Influence on Histologic, Immunohistochemical, and Molecular Subtypes on Therapeutics
Breast cancer is a heterogeneous disease that may be classified according to clinical, histopathological, immunohistochemical, and, more recently, molecular characteristics. The features of breast cancer gene expression led to the classification of tumors into distinct molecular subtypes. These subtypes present different clinical outcomes, including different responses to available therapies. The incorporation of gene signatures could better identify which patients may benefit from chemotherapy and the subtypes that have the best response to neoadjuvant chemotherapy. In this chapter, the main subgroups and their influence on therapy are described.
KeywordsSystemic treatment Molecular subtype Genomic profile Disease burden
- 1.Cardoso F, Vant Veer LJ, Bogaerts L, et al. 70 gene signatures as an aid to treatment decisions in early breast cancer. New Eng J Med. 2016;375(8):717–29. A randomized study (Mindact - microarray in node negative disease may avoid chemotherapy in Breast Cancer) that evaluated the employment of mammaprint in 6,693 women and compared the genomic risk (employing mammaprint) combined to clinical risk (assessed by Adjuvant On line). There was no benefit to undergo chemotherapy treatment in low clinical risk and high genomic risk patients, as well as in those of high clinical risk and low genomic risk. CrossRefGoogle Scholar
- 2.Krop I, Ismaila N, Andre F, et al. Use of biomarkers to guide decisions on adjuvant systemic therapy for women with early_stage invasive breast cancer: American Society of Clinical Oncology Practice Guideline Focused Update. J Clin Oncol on line. 2017;10. Recommendations regarding biological markers, encompassing genetic signatures, in treatment decision. Google Scholar
- 3.Mamounas E, Tang G, Fisher B, et al. Association between the 21-gene recurrence score assay and risk of locoregional recurrence in node-negative, estrogen receptor–positive breast cancer: results from NSABP B-14 and NSABP B-20. J Clin Oncol. 2010;28:1677–83. It evaluated the local recurrence in patients from B14 and B20 studies and demonstrated an association between RS and local recurrence. CrossRefGoogle Scholar
- 5.Sparano JA, Gray RJ, Makower DF, et al. Prospective validation of a 21-Gene expression assay in breast cancer. New Eng J Med. 2015;373(21):2005–14. Study that evaluated the recurrence of breast cancer in T1-2, N0, N0, RH +, and Her-2 negative tumors, classified as low risk recurrence score (RS <10) according to ODX 21, included in the TaylorX study. Among the 1,626 women (15.9% of the 10,223 women included) with RS <10 and who solely received hormone therapy not followed by chemotherapy after local treatment, overall 5-year survival was 98%, demonstrating safety to dismiss the adjuvant chemotherapy in this population. CrossRefGoogle Scholar