- The 21-gene recurrence score assay (Oncotype DX):
- Is a reverse-transcriptase-polymerase-chain-reaction assay of:
- 16 prospectively selected genes and 5 reference genes
- Is a reverse-transcriptase-polymerase-chain-reaction assay of:
- Analysis is performed in:
- Paraffin-embedded tumor tissue
- This assay was developed from:
- NSABP B-14 and validated with data and specimens from NSABP B-20
- It estimates the 10-year risk of distant recurrence:
- By categorizing results into:
- Low-risk (RS<18) group
- Intermediate-risk (RS 18-30) group
- High-risk (RS>30) group
- By categorizing results into:
- A low recurrence score:
- Predicts little benefit of chemotherapy
- The 21-gene recurrence score assay is proven to be prognostic for women with:
- Node-negative
- ER-positive breast cancer:
- Treated with tamoxifen
- Retrospective data obtained via optional tumor banking:
- In accordance with the SWOG 8814 trial:
- Which demonstrated postmenopausal women with node-positive ER-positive tumors achieved:
- Superior survival when cyclophosphamide, doxorubicin, and fluorouracil was given before tamoxifen
- Which demonstrated postmenopausal women with node-positive ER-positive tumors achieved:
- The SWOG 8814 trial:
- Allowed for retrospective assessment of recurrence score on DFS by treatment group
- Analysis demonstrated the recurrence score results:
- To be both prognostic and predictive of benefit to adjuvant chemotherapy:
- As there was no added benefit to adjuvant systemic chemotherapy:
- In women with low recurrence scores and
- An improvement of DFS:
- In those with high recurrence scores
- As there was no added benefit to adjuvant systemic chemotherapy:
- To be both prognostic and predictive of benefit to adjuvant chemotherapy:
- In accordance with the SWOG 8814 trial:
- These hypothesis-generating results serve as preliminary basis:
- For the RxPonder trial:
- Which is currently enrolling as a phase III trial:
- Randomizing women with hormone receptor-positive and HER2-negative breast cancer involving 1 to 3 lymph nodes and a 21-gene assay recurrence score of 25 or less:
- To endocrine therapy alone versus chemotherapy followed by endocrine therapy
- Randomizing women with hormone receptor-positive and HER2-negative breast cancer involving 1 to 3 lymph nodes and a 21-gene assay recurrence score of 25 or less:
- Which is currently enrolling as a phase III trial:
- For the RxPonder trial:
- The 21-gene recurrence score:
- Is not used in patients with HER2-positive breast cancer
REFERENCES
- Paik S, Shak S, Tang G, et al. A multigene assay to predict recurrence of tamoxifen-treated, node-negative breast cancer. N Engl J Med. 2004;351(27):2817-2826.
- Paik S, Tang G, Shak S, et al. Gene expression and benefit of chemotherapy in women with node-negative, estrogen receptor-positive breast cancer. J Clin Oncol. 2006;24(23):3726-3734.
- Albain KS, Barlow WE, Shak S, et al. Prognostic and predictive value of the 21-gene recurrence score assay in postmenopausal women with node-positive, oestrogen-receptor-positive breast cancer on chemotherapy: a retrospective analysis of a randomised trial. Lancet Oncol. 2010;11(1):55-65.
- Ramsey SD, Barlow WE, Gonzalez-Angulo AM, et al. Integrating comparative effectiveness design elements and endpoints into a phase III, randomized clinical trial (SWOG S1007) evaluating oncotypeDX-guided management for women with breast cancer involving lymph nodes. Contemp Clin Trials. 2013;34(1):1-9.
#Arrangoiz #Surgeon #BreastSurgeon #CancerSurgeon #SurgicalOncology #BreastCancer
Rodrigo Arrangoiz MS, MD, FACS, FSSO 