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- Sjöström, Martin, et al.
(author)
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Clinicogenomic Radiotherapy Classifier Predicting the Need for Intensified Locoregional Treatment After Breast-Conserving Surgery for Early-Stage Breast Cancer.
- 2019
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In: Journal of clinical oncology : official journal of the American Society of Clinical Oncology. - 1527-7755. ; 37:35, s. 3340-3349
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Journal article (peer-reviewed)abstract
- Most patients with early-stage breast cancer are treated with adjuvant radiotherapy (RT) after breast-conserving surgery (BCS) to prevent locoregional recurrence (LRR). However, no genomic tools are used currently to select the optimal RT strategy.We profiled the transcriptome of primary tumors on a clinical grade assay from the SweBCG91-RT trial, in which patients with node-negative breast cancer were randomly assigned to either whole-breast RT after BCS or no RT. We derived a new classifier, Adjuvant Radiotherapy Intensification Classifier (ARTIC), comprising 27 genes and patient age, in three publicly available cohorts, then independently validated ARTIC for LRR in 748 patients in SweBCG91-RT. We also compared previously published genomic signatures for ability to predict benefit from RT in SweBCG91-RT.ARTIC was highly prognostic for LRR in patients treated with RT (hazard ratio [HR], 3.4; 95% CI, 2.0 to 5.9; P < .001) and predictive of RT benefit (Pinteraction = .005). Patients with low ARTIC scores had a large benefit from RT (HR, 0.33 [95% CI, 0.21 to 0.52], P < .001; 10-year cumulative incidence of LRR, 6% v 21%), whereas those with high ARTIC scores benefited less from RT (HR, 0.73 [95% CI, 0.44 to 1.2], P = .23; 10-year cumulative incidence of LRR, 25% v 32%). In contrast, none of the eight previously published signatures were predictive of benefit from RT in SweBCG91-RT.ARTIC identified women with a substantial benefit from RT as well as women with a particularly elevated LRR risk in whom whole-breast RT was not sufficiently effective and, thus, in whom intensified treatment strategies such as tumor-bed boost, and possibly regional nodal RT, should be considered. To our knowledge, ARTIC is the first classifier validated as predictive of benefit from RT in a phase III clinical trial with patients randomly assigned to receive or not receive RT.
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| 2. |
- Sjöström, Martin, et al.
(author)
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Comprehensive transcriptomic profiling identifies breast cancer patients who may be spared adjuvant systemic therapy.
- 2020
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In: Clinical cancer research : an official journal of the American Association for Cancer Research. - 1078-0432. ; 26:1, s. 171-182
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Journal article (peer-reviewed)abstract
- There is currently no molecular signature in clinical use for adjuvant endocrine therapy omission in breast cancer. Given the unique trial design of SweBCG91-RT, where adjuvant endocrine and chemotherapy were largely unadministered, we sought to evaluate the potential of transcriptomic profiling for identifying patients who may be spared adjuvant endocrine therapy.We performed a whole transcriptome analysis of SweBCG91-RT, a randomized phase III trial of +/- radiotherapy after breast-conserving surgery for node-negative stage I-IIA breast cancer. 92% of patients were untreated by both adjuvant endocrine therapy and chemotherapy. We calculated 15 transcriptomic signatures from the literature and combined them into an Average Genomic Risk, which was further used to derive a novel 141-gene signature (MET141). All signatures were then independently examined in SweBCG91-RT, and in the publicly-available METABRIC cohort.In SweBCG91-RT, 454 patients were node-negative, post-menopausal and systemically untreated with ER-positive, HER2-negative cancers, which constitutes a low-risk subgroup and potential candidates for therapy omission. Most transcriptomic signatures were highly prognostic for distant metastasis, but considerable discordance was observed on the individual patient level. Within the MET141 low-risk subgroup (lowest 25th percentile of scores), 95% of patients were free of metastasis at 15 years even in the absence of adjuvant endocrine therapy. In a clinically low-risk subgroup of the METABRIC cohort not treated with systemic therapy, no breast cancer death occurred among the MET141 low-risk patients.Transcriptomic profiling identifies patients with an excellent outcome without any systemic adjuvant therapy in clinically low-risk patients of the SweBCG91-RT and METABRIC cohorts.
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