Prognostic utility of the 21-gene assay in hormone receptor-positive operable breast cancer compared with classical clinicopathologic features.
OBJECTIVE
Adjuvant! is a standardized validated decision aid that projects outcomes in operable breast cancer based on classical clinicopathologic features and therapy. Genomic classifiers offer the potential to more accurately identify individuals who benefit from chemotherapy than clinicopathologic features.


METHODS
A sample of 465 patients with hormone receptor (HR) -positive breast cancer with zero to three positive axillary nodes who did (n = 99) or did not have recurrence after chemohormonal therapy had tumor tissue evaluated using a 21-gene assay. Histologic grade and HR expression were evaluated locally and in a central laboratory.


RESULTS
Recurrence Score (RS) was a highly significant predictor of recurrence, including node-negative and node-positive disease (P < .001 for both) and when adjusted for other clinical variables. RS also predicted recurrence more accurately than clinical variables when integrated by an algorithm modeled after Adjuvant! that was adjusted to 5-year outcomes. The 5-year recurrence rate was only 5% or less for the estimated 46% of patients who have a low RS (< 18).


CONCLUSIONS
The 21-gene assay was a more accurate predictor of relapse than standard clinical features for individual patients with HR-positive operable breast cancer treated with chemohormonal therapy and provides information that is complementary to features typically used in anatomic staging, such as tumor size and lymph node involvement. The 21-gene assay may be used to select low-risk patients for abbreviated chemotherapy regimens similar to those used in our study or high-risk patients for more aggressive regimens or clinical trials evaluating novel treatments.
Goldstein
Lori J
LJ
Eastern Cooperative Oncology Group, Boston, MA, USA.
Gray
Robert
R
Badve
Sunil
S
Childs
Barrett H
BH
Yoshizawa
Carl
C
Rowley
Steve
S
Shak
Steven
S
Baehner
Frederick L
FL
Ravdin
Peter M
PM
Davidson
Nancy E
NE
Sledge
George W
GW
Perez
Edith A
EA
Shulman
Lawrence N
LN
Martino
Silvana
S
Sparano
Joseph A
JA
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000235:genetics* / Q000601:surgery; D005260:Female; D020869:Gene Expression Profiling / Q000379:methods; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008495:Medical Oncology / Q000379:methods*; D008875:Middle Aged; D011379:Prognosis; D011960:Receptors, Estrogen / Q000096:biosynthesis*; D012008:Recurrence; D012306:Risk; D013997:Time Factors
D011960:Receptors, Estrogen