Neoadjuvant letrozole for postmenopausal estrogen receptor-positive, HER2-negative breast cancer patients, a study from the Danish Breast Cancer Cooperative Group (DBCG)

Figures & data

Table 1. Patients- and tumor characteristics of 112 Danish early Breast Cancer patients treated with neoadjuvant letrozole between 2009 and 2012.

	Patients (n = 112)
Variable	n	%
Age (years)
60–69	66	59
70–89	46	41
Tumor size (mm)^a
<20	50	45
>20	62	55
Histological subtype
Ductal invasive	82	73
Other invasive^b	30	27
Malignancy grade^c
1	42	45
2	47	50
3	5	5
Axillary node status prior to treatment^d
Negative	60	54
Positive	51	46
Unknown	1	1
Estrogen receptor status (%)
10–99	19	17
100	93	83
Progesterone receptor status (%)
10–99	70	63
100	29	26
Unknown	13	12
Ki67 index (%)
<14	62	55
≥14	27	24
Unknown	23	21

Data reported as n (col %).

^a Range of tumor size: 11–100 mm.

^b lobular tumors n = 12, Mucinous carcinomas n = 8, Tubular carcinomas n = 2, Medullary carcinomas n = 1, not specified n = 7.

^c n = 94 (only lobular and ductal tumors graded).

^d Axillary status assessed by either diagnostic fine needle aspiration cytology (FNAC) or sentinel node (SN), one patient had earlier breast surgery rendering both SN and FNAC impossible.

Figure 1. Relative reduction (%) in tumor size for each of the 109 patients with records of clinical outcome (one bar per patient). No change (n = 26) visualized by a straight line, negative values symbolizes growth (n = 20) and positive values tumor reduction (n = 63). Groups represent clinical response according to RECIST 1.1; Complete response (n = 2), Partial response (n = 36), Stable disease (n = 57) and Progressive disease (n = 14).

Table 2. Univariate analyses for factors associated with clinical and pathological outcome after neoadjuvant treatment with letrozole in early breast cancer patients.

	Clinical response^a		Odds ratio (95% CI)	p^b	Relative tumorreduction^c	p^d	Pathological Response		Odds ratio (95% CI)	p^b
Variable	n^e	%	Median	n^f	%
Age (years)				.10		.31				.51
60–69	27	41	1.00		19		35	53	1.00
70–89	11	26	0.50 (0.21–1.15)		7		25	60	1.30 (0.60–2.85)
Tumor size (mm)				.04		.04				.06
<20	22	46	2.38 (1.06–5. 32)		27		32	65	2.08 (0.96–4.54)
≥20	16	26	1.00		2		28	47	1.00
Subtype				.72		.09				.03
Ductal	28	36	1.00		19		48	62	1.00
Other invasive	10	32	0.85 (0.35–2.06)		0		12	39	0.38 (0.16–0.89)
Malignancy grade				.98		.006				.36
1	14	39	1.09 (0.43–2.79)		23		21	64	0.94 (0.36–2.47)
2	14	37	1.00		16		26	65	1.00
3	0	0	<0.001		−27		1	25	0.18 (0.02–1.90)
Axillary node status prior to treatment				.002		.01				.99
Negative	28	47	1.00		25		32	55	1.00
Positive	9	18	0.25 (0.10–0.60)		0		27	55	1.00 (0.46–2.14)
Unknown	1	100	–		33		1	100	–
Estrogen receptor status (%)				.17		.02				.19
10–99	4	21	0.44 (0.14–1.43)		0		8	42	0.52 (0.19–1.41)
100	34	38	1.00		18		52	58	1.00
Progesterone receptor status (%)				.49		.21				.75
0–99	22	33	0.65 (0.26–1.61)		9		35	52	0.75 (0.30–1.86)
100	12	43	1.00		23		16	59	1.00
Unknown	4	33	0.67 (0.16–2.74)		0		9	75	2.06 (0.48–9.39)
Ki67 index (%)				.36		.17				.09
0–13	24	40	1.00		19		34	57	1.00
≥14	8	30	0.63 (0.24–1.67)		0		10	37	0.45 (0.18–1.14)
Unknown	6	27	0.56 (0.19–1.64)		8		16	76	2.45 (0.79–7.55)

Data reported as n (row %).

^a Clinical response = Partial response and Complete response according to RECIST 1.1.

^b Pearson’s Chi square.

^c Relative reduction (%) from baseline till surgery.

^d Wilcoxon Rank Sum.

^e total n evaluated = 109.

^f total n evaluated = 108.

Table 3. Association between biomarker change and clinical tumor change to pathological outcome after neoadjuvant treatment with letrozole in early breast cancer patients.

Variable	Total		Pathological response		Odds ratio (95% CI)	p value^a
n	% col	n	% row
Estrogen Receptor						.55
Increase	10	9	4	40	0.62 (0.14–2.72)
Decrease	25	23	13	52	1.00
No change	71	65	41	58	1.26 (0.51–3.15)
Missing	2	2	2	100	–
Progesterone Receptor						.30
Increase	5	5	2	40	0.32 (0.05–2.19)
Decrease	34	32	23	68	1.00
No change	7	7	3	43	0.36 (0.07–1.89)
Missing	59	56	31	53	0.53 (0.22–1.28)
KI67 index						.23
Increase	24	22	9	38	0.53 (0.20–1.44)
Decrease	49	45	26	53	1.00
No change	12	11	8	67	1.77 (0.47–6.66)
Missing	23	21	17	74	2.51 (0.85–7.43)
Relative tumor change						.16
Increase	20	19	10	50	0.62 (0.22–1.70)
Decrease	63	59	39	62	1.00
No change	23	22	9	39	0.40 (0.15–1.05)
Response according to RECIST 1.1						.14
Progressive disease	14	13	5	36	0.29 (0.08–1.04)
Complete or partial response	38	36	25	66	1.00
Stable disease	54	51	28	52	0.56 (0.24–1.32)

^a Excluding unknowns.