TY - JOUR
T1 - Breast conserving surgery with intraoperative electron beam radiation therapy for low-risk breast cancer
T2 - Five-year follow-up of 306 patients
AU - de Jonge, Charlotte
AU - Schipper, Robert-Jan
AU - Walstra, Coco J. E. F.
AU - Van Riet, Yvonne E.
AU - Verrijssen, An-Sofie E.
AU - Voogd, Adri C.
AU - van der Sangen, Maurice J. C.
AU - Theuws, Jacqueline
AU - Degreef, Ellen
AU - Gielens, Maaike P. M.
AU - Bloemen, Johanne G.
AU - van den Berg, Hetty A.
AU - Nieuwenhuijzen, Grard A. P.
PY - 2024/10/1
Y1 - 2024/10/1
N2 - Recent studies have reported a higher than expected risk of ipsilateral breast tumor recurrence (IBTR) after breast conserving surgery (BCS) and a single dose of electron beam intra-operative radiotherapy (IORT). This finding was the rationale to perform a retrospective single center cohort study evaluating the oncologic results of consecutive patients treated with BCS and IORT. Women were eligible if they had clinical low-risk (N0, ≤2 cm unifocal, Bloom and Richardson grade 1–2), estrogen receptor-positive and human-epidermal-growth-factor-receptor-2-negative breast cancer. Prior to BCS, pN0 status was determined by sentinel lymph node biopsy. Data on oncologic follow-up were analyzed. Between 2012 and 2019, 306 consecutive patients were treated and analyzed, with a median age of 67 (50–86) years at diagnosis. Median follow-up was 60 (8–120) months. Five-year cumulative risk of IBTR was 13.4% (95% confidence interval [CI] 9.4–17.4). True in field recurrence was present in 3.9% of the patients. In 4.6% of the patients, the IBRT was classified as a local recurrence due to seeding of tumor cells in the cutis or subcutis most likely related to percutaneous biopsy. In 2.9% of the patients, the IBRT was a new outfield primary tumor. Three patients had a regional lymph node recurrence and two had distant metastases as first event. One breast cancer-related death was observed. Estimated 5-year overall survival was 89.8% (95% CI 86.0–93.6). In conclusion, although some of IBTR cases could have been prevented by adaptations in biopsy techniques and patient selection, BCS followed by IORT was associated with a substantial risk of IBTR.
AB - Recent studies have reported a higher than expected risk of ipsilateral breast tumor recurrence (IBTR) after breast conserving surgery (BCS) and a single dose of electron beam intra-operative radiotherapy (IORT). This finding was the rationale to perform a retrospective single center cohort study evaluating the oncologic results of consecutive patients treated with BCS and IORT. Women were eligible if they had clinical low-risk (N0, ≤2 cm unifocal, Bloom and Richardson grade 1–2), estrogen receptor-positive and human-epidermal-growth-factor-receptor-2-negative breast cancer. Prior to BCS, pN0 status was determined by sentinel lymph node biopsy. Data on oncologic follow-up were analyzed. Between 2012 and 2019, 306 consecutive patients were treated and analyzed, with a median age of 67 (50–86) years at diagnosis. Median follow-up was 60 (8–120) months. Five-year cumulative risk of IBTR was 13.4% (95% confidence interval [CI] 9.4–17.4). True in field recurrence was present in 3.9% of the patients. In 4.6% of the patients, the IBRT was classified as a local recurrence due to seeding of tumor cells in the cutis or subcutis most likely related to percutaneous biopsy. In 2.9% of the patients, the IBRT was a new outfield primary tumor. Three patients had a regional lymph node recurrence and two had distant metastases as first event. One breast cancer-related death was observed. Estimated 5-year overall survival was 89.8% (95% CI 86.0–93.6). In conclusion, although some of IBTR cases could have been prevented by adaptations in biopsy techniques and patient selection, BCS followed by IORT was associated with a substantial risk of IBTR.
KW - breast cancer
KW - intra-operative radiotherapy
KW - recurrence
KW - IRRADIATION
KW - RADIOTHERAPY
KW - RECURRENCE
KW - MASTECTOMY
KW - IORT
KW - LOCALIZATION
KW - SURVIVAL
KW - ELIOT
U2 - 10.1002/ijc.35033
DO - 10.1002/ijc.35033
M3 - Article
SN - 0020-7136
VL - 155
SP - 1237
EP - 1247
JO - International Journal of Cancer
JF - International Journal of Cancer
IS - 7
ER -