: RT is associated with lower iDCIS and iIBC risk up to 10 years after BCS, but this effect wanes thereafter.

UR - http://www.scopus.com/inward/record.url?scp=85113305873&partnerID=8YFLogxK

U2 - 10.1038/s41416-021-01496-6

DO - 10.1038/s41416-021-01496-6

M3 - Article

AN - SCOPUS:85113305873

SN - 0007-0920

VL - 125

SP - 1443

EP - 1449

JO - British journal of cancer

JF - British journal of cancer

IS - 10

ER -