Table 2.

Relationship between pCR, other important prognostic factors and EFS: a two-step multivariate Cox regression model^a—HRs with 99% CI (landmark method—N = 1212)

Factor	HR (99% CI)			P valueb
Age (years)
≤40	1.00			0.024
41–50	0.67 (0.46–0.98)
51–70	0.66 (0.35–1.25)
Menopausal status
Premenopausal	1.00			0.603
Postmenopausal	1.12 (0.63–1.99)
cT stage
T1–T2	1.00			<0.001
T3	1.82 (1.33–2.49)
T4	2.85 (1.89–4.31)
cN stage
N0	1.00			<0.001
N1	1.54 (1.13–2.10)
N2–N3	2.17 (1.18–4.00)
Histological type
Lobular	1.00			0.773
Ductal	0.93 (0.56–1.53)
Other	0.79 (0.34–1.84)
Pathological response
No pCR pCR	1.00 0.40 (0.25–0.64)			<0.001
Treatment arm
FEC	1.00			0.004
T-ET	0.73 (0.54–0.97)
Intrinsic subtype
–	–			<0.001
TP53
–	–			0.004
TP53 by intrinsic subtype
	Wild type	Mutated	Not done or failurec	0.100
Luminal A-like	1.00	1.39 (0.75–2.55)	0.77 (0.34–1.75)
Luminal B-like (HER2 negative)	1.00	1.18 (0.52–2.68)	0.74 (0.20–2.65)
Luminal B-like (HER2 positive)	1.00	1.13 (0.60–2.16)	0.91 (0.41–2.00)
HER2 positive (non-luminal)	1.00	0.36 (0.15–0.85)	0.60 (0.24–1.52)
Triple negative	1.00	1.17 (0.53–2.59)	0.71 (0.26–1.94)

Note that while subtype and TP53 were included as main effects in the model, we have not reported HR effects as these are difficult to interpret in the presence of a significant interaction between these terms.

^aSee supplementary Figure S1, available at Annals of Oncology online.

^bSignificance level α = 0.1 for interaction tests; α = 0.01 for main effects.

^cTP53 not tested. The main reason was samples with <20% tumour cells.

pCR, Pathological complete response; EFS, event-free survival; HR, hazard ratios; CI, confidence interval; FEC, 5-fluorouracil, epirubicin and cyclophosphamide; T-ET, docetaxel followed by epirubicin and docetaxel.