PANENDOSCOPY IN HEAD AND NECK CANCER
SOURCE: Dept. of Otolaryngology, UTMB, Grand Rounds
DATE: January 16, 1996
RESIDENT PHYSICIAN: James Grant, M.D.
FACULTY: Christopher H. Rassekh, M.D.
SERIES EDITOR: Francis B. Quinn, Jr., M.D.
“This material was prepared by resident physicians in partial fulfillment of educational requirements established for the Postgraduate Training Program of the UTMB Department of Otolaryngology/Head and Neck Surgery and was not intended for clinical use in its present form. It was prepared for the purpose of stimulating group discussion in a conference setting. No warranties, either express or implied, are made with respect to its accuracy, completeness, or timeliness. The material does not necessarily reflect the current or past opinions of members of the UTMB faculty and should not be used for purposes of diagnosis or treatment without consulting appropriate literature sources and informed professional opinion.”
PANENDOSCOPY IN HEAD AND NECK CANCER
Head and neck cancer represents approximately 5% of all reported cancer cases in the United States, roughly accounting for 40,000 new cases each year. From an epidemiological standpoint, the majority of patients are male (3 – 4 : 1 male to female ratio), over the age of 40, and with an incidence rate of those in lower socioeconomic groups and blacks increasing. The etiology of head and neck cancer remains a perplexing, complex issue, but there are several well documented factors that show a strong association with the development of cancer in the head and neck region. The use of tobacco, especially cigarette, has been noted to be a common factor in approximately 90% of these patients. Additionally, the role of alcohol has been implicated as a synergistic factor in malignant transformation. To illustrate, in a paper by L.W. Thompson, his data showed that a nondrinking, heavy smoker has a five (5) times greater risk for head and neck cancer than the nonsmoker, nondrinker; in contrast, the heavy smoker and heavy drinker has a fifteen (15 ) times greater relative risk of developing cancer in this area. Poor oral hygiene, chronic mechanical trauma (i.e. dentures), low vitamin A levels, iron deficiency, infectious (i.e. syphilis, candidiasis, herpes viral family, HI), and inherent chromosomal sensitivity have also been implicated as possible etiological agents for the development of cancer. The basic fact that the entire mucosal surface lining the aeordigestive tract is subject to contact by these agents, relating mainly to alcohol and cigarette smoke, makes the high incidence of second primary cancers a biologically plausible event.
The head and neck cancer patient must be evaluated in a systematic and thorough manner. In the initial assessment, usually in an office setting, of the patient with suspected head and neck cancer, a detailed history is taken with special attention given to exposure or use of tobacco and / or alcohol. A quantitative history is important. Symptoms or signs that should signal the physician to search for malignancy, especially in those with long history of tobacco or alcohol use, includes prolonged sore throat, dysphagia, odynophagia. change in denture fit, or trismus. In addition, hoarseness, dysphonia, respiratory problems (i.e. stridor), hemoptysis, chronic cough, nasal stuffiness or obstruction, neurological complaints (i.e. facial numbness, motor weakness), otalgia and neck swelling or presence of a mass are also important. The signs and symptoms remain varied, if present at all in some patients, requiring the physician to maintain a high index of suspicion for cancer. The otorhinological examination must be thorough, with systematic evaluation of the nose, ears, oral cavity / oral pharynx, and neck.
While the oral cavity and oral pharynx may be inspected directly, visualizing the nasopharynx, hypopharynx, and larynx requires the use of indirect mirror laryngoscopy and/or flexible fiberoptic endoscopy or rigid telescope (nasal cavity). Radiographic studies may be indicated such as CT, MRI, panorex, as well as routine chest x-ray (searching for evidence of metastatic disease an a second primary) and possibly, depending on if the patient is symptomatic and / or the institutions policy on routine screening studies, a upper gastrointestinal contrast study is obtained. Histological diagnosis is, of course, paramount with certain lesions being accessible for simple office biopsy (fine needle aspiration, punch biopsy); whereas, other lesions may require obtaining a tissue sample under general anesthesia. The role of using panendoscopy as routine aspect in evaluating the head and neck cancer patient has remained controversial, especially regarding whether radiological screening studies may supplant the endoscopic procedure. This will be discussed further.
Panendoscopy encompasses the use of direct laryngoscopy, bronchoscopy, and esophagoscopy in the evaluation of the head and neck cancer patient. The basic goals of the endoscopic procedures is to map the extent of the already documented lesion for staging purposes / efficacious treatment planning, to search for a recurrence in an already treated patient, to obtain a tissue sample of an otherwise in accessible lesion, to examine for an unknown primary in a patient with documented cervical metastasis, and to search for a other malignant lesions in the aerodigestive tract (synchronous primaries). The concept of searching for multiple primaries is important and plays an integral role in the use of routine panendoscopy. Historically, in 1860 Bilroth presented the first documented case of multiple primary carcinomas, which later Warren and Gates, in 1932, describe a 3.7% incidence of multiple neoplasms in a study based on 1,078 autopsies. The criteria for defining a second primary malignancy were established by Warren and Gates and include the following characteristics : (1) the tumor must be clearly malignant by histological examination, (2) each tumor must be geographically distinct and not connected by submucosal or intraepithelial changes, and (3) the possibility of the second tumor representing a metastasis must be excluded. This criteria has been the classical premise applied in the literature as labelling a tumor as a second primary.
Slaughter, et al. reviewed cases of patients with lip, oral cavity, and pharyngeal carcinoma in an effort to explain the increased incidence of multiple primary malignancies in the head and neck cancer patient. By studying the tumors of these patients both macroscopically and microscopically, he found that most oral cavity cancers have a greater linear extent along the mucosa than actual depth of invasion and that the epithelium beyond the margins of the malignancy demonstrated a variety of microscopic changes such as hyperplasia, hyperkeratinization, and round cell infiltration. In addition, he found that in every instance in which a tumor was greater than one centimeter in diameter, a separate focus of in situ cancer was noted. Based on his findings, Slaughter presented the concept of “field cancerization” to elucidate the presence of multiple primary lesions. According to this concept, the protracted and intense use of certain agents (i.e. tobacco, alcohol), produces a regional surface contact carcinogenic effect in which a preconditioned epithelium is activated over a widespread area allowing multiple groups of cells to undergo a process of irreversible transformation to cancer.
Most medical centers treating head and neck cancer patients perform an endoscopic procedure on the patient prior to making a treatment plan. At the very least, it is performed to examine the true extent of the tumor or to obtain a biopsy in an inaccessible region. The use of triple endoscopy, however, in examining for the presence of multiple primary tumors is what remains controversial. Several centers believe that a screening radiographic study is sufficient to rule out the presence of a lesion, especially in the asymptomatic patient. Especially in today’s healthcare system of cost containment, the price of panendoscopy is not justified, according to certain investigators, if the easier, less costly, radiographic studies are negative. On the other hand, several investigators argue that there are several false negative radiographic studies and that the documented high incidence of multiple primary malignancies in the head and neck cancer patient justifies panendoscopy. Certain studies are presented for review.
In a study published in 1979, D.P Vrabece reported an 11.5% rate of multiple primary cancers out of 1518 patients examined. Additionally, the frequency of the site of second malignancies was studied in relationship to the site of the index tumor. His results showed that when the index tumor was in the oral cavity the most common location of the synchronous primary was also on the oral cavity, followed by the lung. In contrast, when the index tumor was laryngeal or pharyngeal, the most common site for a second primary tumor was the lung, followed by the esophagus. The paper also addressed the high incidence of false negative finding on barium swallow (64%) when an actual lesion was detected on esophagoscopy; furthermore, chest x-ray false negatives approached 56% as lesions were found on bronchoscopic examination. Based on these results, panendoscopy is a justified as a routine preoperative evaluation in this patient population.
In study published by Mc Guirt, et al in 1982, he affirmed the use of panendoscopy in searching for a second primary lesion. With a patient population of 100, he found a 16% incidence rate of second primary lesions. In detail, 8/16 had an esophageal second primary, 5/16 had a second primary in the head and neck region, while 3/16 had a second primary located in the lung. Of