Table 1 Basic patient, tumor and surgery characteristics of all patients included in the study by performance of postoperative (chemo-)radiotherapy

General

Age (years)

57.3 ± 11.0 [15.7–91.6]

56.7 ± 8.8 [37.8–82.3]

57.0 ± 10.1 [15.7–91.6]

Gender (male/female)

312 (84.3%)/58 (15.7%)

246 (84.5%)/45 (15.5%)

558 (84.4%)/103 (15.6%)

Follow up (months)

82.0 ± 53.3 [1.1–263.3]

68.0 ± 53.7 [0.3–252.8]

75,8 ± 53.9 [0.3–263.3]

Tumor origin

Oral cavity

78 (21.1%)

57 (19.6%)

135 (20.4%)

Oropharynx

65 (17.6%)

114 (39.2%)

179 (27.1%)

Hypopharynx

51 (13.8%)

67 (23.0%)

118 (17.8%)

Larynx

176 (47.6%)

53 (18.2%)

229 (34.6%)

Tumor side

bilateral

90 (24.3%)

67 (23.0%)

157 (23.8%)

midline

18 (4.9%)

6 (2.0%)

24 (3.6%)

right

139 (37.6%)

116 (39.9%)

255 (38.6%)

left

123 (33.2%)

102 (35.0%)

225 (34.0%)

Tumor category

pT1

60 (16.2%)

26 (8.9%)

86 (13.0%)

pT2

136 (36.8%)

72 (24.7%)

208 (31.5%)

pT3

126 (34.1%)

113 (38.8%)

239 (36.2%)

pT4

48 (13.0%)

80 (27.5%)

128 (19.4%)

clinical Lymph Node Status

cN0

202 (54.6%)

60 (20.6%)

262 (39.6%)

cN1

62 (16.8%)

49 (16.8%)

111 (16.8%)

cN2

85 (23.0%)

161 (55.3%)

246 (37.2%)

cN3

0 (0.0%)

5 (1.7%)

5 (0.8%)

cNx

21 (5.7%)

16 (5.5%)

37 (5.6%)

pathological Lymph Node Status

pN0

258 (69.7%)

44 (15.1%)

302 (45.7%)

pN1

59 (15.9%)

60 (20.6%)

119 (18.0%)

pN2

53 (14.3)

187 (64.3%)

240 (36.3%)

Distant metastasis during follow-up

M0

353 (95.4%)

247 (84.9%)

600 (90.8%)

M1

17 (4.6%)

44 (15.1%)

61 (9.2%)

Ipsilateral Neck Dissection

any

359 (97.0%)

283 (97.3%)

642 (97.1%)

Level I

69 (18.6%)

51 (17.2%)

120 (18.2%)

Level II

356 (96.2%)

257 (88.3%)

613 (92.7%)

Level III

349 (94.3%)

256 (88.0%)

605 (91.5%)

Level IV

64 (17.3%)

76 (26.1%)

140 (21.2%)

Level V

9 (2.4%)

17 (5.8%)

26 (3.9%)

Contralateral Neck dissection

Any

175 (40.6%)

144 (49.5%)

319 (48.3%)

Level I

34 (9.2%)

20 (6.9%)

54 (8.2%)

Level II

171 (46.2%)

142 (48.8%)

313 (47.4%)

Level III

168 (45.4%)

141 (48.5%)

309 (46.7%)

Level IV

23 (6.2%)

32 (11.0%)

55 (8.3%)

Level V

3 (0.8%)

4 (1.4%)

7 (1.1%)