Real-world survival of Danish patients with HER2-positive metastatic breast cancer

Figures & data

Table 1. Baseline characteristics.

	n = 631 (col %)
Age (mean and range)	62 (26–94)
Metastatic sites
Visceral	450 (71 %)
Non-Visceral	181 (39 %)
Brain	65 (10 %)
Number of metastatic sites
1 (low tumor burden)	209 (33 %)
2 (low tumor burden)	208 (33 %)
3+ (high tumor burden)	214 (34 %)
Disease presentation
De novo	227 (35 %)
Recurrence	404 (65 %)
Aggressive disease^c	101 (25 %)
Non-aggressive disease	303 (75 %)
ER status
Positive	403 (63 %)
Negative	228 (37 %)
HER2 status
IHC positive	494 (79 %)
FISH positive	137 (21 %)
Neoadjuvant treatment^b	N = 67
EC^a	55
Taxane	54
Pertuzumab	18
Trastuzumab	45
Endocrine therapy	28
Adjuvant treatment^b	N = 238
EC	173
Taxane	144
Trastuzumab	129
Endocrine therapy	163
Unknown treatment^b	N = 82
No systemic treatment^b	N = 17

^aEpirubicin and cyclophosfamide.

^bTreatment given patients in the (neo)adjuvant setting patients with early BC before recurrence.

^cRecurrence 3–24 months after primary diagnosis.

Table 2. Therapy regimen in each line.

	1^st line (n = 631)	2^nd line (n = 436)	3^rd line (n = 260)
Trastuzumab, Pertuzumab and chemotherapy^a	483	53	11
TDM-1	12	196	53
Capecitabine and Trastuzumab	7	9	40
Capecitabine and Lapatinib	0	10	20
Other chemotherapy and anti-HER2 treatment	31	22	47
Endocrine treatment and anti HER2	55	70	34
Other^b	43	76	55

^a85%, 12% and 3% of the patients received Vinorelbine, a taxane or another chemotherapy as backbone in first line treatment, respectively.

^bTrastuzumab + Lapatinib or monotherapy with either anti-HER2 treatment, chemotherapy, endocrine treatment, palliative radiotherapy or palliative surgery.

Figure 1. Overall survival for all patients and according to subgroups. Adherence to guidelines analyzed as a time dependent variable. CNS metastases according to presence at index. Median overall survival (mOS) and log-rank test are shown together with patients at risk according to different time-point.

Figure 2. Cumulative incidence of brain metastases and death as competing event according to time since index. Patients at risk according to different time-point are listed below the x-axis.

Table 3. Fine and Gray sub-distributional proportional hazard models for risk of developing brain metastases.

	Hazard Ratio
	Unadjusted (95% CI)	Adjusted (95% CI)
Disease presentation
Recurrent vs de novo	1.19 (95% CI, 0.83–1.70), p = 0.30
Aggressive ^a vs non-aggressive	1.04 (95% CI, 0.63–1.70), p = 0.89
ER
Positive vs negative	0.71 (95% CI, 0.51–1.01), p = 0.06	0.69 (95% CI, 0.49–0.98), p = 0.047
Tumor burden High vs low^b
≤12 months after index	1.10 (95% CI 0.69–1.75), p = 0.67	1.13 (95% CI 0.71–1.79), p = 0.61
12+ months	2.63 (95% CI 1.42–4.88), p = 0.002	2.69 (95% CI 1.45–5.00) p = 0.002

^aRecurrence 3–24 months from primary diagnosis.

^bHigh tumor burden defined as ≥3 metastatic sites at index, overall p-value = 0.006.

Data availability statement

The data supporting the findings of this study are not publicly available due to institutional restrictions. The data can be made available to qualified researchers through application to the Danish Breast Cancer Group.