Table 1. The clinicopathological characteristics of OSCC patients treated by segmental mandibulectomy.
| Characteristics (n, %) | Reconstruction | P | |
| Non-Fibular (n = 125) | Fibular (n = 185) | ||
| (n, %) | (n, %) | ||
| Sex | 0.518 | ||
| Male (291, 93.9) | 116 (92.8) | 175 (94.6) | |
| Female (19, 6.1) | 9 (7.2) | 10 (5.4) | |
| Age (years), 25–85 (median 52) | 0.191 | ||
| <65 (263, 84.8) | 102 (81.6) | 161 (87.0) | |
| ≥65 (47, 15.2) | 23 (18.4) | 24 (13.0) | |
| Tumor subsites | <0.001 | ||
| Tongue (13, 4.2) | 9 (7.2) | 4 (2.2) | |
| Mouth floor (23, 7.4) | 7 (5.6) | 16 (8.6) | |
| Lip (3, 1.0) | 2 (1.6) | 1 (0.5) | |
| Buccal (109, 35.2) | 59 (47.2) | 50 (27.0) | |
| Alveolar ridge (133, 42.9) | 36 (28.8) | 97 (52.4) | |
| Retromolar (29, 9.4) | 12 (9.6) | 17 (9.2) | |
| Clinical T-status | 0.003 | ||
| cT1-2 (48, 15.5) | 10 (8.0) | 38 (20.5) | |
| cT3-4 (262, 84.5) | 115 (92.0) | 147 (79.5) | |
| Clinical N-status | 0.001 | ||
| cN0-1 (204, 65.8) | 69 (55.2) | 135 (73.0) | |
| cN2 (106, 34.2) | 56 (44.8) | 50 (27.0) | |
| Clinical Stage | 0.148 | ||
| I–III (62, 20.0) | 20 (16.0) | 42 (22.7) | |
| IV (248, 80.0) | 105 (84.0) | 143 (77.3) | |
| Two flaps reconstruction | <0.001 | ||
| No (249, 81.6) | 119 (99.2) | 130 (70.3) | |
| Yes (56, 18.4) | 1 (0.8) | 55 (29.7) | |
| Free-flap reconstruction | <0.001 | ||
| Single (246, 82.3) | 117 (99.2) | 129 (71.3) | |
| Double (53, 17.7) | 1 (0.8) | 52 (28.7) | |
| Inferior maxillectomy | 0.004 | ||
| No (217, 70.0) | 76 (60.8) | 141 (76.2) | |
| Yes (93, 30.0) | 49 (39.2) | 44 (23.8) | |
| Tumor differentiation | 0.012 | ||
| Well/moderate (279, 90.0) | 106 (84.8) | 173 (93.5) | |
| Poor (31, 10.0) | 19 (15.2) | 12 (6.5) | |
| Pathological T-status | <0.001 | ||
| pT1-2 (58, 18.7) | 11 (8.8) | 47 (25.4) | |
| pT3-4 (252, 81.3) | 114 (91.2) | 138 (74.6) | |
| Pathological N-statusa | 0.002 | ||
| pN0-1 (199, 64.4) | 68 (54.4) | 131 (71.2) | |
| pN2 (110, 35.6) | 57 (45.6) | 53 (28.8) | |
| Pathological stageb | 0.007 | ||
| I–III (63, 20.3) | 16 (12.8) | 47 (25.4) | |
| IV (247, 79.7) | 109 (87.2) | 138 (74.6) | |
| Extracapsular spreada | 0.001 | ||
| No (197, 63.5) | 65 (52.0) | 132 (71.4) | |
| Yes (113, 36.5) | 60 (48.0) | 53 (28.6) | |
| Level IV/V metastases | 0.030 | ||
| No (297, 95.8) | 116 (92.8) | 181 (97.8) | |
| Yes (13, 4.2) | 9 (7.2) | 4 (2.2) | |
| Tumor depth (mm) c , d | <0.001 | ||
| <15 (153, 49.4) | 46 (36.8) | 107 (57.8) | |
| ≥15 (157, 50.6) | 79 (63.2) | 78 (42.2) | |
| Margin status (mm) a | 0.143 | ||
| ≤4 (33, 10.7) | 17 (13.9) | 16 (8.6) | |
| >4 (274, 89.3) | 105 (86.1) | 169 (91.4) | |
| Bone marrow invasion | 0.448 | ||
| No (147, 47.4) | 56 (44.8) | 91 (49.2) | |
| Yes (163, 52.6) | 69 (55.2) | 94 (50.8) | |
| Skin invasion | <0.001 | ||
| No (245, 79.0) | 86 (68.8) | 159 (85.9) | |
| Yes (65, 21.0) | 39 (31.2) | 26 (14.1) | |
| Perineural invasiona | 0.055 | ||
| No (200, 64.7) | 73 (58.4) | 127 (69.0) | |
| Yes (109, 35.3) | 52 (41.6) | 57 (31.0) | |
| Vascular invasiona | 0.532 | ||
| No (299, 96.8) | 120 (96.0) | 179 (97.3) | |
| Yes (10, 3.2) | 5 (4.0) | 5 (2.7) | |
| Lymphatic invasiona | 0.771 | ||
| No (280, 90.6) | 114 (91.2) | 166 (90.2) | |
| Yes (29, 9.4) | 11 (8.8) | 18 (9.8) | |
| Treatment mode | 0.033 | ||
| S alone (74, 23.9) | 22 (17.6) | 52 (28.1) | |
| S plus RT/CCRT (236, 76.1) | 103 (82.4) | 133 (71.9) | |
S, surgery; RT, radiotherapy; CCRT, concurrent chemoradiotherapy.
a
Unavailable data: pN status (n = 1), margin (n = 3), perineural invasion (n = 1), vascular invasion (n = 1), lymphatic invasion (n = 1).
b
Patient who did not receive neck dissection (n = 1) was classified as pN0.
c
Optimal cut-off value for disease-free survival.
d
Tumor depth was defined as the measured thickness from the surface of the normal mucosa to the deepest portion of the tumor.