BRCAness digitalMLPA profiling predicts benefit of intensified platinum-based chemotherapy in triple-negative and luminal-type breast cancer

Table 5 Multivariate Cox proportional-hazard analysis of the risk of death and digitalMLPA BRCAness status in all patients, patients with TN tumors, and patients with HR-positive tumors

Variable	All 114 patients with 47 events				37 TN patients with 17 events				77 HR pos patients with 30 events
Variable	No. events/no. patients	Hazard ratio	95% CI	p value	No. events/no. patients	Hazard ratio	95% CI	p value	No. events/no. patients	Hazard ratio	95% CI	p value
pT-stage
pT1/pT2	36/100	1.00			12/31	1.00			24/69	1.00
pT3	11/14	2.87	1.35–6.08	0.006	5/6	1.92	0.63–5.87	0.249	6/8	1.71	1.50–10.94	0.06
Histologic grade
I/II	21/60	1.00			3/8	1.00			18/52	1.00
III	26/54	1.96	1.01–3.81	0.0478	14/29	1.97	0.52–7.47	0.318	12/25	1.25	0.96–4.78	0.064
digitalMLPA
Non-BRCA-like tumor	23/58	1.00			5/10	1.00			18/48	1.00
BRCA-like tumor	24/56	0.94	0.50–1.76	0.845	12/27	1.18	0.29–2.50	0.765	12/29	1.79	0.44–2.05	0.906
BRCA-like tumor
FE₉₀C chemotherapy	21/29	1.00			10/14	1.00			11/15	1.00
HD-CTC chemotherapy	3/27	0.12	0.04–0.44	0.001	2/13	0.15	0.03–0.73	0.0185	1/14	0.09	0.01–0.80	0.0311
Non-BRCA-like		p interaction = 0.011*				p interaction = 0.072				p interaction = 0.070
FE₉₀C chemotherapy	10/22	1.00			3/6	1.00			7/16	1.00
HD-CTC chemotherapy	13/36	0.90	0.37–2.18	0.818	2/4	0.91	0.10–8.02	0.934	11/32	0.75	0.28–1.97	0.558

Three separate multivariate Cox regression models were run in all patients (n = 114 patients with complete clinical variables), in patients with TN tumors, and in patients with HR-pos tumors^§ (see top row) and an *interaction term with treatment. The first model was stratified for number of lymph nodes (4–9 vs. ≥ 10) and triple-negative status (ER < 10% and PR < 10% vs. others) and based on 114 patients. For patients with TN tumors (37 patients) and with HR-pos tumors (77 patients) only, models were stratified for lymph node status. *Test of homogeneity of treatment-specific hazard ratios based on an interaction term. TN triple-negative, HR-pos hormone receptor-positive, pT-stage pathological tumor size, FE₉₀C 5-fluorouracil-epirubicin-cyclophosphamide, HD-CTC high-dose cyclophosphamide-thiotepa-carboplatin

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