Residency · Residency · Otolaryngology

Head and Neck Cancer Staging and Workup

Overview

Head and neck squamous cell carcinoma (HNSCC) is the 6th most common cancer worldwide. A systematic, evidence-based workup including clinical examination, imaging, tissue diagnosis, and multidisciplinary tumor board discussion is essential for accurate staging and treatment planning. The AJCC 8th edition introduced major changes, particularly the separation of HPV-positive oropharyngeal carcinoma into a distinct staging system.

Epidemiology

~65,000 new cases per year in the United States. Male predominance (3:1); narrowing due to HPV-related disease. Traditional risk factors: tobacco and alcohol (synergistic effect). HPV (type 16 primarily): rising cause of oropharyngeal SCC in younger, non-smoking patients. Other risk factors: betel nut (oral cavity in South/Southeast Asia), Epstein-Barr virus (nasopharyngeal carcinoma), occupational exposures, poor oral hygiene, immunosuppression.

Subsites of the Head and Neck

Oral cavity: lips, oral tongue (anterior 2/3), floor of mouth, buccal mucosa, gingiva, hard palate, retromolar trigone. Oropharynx: base of tongue, tonsils, soft palate, posterior pharyngeal wall. Hypopharynx: piriform sinus, postcricoid area, posterior hypopharyngeal wall. Larynx: supraglottis, glottis, subglottis. Nasopharynx: superior, posterior, and lateral walls including fossa of Rosenmuller. Nasal cavity and paranasal sinuses: covered in Topic 19. Salivary glands: covered in Topics 57-60.

Initial Workup

History

Duration and progression of symptoms. Pain, dysphagia, odynophagia, otalgia (referred via CN V, IX, X), voice change, globus. Weight loss (prognostic significance), Tobacco and alcohol history (pack-years, current use), Sexual history (HPV-related risk for oropharyngeal SCC), Prior radiation or cancer history, Performance status (ECOG or Karnofsky).

Physical Examination

Complete head and neck examination including: Oral cavity: bimanual palpation of floor of mouth, tongue base, assessment of trismus. Oropharynx: tonsils, base of tongue, soft palate. Neck: systematic palpation of all nodal levels; note size, fixation, laterality. Cranial nerve examination (especially V, VII, IX, X, XI, XII). Flexible nasopharyngolaryngoscopy: visualization of nasopharynx, hypopharynx, larynx; vocal fold mobility. Skin examination of head and neck (cutaneous malignancy).

Tissue Diagnosis

Fine-needle aspiration (FNA): first-line for neck masses; ultrasound-guided preferred. Sensitivity and specificity >90% for malignancy. Core needle biopsy if FNA non-diagnostic. Avoid open/excisional biopsy of a neck mass as initial diagnostic step (tumor seeding, complicates subsequent neck dissection). Biopsy of primary site: office-based biopsy of visible oral cavity or oropharyngeal lesions; operative biopsy (EUA with panendoscopy) for deeper or inaccessible lesions. p16 immunohistochemistry: surrogate marker for HPV; positive = strong and diffuse nuclear/cytoplasmic staining in >70% of tumor cells; standard of care for all oropharyngeal SCC.

Panendoscopy (EUA)

Examination under anesthesia with direct laryngoscopy, esophagoscopy, and bronchoscopy. Maps the primary tumor extent. Rules out synchronous second primary tumors (3-5% incidence; "field cancerization"). Biopsies of primary site and suspicious areas.

Imaging

CT with Contrast

Workhorse imaging modality for HNSCC. Evaluates primary tumor extent, nodal disease, and bony invasion. CT neck from skull base to thoracic inlet. CT chest: to rule out pulmonary metastases or second primary (especially in smokers).

MRI

Superior soft tissue contrast; best for: Oral cavity (tongue base invasion, floor of mouth, perineural spread). Nasopharyngeal carcinoma (skull base invasion, intracranial extension). Parotid and parapharyngeal space tumors. Differentiation of tumor from post-treatment changes. Less useful for larynx (motion artifact) unless dedicated protocols.

PET/CT (18F-FDG)

Indicated for: Stage III-IV disease: detection of distant metastases (lung, liver, bone). Unknown primary: localization of primary site in cervical metastasis of unknown primary SCC. Post-treatment surveillance: differentiation of residual/recurrent disease from post-treatment changes (typically performed at 12 weeks post-treatment). Evaluation of treatment response. False positives: inflammation, infection, granulomatous disease. False negatives: small tumors (<8 mm), well-differentiated tumors, post-treatment edema.

Ultrasound

Thyroid nodule assessment if palpated, Guided FNA of neck nodes, Real-time, no radiation, inexpensive.

AJCC 8th Edition Staging (Key Changes)

HPV-Positive (p16+) Oropharyngeal Carcinoma -- NEW Staging

Separate staging system recognizing the vastly different biology and prognosis. T-staging: similar to HPV-negative. T0-T4 based on tumor size and local extension. N-staging (clinical): simplified. N0: no nodes. N1: ipsilateral node(s), none >6 cm. N2: contralateral or bilateral nodes, none >6 cm. N3: node(s) >6 cm. N-staging (pathologic -- post-surgical): based on number of nodes. pN0: no nodes. pN1: 1-4 positive nodes. pN2: 5+ positive nodes. No stage IV: maximum stage is stage III (reflecting the favorable prognosis). Extranodal extension (ENE) does NOT affect N-staging in p16+ disease (controversial).

HPV-Negative Oropharyngeal and Other Sites

Traditional TNM staging. Major update: extranodal extension (ENE) incorporated into N-staging. ENE+ automatically upgrades to N3b regardless of node size or number. ENE is the single strongest adverse prognostic factor in non-HPV HNSCC. Depth of invasion (DOI) added to oral cavity T-staging: T1: DOI ≤5 mm. T2: DOI >5 mm and ≤10 mm. T3: DOI >10 mm. (Size criteria also apply; whichever gives higher T-stage is used).

Nasopharyngeal Carcinoma

Separate staging system (EBV-related), Predominantly treated with chemoradiation (not surgery).

Multidisciplinary Tumor Board

Essential for treatment planning. Members: head and neck surgeon, radiation oncologist, medical oncologist, radiologist, pathologist, speech-language pathologist, dietitian, social worker, dentist. Discuss: staging, treatment options (surgery vs. radiation vs. chemoradiation), reconstruction, functional outcomes, clinical trials. Pre-treatment dental evaluation to prevent osteoradionecrosis.

General Treatment Principles

Early stage (I-II): single modality (surgery OR radiation); equivalent outcomes for many sites. Advanced stage (III-IV): multimodality therapy (surgery + adjuvant radiation/chemoradiation OR primary chemoradiation). Adjuvant radiation indicated for: advanced T-stage, positive margins, perineural invasion, lymphovascular invasion, multiple positive nodes. Adjuvant chemoradiation (cisplatin) indicated for: positive margins and/or extranodal extension (based on RTOG 9501 and EORTC 22931). Site-specific considerations discussed in individual topics.

<image>Diagram of the cervical lymph node levels (I-VII) as used in head and neck oncology staging and neck dissection planning. Levels I through VI are shown on an anterior view of the neck with anatomic boundaries defined by muscles, vessels, and bony landmarks. Level I (submandibular/submental), Level II (upper jugular, subdivided IIA/IIB by spinal accessory nerve), Level III (middle jugular), Level IV (lower jugular), Level V (posterior triangle, VA/VB), Level VI (central compartment), and Level VII (superior mediastinal). Key anatomic landmarks labeled: digastric muscle, hyoid bone, cricoid cartilage, IJV, SCM, spinal accessory nerve, carotid bifurcation.</image>

<image>Comparison of AJCC 8th edition N-staging for HPV-positive (p16+) oropharyngeal carcinoma vs. HPV-negative head and neck SCC. Two side-by-side tables showing the simplified p16+ clinical and pathologic N-staging (N0-N3 for clinical; pN0-pN2 for pathologic based on node count) vs. the traditional N-staging for HPV-negative disease with N1-N3b categories and the incorporation of extranodal extension (ENE) as an automatic N3b upstaging factor. Key differences are highlighted.</image>

<image>PET/CT images showing a case of oropharyngeal squamous cell carcinoma. Axial fused PET/CT showing FDG-avid left tonsil primary tumor and an ipsilateral level II cervical lymph node metastasis. A whole-body maximum intensity projection (MIP) image is shown alongside to demonstrate the utility of PET for detecting distant metastases. Labels indicate the primary tumor, nodal metastasis, and physiologic uptake in the brain, heart, kidneys, and bladder.</image>

Clinical Pearls

Never perform an excisional biopsy of a neck mass as the initial diagnostic step in a suspected HNSCC -- FNA first. p16 immunohistochemistry is a mandatory part of the pathologic workup for all oropharyngeal SCC; it determines which staging system is used. Depth of invasion (DOI) is now part of oral cavity T-staging and is one of the most important prognostic factors for occult nodal metastasis. Extranodal extension (ENE) is the strongest adverse prognostic factor in HPV-negative HNSCC and automatically upstages nodal disease to N3b. PET/CT at 12 weeks post-treatment is the standard for response assessment and has reduced the need for planned post-treatment neck dissections. Synchronous second primary tumors occur in 3-5% of HNSCC due to field cancerization -- panendoscopy is essential. A CT chest (or PET/CT) is important for staging advanced disease and for detecting second primary lung cancer in smokers. All HNSCC patients should have pre-treatment dental evaluation to extract non-viable teeth and reduce the risk of osteoradionecrosis.

References

• Amin MB, Edge SB, Greene FL, et al. AJCC Cancer Staging Manual. 8th ed. Springer; 2017.
• National Comprehensive Cancer Network (NCCN). "Head and Neck Cancers." Version 2.2024.
• Cooper JS, Pajak TF, Forastiere AA, et al. "Postoperative concurrent radiotherapy and chemotherapy for high-risk squamous-cell carcinoma of the head and neck." N Engl J Med. 2004;350(19):1937-1944.
• Bernier J, Domenge C, Ozsahin M, et al. "Postoperative irradiation with or without concomitant chemotherapy for locally advanced head and neck cancer." N Engl J Med. 2004;350(19):1945-1952.

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