Neha Vapiwala, MD Abramson Cancer Center of the University of Pennsylvania
Head and neck malignancies account for only about 5-7% of all new cancer cases in the US, occurring more than twice as often in men as in women. Mortality rates have been declining steadily since the 1980's, with a ten-year survival rate in 1999 of 46%. Notably, the prevalence of these cancers is highest amongst populations with habitual tobacco and excessive alcohol use. The broad category of head and neck cancers can be further subdivided according to the primary tumor site, reflecting the complex anatomy of the head and neck region. These sites include the nasal fossa and paranasal sinuses, skull base, nasopharynx, oral cavity, oropharynx, salivary gland, larynx and the neck.
Epidemiology and Etiology
Incidence of 40,000 new cases in the US each year, with the highest overall incidence rate in black males. Mortality rate of 12,000 US deaths annually.
Etiology is linked to tobacco use for all tumor sites, as every form of tobacco is known to result in dysplastic and carcinogenic injuries. Alcohol is thought to play a synergistic role with tobacco, though its use alone is not clearly linked to cellular damage and malignancy.
Hereditary factors are not clearly identified.
Risk factors include heavy smoking and drinking, which both have a linear dose-risk effect where duration is more important than intensity; EBV infection in cancer of the nasopharynx; vitamin deficiencies and malnutrition; poor orodental hygiene; chronic inflammation in laryngeal cancer; sun exposure in carcinoma of the lip .
Annual physical exam and routine dental care may be most appropriate screening guidelines available for detecting early head and neck malignancies .
History: Generally present with weight loss and persistent lump or mass from advanced disease, but symptoms also vary based on anatomic site involved
Physical exam: Usually palpable or visible lump/mass; can also include associated cranial nerve defects, gingival hyperplasia, nonhealing ulcerative or exophytic oral lesions, erythroplakia, stridor from large glottic tumors
Lab studies: Not very valuable in diagnosis
Radiologic studies: Plain x-ray films, CT, MRI best for demarcating depth of tumor invasion and distinguishing malignant change from inflammation, angiography depending on tumor location, upper GI series
Diagnostic studies: Flexible fiberoptic nasopharyngoscopy with biopsies, direct laryngoscopy with esophagoscopy, videostroboscopy for laryngeal tumors
Natural Course and Pathology
Staging follows the American Joint Committee on Cancer criteria and is uniform for tumors of all head and neck primary sites, except for the nasopharynx.
Prognosis for cure worsens as depth of tumor invasion increases and degree of cellular differentiation decreases . Nutritional status and over-expression or mutation of the p53 gene may also play a role.
Histologic grade is extremely important predictor of long-term outcome. Cell type in majority of cases is squamous cell carcinoma, which is further categorized as either macroscopic if changes are observed pathologically, or microscopic if magnification is required. Adenocarcinomas of salivary gland origin also possible and include mucoepidermoid and adenoid cystic subtypes.
Early stage disease
Surgery alone is often the standard of care for early stage disease.
Radiation therapy alone is also acceptable for stage I and II malignancies, although squamous cells are only moderately radiosensitive.
In patients with N0 or N1 supraglottic carcinoma, local control was achieved in up to 86% of cases, but with relapse rates as high as 79% .
Advantages over surgery usually include improved function and cosmesis.
Brachytherapy and interstitial implants are sometimes used for tumors involving tongue, lip, floor of mouth, skin and buccal mucosa.
Late stage disease
Surgery is part of a combination approach, either before or after other modalities.
Radical or modified neck dissection if there is cervical lymph node spread.
Reconstructive procedures are very important adjunct to tumor resection.
Radiation therapy plays role in large, unresectable tumors for palliation and preservation of speech and swallowing functions .
Chemotherapy combination regimens have not yet demonstrated better tumor control or survival when used alone. However, many late stage disease patients are at risk of occult metastases and/or recurrence, thus chemotherapy plays a role.
Induction chemotherapy for recurrent or metastatic disease found to decrease rate of distant metastases, as compared to patients who did not receive chemotherapy .
Neoadjuvant regimens including cisplatin and 5-FU found to have excellent tumor response, with lower rate of distant metastases compared to untreated. Survival, however, is unchanged compared to those treated with conventional surgery and radiation .
Chemoradiation for stage II or III to synergistically improve tumor response, but at cost of significant toxicities .
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