Cyclooxygenase-2 expression correlates with diminished survival in invasive breast cancer treated with mastectomy and radiotherapy.
OBJECTIVE
To evaluate the relationship between cyclooxygenase-2 (COX-2) expression and pathologic features and outcome in invasive breast cancer.


METHODS
Formalin-fixed, paraffin-embedded tumor specimens from 23 women with invasive breast cancer were stained for COX-2 expression. All women underwent mastectomy and locoregional radiotherapy. The distribution (percentage of positive staining cells) and intensity of COX-2 expression within the tumor cells were compared with clinical factors, including stage, grade, lymph node involvement, and outcome.


RESULTS
For invasive breast cancer, the distribution and intensity of COX-2 tumor expression correlated significantly with diminished overall survival. The 5-year overall survival rate was 100% for patients with <75% of breast cancer cells expressing COX-2 compared with 49% for patients with > or =75% (p = 0.044). The 5-year overall survival rate was 100% for patients with COX-2 intensity <80 compared with 60% for patients with COX-2 intensity > or =80 (p = 0.018). The percentage and intensity of COX-2 expression also correlated significantly with disease-free survival. The percentage of cells expressing COX-2 was significantly greater in women <40 years old than in women > or =40 years old (81% vs. 59%, respectively, p = 0.04).


CONCLUSIONS
Both the distribution and the intensity of COX-2 expression correlated significantly with disease-free and overall survival in patients with invasive breast cancer. Younger patients with invasive breast cancer may have a greater percentage of COX-2 expression in their tumors.
Department of Radiation Oncology, University of Utah, Salt Lake City, UT 84132, USA.
John K
JK
O'Connor
James
J
Avent
R Jeffrey
RJ
Lee
Jennifer
J
Fischbach
David K
DK
Gaffney
D000328:Adult; D001943:Breast Neoplasms / Q000201:enzymology* / Q000401:mortality* / Q000628:therapy; D003131:Combined Modality Therapy; D051546:Cyclooxygenase 2; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000032:analysis*; D008408:Mastectomy; D008565:Membrane Proteins; D009363:Neoplasm Proteins / Q000032:analysis*; D011379:Prognosis; D011451:Prostaglandin-Endoperoxide Synthases / Q000032:analysis*; D013223:Statistics as Topic; D015996:Survival Rate
D007527:Isoenzymes; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases