Management of the neck lymph nodes is a critical factor in the success of treatment for patients with malignant head and neck tumors. Recurrence in the neck is an important cause of treatment failure, second in frequency only to recurrence at the primary site [1,2].
For such a fundamental issue in patient management, there remains a surprising amount of controversy. Dr. Stringer's review covers most of the unsettled issues well. He presents a balanced discussion of the value of surgery and radiation therapy, which is supported by relevant literature and personal experience. The reference list includes many of the papers that have shaped opinion in this field over the past century.
Like Dr. Stringer, our approach to elective treatment of the neck in patients with no palpable lymph nodes has been influenced by the availability of conservative surgical techniques and sensitive imaging studies. When we choose to excise the patient's primary cancer through a cervical incision, the appropriate selective neck dissection is almost always included. Bilateral selective neck dissection lessens the likelihood of neck failure in patients with supraglottic laryngeal cancer and other midline tumors. Similarly, elective neck irradiation is usually given to the patient whose primary tumor is best treated with radiation therapy. An imaging study, usually computerized tomography, is obtained in surgical patients who do not require an open cervical approach. If the CT scan fails to show evidence of pathologic adenopathy, the neck is observed.
Approach to Lymph Node Metastases
In patients with lymph node metastases, the results of even radical surgery, done alone without adding irradiation, have never been particularly good [3]. Moreover, radical neck dissection has several important disadvantages with regard to safety and postoperative quality of life.
There has never been a randomized study comparing the efficacy of today's modified neck dissections to radical neck dissection (and it is unlikely that such a study will ever be conducted). However, the value of modified radical [4] and selective [5] neck dissections has been repeatedly validated among patients with squamous cell carcinoma of the upper aerodigestive tract. Combination therapy, usually consisting of a modified neck dissection followed by the initiation of postoperative radiation therapy within 3 to 6 weeks, leads to a very high incidence of local control in patients with previously untreated disease.
Radiation alone is effective treatment for palpable nodes that are less than 3 cm in size, and can be expected to control even bulkier neck disease when the primary cancer is situated in the nasopharynx or tonsil. Regardless of response to irradiation, a neck dissection is recommended following the completion of radiation therapy in patients whose original neck tumor was larger than 3 cm in greatest dimension and whose primary cancer was not located in the nasopharynx or tonsil. If the primary is in either of these sites, a CT scan is obtained 3 to 6 weeks following the completion of irradiation, and no surgery is recommended if the scan and clinical examination fail to show residual adenopathy.
As Dr. Stringer points out, the presence of extracapsular spread beyond the confines of an involved lymph node is a poor prognostic sign. At least one phase II study suggests that triple therapy, ie, adding chemotherapy to standard postoperative irradiation, improves the outlook for these patients. We do offer chemotherapy to this group of patients, although we are still uncertain about its benefit.
