Triple-Negative Phenotype Boosts Prognostic Power of Traditional Staging
Incorporating receptor status could improve TNM staging prognostic accuracy for women with ductal breast carcinoma
- Date: 06 Dec 2013
- Author: Lynda Williams, Senior medwireNews Reporter
- Topic: Breast Cancer / Imaging, Diagnosis and Staging / Pathology/Molecular Biology
medwireNews: The tumour node metastasis (TNM) staging system for breast cancer should take into consideration the triple-negative Phenotype (TNP), US researchers believe.
The team found that adjusting for oestrogen receptor (ER), progesterone receptor (PR), and human Epidermal growth factor 2 (HER2) status during TNM staging significantly altered the prognosis of 1842 women with primary invasive ductal breast carcinoma.
Over a median of 4.3 years of follow-up, the survival of the 15.2% of women with TNP breast cancer was comparable to that of the women with non-TNP disease that was one stage higher, report Armando Giuliano, from Cedars-Sinai Medical Center in Los Angeles, California, and co-workers.
Thus, the 5-year overall survival for women with stage I TNP was similar to that of women with non-TNP stage II disease (92.2% vs. 93.4%), while stage II TNP matched stage III non-TNP (83.9% vs. 78.5%) and stage III TNP approached that of stage IV non-TNP (58.4% vs. 34.6%). For women with stage IV TNP tumours, the 5-year overall survival rate fell to 14.3%.
Adjusting the TNM staging system to upstage all patients with TNP breast cancer altered the TNM stage of around 15% of patients. Of note, the number of patients with stage I disease significantly decreased from 51.1% with TNM alone to 44.6% when including TNP, the researchers report in JAMA Surgery.
Moreover, multivariate analysis showed that age (hazard ratio [HR]=1.05), tumour (HR=1.59), node (HR=1.44), metastasis (HR=5.45), and TNP phenotype (HR=2.71) all significantly predicted 5-year overall survival. And the addition of TNP phenotype – also known as TNM-Biology (B) – to the staging system significantly improved its prognostic value.
“Stage reclassification that incorporates TNP status can be a first step in recognizing the importance of nonanatomic factors in the staging of breast cancer and could help clinicians provide better cancer care,” says the team.
“This study provides a preliminary proof of principle that the breast cancer staging system could be improved by the inclusion of biomarkers that complement TNM and are available worldwide.”
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