Surgical Approach to Organ Preservation in the Treatment of Cancer of the Larynx
Surgical Approach to Organ Preservation in the Treatment of Cancer of the Larynx
It is important that the clinician counseling a patient about alternative approaches for preserving the larynx in the treatment of laryngeal cancer not only focus on the role of nonsurgical approaches but also explain the role of surgical approaches for organ preservation. Currently, a broad spectrum of surgical procedures are available for preserving the larynx in the setting of laryngeal carcinoma. The only way a clinician can appropriately counsel a patient with laryngeal cancer about treatment options is to gain a thorough understanding of both the surgical and nonsurgical alternatives.
In an era when patients have ready access to the medical literature via the Internet, it is even more important for clinicians to be prepared for educated questions, and to have a thorough understanding of the options that may benefit their patients. After a discussion of fundamental concepts, including the differences between surgical and nonsurgical organ-preservation approaches, this article will review the oncologic and functional outcomes associated with specific surgical approaches.
To begin with, we must ask what "saving the voice box" means. The basic function of a normal larynx is to allow for effective swallowing without aspiration. Almost all animals have some type of valve or sphincter that separates the alimentary tract from the respiratory tract, and like all other animals, we use the larynx to facilitate swallowing. If the larynx is not functioning adequately, then symptoms of dysphagia may become evident, and aspiration of food or saliva into the trachea may occur.
The second function of the larynx is in respiration. The larynx opens and closes spontaneously to allow for appropriate respiration. Naturally, we also use our larynx for communication. In that regard, the larynx functions as the generator of a tone. As air passes over the vocal cords or folds, they vibrate, thereby generating a tone. The true test of a treatment’s efficacy as a "laryngeal-preservation approach," however, is whether, the patient is still able to speak and eat without a permanent tracheostomy at the point when no local recurrence is expected (about 2 years or so for most treatments).
Side Effects of Laryngectomy
The issue of a permanent tracheostomy is particularly important because the main cause of a decline in quality of life associated with total laryngectomy is the permanent stoma. In fact, after total laryngectomy most patients are able to speak by using either an electrolarynx (an electronic tone generator), via esophageal speech, or with a voice prosthesis inserted into a tracheoesophageal fistula. All these methods of voice rehabilitation stem from the fact that what really needs to be replaced when the larynx is removed is a tone generator.
When the larynx is removed, the pharyngeal mucosa collapses on itself and can be made to vibrate as air passes over it. This can be accomplished by esophageal speech, for which the patient is taught to swallow air and expel it past the pharyngeal mucosa in a controlled fashion, causing the pharyngeal mucosa to vibrate and, in turn, to generate a tone. Today, speech is rehabilitated more commonly with a voice prosthesis that is inserted via a tracheoesophageal fistula. With a voice prosthesis, air can be forced from the trachea into the esophagus and pharynx via a small plastic one-way valve that prevents liquid and food from passing from the pharynx back into the trachea.
Nonetheless, patients frequently have the misconception that the main problem with total laryngectomy is that they will not be able to speak postoperatively. Consultation with a qualified speech pathologist can help a patient understand that almost all the chronic side effects of total laryngectomy are related to the stoma and that the loss of the ability to speak is not, in fact, the major problem. Stoma-related side effects include (1) a diminished sense of smell and therefore taste, because the patient can no longer breathe through the nose and mouth but instead must breathe through the tracheostoma; (2) difficulty in swallowing, related to changes in the pharyngeal anatomy; (3) the emotional and cosmetic effects of both losing an organ and living with a permanent tracheostoma; and (4) other lesser complaints.[3,4]
Risk of Treatment Failure
Why stress the issues related to total laryngectomy in an article about using surgery to save the larynx? A myth shared by many patients and clinicians is that choosing either a surgical or nonsurgical organ-preservation strategy means that the patient will avoid total laryngectomy and, therefore, does not need to be "disturbed" by any mention of this radical procedure. In fact, every organ-preservation treatment regimen, surgical and nonsurgical, is associated with some risk of local failure. Regardless of how high the reported local control rate of a particular treatment regimen may be, the patient must always be counseled about the possible need for total laryngectomy in case the primary treatment modality fails.
Obviously, if we are dealing with a very small T1 glottic carcinoma for which all treatment regimens offer a high probability of laryngeal preservation, the issues related to total laryngectomy in the event of failure may be mentioned but do not have to be stressed. Common sense dictates that a reported 5% local failure rate is low enough that most patients will never have to deal with the problems associated with a recurrence of the cancer. Nonetheless, patients in whom local treatment fails may become angry if they had previously been counseled that local failure never occurs or is so infrequent that they need not worry about it. A 5% rate of failure is not equivalent to a 0% failure rate. It is wise to advise patients that even though only a small percentage of patients with small T1 cancer may fail treatment, those who do fail after radiation therapy usually require total laryngectomy.
If the approach being recommended for a T2 glottic carcinoma is nonsurgical, then the clinician counseling the patient is obliged to discuss total laryngectomy in greater detail. Given the higher local failure rate, for example, following radiation therapy in patients with T2 lesions, there is approximately a 30% risk that patients so treated will ultimately need a total laryngectomy.
The issue of counseling patients about the impact of total laryngectomy becomes even more critical when treating a larger cancer such as a T3 glottic carcinoma with radiation or a chemoradiation approach such as the Veterans Affairs (VA) protocol. In the VA protocol, induction chemotherapy is followed by radiation therapy in patients with a 50% response at the primary site and by total laryngectomy with radiation therapy in patients with less than a 50% response. The critical point to stress to patients who will be receiving the VA protocol is that they are at significant risk (36%) of needing a total laryngectomy following either induction chemotherapy or definitive treatment.
For the VA protocol to be successful from a survival standpoint, patients must be followed very closely by a clinician who is competent at detecting a local recurrence. Discovering a local recurrence early may be a difficult proposition, even for an experienced clinician, because of the inflammatory changes and scarring that develop after irradiation of the larynx.
In summary, surgical salvage is an important aspect of organ-preservation approaches, with total laryngectomy being the most common salvage procedure. Prior to organ-preservation treatment, a speech pathologist should be consulted to counsel high-risk patients about the functional impact of total laryngectomy in the event it becomes necessary.
The goal of organ-preservation surgery is to remove enough of the larynx to allow for local control of the cancer, while preserving enough of the larynx to allow for speech and swallowing without a permanent tracheostomy. The open surgical approach, in which the skin is incised and the larynx is opened to remove the cancer, is known as conservation laryngeal surgery. In the late 19th century and most of the 20th century, vertical partial laryngectomy was the dominant technique in conservation laryngeal surgery, and then, as today, it was used for the treatment of selected glottic carcinomas.
In 1947, the supraglottic partial laryngectomy was introduced for the treatment of selected supraglottic carcinomas. When vertical partial laryngectomies and supraglottic partial laryngectomies were performed in patients with selected (mostly early) carcinomas, the local control rate as well as attainment of speech and swallowing without a permanent tracheostomy was high.[11,12] The problem with an approach limited to the use of a vertical partial laryngectomy or supraglottic partial laryngectomy was that a large number of patients with laryngeal cancers were not candidates for these procedures. The remaining surgical options were either the near-total or total laryngectomy—both of which require a permanent tracheostoma.
In response to this situation, some surgeons tried to expand the indication for vertical partial laryngectomy and supraglottic partial laryngectomy with so-called extended procedures. The problem with these approaches, however, was that extended vertical partial and extended supraglottic partial laryngectomies tended to be reported in small numbers, and the functional outcome and local control rates were variable.[14-17] In addition, these procedures were reported with a plethora of difficult-to-reproduce laryngeal reconstructions. A resident or fellow in training might have been exposed to few, if any, extended vertical partial and extended supraglottic partial laryngectomies, making it difficult for them to use these procedures in practice.
Thus, from a practical standpoint, the surgical management of laryngeal carcinoma in the United States included vertical partial laryngectomy and supraglottic partial laryngectomy for smaller lesions, with total laryngectomy reserved for larger lesions. Although this strategy led to a high local control rate, it also resulted in a large number of patients requiring a total laryngectomy and, hence, a permanent tracheostoma.
The VA Protocol
In response to the limitations associated with the conservation surgical approach to avoid a permanent tracheostoma in patients with higher-stage tumors, nonsurgical organ-preservation protocols using novel combinations of radiation and chemotherapy were developed. One such approach, the VA protocol resulted in laryngeal preservation in 64% of patients, without a decrease in survival when compared to total laryngectomy with postoperative radiation therapy. Despite the obviously superior outcome in terms of laryngeal preservation compared to total laryngectomy, many patients (36%) still lost their larynges.
In addition, another prospective randomized European trial recently evaluated the VA protocol and found that for T3 laryngeal carcinoma, survival was significantly superior in the total laryngectomy and postoperative radiation therapy arm (84%) vs the chemotherapy and radiation arm (69%). Although there were some weaknesses in the design of this European trial, a particular strength, compared to the original VA trial, was that it enrolled only patients with T3 cancer; the original VA protocol included patients with all T stages.