66 HEAD AND NECK CANCER
Harrison’s Manual of Medicine
HEAD AND NECK CANCER
Incidence and Epidemiology
Epithelial cancers may arise from the mucosal surfaces of the head and neck including the sinuses, oral cavity, nasopharynx, oropharynx, hypopharynx, and larynx. These tumors are usually squamous cell cancers. Thyroid cancer is discussed in Chap. 171.
Incidence and Epidemiology
About 40,000 cases are diagnosed each year. Oral cavity, oropharynx, and larynx are the most frequent sites of primary lesions in the U.S.; nasopharyngeal primaries are more common in the Far East and Mediterranean countries. Alcohol and tobacco (including smokeless) abuse are risk factors.
Nasopharyngeal cancer in the Far East has a distinct histology, nonkeratinizing undifferentiated carcinoma with infiltrating lymphocytes called lymphoepithelioma, and a distinct etiology, Epstein-Barr virus. Squamous cell head and neck cancer may develop from premalignant lesions (erythroplakia, leukoplakia), and the histologic grade affects prognosis. Pts who have survived head and neck cancer commonly develop a second cancer of the head and neck, lung, or esophagus, presumably reflecting the exposure of the upper aerodigestive mucosa to similar carcinogenic stimuli.
Chromosomal deletions and mutations have been found in chromosomes 3p, 9p, 17p, 11q, and 13q; mutations in p53 have been reported. Cyclin D1 may be overexpressed.
Most occur in people > 50 years. Symptoms vary with the primary site. Nasopharynx lesions do not usually cause symptoms until late in the course and then cause unilateral serous otitis media or nasal obstruction or epistaxis. Oral cavity cancers present as nonhealing ulcers, sometimes painful. Oropharyngeal lesions also present late with sore throat or otalgia. Hoarseness may be an early sign of laryngeal cancer. Rare pts present with painless, rock-hard cervical or supraclavicular lymph node enlargement. Staging is based upon size of primary tumor and involvement of lymph nodes. Distant metastases occur in < 10% of pts.
Three categories of disease are common: localized, locally or regionally advanced, and recurrent or metastatic. Local disease is treated with curative intent by surgery or radiation therapy. Radiation therapy is preferred for localized larynx cancer to preserve organ function; surgery is used more commonly for oral cavity lesions. Locally advanced disease is the most common presentation. Surgery followed by radiation therapy is standard; however, the disease is responsive to chemotherapy, and the use of three cycles of cisplatin (100 mg/m2 IV day 1) plus 5-fluorouracil (1000 (mg/m2)/d by 96- to 120-h continuous infusion) before or delivery of the same regimen during radiation therapy is as effective as (or more effective than) surgery plus radiation therapy. Head and neck cancer pts are frequently malnourished and often have intercurrent illness. Concomitant chemotherapy and radiation therapy shows a survival advantage, but mucositis is worse. Pts with recurrent or metastatic disease are treated palliatively with cisplatin plus 5-fluorouracil or paclitaxel (200–250 mg/m2 with G-CSF support). Treatment outcome varies somewhat with primary site; in general, pts with localized disease have about 75% 5- year survival, those with locally advanced disease have about 35% 5-year survival, and those with metastatic disease have about 15% 5-year survival.
Pts with head and neck cancer who are rendered disease-free may benefit from chemopreventive therapy with cis-retinoic acid (3 months of 1.5 (mg/kg)/d followed by 9 months of 0.5 (mg/kg)/d PO). Trial results are mixed.
For a more detailed discussion, see Vokes EE: Head and Neck Cancer, Chap. 87, p. 559, in HPIM-15.