Dataset Information

A population-based study of tumor gene expression and risk of breast cancer death among lymph node-negative patients.

ABSTRACT:

Introduction

The Oncotype DX assay was recently reported to predict risk for distant recurrence among a clinical trial population of tamoxifen-treated patients with lymph node-negative, estrogen receptor (ER)-positive breast cancer. To confirm and extend these findings, we evaluated the performance of this 21-gene assay among node-negative patients from a community hospital setting.

Methods

A case-control study was conducted among 4,964 Kaiser Permanente patients diagnosed with node-negative invasive breast cancer from 1985 to 1994 and not treated with adjuvant chemotherapy. Cases (n = 220) were patients who died from breast cancer. Controls (n = 570) were breast cancer patients who were individually matched to cases with respect to age, race, adjuvant tamoxifen, medical facility and diagnosis year, and were alive at the date of death of their matched case. Using an RT-PCR assay, archived tumor tissues were analyzed for expression levels of 16 cancer-related and five reference genes, and a summary risk score (the Recurrence Score) was calculated for each patient. Conditional logistic regression methods were used to estimate the association between risk of breast cancer death and Recurrence Score.

Results

After adjusting for tumor size and grade, the Recurrence Score was associated with risk of breast cancer death in ER-positive, tamoxifen-treated and -untreated patients (P = 0.003 and P = 0.03, respectively). At 10 years, the risks for breast cancer death in ER-positive, tamoxifen-treated patients were 2.8% (95% confidence interval [CI] 1.7-3.9%), 10.7% (95% CI 6.3-14.9%), and 15.5% (95% CI 7.6-22.8%) for those in the low, intermediate and high risk Recurrence Score groups, respectively. They were 6.2% (95% CI 4.5-7.9%), 17.8% (95% CI 11.8-23.3%), and 19.9% (95% CI 14.2-25.2%) for ER-positive patients not treated with tamoxifen. In both the tamoxifen-treated and -untreated groups, approximately 50% of patients had low risk Recurrence Score values.

Conclusion

In this large, population-based study of lymph node-negative patients not treated with chemotherapy, the Recurrence Score was strongly associated with risk of breast cancer death among ER-positive, tamoxifen-treated and -untreated patients.

SUBMITTER: Habel LA

PROVIDER: S-EPMC1557737 | biostudies-literature | 2006

REPOSITORIES: biostudies-literature

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Publications

A population-based study of tumor gene expression and risk of breast cancer death among lymph node-negative patients.

Habel Laurel A LA Shak Steven S Jacobs Marlena K MK Capra Angela A Alexander Claire C Pho Mylan M Baker Joffre J Walker Michael M Watson Drew D Hackett James J Blick Noelle T NT Greenberg Deborah D Fehrenbacher Louis L Langholz Bryan B Quesenberry Charles P CP

Breast cancer research : BCR 20060531 3

<h4>Introduction</h4>The Oncotype DX assay was recently reported to predict risk for distant recurrence among a clinical trial population of tamoxifen-treated patients with lymph node-negative, estrogen receptor (ER)-positive breast cancer. To confirm and extend these findings, we evaluated the performance of this 21-gene assay among node-negative patients from a community hospital setting.<h4>Methods</h4>A case-control study was conducted among 4,964 Kaiser Permanente patients diagnosed with no ...[more]

PMID: 16737553

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Project description:IntroductionAlthough lymph node negative (LN-) breast cancer patients have a good 10-years survival (?85%), most of them still receive adjuvant therapy, while only some benefit from this. More accurate prognostication of LN- breast cancer patient may reduce over- and under-treatment. Until now proliferation is the strongest prognostic factor for LN- breast cancer patients. The small molecule microRNA (miRNA) has opened a new window for prognostic markers, therapeutic targets and/or therapeutic components. Previously it has been shown that miR-18a/b, miR-25, miR-29c and miR-106b correlate to high proliferation.MethodsThe current study validates nine miRNAs (miR-18a/b miR-25, miR-29c, miR-106b, miR375, miR-424, miR-505 and let-7b) significantly correlated with established prognostic breast cancer biomarkers. Total RNA was isolated from 204 formaldehyde-fixed paraffin embedded (FFPE) LN- breast cancers and analyzed with quantitative real-time Polymerase Chain Reaction (qPCR). Independent T-test was used to detect significant correlation between miRNA expression level and the different clinicopathological features for breast cancer.ResultsStrong and significant associations were observed for high expression of miR-18a/b, miR-106b, miR-25 and miR-505 to high proliferation, oestrogen receptor negativity and cytokeratin 5/6 positivity. High expression of let-7b, miR-29c and miR-375 was detected in more differentiated tumours. Kaplan-Meier survival analysis showed that patients with high miR-106b expression had an 81% survival rate vs. 95% (P?=?0.004) for patients with low expression.ConclusionHigh expression of miR-18a/b are strongly associated with basal-like breast cancer features, while miR-106b can identify a group with higher risk for developing distant metastases in the subgroup of Her2 negatives. Furthermore miR-106b can identify a group of patients with 100% survival within the otherwise considered high risk group of patients with high proliferation. Using miR-106b as a biomarker in conjunction to mitotic activity index could thereby possibly save 18% of the patients with high proliferation from overtreatment.

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Dataset Information

A population-based study of tumor gene expression and risk of breast cancer death among lymph node-negative patients.

Introduction

Methods

Results

Conclusion

Publications

A population-based study of tumor gene expression and risk of breast cancer death among lymph node-negative patients.

Similar Datasets

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