Risk of loco-regional recurrence and distant metastases of patients with invasive breast cancer up to ten years after diagnosis – results from a registry-based study from Germany

Table 4 Distribution of age and tumor characteristics of breast cancer patients of the study sample (N = 8511) and those included in the analysis of the risk of BRC recurrence (N = 5311)

Category		Study sample		Patients with a local R0 resection, available follow-up and without recurrence within 3 months
		N	% ^a	N	% ^a
Overall		8518		5311
Age	< 70 years	5725	67.2	3714	69.9
	≥ 70 years	2793	32.8	1597	30.1
Laterality	available	8508	99.9	5307	99.9
	unilateral	8306	97.6	5198	97.9
	synchronous bilateral ^b	202	2.4	109	2.1
Clinical stage	available	7447	87.4	5064	95.3
	T1/2N0	4132	55.5	2918	57.6
	T1/2N+	2379	31.9	1613	31.9
	T3/4N0	205	2.8	124	2.4
	T3/4N+	731	9.8	409	8.1
Microscopically verified		8482	99.6	5311	100.0
Morphology	available	8477	99.5	5311	100.0
	invasive ductal	5883	69.4	3690	69.5
	invasive lobular	1190	14.0	758	14.3
	mixed type	654	7.7	459	8.6
	other	750	8.8	404	7.6
Histopathologic grade	available	8216	96.5	5376	99.3
	1	610	7.4	447	8.5
	2	5232	63.7	3332	63.2
	3/4	2374	28.9	1497	28.4
HR expression	available	7424	87.2	4907	92.4
	positive ^c	6235	84.0	4132	84.2
	negative	1189	16.0	775	15.8
HER2/neu expression	available	5938	69.7	3913	73.7
	positive ^d	1466	24.7	972	24.8
	negative	4472	75.3	2941	75.2
Subtype based on immunohistochemical surrogates	HR and HER2/neu status available	7197	84.5	4742	89.3
	’HR positive‘	6235	86.6	4132	87.1
	‚HER2/neu positive‘^e	368	5.1	234	4.9
	‚triple negative‘^f	594	8.3	376	7.9
Follow-up available		8380	98.4	5311	100.0
		years		years
Mean observation time		10.3		10.2

The sample includes female patients with primary invasive breast cancer (BRC) (ICD-10 code: C50) without distant metastases from Saarland diagnosed between 1999 and 2009. T, N T and N category of TNM classification, HR hormone receptor, HER2/neu human epidermal growth factor receptor 2. ^a figures printed in normal text represent numbers and proportions of the study sample and of patients with a local R0 resection who were included in the analysis of the risk of BRC recurrence, figures printed in italic text represent proportions of patients of the respective sample with available information, ^b tumors were classified as synchronous bilateral if the time interval between their detection was ≤3 months, ^c includes tumors with mixed HR expression (either estrogen or progesterone receptor positive), ^d includes tumors with borderline expression of HER2/neu, ^e HER2/neu positive, but HR negative, ^f both HR negative and HER2/neu negative

ISSN: 1471-2407