Head and Neck Malignancy

I

Epidemiology

• 1.

  Worldwide, it is estimated that 300,000 people are living with oral cavity and pharynx cancer. Approximately 48,000 head and neck cancers are diagnosed in the United States annually, representing nearly 3% of cancers diagnosed in North America and 1.6% of all cancer deaths. The male-to-female ratio is almost 3:1, and the median age of onset is 62 years. The 5-year survival rate is 64% but varies greatly depending on the site of the primary.

• 2.

  The majority of these malignancies are squamous cell in origin (90%), with primary salivary gland tumors being the next most common. Squamous cell are categorized by location and are most commonly found in the oral cavity (29.5%), larynx (20.4%), hypopharynx (19.8%), oropharynx (14.7%), nose and paranasal sinuses (7%), and nasopharynx (3.2%).

• 3.

  Risk factors for head and neck squamous cell carcinoma (HNSCC) classically have been smoking and heavy alcohol exposure, which act synergistically to increase the risk of HNSCC 60–100-fold. A recent increase in human papillomavirus (HPV)–associated HNSCC is most strongly associated with tumors of the oropharynx, including tonsils and base of tongue cancers. Nearly 16,000 new cases of HPV-associated HNSCC are diagnosed each year, which now makes up 70% of oropharyngeal HNSCC. HPV-associated HNSCC have a strong male association, nearly 4:1. Fortunately, HPV-associated HNSCC of the oropharynx has a 54% better survival rate compared with HNSCC not associated with HPV. Approximately 80% of people are exposed to HPV over their lifetime, but not all exposures become clinically significant. Those who do develop malignancies typically do so 20–30 years after exposure to the virus. Some early studies have found that the HPV vaccine affords strong protection against oral HPV infections, potentially decreasing the risk of HPV-associated HNSCC.

II

Work-Up of a Neck Mass

• 1.

  Unknown primary: a malignant neoplasm metastatic to cervical lymph nodes without an identifiable primary tumor

  • a.

    Vast majority will be squamous cell cancer and will present as a neck mass.

    • (1)

      Less commonly present as pain (9%), weight loss (7%), dysphagia (4%)

  • b.

    Diagnostic algorithm ( Fig. 34.1 )

    • (1)

      CT of neck

    • (2)

      Positron emission tomography–computed tomography (PET CT) may help to identify the primary site, as well as the extent of nodal and or metastatic disease.

    • (3)

      Fine-needle aspiration (FNA) (see diagram for FNA algorithm)

    • (4)

      If still unable to localize, endoscopy with direct biopsies of the most common areas (base of tongue) and tonsillectomy

      • (a)

        Panendoscopy: direct laryngoscopy, nasal endoscopy, esophagoscopy, and bronchoscopy

    

III

Neck Dissection

• 1.

  Radical neck dissection : removes sternocleidomastoid muscle (SCM), internal jugular (IJ) vein, and spinal accessory nerve (CN XI)

  • a.

    This is rarely performed nowadays, because of morbidity; it is indicated only for clinically positive nodes with extracapsular extension and involvement of SCM, IJ vein, or CN XI.

  • b.

    If bilateral is required, spare one IJ vein to avoid potential neurologic complications from venous congestion.

• 2.

  Modified radical neck dissection: Rationale is that lymphatics in the neck are fibroadipose tissue contained within a complex system of aponeurotic partitions that are separate from the SCM and IJ vein. There is equally effective oncologic resection with lower morbidity.

  • a.

    Type I: spares CN XI

  • b.

    Type II: spares IJ vein and CN XI

  • c.

    Type III (also known as functional): spares SCM, IJ vein, and CN XI

• 3.

  Selective neck dissection: Rationale is that it removes nodal levels at high risk and is based on the location of the primary tumor and its known pattern of spread.

  • a.

    En bloc resection of one or more lymph node basins

    • (1)

      Selective neck dissections are described with respect to the lymph node levels removed. For example, a supraomohyoid neck dissection is described as a selective neck dissection (I-III).

      • (a)

        Indication: performed in the clinically N0 neck

• 4.

  Lymph node groups—If you have node-positive (N+) disease, long-term survival decreases by 50%.

  • a.

    Level i: submental and submandibular nodes

  • b.

    Level ii: upper jugular nodes

  • c.

    Level iii: middle jugular nodes

  • d.

    Level iv: lower jugular and supraclavicular nodes

  • e.

    Level v: posterior triangle nodes (postauricular, occipital, spinal accessory chain)

  • f.

    Level vi: anterior nodes (pretracheal and paratracheal nodes, Delphian node)

IV

Treatment of Cancer by Site