Table 1.

Patient and tumour characteristics

Characteristic	Premenopausal (n = 251)		Postmenopausal (n = 478)
	Years	Min–max	Years	Min–max
Median age at start of systemic therapy	45.1	23.4–69.4	62.8	37.6–84.0
	Mean	SD	Mean	SD
BMI at enrolment, kg/m2	25.5	5.04	27.5	5.57
Patients with comorbidity at diagnosis	n	%	n	%
Any comorbiditya	95	37.8	335	70.1
CCI = 0b	232	92.4	412	86.2
CCI ≥ 1b	19	7.6	66	13.8
Hypertension	23	9.2	193	40.4
Diabetes	1	0.4	50	10.5
Cardiovascular disorders	5	2.0	25	5.2
Receptor status at diagnosis
HR-positive, HER2-negative	158	62.9	279	58.4
HR-positive, HER2-positive	41	16.3	72	15.1
HR-negative, HER2-positive	12	4.8	37	7.7
Triple negative	38	15.1	80	16.7
Unknown*	2	0.8	10	2.1
Tumour stage at diagnosisc
I	60	23.9	134	28.0
II	119	47.4	218	45.6
III	39	15.5	77	16.1
Not determined/Unknownd	33	13.2	49	10.2
Nodal stage at diagnosis
Positive	120	47.8	209	43.7
Negative (N0)	121	48.2	260	54.4
Unknown (NX + missing)	10	4.0	9	1.9

BMI Body Mass Index, HR hormone receptor, HER2 human epidermal growth factor receptor 2, Max maximum, Min minimum, SD standard deviation

*This category includes three patients with HR-positive tumours and unknown HER2-status

^aComorbidity according to Charlson [48] or additional concomitant diseases

^bCharlson Comorbidity Index (CCI) according to Quan [49]

^cTumour stage according to AJCC/UICC 7th edition

^dFor some patients the exact stage could not be determined because of unknown parameters (TX, NX, MX)