TABLE 1.
Characteristics of patients with parotid carcinomas stratified by parapharyngeal extension
| Characteristics | No parapharyngeal extension (no. of patients = 169; 88.5%) | Parapharyngeal extension (no. of patients = 22; 11.5%) | p-value |
|---|---|---|---|
| Age | |||
| Median (range) | 60.0 (6–98) | 55.5 (31–82) | 0.422 |
| Sex | |||
| Female | 76 (45.0%) | 10 (45.5%) | 1.000 |
| Male | 93 (55.0%) | 12 (54.5%) | |
| Neck dissection | |||
| No | 87 (51.5%) | 12 (54.6%) | 0.824 |
| Yes | 82 (48.5%) | 10 (45.4%) | |
| cT classification (AJCC 8th ed.) | |||
| T1 | 53 (31.4%) | 4 (17%) | 0.316 |
| T2 | 62 (36.7%) | 13 (61%) | |
| T3 | 31 (18.3%) | 3 (13%) | |
| T4 | 22 (13.0%) | 2 (9%) | |
| Tx | 1 (0.6%) | 0 | |
| cN status (AJCC 8th ed.) | |||
| N0 | 141 (83.4%) | 19 (86.4%) | 0.505 |
| N+ | 28 (16.6%) | 3 (13.6%) | |
| cM classification (AJCC 8th ed.) | |||
| M0 | 165 (97.6%) | 22 (100%) | 0.610 |
| M1 | 4 (2.4%) | 0 | |
| pT classification (AJCC 8th ed.) | |||
| T1 | 61 (36.1%) | 3 (13.7%) | 0.143 |
| T2 | 44 (26.0%) | 8 (36.3%) | |
| T3 | 13 (7.7%) | 2 (9.1%) | |
| T4 | 50 (29.6%) | 9 (40.9%) | |
| Tx | 1 (0.6%) | 0 | |
| pN status (AJCC 8th ed.) | |||
| N0/Nx | 132 (78.1%) | 17 (77.3%) | 1.000 |
| N+ | 37 (21.9%) | 5 (22.7%) | |
| pStage (AJCC 8th ed.) | |||
| Stage I | 59 (34.9%) | 3 (13.6%) | 0.132 |
| Stage II | 39 (23.1%) | 7 (31.8%) | |
| Stage III | 8 (4.7%) | 2 (9.1%) | |
| Stage IV | 62 (36.7%) | 10 (45.5%) | |
| Unknown | 1 (0.6%) | 0 | |
| Perineural invasion | |||
| No | 92 (54.4%) | 11 (50.0%) | 0.812 |
| Yes | 65 (38.5%) | 9 (40.9%) | |
| Unknown | 12 (7.1%) | 2 (9.1%) | |
| Vascular invasion | |||
| No | 115 (68.0%) | 15 (68.2%) | 1.000 |
| Yes | 36 (21.3%) | 4 (18.2%) | |
| Unknown | 18 (10.7%) | 3 (13.6%) | |
| Adjuvant therapy | |||
| None | 80 (47.4%) | 8 (36.4%) | 0.617 |
| RT | 68 (40.2%) | 11 (50%) | |
| CRT | 20 (11.8%) | 3 (13.6%) | |
| Chemotherapy alone | 1 (0.6%) | 0 | |
| Histology/grade | |||
| Mucoepidermoid carcinoma | 57 (33.7%) | 4 (18.2%) | |
| Low | 31 | 4 | |
| Intermediate | 13 | ||
| High | 13 | ||
| Carcinoma ex-pleomorphic adenoma | 30 (17.8%) | 8 (36.4%) | |
| Low | 5 | 1 | |
| Intermediate | 1 | ||
| High | 24 | 7 | |
| Acinic cell carcinoma | 26 (15.4%) | 2 (9.1%) | |
| Low | 20 | 2 | |
| Intermediate | 1 | ||
| High | 5 | ||
| Salivary duct carcinoma | 23 (13.6%) | 2 (9.1%) | |
| High | 23 | 2 | |
| Adenoid cystic carcinoma | 13 (7.7%) | 1 (4.6%) | |
| Low | 3 | ||
| Intermediate | 9 | 1 | |
| High | 1 | ||
| Adenocarcinoma | 8 (4.7%) | 1 (4.6%) | |
| Low | 3 | ||
| Intermediate | 1 | ||
| High | 4 | 1 | |
| Epithelial-myoepithelial carcinoma | 8 (4.7%) | 1 (4.6%) | |
| Low | 5 | 1 | |
| Intermediate | 2 | ||
| High | 1 | ||
| Adenosquamous carcinoma | 3 (1.8%) | 1 (4.6%) | |
| High | 3 | 1 | |
| Polymorphous low-grade adenocarcinoma | 1 (0.6%) | 2 (9.1%) | |
| Low | 1 | 2 | |
| Pathologic risk group15,16 | |||
| Low | 83 (49.1%) | 10 (45.5%) | 0.936 |
| Intermediate | 12 (7.1%) | 1 (4.5%) | |
| High | 74 (43.8%) | 11 (50.0%) | |
| Surgical margin | |||
| Negative | 65 (38.4%) | 9 (40.9%) | 0.479 |
| Close | 42 (24.9%) | 3 (13.6%) | |
| Positive | 59 (34.9%) | 10 (45.5%) | |
| Unknown | 3 (1.8%) | 0 |
Abbreviations: AJCC, American Joint Committee on Cancer; c, clinical; CRT, chemoradiotherapy; p, pathological; RT: radiotherapy.