Head and neck surgery is a diverse regional subspecialty, whose central focus is treatment of oncologic disorders of the neck. "Neck dissection is relevant to treatment of such disorders as squamous cell cancers of the upper aerodigestive tract, tongue cancer, laryngeal cancer, thyroid cancer, salivary gland cancer, and skin cancers of the head/neck region, including melanoma," explained William I. Kuhel, MD, the Director of the Head and Neck Service, Department of Otorhinolaryngology, at NewYork-Presbyterian/Weill Cornell Medical Center, and Associate Professor of Clinical Otorhinolaryngology at Weill Cornell Medical School.
"For many years, the radical neck dissection was the standard operation for removal of metastatic disease involving the lymph nodes in the neck, but that operation evolved into what are referred to as modified and selective neck dissections, which spare some of the important structures in the neck," said Dr. Kuhel.
Salvatore M. Caruana, MD, the Director of the Division of Head and Neck Surgery at NewYork-Presbyterian/Columbia University Medical Center, and Assistant Clinical Professor of Otolaryngology and Head and Neck Surgery at Columbia University College of Physicians and Surgeons, explained further. "The trend these days is to do smaller operations to get the same effect. Over the years it has become clear that certain areas of a radical neck dissection do not have to be included for diseases at specific levels. Our knowledge base has allowed us to make smaller operations to address the same problems." Greater experience has also allowed for more common use of adjuvant therapies, such as radiation and chemotherapy, he added. "We may sometimes simply remove the largest mass in the neck and give chemoradiotherapy for the rest."
Physicians interested in learning the latest developments in head and neck surgery should view this webcast, which features Drs. Caruana and Kuhel, both leaders in the field, who represent the campuses of NewYork-Presbyterian Hospital.
"Although advancements in imaging often enable us to more accurately assess the status of the neck, high-tech intraoperative technology is really not a driver in the discussion of this particular topic," said Dr. Kuhel. "Our progress has been based on a better understanding of patterns of lymphatic spread to the lymph nodes in the neck, advances in surgical skill, and better imaging, and these factors have enabled us to progress to the application of selective neck dissections, which spare certain lymph node groups in the neck."
"We have more accurate staging because of our better imaging techniques," Dr. Caruana said, "and, because of our historical data, we better understand what is and is not necessary. These selective operations hopefully lead to less postoperative debility from the operation."
The neck has been mapped out into six distinct levels, useful when comparing results from different tumor types. Historical data show, for example, that a tumor of the supraglottic larynx might generally spread to levels 2, 3 and 4. "Over the years we have learned that we don't have to perform a neck dissection to levels 1-5 when addressing levels 2-4 will do, since that is almost certainly where the tumor is going to be," Dr. Caruana explained. "And that means a smaller operation, less morbidity for the patient, and greater preservation of normal, unaffected tissue."
Despite important advances that have been made in reducing the morbidity from the surgical treatment of head and neck cancer, the mortality for head and neck squamous cell cancer has not improved during the past thirty years. "Surgeons have taken satisfaction in the fact that the functional outcomes are better even though the cure rate hasn't been improved," Dr. Kuhel said. "There have been huge advances in terms of reconstruction with microvascular free flaps."
New surgical approaches, new chemotherapeutic agents, and greater understanding of the molecular mechanisms of disease are all being utilized to try to improve the outcomes of patients with head and neck cancer. One new approach is natural orifice surgery, as explained by Dr. Caruana. "We are doing transoral laser microsurgery where we take certain tumors out through the mouth, obviating the need for a tracheostomy. Patients can usually swallow sooner than with a big open procedure, and we can sometimes lower the dose of radiation therapy, or even eliminate the need for radiation completely." Another hopeful area is the ongoing development of new chemotherapeutic agents, as well as new regimens using molecular targeted therapy (MTT). "MTT cells are designed to correct a molecular defect in the tumor," explained Dr. Caruana. "For instance, one of the major defects in the case of medullary thyroid cancer is a defect in the tyrosine kinase receptor. If you give MTT that blocks the function of that receptor, you have now in effect eliminated the fact that there is this defect."
Dr. Kuhel agreed. "The answer in terms of cancer is going to come from a better understanding of the molecular basis of the disease. When I was in medical school I heard lectures on the treatment of stomach ulcers, which discussed surgery, the cutting of certain nerves in the stomach, debate about whether it should be done endoscopically, etc. Ultimately, however, our knowledge improved to the point where we now know that these ulcers were caused by an infection. I believe that eventually when we understand the molecular mechanisms of cancer, head and neck surgery will become very anachronistic."