Table 1 Baseline characteristics

Patient characteristics

Age (years)

67.7 ± 9.0

63.1 ± 12.7

0.193

BMI (kg/m²)

27.8 ± 4.9

26.1 ± 4.5

0.257

ASA (I / II / III)

6 / 13 / 1

5 / 14 / 1

0.770

Tumour characteristics

Indication for surgery

0.019

  Invasive carcinoma NST

  Invasive lobular carcinoma

  Carcinoma in situ

19

0

1

12

6

2

Unilateral / bilateral

19 / 1

19 / 1

1.000

Sentinel node excision (Y / N)

15 / 5

16 / 4

0.705

Oestrogen receptor (+/-/unknown)

18 / 2 / 0

16 / 3 / 1

0.589

Progesterone receptor (+/-/unknown)

15 / 5 / 0

14 / 5 / 1

0.925

Her2Neu receptor (+/-/unknown)

2 / 18 / 0

1 / 15 / 4

0.686

Additional treatment

Neo-adjuvant chemotherapy (Y / N)

0 / 20

6 / 14

0.008

Letrozole (Y / N)

4 / 16

4 / 16

1.000