Table 2. COX-2 expression and clinicopathological parameters in women with DCIS (n=187) and IBC (n=65).

Parameter	Number	% COX-2 +ve	P-valuea
DCIS
Age (years)
<50	35	62%	0.34
⩾50	152	69%
Nuclear grade
Low	27	44%
Intermediate	64	64%	0.003
High	96	75%
ER status
Positive	111	58%	0.003
Negative	75	80%
Ki67 cell proliferation
<10%	93	55%	<0.0001
⩾10%	90	79%
HER-2 status
Positive	102	82%	<0.0001
Negative	85	48%
Invasive cancer
Age (years)
<50	23	64%	0.67
⩾50	42	62%
Nuclear grade
I	17	53%
II	17	58%	0.43
III	21	71%
ER status
Positive	40	50%	0.005
Negative	25	84%
Ki67 cell proliferation
<10%	29	50%	0.04
⩾10%	36	74%
HER-2 status
Positive	29	79%	0.014
Negative	36	50%

Age above and below 50 years was used to separate pre- and postmenopausal patients crudely. Oestrogen receptor positivity was a tumour with ⩾5% nuclei expressing the ER receptor for both DCIS and IBC. A comparison of COX-2 positivity with Ki67 cell proliferation above and below 10% was used because the median DCIS cell proliferation was approximately 10%. HER-2 positivity was an immunostaining score of ⩾2+ (reference laboratory standard). Categorical variables were compared differences using the χ² test. COX-2=cyclooxygenase type-2; DCIS=ductal carcinoma in situ; IBC=invasive breast cancer; ER=oestrogen receptor.

^aχ² test.