In general, tumors of the major salivary glands are staged according to size, extraparenchymal extension, lymph node involvement (in parotid tumors, whether or not the facial nerve is involved), and presence of metastases.[1,2,3,4] Tumors arising in the minor salivary glands are staged according to the anatomic site of origin (e.g., oral cavity and sinuses). (Refer to the PDQ summaries on Laryngeal Cancer Treatment, Lip and Oral Cavity Cancer Treatment, Nasopharyngeal Cancer Treatment, Hypopharyngeal Cancer Treatment, and Paranasal Sinus and Nasal Cavity Cancer Treatment for more information.)

Clinical stage, particularly tumor size, may be the critical factor to determine the outcome of salivary gland cancer and may be more important than histologic grade.[5,6] Diagnostic imaging studies may be used in staging. With excellent spatial resolution and superior soft tissue contrast, magnetic resonance imaging (MRI) offers advantages over computed tomographic scanning in the detection and localization of head and neck tumors. Overall, MRI is the preferred modality for evaluation of suspected neoplasms of the salivary glands.[7]

The American Joint Committee on Cancer (AJCC) has designated staging by TNM classification.[5]

TNM Definitions

Primary tumor (T)

• TX: Primary tumor cannot be assessed
• T0: No evidence of primary tumor
• T1: Tumor 2 cm or less in greatest dimension without extraparenchymal extension*
• T2: Tumor more than 2 cm but 4 cm or less in greatest dimension without extraparenchymal extension*
• T3: Tumor more than 4 cm and/or tumor having extraparenchymal extension*
• T4a: Tumor invades skin, mandible, ear canal, and/or facial nerve
• T4b: Tumor invades skull base and/or pterygoid plates and/or encases carotid artery

*Extraparenchymal extension is clinical or macroscopic evidence of invasion of soft tissues. Microscopic evidence alone does not constitute extraparenchymal extension for classification purposes.

Regional lymph nodes (N)

• NX: Regional lymph nodes cannot be assessed
• N0: No regional lymph node metastasis
• N1: Metastasis in a single ipsilateral lymph node, 3 cm or less in greatest dimension
• N2: Metastasis in a single ipsilateral lymph node, more than 3 cm but 6 cm or less in greatest dimension; or in multiple ipsilateral lymph nodes, 6 cm or less in greatest dimension; or in bilateral or contralateral lymph nodes, 6 cm or less in greatest dimension
  • N2a: Metastasis in a single ipsilateral lymph node, more than 3 cm but 6 cm or less in greatest dimension
  • N2b: Metastasis in multiple ipsilateral lymph nodes, 6 cm or less in greatest dimension
  • N2c: Metastasis in bilateral or contralateral lymph nodes, 6 cm or less in greatest dimension
• N3: Metastasis in a lymph node more than 6 cm in greatest dimension

Distant metastasis (M)

• MX: Distant metastasis cannot be assessed
• M0: No distant metastasis
• M1: Distant metastasis

AJCC Stage Groupings