Journal of Surgical Oncology 2006;93:464–467

Elective Lateral Neck Dissection For LaryngealCancer in the Clinically Negative Neck

BIN ZHANG, MD,* ZHEN-GANG XU, MD, AND PING-ZHANG TANG, MD

Department of Head and Neck Surgery Cancer Hospital (Institute), Chinese Academy of Medical Sciences,Peking Union Medical College, Beijing, P.R. China

Background: Despite the introduction of modern imaging techniques, it is stilldifficult to detect microscopic disease in neck nodes. The purpose of this study is toevaluate the efficacy of the lateral neck dissection (LND) for elective treatment of theclinically node negative neck (cN0) in laryngeal squamous cell carcinoma (SCC).Methods: The clinical records of 110 cN0 patients with laryngeal SCC treated in thishospital from January 1997 to December 2002 were reviewed retrospectively.Results: One hundred ten patients received 145 elective LND. Occult metastasis wasdetected in 22 (20.0%) of this group of patients. The distribution of the 37 positivenodes was as follows: Level II 56.8%; Level III 37.8%; Level IV 5.4%. The 3-yearneck recurrence rate estimated by the Kaplan-Meier approach for all cN0 patients(n¼ 110) was 5.4% [95% CI: 0.0%; 12.5%]. No significant difference in 3-year lymphnode recurrence was found between node negative and node positive groups, betweensupraglottis and glottis groups, or between surgery alone and combined therapygroups.Conclusion: The lateral neck dissection is effective in elective treatment of the neck inpatients with laryngeal carcinoma.J. Surg. Oncol. 2006;93:464–467. � 2006 Wiley-Liss, Inc.

KEY WORDS: neck dissection; selective neck dissection; lymphatic metastasis;survival rate; laryngeal carcinoma

INTRODUCTION

Cervical lymph node metastases represent the singlemost important prognostic factor influencing the outcomein patients with squamous cell carcinoma of the head andneck [1]. Despite the introduction of modern imagingtechniques such as ultrasonography, CT, MRI, and PET, itwill probably never be possible to detect microscopicdisease in neck nodes. Occult metastasis determined fromspecimens of elective neck dissection is approximately30% in supraglottic carcinoma [2,3] and 20% in T3/T4glottic carcinoma [4]. Three treatment options areavailable for management of the clinically negative neck(cN0): elective neck dissection, elective neck irradiation,or observation with therapeutic neck dissection per-formed if regional metastases become clinically apparent.Most of the current literature favors elective treatmentbecause of improved survival [2,3,5,6]. Generally, theoption chosen for the neck is consistent with optimaltreatment of the primary lesion. Because early lymph

node metastases of laryngeal carcinoma follow predict-able routes, lateral neck dissection (LND) in cN0 hasbecome an accepted treatment method [7–10]. However,there were only limited reports of the effectiveness ofLND specifically for laryngeal disease [10]. SinceJanuary 1997, the Department of Head and Neck Surgeryat the Cancer Hospital of the Chinese Academy ofMedical Sciences, has routinely treated patients with cN0supraglottic cancer and T3/T4 glottic cancer with electiveLND [11]. The purpose of this study was to evaluate theeffectiveness of LND for patients with laryngeal cancerin Asian people.

*Correspondence to: Bin Zhang, MD, Department of Head and NeckSurgery, Cancer Hospital, Chinese Academy of Medical Sciences, P.O Box2258, Beijing, 100021, China. Fax: 010 6773 7578E-mail: docbinzhang@hotmail.com

Received 22 December 2004; Accepted 17 November 2005

DOI 10.1002/jso.20478

Published online in Wiley InterScience (www.interscience.wiley.com).

� 2006 Wiley-Liss, Inc.

MATERIALS AND METHODS

The tumor registry in the Department of Head andNeck Surgery at the Cancer Hospital of the ChineseAcademy of Medical Sciences was used to identifypatients for this study. Records of patients with squamouscell carcinoma (SCC) of the larynx and clinicallynegative neck (cN0) who underwent lateral neck dissec-tion (LND) between January 1997 and December 2002were reviewed retrospectively. Patients with simulta-neous distant metastases, previous or simultaneoussecond malignancy, previous treatment to the head andneck region with chemotherapy, radiation, or surgerywere excluded. Laryngeal tumor and neck node stagingwas done according to the 2002 UICC/AJCC criteria.

Of 155 patients, 110 fulfilled the inclusion criteria, inwhich 145 LND procedures were performed. For clinicalexamination of the neck nodes, palpation and ultrasono-graphy were routinely used. A total of 85% of patientshad CT imaging. Clinically negative neck was definedas nodes smaller than 1.0 cm. There was no patientdiagnosed as clinically occult with ultrasonography butturned to be nodal metastasis by CT scan and excluded inthis study.

Tissue removed was classified according to the mono-graph on neck dissection published by the AmericanAcademy of Otolaryngology-Head and Neck Foundation[12]. The lymph nodes of Levels II, III, and IV wereremoved in the LND procedures. The lymph nodes ofLevel IIB were also routinely removed [13]. All patientswere treated curatively by total or partial laryngectomyand unilateral or bilateral neck dissection. Bilateral LNDwas used for patients with advanced supraglottic carci-noma or at the surgeon’s discretion.

Twenty (18.2%) patients received postoperative radio-therapy using a daily fraction of 200c Gy for 5 days perweek. The average dose of irradiation was 58.3 Gy(50 Gy–64 Gy). Indications for postoperative radio-therapy included advanced stage of the primary tumor,positive margin, more than three lymph node metastases,and lymph node metastases with extracapsular spread(ECS). The radiation was delivered to the primary siteand both necks.

The median age of 110 patients was 61 years (range,36–80 years). There were 90 men and 20 women. The

subsite of the larynx was supraglottis in 72 (65.5%), andglottis in 38 (34.5%), which included 1 transglotticlesion. The tumor categories (T) and the numbers ofLNDs carried out are listed in Table I.

The median follow-up interval was 24 months, with arange of 6–73 months. Control of neck disease after LNDwas the main endpoint assessed. Regional recurrencerates and survival rates were calculated by the Kaplain-Meier method [14]. The time to regional recurrence wasdefined as the interval between the date of surgery and thedate of diagnosis of neck node metastasis in the dissectedneck with primary disease controlled. The overallsurvival time was defined as the interval between thedate of surgery and the last follow-up or the date of death.

RESULTS

Histopathologic Findings in the Neck

Among 110 cN0 patients who had elective LND, thesurgical specimens contained metastases in 22 (20.0%)patients. The pathologic neck (pN) categories wereclassified as pN1 in 13 patients and pN2 in 9 patients.Patients with supraglottic carcinoma had an incidence of20.8% occult metastases. Patients with glottic carcinomahad 18.4% occult metastases (Table II). The percentagesof patients irradiated in the different pN categories wereas follows: pN0, 14.8%; pN1, 30.8%; and pN2, 33.3%.

The average number of lymph nodes examined was20 per neck. Histopathologic node-negative neck wasfound in 121 neck dissection specimens. One or morelymph node metastases were found in 24 (17%) speci-mens. Nodal metastases with ECS were detected in 4(16.7%) node-positive neck dissections. The total num-bers of metastatic nodes were 37. Twenty-one (56.8%)

Journal of Surgical Oncology DOI 10.1002/jso

TABLE I. Distribution of Subsites, T and LND

T category Neck dissection

T1 T2 T3 T4 Ipsilateral Bilateral Total

Supraglottis 12 (16%) 24 (33%) 30 (42%) 6 (8%) 44 (61%) 28 (39%) 72

Glottis 0 13 (34%) 14 (37%) 11 (29%) 31 (82%) 7 (18%) 38

Total 12 (11%) 37 (34%) 44 (40%) 17 (15%) 75 (68%) 35 (32%) 110

TABLE II. Occult Lymph Node Metastases (pNþ) in PatientsAccording to pT Categories

Supraglottis (n¼ 72) Glottis (n¼ 38)

pT1 1/12 (8.3%) 0

pT2 6/24 (25.0%) 1/13 (7.8%)

pT3 7/30 (23.3%) 2/14 (14.3%)

pT4 1/6 (16.7%) 4/11 (36.4%)

Total 15/72 (20.8%) 7/38 (18.4%)

Elective Lateral Neck Dissection 465

were located in Level II, and 14 (37.8%) in Level III,while only 2 (5.4%) were found in Level IV (Table III).

Neck Recurrences

Twelve (11.9%) patients experienced tumor recurrenceduring the follow-up period. Seven of them had localrecurrence, three regional recurrence, two distant metas-tasis. Seven patients were treated by salvage surgery andone received palliative radiotherapy.Three patients developed regional recurrence in the

dissected neck at the 5th, 7th, and 35th month aftersurgery, respectively. One of them had bilateral recur-rence after initial unilateral neck dissection. Two of threerecurrences were found within the dissected fields(Levels II and III, respectively). One of three recurrenceswas outside the dissected field (Level VI). All of themdied of recurrent disease. One had salvage surgery, whichwas not curative.The 3-year neck recurrence rate as estimated by the

Kaplan-Meier approach for all patients (n¼ 110) was5.4% [95% CI: 0.0%; 12.5%]. Comparison of the 3-yearneck recurrence rate was carried out by pN status, subsite,and treatment modality (Table IV). No significantdifference in the incidence of 3-year neck recurrencewas found between pN0 and pNþ groups, betweensupraglottis and glottis groups, or between surgery aloneand combined therapy groups.

Survival

A total of 10 patients died during the follow-up period.Of them, six died of recurrence of tumor, two of a secondprimary tumor, and two of intercurrent disease. The 3-and 5-year overall survival rate was 94.0% [95% CI:

88.9%; 99.2%] and 89.8% [95% CI: 80.1%; 99.4%],respectively.

DISCUSSION

The concept that squamous cell carcinoma (SCC) ofthe head and neck metastasizes to regional lymph nodesin a predictable distribution has been generally accepted.According to Shah [8], the relative risk of neck metastasisof cN0 SCC of larynx was Level I: 14%, Level II: 52%,Level III: 55%, Level: IV 24%, and Level V: 7%.Selective neck dissection for patients with cN0 SCC ofhead and neck has become routine in a significant numberof institutions because it is an anatomically andoncologically sound procedure based on the probabilityof metastasis. Elective SND is as effective as modifiedradical neck dissection [9–11].Literature reports of regional recurrence rates after

elective neck dissection for cN0 SCC of larynx rangedfrom 3.0% to 10.6% [10,15–17]. The results of this seriesdemonstrated that LND is appropriate for electivemanagement of the cN0 neck. The regional recurrencewas only 5.4% [95% CI: 0.0%; 12.5%]. LND waseffective in controlling neck recurrence in 94.1% of pN0and 100% pNþ patients. Metastasis with ECS predicts anegative impact on patients’ outcome [18]. Due to thelimited number of patients with ECS (n¼ 4), the datawere not subjected to statistical analysis, as the resultswould not be valid.In this study, occult metastases were confirmed

pathologically in 20.8% of patients with supraglotticcancer and in 18.4% of patients with glottic cancer. Therelatively high rate of undetected metastases in the T3/T4carcinoma of glottic larynx is in fact comparable to thatreported by others [2,4], and makes a strong argument infavor of elective neck dissection for the advancedcarcinoma of glottic larynx. Four of seven patients withT4 disease had occult metastasis in this study. This couldpartly be explained by including transglottic cancer in theglottis group, because it is hard to differentiate transglot-tic cancer from some T4 glottic cancer. Rate of occultmetastasis is low for T1 carcinomas of the supraglotticlarynx (8.3%) and T2 carcinomas of the glottic larynx

Journal of Surgical Oncology DOI 10.1002/jso

TABLE III. Number of Metastatic Nodes in Level II–IV

Level Metastatic nodes

Level II 21 (56.8%)

Level III 14 (37.8%)

Level IV 2 (5.4%)

Total 37 (100.0%)

TABLE IV. Three-Year Neck Recurrence Rate by pN Status, Subsite, and Treatment Modality

pN categories Subsite Treatment modality

pN0

(n¼ 88)

pNþ(n¼ 22)

Supraglottis

(n¼ 72)

Glottis

(n¼ 38)

S alone

(n¼ 90)

SþRT

(n¼ 20)

Neck recurrence [95% CI] 5.9% [0.0%; 13.5%] 0.0% 6.1% [0.0%; 15.6%] 2.6% [0.0%; 5.4%] 6.3% [0.0%; 14.7%] 0.0%

Log rank 0.52 0.01 0.61

P 0.470 0.939 0.435

S, surgery; RT, radiotherapy.

466 Zhang et al.

(7.8%); therefore, a policy of observation is warrantedin these patients. LND is a reliable staging procedureproviding important prognostic information, such asmultiple node metastasis, Level IV metastases, andECS, which warrant postoperative radiation.

In our study, the 3-year neck recurrence rate in patientstreated with surgery alone was 6.3%, while the 3-yearrecurrence rate after combined therapy was 0.0%. Inreview of the literature, there was a trend to give post-operative radiotherapy for patients with multi-node meta-stasis, or metastases with ECS.

No recurrence developed in Level I or Level V. Theonly recurrence outside the dissected area was found inLevel VI, which is outside the field of comprehensiveneck dissection. This finding suggests that elective LNDcan be as effective as comprehensive neck dissection.

Metastasis on the contralateral side of neck dissectionwas found in only one patient (0.9%), in contrast with ourprevious report of 18% (3/17) after radical neckdissection (RND) or modified radical neck dissection(MRND) [19]. The lower incidence of contralateralmetastasis in LND patients is probably due to the morefrequently employed bilateral neck dissection than inRND/MRND patients (32% vs. 7%). Bocca [5] andMyers [2] reported that patients with supraglotticcarcinoma who had bilateral neck dissections have adecreased incidence of regional recurrence. However, themorbidity related to RNDwas high, according to Schuller[20]; 30–45% of patients after RND did not return totheir usual work or experienced adverse effects on theirsocial activities. The morbidity and mortality associatedwith elective bilateral RND/MRND impeded its use.Compared to RND or MRND, LND is less invasivesurgery that reduces morbidity and postoperative dys-function and therefore can be used bilaterally in the neck.One of our studies [21] showed that complications weredecreased in the LND group when compared with theRND group (6.7% vs. 38.5%). In a functional evaluationof selective neck dissection by questionnaire, patients hadbetter functional and cosmetic results following SNDthan patients following MRND and RND [22].

Our result confirmed the validity of LND in electivetreatment of Chinese patients with cN0 laryngeal SCC.The LND procedure provides not only valuable staginginformation for adjuvant therapy, but also is as effectiveas comprehensive neck dissection in controlling neckdisease in the cN0 neck.

ACKNOWLEDGMENTS

The authors thank Ms. Yali Zhang, MS. Departmentof epidemiology, Cancer Institute, Chinese Academy ofMedical Sciences for the assistance in the statisticalanalysis.

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