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Treating Head and Neck Cancer Requires Extraordinary Coordination Among Disciplinesby Dawn Chalaire
Treating cancer always necessitates a balance between eradicating the disease and preserving function and appearance, and this equilibrium is particularly precarious in the treatment of head and neck cancer. As soon as surgeons became technically capable of performing extensive resections of head and neck tumors, they raised the question of whether the benefits of these procedures were worth the price. Many patients were cured of their cancer but left with cosmetic deformities or speech or swallowing impairments. It became clear that combining or replacing surgery with other types of treatment to preserve form and function would require a great deal of coordination among different individuals, departments, and disciplines. And so it was that in the treatment of head and neck tumors, the concept of multidisciplinary care was first conceived and practiced at The University of Texas M. D. Anderson Cancer Center in the late 1960s. “There was a lot of resistance to multidisciplinary care when it was developed because treatment 30 years ago was very territorial,” said Randal S. Weber, M.D., professor and chair of the Department of Head and Neck Surgery. “The true multidisciplinary team concept really grew out of the need to achieve the two goals in cancer care, which are to maximize survival and preserve or restore form and function.” Changes wrought by multidisciplinary care The advent of multidisciplinary care has led to many changes in the treatment of head and neck cancer. For example, tumors of the posterior tongue and tonsil once often necessitated removal of part or all of the tongue, which frequently left patients unable to swallow properly or speak. Now, these tumors can often be treated with radiation therapy alone or in combination with chemotherapy. In disease sites where surgery is still the principal treatment approach, new techniques may allow surgeons to limit the amount of tissue they remove. For example, laser surgery can now be performed on patients with cancers of the larynx to avoid a tracheostomy and permanent loss of the voice. However, conventional surgery is still required to treat some very advanced cancers, or those of the skin, thyroid, salivary glands, and front part of the tongue, because other treatment modalities for these cancers are not as effective. “So we’re left with the problem that surgery may still create cosmetic and functional loss,” Dr. Weber said. To minimize and restore the deficits created by surgery, head and neck surgeons consult with plastic surgeons to plan combined extirpative and complex reconstructive procedures using the patient’s own soft tissues and bone, which are harvested with blood vessels from a variety of donor sites in the body and attached to blood vessels and other tissues in the head and neck region. In some cases, when immediate reconstruction is not feasible or desirable, resected facial structures such as the nose or an ear are replaced with prosthetics created in the Department of Head and Neck Surgery’s Section of Oncologic Dentistry and Prosthodontics. Researchers in the Department of Plastic Surgery are also investigating the use of engineered tissue that can grow and differentiate around a scaffold to replace missing structures. Pros and cons of chemotherapy and radiation therapy Treating head and neck tumors with chemotherapy, radiation therapy, or both has enabled physicians to leave certain organs and structures intact, but organ preservation often comes at a significant cost—acute toxic effects that can create scar tissue and damage nerves, adversely affecting the function of the tongue and the larynx. “What we’ve done over the past decade is intensify radiation therapy using a twofold approach. One approach is to deliver hyperfractionation, or more than one radiation treatment a day. The other approach we’ve taken is adding radiotherapy sensitizers to the treatment regimen, and that is where chemotherapy comes in. Chemotherapy enhances the effect of radiation, but the downside is that it is toxic. So we are preserving organs, but some of those organs don’t function so well because of the toxic effects,” Dr. Weber said. In a recent study led by Moshe Maor, M.D., a professor in the Department of Radiation Oncology at M. D. Anderson, investigators found that patients with laryngeal cancer who were treated with radiation therapy and chemotherapy concurrently were less likely to require surgical removal of the voice box within two years after treatment than were patients treated with chemotherapy followed by radiation therapy or radiation therapy alone.
Radiation therapy and chemotherapy can also be used after surgery to improve local-regional control and survival in patients with advanced head and neck tumors. In the May 6, 2004, issue of the New England Journal of Medicine, similar results were reported from two randomized clinical trials comparing concurrent chemotherapy and radiation therapy versus radiation therapy alone in postoperative patients with advanced head and neck cancer. In both studies, disease-free survival was longer in the patients who received concurrent therapy; however, patients treated with both radiation therapy and chemotherapy were much more likely to have moderate to severe side effects such as nausea, vomiting, pain, and difficulty swallowing. Even patients treated with radiation therapy alone may suffer from long-term effects, especially a decrease in saliva production. Besides causing discomfort and making it more difficult to speak and swallow, a decrease in saliva can make the teeth more susceptible to cavities, necessitating long-term prophylaxis, including daily fluoride treatments. To avoid damaging the salivary glands during radiation therapy, different approaches are under investigation. Intensity-modulated radiation therapy is used to focus the treatment beams on the tumor with less damage to surrounding tissues, such as the salivary glands, than that caused by conventional radiation therapy delivery methods. Follow-up care of patients treated for head and neck cancer Patients who have been treated for cancers of the head and neck require frequent and extensive follow-up after treatment. Patients with a history of smoking or alcohol abuse are at high risk for a second primary tumor, including lung cancer, esophageal cancer, or another tumor in the head and neck region, and should be referred to alcohol and tobacco cessation programs during treatment recovery. After treatment, many patients are referred to swallowing therapists, who, among other things, perform tests to assess swallowing function, prescribe exercises to facilitate swallowing, and refer patients to clinical nutritionists for recommendations to develop a balanced diet of foods that the patient is able to swallow. Head and neck cancer is particularly cruel because the tumor and its treatment can affect two elements that are critical for human interactions—the face and the voice. Speech therapists improve or maintain the patients’ ability to speak through exercises and voice conservation techniques. For patients who receive a voice prosthesis following loss of the larynx, the therapists can help them become acclimated to the device and show them how to use it properly. In addition to educating patients about oral hygiene and fluoride prophylaxis after radiation therapy, dental oncologists make adjustments to facial prostheses as needed owing to tissue changes and scar contractures. New treatment approaches on the horizon Dr. Weber predicts that in the future, the war on head and neck cancer will be waged on several fronts: identifying patients’ genetic risk for developing head and neck cancer and thus selecting them for intensive cancer screening, lifestyle intervention, and drug therapy that may reverse the progression to malignancy; selecting treatment modalities based on the genetic profile of a patient’s tumor; and developing more effective, less toxic treatment combinations. Erich Sturgis, M.D., an assistant professor in the departments of Head and Neck Surgery and Epidemiology, and his colleagues are attempting to identify genetic profiles that increase the risk of thyroid, salivary, and squamous cell cancers of the head and neck. In a case-control study, Dr. Sturgis and his colleagues demonstrated that exposure to human papillomavirus type 16 (HPV-16) is the primary risk factor for oropharyngeal cancers in individuals who have never smoked. They also showed that this risk is heightened by a mutation in the p53 tumor suppressor gene. However, in contrast to previous studies, they found no evidence that HPV-16 exposure decreased survival duration. Mutations in the p53 gene are implicated in many types of cancer, and gene therapy involving the adenoviral vector–mediated delivery of the wild-type p53 gene is being studied in head and neck cancer. Gary Clayman, M.D., a professor in the Department of Head and Neck Surgery, is actively investigating intratumoral administration of the normal p53 gene in patients with squamous cell carcinoma of the head and neck. To improve treatment efficacy while limiting toxicity, biologic agents such as proteins, antibodies, and small molecules are being added to chemotherapy or radiation therapy. In a study led by investigators at the University of Alabama at Birmingham and M. D. Anderson and presented at the American Society of Clinical Oncology annual meeting in June 2004, adding the epidermal growth factor receptor (EGFR) inhibitor cetuximab to radiation therapy was shown to significantly increase survival duration without increasing toxicity in patients with localized head and neck cancer. In addition to EGFR inhibitors, researchers are conducting clinical trials of treatment combinations with antiangiogenic agents. “These targeted agents can attack pathways specific to cancer cells, which may permit other treatments used in combination to be more effective in eradicating a cancer cell,” said Dr. Weber. “We are making definite progress towards our dual goals of eradicating head and neck cancer while at the same time preserving form and function.” For more information on this topic or for questions about M. D. Anderson’s treatments, programs, or services, call askMDAnderson at (877) MDA-6789. Other articles in OncoLog, October 2004 issue:
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