Validation of UBE2C protein as a prognostic marker in node-positive breast cancer.
BACKGROUND
We recently identified and validated UBE2C RNA as a prognostic marker in 252 node-positive (N+) breast cancers by means of a microarray study. The aim of this study was to validate UBE2C protein as a prognostic marker in N+ breast cancer by immunohistochemistry (IHC).


METHODS
To this end, 92 paraffin-embedded blocks were used. The impact of UBE2C IHC value on metastasis-free survival (MFS) and overall survival (OS) was evaluated and compared with Ki-67 and Nottingham prognostic index (NPI) performances.


RESULTS
In accordance with genomic data, UBE2C IHC had a significant impact both on MFS and OS (hazard ratio=6.79 - P=0.002; hazard ratio=7.14 - P=0.009, respectively). Akaike information criterion proved that the prognostic power of UBE2C IHC was stronger than that of Ki-67 (and close to that of NPI). Furthermore, multivariate analyses with NPI showed that, contrary to Ki-67 IHC, UBE2C IHC remained an independent factor, both for MFS (adjusted P=0.02) and OS (adjusted P=0.04).


CONCLUSIONS
We confirmed that UBE2C protein measured by IHC could be used as a prognostic marker in N+ breast cancer. The potential predictive interest of UBE2C as a marker of proteasome activity needs further investigations.
Loussouarn
D
D
Service d'Anatomie Pathologique B, Hôpital G&R Laënnec, Bd J Monod, Nantes, Saint Herblain Cedex, France.
Campion
L
L
Leclair
F
F
Campone
M
M
Charbonnel
C
C
Ricolleau
G
G
Gouraud
W
W
Bataille
R
R
Jézéquel
P
P
D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000235:genetics / Q000378:metabolism; D008207:Lymphatic Metastasis; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D011379:Prognosis; D015203:Reproducibility of Results; D044763:Ubiquitin-Conjugating Enzymes / Q000235:genetics / Q000378:metabolism*
D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen; C105156:UBE2C protein, human; D044763:Ubiquitin-Conjugating Enzymes