Table 2.
Incidence of tumor parapharyngeal extension by anatomic site.
| Anatomic site | Death | Local failure | Distant metastasis | |||
|---|---|---|---|---|---|---|
| HR* (95% CI) | P | HR* (95% CI) | P | HR* (95% CI) | P | |
| Masticator space | ||||||
| None | 0.551 (0.400–0.760) | <0.001 | 0.457 (0.267–0.782) | 0.004 | 0.394 (0.256–0.606) | <0.001 |
| Medial pterygoid muscle | 0.623 (0.445–0.873) | 0.006 | 0.940 (0.566–1.561) | 0.812 | 0.584 (0.386–0.884) | 0.011 |
| Lateral pterygoid muscle | 1 | 1 | 1 | |||
| Staging masticator space | 0.906 (0.522–1.573) | 0.727 | 1.147 (0.467–2.819) | 0.765 | 1.067 (0.563–2.023) | 0.842 |
| Masticator space | ||||||
| None | 0.885 (0.651–1.202) | 0.433 | 0.486 (0.302–0.780) | 0.003 | 0.675 (0.439–1.037) | 0.073 |
| Medial pterygoid muscle | 1 | 1 | 1 | |||
| Lateral pterygoid muscle and beyond | 1.572 (1.143–2.163) | 0.005 | 1.091 (0.678–1.754) | 0.720 | 1.734 (1.172–2.567) | 0.006 |
| Carotid space | ||||||
| None | 0.735 (0.586–0.921) | 0.008 | 0.693 (0.482–0.996) | 0.048 | 0.689 (0.502–0.947) | 0.022 |
| Anterior carotid space | 1 | 1 | 1 | |||
| Posterior carotid space | 1.085 (0.787–1.497) | 0.618 | 1.035 (0.802–1.507) | 0.621 | 1.425 (0.952–2.132) | 0.085 |
| Parapharyngeal extension | ||||||
| None | 0.678 (0.494–0.931) | 0.016 | 0.659 (0.395–1.099) | 0.110 | 0.832 (0.523–1.325) | 0.439 |
| Paranasopharyngeal | 1 | 1 | 1 | |||
| Paraoropharyngeal | 1.169 (0.756–1.809) | 0.482 | 1.734 (0.952–3.158) | 0.072 | 1.257 (0.857–2.213) | 0.312 |
*HR adjusted for age, gender, chemotherapy, T category, and N category according to the seventh edition AJCC system.