Reference
Complete the bibliographic reference for the article according to AJE format.

Paik, Soonmyung, et al. A multigene assay to predict recurrence of tamoxifen-treated, node-negative breast cancer. New Engl J Med 2004;351:2817-26.

Category of HuGE information
Specify the types of information (from the list below) available in the article:

1. Prevalence of gene variant
2. Gene-disease association
3. Gene-environment interaction
4. Gene-gene interaction
5. Genetic test evaluation/monitoring

2. Gene-disease association: breast cancer

Study hypotheses or purpose
The authors study hypotheses or main purpose for conducting the study

Gene(s)
Identification of the following:

1. Gene name
2. Chromosome location
3. Gene product/function
4. Alleles
5. OMIM #
6. GDPInfo link

Gene name: Ki67
Chromosome location: 10q25-qter
Gene product/function:
Alleles:
OMIM #: 176741
Go to GDPInfo Genes A-Z result

Gene name: STK15
Chromosome location: 20q13.2-q13.3
Gene product/function:
Alleles:
OMIM #: 602687
Go to GDPInfo Genes A-Z result

Gene name: Survivin
Chromosome location: 17q25
Gene product/function:
Alleles:
OMIM #: 603352
Go to GDPInfo Genes A-Z result

Gene name: cyclin B1
Chromosome location: 5q12
Gene product/function:
Alleles:
OMIM #: 123836
Go to GDPInfo Genes A-Z result

Gene name: MYBL2
Chromosome location: 20q13.1
Gene product/function:
Alleles:
OMIM #: 601415
Go to GDPInfo Genes A-Z result

Gene name: MMPH11 (Stromolysin 3)
Chromosome location: 22q11.2
Gene product/function:
Alleles:
OMIM #: 185261
Go to GDPInfo Genes A-Z result

Gene name: CTSL2 (Cathepsin L2)
Chromosome location: 9q22.2
Gene product/function:
Alleles:
OMIM #: 603308
Go to GDPInfo Genes A-Z result

Gene name: HER2
Chromosome location: 17q21.1
Gene product/function:
Alleles:
OMIM #: 164870
Go to GDPInfo Genes A-Z result

Gene name: GRB7
Chromosome location: 17q21-q22
Gene product/function:
Alleles:
OMIM #: 601522
Go to GDPInfo Genes A-Z result

Gene name: GSTM1
Chromosome location: 1p13
Gene product/function:
Alleles:
OMIM #: 138350
Go to GDPInfo Genes A-Z result

Gene name: CD68
Chromosome location: 17p13
Gene product/function:
Alleles:
OMIM #: 153634
Go to GDPInfo Genes A-Z result

Gene name: BAG1
Chromosome location: 9p12
Gene product/function:
Alleles:
OMIM #: 601497
Go to GDPInfo Genes A-Z result

Gene name: ER
Chromosome location: 6q25.1
Gene product/function:
Alleles:
OMIM #: 133430
Go to GDPInfo Genes A-Z result

Gene name: PGR
Chromosome location: 11q22
Gene product/function:
Alleles:
OMIM #: 607311
Go to GDPInfo Genes A-Z result

Gene name: BCL2
Chromosome location: 18q21.3
Gene product/function:
Alleles:
OMIM #: +151430
Go to GDPInfo Genes A-Z result

Gene name: SCUBE2
Chromosome location: 11p15.3
Gene product/function:
Alleles:
OMIM #:
Go to GDPInfo Genes A-Z result

Environmental factor(s)
Identification of the major environmental factors studied (infectious, chemical, physical, nutritional, and behavioral)

N/A

Health outcome(s)
Identification of the major health outcome(s) studied

No recurrence of breast cancer.

1. Case-control
2. Cohort 
3. Cross-sectional
4. Descriptive or case series
5. Clinical trial
6. Population screening

2. Cohort (retrospective)

1. Disease case definition
2. Exclusion criteria
3. Gender
4. Race/ethnicity
5. Age
6. Time period
7. Geographic location
8. Number of participants

1. Control selection criteria
2. Matching variables
3. Exclusion criteria
4. Gender
5. Race/ethnicity
6. Age
7. Time period
8. Geographic location
9. Number of participants

1. Control selection criteria:
2. Matching variables:
3. Exclusion criteria:
4. Gender:
5. Race/ethnicity: [if not specified, state ‘not specified']
6. Age:
7. Time period:
8. Geographic location: [if not specified, state ‘not specified'] Number of participants: N (% of total eligible)

Cohort definition
For study designs 2, 3, and 6, define the following if available:

1. Cohort selection criteria
2. Exclusion criteria
3. Gender
4. Race/ethnicity
5. Age
6. Time period
7. Geographic location
8. Number of participants (% of total eligible)

1. Cohort selection criteria: Tamoxifen-treated breast cancer patients from NSABP trial with available tumor blocks
2. Exclusion criteria: insufficient tumor tissue, insufficient RNA, weak RT-PCR signal
3. Gender: female
4. Race/ethnicity: not specified
5. Age: less than 40 to over 60
6. Time period: 10 years
7. Geographic location: USA & Canada
8. Number of participants: 668(98% of total eligible)

1. Environmental factor
2. Exposure assessment
3. Exposure definition
4. Number of participants with exposure data (% of total eligible)

1. Gene
2. DNA source
3. Methodology
4. Number of participants genotyped (% of total eligible) 

1. Gene: Ki67, STK15, Survivin, CCNB1(cyclin B1), MYBL2, MMP11 (stromolysin 3), CTSL2 (cathepsin L2), HER2, GRB7, GSTM1, CD68, BAG1, ER, PGR, BCL2, SCUBE2
2. DNA source: paraffin-embedded tumor tissue
3. Genotyping method: reverse-transcriptase-polymerase-chain-reaction (RT-PCR)
4. Number of participants genotyped: 668(100% of total eligible)

Analysis
Comment on the analysis carried out by the author(s), e.g. matching, modeling or statistical tests used. Were the analyses appropriate?

A recurrence scoring system was developed based on the level of expression of the 16 cancer-associated genes in the tumors. Risk categories were determined by analyzing the results of three previous studies. Three pathologists independently analyzed the tumors to rate them for likelihood of recurrence. Kaplan-Meier estimate of the rate of distant recurrence at 10 years for the proportion of patients in low, intermediate, and high risk categories.

1. Prevalence of gene variant
2. Gene-disease association
3. Gene-environment interaction
4. Gene-gene interaction
5. Genetic test evaluation/monitoring

2. Gene-disease association – patients with low risk-of-recurrence scores were less likely to have a distant recurrence of breast cancer (93.2% were cancer-free) after 10 years.

Patients with high risk-of-recurrence scores were more likely to have a distant recurrence of breast cancer (only 69.5% were cancer-free) after 10 years.

The likelihood of distant recurrence in tamoxifen-treated patients with node-negative, estrogen-receptor-positive breast cancer can be quantified using a reference score based on the expression of 16 genes in tumor tissue.

• The reference score provides a continuous scoring tool to help patients and their healthcare providers determine the level of risk of recurrence of breast cancer.

• The study looked only at women who had been treated with tamoxifen and chemotherapy, so some non-recurrence of breast cancer could have been due to good treatment response and not because of lower levels of expression of the cancer genes.

• Tumor grading is subjective to some extent and interobserver reproducibility of results is only moderate at best.

• The presence of the genes studied cannot be used to determine which women should take tamoxifen.