Pharyngeal Cancer Treatment Approaches
Department of Surgery

Surgery is the preferred treatment for most pharyngeal cancers. If the cancer is considered localized, surgery may be performed if the tumor is considered surgically resectable and is likely to obtain clean surgical margins when the edges of the tissue removed do not contain tumor cells.

The surgeon will remove the cancer and possibly some surrounding tissue. In the event of suspected metastasis to local lymph nodes, a neck dissection will be performed and cancerous nodes removed. If a significant amount of tissue needs to be removed, reconstructive surgery may be required. In later-stage or aggressive cancers, near-total or total laryngopharyngectomy (removal of the larynx and pharynx) may be necessary. This has a significant impact on the patient, who may have to use an artificial larynx to speak.

A notable exception to the general rule of surgery being first-line treatment in pharyngeal cancers is nasopharyngeal cancer, which is primarily treated with radiotherapy. The keratinizing form of nasopharyngeal carcinoma is much less responsive to radiotherapy than the non-keratinizing forms, and would therefore benefit from surgery. Historically, surgical removal of tumors in the nasopharynx has proved difficult because of the complex anatomy of the region and the proximity of vital structures, which made access challenging. Now, modern techniques in skull base surgery may enable removal of certain tumors from the nasopharynx.

Radiotherapy

Because many types of pharyngeal cancers are advanced at diagnosis and/or prone to recurrence and metastasis, postoperative radiation therapy is often recommended to improve clinical outcomes. This is especially important in cases of higher-stage or larger tumors, or evidence of local invasion or metastasis.

Radiotherapy may be used by itself or in combination with chemotherapy in cases where the tumor may be too large to be surgically removed, where surgery would be unacceptably disfiguring, or if the tumor is inoperable for other reasons. Radiotherapy is also used as the primary treatment modality in most cases of nasopharyngeal cancer, as described above. Radiotherapy may also be useful as palliative treatment, i.e., to reduce symptoms such as pain and obstruction. Preoperative radiation may sometimes be employed in order to make the tumor more readily operable.

City of Hope's Radiation Oncology was the first in the western United States to offer the helical TomoTherapy Hi-Art System, one of the first radiation therapy systems of its kind to incorporate not only radiation therapy, but also tumor imaging capabilities comparable to a diagnostic computed tomography (CT) scan.

Two types of technology are integrated  spiral CT scanning and intensity modulated radiation therapy, or IMRT  thus producing hundreds of pencil beams of radiation (each varying in intensity) that rotate spirally around a tumor. The high-dose region of radiation can be shaped or sculpted to fit the exact shape of each patients tumor, resulting in more effective and potentially curative doses to the cancer. This also reduces damage to normal tissues and results in fewer complications.

Chemotherapy

Chemotherapy is sometimes used with radiation in cases of pharyngeal cancer where the disease is metastatic, unresectable and/or recurrent. It may also be employed postsurgically (along with radiation) in late-stage or aggressive cancers. Chemotherapy is rarely effective by itself in pharyngeal cancer, but is instead a valuable part of a multimodality treatment approach.

Chemotherapy regimens vary depending on the particular cell type in question. Sometimes, in order to use high-dose chemotherapy regimens (so as to destroy the maximum number of tumor cells), autologousperipheral blood stem cell transplantation is performed. This enables a rescue of the blood and bone marrow, which are hard hit by the intensive chemotherapy.

New Developments in Targeted Chemotherapy and Biologic Therapy

Studies suggest that three relatively new classes of drugs may show promise in treating pharyngeal cancers. The first is a drug class known as vascular endothelial growth factor (VEGF) inhibitors. These drugs are monoclonal antibodies that inhibit angiogenesis, the formation of new blood vessels necessary for tumors to continue growing and metastasizing. A VEGF inhibitor that has been used with some degree of success is bevacizumab (Avastin).

A second class of drugs is known as epidermal growth factor receptor (EGFR) inhibitors. EGFR is an oncogene, and its overexpression leads to uncontrolled cell growth, and thus cancer. Most pharyngeal cancers are known to overexpress EGFR. By inhibiting the EGFR gene, the drugs help to control tumor proliferation.

Immunotherapy in Advanced Nasopharyngeal Cancers

Because many nasopharyngeal cancers are associated with Epstein-Barr virus (EBV) infection, an immunotherapeutic treatment was devised to target this virus. Investigators isolated T cell s from the blood of EBV-positive nasopharyngeal cancer patients, and then modified the T cells to attack the EBV virus. Preliminary data suggest this approach can yield encouraging results.

Clinical Trials

City of Hope has several clinical trials involving experimental therapies for advanced solid tumors of the head and neck. Some of these may apply to pharyngeal cancers.  Click here for more information.

Follow-up

Because pharyngeal cancers often recur, patients should be followed closely for any signs of recurrence or metastasis. This is accomplished by regular physical exams that include thorough examination of the pharynx and neck as well as multiple imaging modalities, e.g., CT, magnetic resonance imaging and positron emission tomography scans.