A. State of the Science Multidisciplinary Tumor Board Concept
Patients with head and neck cancer should be evaluated before initiation of therapy by representatives of each discipline responsible for administering cancer care. Having a multidisciplinary tumor board composed of otolaryngologists, plastic surgeons, oral and maxillofacial surgeons, radiation oncologists, medical oncologists, dental oncologists, pathologists, radiologists, and allied health professionals facilitates this approach. Patients and their family members should attend this tumor board or conference.
After they review the case histories, microscopic slides, and pertinent studies from diagnostic imaging (e.g., computed tomography, magnetic resonance imaging, plain X-ray films), representatives of each discipline should examine the patient. The tumor board process is useful in establishing a correct pathologic diagnosis, determining the extent of disease, detecting other simultaneous head and neck primary cancers that might have escaped detection, and facilitating dental evaluation, which is particularly important in patients whose treatment will include irradiation, chemotherapy, or resection of oral or oropharyngeal tissues.
After examination of the patient, the board should reconvene to discuss therapeutic alternatives and to formulate a recommendation for treatment based on expected outcome (function, cosmesis, impact of treatment on lifestyle and career) and the expertise available at the treating institution. If the board believes that either the necessary expertise or technology is not available at its institution, or if the patient and family so desire, the board may recommend referral to another institution or physician. If no curative option exists, the board may recommend treatment with palliative intent. If further workup is indicated, there may be a recommendation to obtain other tests and re-present the patient’s case to the board once additional information becomes available. Members of the board discuss these alternatives and recommendations with the patient and family, and in many instances, the patient and family are active participants in the decision-making process about the case. Patients are routinely advised to discontinue use of all tobacco products and alcohol.
Secondary benefits that accrue to patients and physicians from a multidisciplinary tumor board include the efficiency of: having multiple consultations by a number of specialists in a short period of time without having the patient travel from one office to the next; avoiding delays in obtaining consultative appointments; providing patient, family, and physician education; and assuring that the most appropriate therapy is applied first (as opposed to the commonplace situation in which the first practitioner to evaluate the patient provides the treatment as well).
Treatment Selection for the Primary Site: General Principles
Surgery or radiotherapy is curative for most early carcinomas of the oral cavity and oropharynx; cure rates for the two modalities are similar. Chemotherapy is not curative and is used only as an adjunct. Selection of the treatment modality must be based on factors such as functional outcome, cost, length of treatment, risk of complications, the patient’s general medical condition, and patient preference. Choices are also influenced by clinicians’ skills, experience and philosophies, and by available facilities.
More advanced lesions typically require combined radiotherapy and surgery to obtain optimal cure rates. In the past, preoperative radiotherapy of the primary site was common, but in recent years most centers have preferred to use postoperative radiotherapy, primarily because surgical complication rates are lower if irradiation is withheld until then. Postoperative radiotherapy is also used when the primary surgical specimen is found to have vascular or perineural invasion or close surgical margins.
Management of the Neck: General Principles
The incidence of cervical nodal metastases for each oral primary site increases with increasing local stage of disease. The patient with no neck disease or very early stage positive neck disease (N1) may be treated electively by radiotherapy or neck dissection. Because cure rates are the same, the neck is generally treated with the same modality selected for the primary site. If the risk of lymph node metastases is believed to be less than 15%, the clinician may simply observe the neck for the occurrence of metastases.
More advanced neck disease generally requires combined treatment for optimal regional disease control. Combined therapy is essential if there is extranodal spread of cancer or multiple positive nodes are identified. If surgery was used to treat the primary site, postoperative radiotherapy is appropriate. The only exceptions are when the nodal mass is fixed to the carotid artery or the cervical fascia; then preoperative radiotherapy is given. When radiotherapy is selected for the primary tumor, the neck dissection is generally performed 4-6 weeks after radiotherapy has been completed.
Most centers advocate surgical excision for early-stage primary disease (T1-T2) of the lip, floor of mouth, oral tongue, alveolar ridge, retromolar trigone, hard palate, or buccal mucosa. The CO laser may also be used as a cutting tool in removing oral cavity cancers. In addition, this laser may be useful in removing dysplastic lesions without scarring the area significantly. However, clinicians must still observe the patient closely after the lesions are removed, as there is a significant likelihood of recurrence.
Although radiotherapy may work as well as surgery for early malignant lesions in several of these subsites, such as the floor of mouth, concern about complication rates has made surgery the choice for most of these lesions. However, more advanced primary tumors in any of these sites typically require a combination of surgery and radiotherapy. Advanced primary tumors adjacent to the mandible may require a rim mandibulectomy, and those tumors that frankly invade the mandible are treated with a segmental mandibulectomy. The plan for surgical resection must also include reconstructive options; reconstructive teams composed of head and neck surgeons, oral surgeons, and prosthodontists are most successful at achieving the best functional and cosmetic result. (Chapter VIII contains a full discussion of reconstruction and rehabilitation.)
Most radiotherapy for carcinoma of the oral cavity uses an interstitial implant either alone or combined with external beam. For carcinoma of the oral tongue and buccal mucosa, the results of an interstitial implant alone or combined with external beam radiotherapy are generally better than those achieved with external beam radiotherapy alone.
Recurrence rates vary by primary site and increase with increasing primary stage. For lesions on the floor of the mouth, 5-year cause-specific survival rates by stage are as follows: I: 90%, II: 80%, III: 70%, favorable IV: 40-50%, and unfavorable IV: 20%. Five-year cause-specific survival rates for oral tongue cancers by stage approximate the following: I and II: 70-80%, III: 40%, and IV: 15 20%. (2)
The main goals in treating patients with oropharyngeal cancer are achieving a cure and preserving (3) both speech and swallowing functions. Although some institutions favor surgery alone or in combination with radiotherapy, a review of the literature showed no definite advantage for surgery (4) over radiotherapy in either tumor control or survival; surgery has the added disadvantage of causing losses (e.g., of velopharyngeal competency, of tongue musculature or tongue mobility, of all or part of the mandible, or of the larynx) that are not always fully compensated by reconstructive procedures. Thus, in a great many institutions, treatment consists of radiotherapy to the primary site, with or without subsequent neck dissection.
Base of Tongue
Because it responds strongly to irradiation, frequently metastasizes to the lymph nodes, and has poorly differentiated histology, carcinoma of the base of the tongue is usually treated by radiotherapy. Surgery for more advanced lesions usually results in a loss of major organ function. However, there remains disagreement about th