Estrogen- and progesterone-receptor status in ECOG 2197: comparison of immunohistochemistry by local and central laboratories and quantitative reverse transcription polymerase chain reaction by central laboratory.
OBJECTIVE
Central and local laboratory concordance for hormone receptor measurement is therapeutically important. This study compares estrogen receptor (ER) and progesterone receptor (PR) measured by local laboratory immunohistochemistry (IHC), central IHC, and central reverse-transcriptase polymerase chain reaction (RT-PCR) using a proprietary 21-gene assay.


METHODS
A case-control sample of 776 breast cancer patients from Eastern Cooperative Oncology Group (ECOG) study E2197 was evaluated. Central IHC Allred score for ER and PR was obtained using tissue microarrays and 1D5 ER antibody and 636 PR antibody. Quantitative RT-PCR for ER and PR in whole sections was performed using the 21-gene assay.


RESULTS
For ER, the concordance between local and central IHC was 90% (95% CI, 88% to 92%), between local IHC and central RT-PCR was 91% (95% CI, 89% to 93%), and between central IHC and central RT-PCR was 93% (95% CI, 91% to 95%). For PR, the concordance between local IHC and central IHC was 84% (95% CI, 82% to 87%), between local IHC and central RT-PCR was 88% (95% CI, 85% to 90%), and between central IHC and central RT-PCR was 90% (95% CI, 88% to 92%). Although concordance was high, IHC ER-negative cases that were RT-PCR positive were more common than IHC ER-positive cases that were RT-PCR negative. In ER-positive patients, ER expression by central IHC Allred score was marginally associated with recurrence (P = .091), and ER expression by central RT-PCR was significantly associated with recurrence (P = .014). However, recurrence score, which incorporates additional genes/pathways, was a highly significant predictor of recurrence (P < .0001).


CONCLUSIONS
There is a high degree of concordance among local IHC, central IHC, and central RT-PCR by the proprietary gene assay for ER and PR status. Although ER expression is marginally associated with relapse in ER-positive patients treated with chemohormonal therapy, recurrence score is a highly significant predictor of recurrence.
Badve
Sunil S
SS
Eastern Cooperative Oncology Group, Boston, MA, USA. sbadve@iupui.edu
Baehner
Frederick L
FL
Gray
Robert P
RP
Childs
Barrett H
BH
Maddala
Tara
T
Liu
Mei-Lan
ML
Rowley
Steve C
SC
Shak
Steven
S
Perez
Edith A
EA
Perez
Edith D
ED
Shulman
Lawrence J
LJ
Martino
Silvana
S
Davidson
Nancy E
NE
Sledge
George W
GW
Goldstein
Lori J
LJ
Sparano
Joseph A
JA
D000328:Adult; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000235:genetics / Q000378:metabolism / Q000556:secondary; D018275:Carcinoma, Lobular / Q000235:genetics / Q000378:metabolism / Q000556:secondary; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis*; D009367:Neoplasm Staging; D009376:Neoplasms, Hormone-Dependent / Q000235:genetics / Q000378:metabolism* / Q000556:secondary; D011379:Prognosis; D011446:Prospective Studies; D011960:Receptors, Estrogen / Q000235:genetics / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D011960:Receptors, Estrogen; D011980:Receptors, Progesterone