Early Stage Throat Cancer
Early stage cancers of the throat are small, localized, and highly curable when treated with surgery and/or radiation therapy. Early stage disease includes stage I, II, and some stage III cancers. Stage I cancer is no more than 2 centimeters in size (about 1 inch) and has not spread to lymph nodes in the area. Stage II cancer is more than 2 centimeters, but less than 4 centimeters (less than 2 inches) and has not spread to lymph nodes in the area. Stage III cancer can be considered “early” if it is small and involves only a single lymph node, which can be surgically removed or treated with radiation with a high probability of cure.
The following is a general overview of treatment for early stage cancer of the throat. Treatment may consist of surgery, radiation, chemotherapy, biological therapy or a combination of these treatment techniques. Multi-modality treatment, which is treatment using two or more techniques, may be the most promising approach for increasing a patient’s chance of cure or prolonging a patient’s survival. However, circumstances unique to each patient’s situation may influence how these general treatment principles are applied and whether the patient decides to receive treatment. The potential benefits of receiving treatment must be carefully balanced with the potential risks. The information on this website is intended to help educate patients about their treatment options and to facilitate a mutual or shared decision-making process with their treating cancer physician.
Treatment of throat cancer is multi-modality in nature. Because the throat is involved in talking, swallowing, and breathing, the type of treatment is selected to minimized impact on these important functions. Furthermore, treatment may be dictated by how it affects a patient’s appearance, and thus, quality of life.
Surgery: The most common treatment of early stage cancer of the throat is surgery, which results in cure for over 80% of patients. In some cases, patients are unable to tolerate surgery or surgery results in significant functional defects, including difficulty in talking or swallowing.
Radiation therapy: Radiation therapy has been shown to produce similar results to that of surgery. The results of one clinical study involving 400 patients with cancer of the tonsil indicated that the use of radiation therapy alone or with surgery to remove only cancerous lymph nodes afforded cure rates as good as those typically achieved with more extensive surgery but with less severe complications. In this study, 100% of patients with stage I disease and 86% of patients with stage II disease survived 5 years after completion of treatment. Control of the cancer in the tonsil area was achieved in more than 80% of patients with stage I and II disease.
In another study, 96% of 57 patients with stage I cancer of the throat treated with radiation were alive 10 years after treatment. Researchers from MD Anderson Cancer Center have also repeated the results of a clinical study evaluating 150 patients with previously untreated squamous cell carcinomas of the tonsils receiving radiation therapy. Irradiation delivered to both sides of the neck (bilateral) was routine in all patients. With a minimum follow-up of 2 years after irradiation, 94% of patients with stage I disease and 79% with stage II reported no recurrence at the site of origin.
Radiation and Surgery: Combined radiation and surgery is usually reserved for larger cancers of the throat. However, this approach may also be used to treat patients who have cancer detected in the margins of the removed tissue or who have only a narrow margin of normal tissue remaining after surgical removal of the cancer.
Treatment of the Lymph Nodes in the Neck
One of the controversies in treatment of early stage cancer of the throat is whether or not to routinely treat the lymph nodes in the neck with surgery and radiation therapy. If left untreated, cancers of the throat ultimately spread throughout the lymph system in the neck. Untreated cancer that has spread to lymph nodes is responsible for cancer recurrence. Thus, identifying whether cancer is present in the lymph nodes in the neck is important for preventing recurrence. Currently, surgical removal of the lymph nodes in the neck is the best way to determine whether cancer is present.
Evaluation of the lymph nodes in the neck consists of surgically removing a majority of lymph nodes on the side of the neck where the cancer is present and is referred to as a “radical lymph node dissection”. A modified radical neck dissection, which is associated with less cosmetic and functional complications than radical neck dissection, is used for elective lymph node dissection in patients without clinical evidence of cancer spread. When positive lymph nodes are identified, patients are usually treated with radiation therapy to the neck. If the lymph node evaluation reveals no evidence of cancer, no further therapy after lymph node dissection is recommended.
At this time, clinical studies have not convincingly demonstrated improved survival for patients with early stage throat cancer subjected to elective lymph node removal compared to close observation and treatment of recurrence with surgery or radiation therapy. The main benefits of lymph node removal appear to be accurate staging and potentially more effective treatment for those with spread of cancer.
Strategies to Improve Treatment
The development of more effective cancer treatments requires that new and innovative therapies be evaluated with cancer patients. Clinical trials are studies that evaluate the effectiveness of new drugs or treatment strategies. Future progress in the treatment of early stage cancer of the throat will result from the continued evaluation of new treatments in clinical trials. Participation in a clinical trial may offer patients access to better treatments and advance the existing knowledge about treatment of this cancer. Patients who are interested in participating in a clinical trial should discuss the risks and benefits of clinical trials with their physician. Areas of active exploration to improve the treatment of early stage cancer of the throat include the following:
Mohs Micrographic Surgery: The usual method of surgery is to remove all the visible cancer with a “safe” margin, usually one to two inches, of tissue that is presumed to be normal. In many areas of the body this creates large defects that have to be corrected with skin grafts. In the Mohs micrographic technique, an attempt is made to remove only cancerous tissue and spare as much normal tissue as possible.
Mohs micrographic surgery is performed under local anesthesia in an outpatient surgical unit. The clinically identifiable tumor is tattooed and the area of cancer is infiltrated with local anesthetic. All visible cancer is completely removed using aggressive curettage (scraping). Removal of cancer with 2-3 mm margins is carried out and the frozen sections of the superficial and deep margins of the surgical specimen are carefully examined. If examination of the tissue from the first Mohs surgical stage reveals cancerous involvement of the margin, then an additional tissue specimen is removed from the appropriately mapped area, and the process is repeated until cancer free margins are achieved.
Although this technique has been used for over 50 years, there is still debate regarding its relative merits over conventional surgery. Conventional surgery usually requires large initial margins with later examination under the microscope. For patients who have cancers in vital areas, removal of “safe” wide margins of normal tissue could result in disfigurement.
Sentinel Lymph Node Biopsy: An alternative to radical lymph node dissection is sentinel lymph node biopsy (SLNB). This technique involves removal of only the primary lymph node that drains the affected area, called the sentinel lymph node. In a SLNB, a radiolabeled dye is injected into the tissue near the cancer and allowed to drain into the lymph nodes. The sentinel lymph node is the first node that the dye reaches. Surgery is then performed to remove this lymph node, which is then examined under a microscope to determine if any cancer exists.
One study conducted in Germany suggests that SLNB may be suited for ear, nose, and throat cancers. SLNB was conduced in nine male patients with squamous cell carcinoma of the head and neck. In 7 out of 9 patients, detection of the sentinel lymph node was successful. On examination of the sentinel lymph node under a microscope, cancer cells were found in 5 patients. The technique is still in development to resolve problems such as the short distance between the primary injection site and the lymph nodes and the influence of the cancer on uptake of the radiolabeled dye.
Photodynamic Therapy: In photodynamic therapy, light from a laser enhanced by photosensitizing agents, can kill cancer cells without damage to normal cells. The basic technique is over 50 years old but the past 5 years have seen the development of reliable, portable lasers and better photosensitizing agents. These advances have made the technique quick, effective, and relatively free from side-effects. For patients with head and neck cancer, functional outcomes with photodynamic therapy are probably better than surgery and radiation therapy. However, there is inadequate long-term survival data at this time.
The outcomes and survival rates of two clinical studies with photodynamic therapy compare favorably with published survival rates for surgery and/or radiotherapy for similar patients, though no comparative studies have been performed. In these studies, photodynamic therapy with temoporfin (Foscan) completely cleared cancers at 12 weeks in 83% of 115 patients with primary head and neck cancers. The one-year survival rate was 87%. This approach was also successful for 50% of 96 patients with recurrent or second primary cancers with a one year survival of 65%.
An advantage of photodynamic therapy is that it can usually be given to outpatients under local anesthesia. Patients receive intravenous temoporfin, followed 4 days later by brief laser illumination of the cancer site. About 10% of some 1000 patients treated worldwide had photosensitivity reactions – mostly only mild erythema. Photosensitivity takes 2–3 weeks to resolve, during which time patients must avoid bright light. There was also significant post-treatment pain, which can require pain medication with opiates.
Photodynamic treatment may also be of palliative benefit in more than 50% of patients with incurable head and neck cancers with complete local cancer control.