Table 1.

Descriptive statistics for invasive female breast cancer among women aged 30–84 years in the Danish Breast Cancer Cooperative Group (DBCG: 1993 through 2010)

	Total cases		ER positive		ER negative		ER unknown		p value for heterogeneity
Sample size	62,549		45,571		12,016		4,962
% Total cases	100%		72·9%		19·2%		7·9%
Mean age (SE)	60.5 (0.05)		60·9 (0·05)		57·9 (0·11)		62·7 (0·19)		p < 0·001
Rates per 100,000	188.7		136·5		37·4		14·8
Variable	Count	Percent	Count	Percent	Count	Percent	Count	Percent	p value
Menopausal surrogate
<50 years	12,291	19.7%	8,221	18·0%	3,158	26·3%	912	18·4%
50+ years	50,258	80.3%	37,350	82·0%	8,858	73·7%	4,050	81·6%	p < 0·001
Tumor Size
≤ 2.0 cm	33,906	54.2%	27,257	59·8%	5,316	44·2%	1,333	26·9%
> 2.0 cm	24,514	39.2%	17,379	38·1%	6,189	51·5%	946	19·1%
Other or unknown	4,129	6.6%	935	2·1%	511	4·3%	2,683	54·1%	p < 0·001
Lymph nodes
negative	30,142	48.2%	23,032	50·5%	5,806	48·3%	1,304	26·3%
positive	27,055	43.3%	20,549	45·1%	5,590	46·5%	916	18·5%
Other or unknown	5,352	8.6%	1,990	4·4%	620	5·2%	2,742	55·3%	p < 0·001
Tumor Grade
I (low)	15,966	25.5%	14,621	32·1%	743	6·2%	602	12·1%
II–III (high)	33,158	53.0%	23,287	51·1%	8,886	74·0%	985	19·9%
Other or unknown	13,425	21.5%	7,663	16·8%	2,387	19·9%	3,375	68·0%	p < 0·001