Table 1 Patient, tumor, and treatment characteristics according to body mass index in 1099 patients with incident invasive breast cancer in the Malmö Diet and Cancer Study

Age at diagnosis, median (IQR)

66.3 (61.2–72.8)

64.9 (59.9–70.5)

68.8 (62.8–73.9)

69.2 (63.3–76.2)

Menopausal status at diagnosis

 Premenopausal

65 (6.4%)

40 (7.7%)

19 (5.5%)

6 (4.0%)

 Postmenopausal

951 (93.6%)

478 (92.3%)

329 (94.5%)

144 (96.0%)

Histological grade according to Nottingham score

 Grade I, 3–5 p

269 (26.6%)

160 (31.2%)

76 (21.7%)

33 (22.4%)

 Grade II, 6–7 p

478 (47.3%)

239 (46.6%)

162 (46.3%)

77 (52.4%)

 Grade III, 8–9 p

263 (26.0%)

114 (22.2%)

112 (32.0%)

37 (25.2%)

Tumor size, mm

  < 10

178 (17.0%)

102 (19.0%)

57 (15.8%)

19 (12.7%)

 10–20

568 (54.3%)

296 (55.1%)

196 (54.4%)

76 (50.7%)

  > 20

301 (28.7%)

139 (25.9%)

107 (29.7%)

55 (36.7%)

Nodal status

 Negative

675 (68.3%)

366 (71.6%)

218 (64.9%)

91 (64.1%)

 Positive

314 (31.7%)

145 (28.4%)

118 (35.1%)

51 (35.9%)

Histological type

 Invasive ductal cancer

714 (69.8%)

353 (68.1%)

256 (71.3%)

105 (71.9%)

 Invasive lobular cancer

201 (19.6%)

110 (21.2%)

63 (17.5%)

28 (19.2%)

 Other

108 (10.6%)

55 (10.6%)

40 (11.1%)

13 (8.9%)

Estrogen receptor status

 Negative

97 (10.1%)

48 (9.9%)

36 (10.8%)

13 (9.3%)

 Positive

860 (89.9%)

436 (90.1%)

297 (89.2%)

127 (90.7%)

Surgical procedure

 Mastectomy

427 (42.1%)

225 (43.1%)

138 (39.9%)

64 (43.8%)

 Breast conserving surgery

587 (57.9%)

297 (56.9%)

208 (60.1%)

82 (56.2%)

Endocrine therapy, planned adjuvant

 No

453 (42.7%)

247 (45.8%)

142 (38.4%)

64 (42.1%)

 Yes

608 (57.3%)

292 (54.2%)

228 (61.6%)

88 (57.9%)

Chemotherapy, planned adjuvant

 No

844 (84.0%)

412 (82.7%)

305 (84.3%)

127 (87.6%)

 Yes

161 (16.0%)

86 (17.3%)

57 (15.7%)

18 (12.4%)

Radiotherapy, planned adjuvant

 No

397 (39.4%)

199 (40.0%)

139 (38.2%)

59 (40.7%)

 Yes

610 (60.6%)

299 (60.0%)

225 (61.8%)

86 (59.3%)

Socioeconomic position

 Low

302 (28.3%)

101 (18.8%)

132 (35.2%)

69 (44.8%)

 Low middle

64 (6.0%)

28 (5.2%)

19 (5.1%)

17 (11.0%)

 High middle

346 (32.4%)

193 (35.9%)

119 (31.7%)

34 (22.1%)

 High

355 (33.3%)

216 (40.1%)

105 (28.0%)

34 (22.1%)

Do you smoke?

 Yes, I smoke regularly

270 (24.6%)

165 (29.7%)

76 (19.8%)

29 (18.2%)

 Yes, I smoke occasionally

35 (3.2%)

21 (3.8%)

10 (2.6%)

4 (2.5%)

 No, I have stopped smoking

333 (30.3%)

161 (29.0%)

122 (31.8%)

50 (31.4%)

 No, I have never smoked

461 (41.9%)

209 (37.6%)

176 (45.8%)

76 (47.8%)