ABSTRACT
PURPOSE: Adjuvant therapy decisions may in part be based on results of Oncotype DX Breast Recurrence Score® (RS) testing of primary tumors. When necessary, lymph node metastases may be considered as a surrogate. Here we evaluate the concordance in gene expression between primary breast cancers and synchronous lymph node metastases, based on results from quantitative RT-PCR-based RS testing between matched primary tumors and synchronous nodal metastases. METHODS: This retrospective, exploratory study included patients (≥ 18 years old) treated at our center (2005-2009) who had ER+ , HER2-negative invasive breast cancer and synchronous nodal metastases with available tumor blocks from both sites. Paired tissue blocks underwent RS testing, and RS and single-gene results for ER, PR, and HER2 were explored between paired samples. RESULTS: A wide distribution of RS results in tumors and in synchronous nodal metastases were modestly correlated between 84 paired samples analyzed (Pearson correlation 0.69 [95% CI 0.55-0.78]). Overall concordance in RS group classification between samples was 63%. ER, PR, and HER2 by RT-PCR between the primary tumor and lymph node were also modestly correlated (Pearson correlation [95% CI] 0.64 [0.50-0.75], 0.64 [0.49-0.75], and 0.51 [0.33-0.65], respectively). Categorical concordance (positive or negative) was 100% for ER, 77% for PR, and 100% for HER2. CONCLUSIONS: There is modest correlation in continuous gene expression, as measured by the RS and single-gene results for ER, PR, and HER2 between paired primary tumors and synchronous nodal metastases. RS testing for ER+ breast cancer should continue to be based on analysis of primary tumors.
Subject(s)
Biomarkers, Tumor , Breast Neoplasms/diagnosis , Breast Neoplasms/genetics , Genomics , Lymph Nodes/pathology , Adult , Aged , Aged, 80 and over , Biopsy , Female , Genomics/methods , Humans , Lymphatic Metastasis , Middle Aged , Neoplasm Recurrence, Local , Neoplasm Staging , Retrospective Studies , Young AdultABSTRACT
CASE STUDY: Ms. J is a 55-year-old woman who was diagnosed with stage IIIA colon cancer three months ago. Prior to her diagnosis, she experienced an unintentional 17-pound weight loss. She underwent an exploratory laparotomy with colon resection. Following recovery from her surgery, she began an adjuvant chemotherapy regimen of 5-fluorouracil, leucovorin, and oxaliplatin. She presents to the clinic today for her third chemotherapy treatment.
