Abstract 3736
Background
For decades, conventionally fractionated whole breast irradiation (CF-WBI) was used after breast conserving surgery (BCS). Pivotal phase 3 trials on hypofractionated-WBI (HF-WBI) showed its non-inferiority as compared to CF-WBI. However, younger patients (<60 years) are not currently worldwide treated with HF-WBI. The aim of this multi-center comparative study is to confirm the safety of HF-WBI in a real-life series of younger patients.
Methods
Between 2010 and 2016, a total of 786 patients aged less than 60 years old with early stage breast cancer were treated with postoperative WBI after BCS in three breast cancer centers: 340 underwent HF-WBI while 446 were treated with CF-WBI. Acute toxicity was evaluated at the end of WBI. Late toxicity was evaluated at 6, 12, 24, and 36 months.
Results
At univariate logistic analysis, hypofractionation showed a significant protective effect in terms of acute edema (p = 0.0001), acute wet desquamation (p = 0.009), chronic edema (p = 0.0001), chronic erythema/pigmentation (p = 0.0001), and breast fibrosis (p = 0.0002). At multivariate logistic analysis, hypofractionation was independent significant factor for acute edema (OR 0.09, 95% CI 0.02 to 0.48; p = 0.005), acute wet desquamation (OR 0.07, 95% CI 0.009 to 0.59; p = 0.014), and chronic edema (OR 0.18, 95% CI 0.04 to 0.75; p = 0.018). Significant association between individual characteristics and toxicity (grade 2 or more) are summarized in Table.Table:
215P
Toxicity | N | Protective factor | p-value | OR (95%CI) | Risk factor | p-value | OR (95%CI) |
---|---|---|---|---|---|---|---|
Acute edema | 43 | Hypofractionation Dmax/Prescribed dose° <107% | 0.0001 0.001 | 0.09 (0.03-0.30) 0.16 (0.06-0.46) | Chemotherapy | 0.002 | 2.63 (1.42-4.90) |
Chronic edema | 50 | Hypofractionation Dmax/Prescribed dose° <107% | 0.0001 0.003 | 0.20 (0.09-0.44) 0.31 (0.14-0.66) | EIC presence Boost dose >10 Gy Breast size >492 cc | 0.0001 0.032 0.003 | 3.0 (1.66-5.46) 9.02 (1.21-67.45) 2.67 (1.41-5.05) |
Acute erythema/ pigmentation | 163 | HER2 positive status Trastuzumab | 0.002 0.022 | 0.30 (0.14-0.63) 0.39 (0.18-0.87) | Smoking habits Boost dose >10 Gy Breast size >492 cc | 0.001 0.038 0.002 | 2.14 (1.37-3.32) 2.60 (1.06-6.41) 1.78 (1.24-2.54) |
Chronic erythema/ pigmentation | 110 | Hypofractionation Dmax/Prescribed dose° <107% | 0.0001 0.001 | 0.40 (0.25-0.63) 0.45 (0.28-0.73) | EIC presence Positive FSM Boost dose >10 Gy Breast size >492 cc | 0.0001 0.002 0.007 0.034 | 2.39 (1.54-3.71) 3.47 (1.56-7.71) 15.43 (2.08-114.3) 1.58 (1.04-2.41) |
Acute wet desquamation | 20 | Hypofractionation Dmax/Prescribed dose° <107% | 0.009 0.047 | 0.14 (0.03-0.61) 0.29 (0.08-0.99) | - | - | - |
Breast fibrosis | 117 | Hypofractionation Tumor grade Ki67 index Dmax/Prescribed dose° <107% | 0.0002 0.022 0.023 0.017 | 0.44 (0.29-0.68) 0.53 (0.31-0.92) 0.60 (0.38-0.93) 0.58 (0.37-0.91) | EIC presence Boost dose >10 Gy Breast size >492 cc | 0.0001 0.022 0.0001 | 3.03 (1.99-4.62) 6.76 (2.04-22.45) 2.84 (1.83-4.41) |
Conclusions
HF-WBI showed significantly improved toxicity outcomes in terms of both acute skin edema and wet desquamation, and chronic skin edema. HF-WBI after BCS should replace CF-WBI independently of age.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
5793 - Real world treatment sequencing patterns in secondary breast cancer (SBC): Pathway visualisation using national datasets.
Presenter: Ashley Horne
Session: Poster Display session 2
Resources:
Abstract
3185 - Utilization Pattern of Bone Targeting Agents in Patients with Solid Tumor in Taiwan, Hong Kong and Korea
Presenter: Shi Jie Lai
Session: Poster Display session 2
Resources:
Abstract
3705 - Clinico-pathological Features and Prognosis of Patients with Pregnancy Associated Breast Cancer – A Matched Case Control Study
Presenter: Ruyan Zhang
Session: Poster Display session 2
Resources:
Abstract
1421 - TRYbeCA-2: A Randomized Phase 2/3 Study of Eryaspase in Combination with Gemcitabine and Carboplatin Chemotherapy versus Chemotherapy Alone As First-Line Treatment in Patients with Metastatic or Locally Recurrent Triple-Negative Breast Cancer
Presenter: Ahmad Awada
Session: Poster Display session 2
Resources:
Abstract
4119 - CONTESSA TRIO: A Multinational, Multicenter, Phase 2 Study of Tesetaxel plus 3 Different PD-(L)1 Inhibitors in Patients with Metastatic Triple-Negative Breast Cancer (TNBC) and Tesetaxel Monotherapy in Elderly Patients with HER2- Metastatic Breast Cancer (MBC)
Presenter: Sara Tolaney
Session: Poster Display session 2
Resources:
Abstract
4545 - Bintrafusp alfa (M7824) and Eribulin Mesylate in Treating Patients With Metastatic Triple Negative Breast Cancer (TNBC)(NCT03579472)
Presenter: Jennifer Litton
Session: Poster Display session 2
Resources:
Abstract
3340 - Effectiveness of Olaparib Plus Trastuzumab in HER2[+], BRCA–mutated (BRCAm) or Homologous Recombination Deficient (HRD) Advanced Breast Cancer (ABC) patients (pts). The OPHELIA Study
Presenter: José Enrique Alés-Martínez
Session: Poster Display session 2
Resources:
Abstract
1113 - RIBOB : A Study on the efficacy and safety of Ribociclib in combination with letrozole in Older women (≥70 years) with hormone receptor-positive (HR+) HER2-negative (HER2-) advanced Breast cancer (aBC) with no prior systemic therapy for advanced disease
Presenter: Cindy Kenis
Session: Poster Display session 2
Resources:
Abstract
4025 - RIbociclib plus Goserelin with Hormonal Therapy versus physician Choice chemotherapy in premenopausal or perimenopausal patients with HR+, HER2– inoperable locally advanced or metastatic breast cancer – RIGHT Choice study
Presenter: Nagi El Saghir
Session: Poster Display session 2
Resources:
Abstract
3516 - Palbociclib Rechallenge in Hormone Receptor (HR)[+]/HER2[-] Advanced Breast Cancer (ABC). PALMIRA Trial
Presenter: Antonio Llombart Cussac
Session: Poster Display session 2
Resources:
Abstract