Contralateral neck dissection in oral cavity cancers crossing midline: A look in the mirror

Sachin Wani; Nishith Modi; M Srinitya; Rajiv Bhatt; Shishir Shah; Ankit Shah; Nikita Choksi

doi:10.4103/jhnps.jhnps_35_22

ORIGINAL ARTICLE

Year : 2022 | Volume : 10 | Issue : 2 | Page : 148-151

Contralateral neck dissection in oral cavity cancers crossing midline: A look in the mirror

Sachin Wani¹, Nishith Modi¹, M Srinitya², Rajiv Bhatt³, Shishir Shah¹, Ankit Shah¹, Nikita Choksi²
¹ HCG Cancer Centre, Vadodara, Gujarat, India
² Department of Head and Neck Oncology, HCG Cancer Centre, Vadodara, Gujarat, India
³ Department of Surgical Oncology, HCG Cancer Centre, Vadodara, Gujarat, India

Date of Submission	09-Jun-2022
Date of Decision	31-Jul-2022
Date of Acceptance	31-Jul-2022
Date of Web Publication	15-Dec-2022

Correspondence Address:
Sachin Wani
HCG Cancer Centre, Vadodara, Gujarat
India

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/jhnps.jhnps_35_22

Abstract

Introduction: Oral cavity cancer is the most common cancer in our country. In patients with oral cavity squamous cell carcinoma (OCSCC) elective neck dissection results in higher rates of overall survival and disease-free survival. Nodal metastasis in OCSCC is related to poor prognosis. Elective ipsilateral node dissection is recommended in all patients. Contralateral nodal metastasis is associated with poorer prognosis. The purpose of our study is to identify the predictors and factors associated with bilateral or contralateral nodal metastasis in oral cavity cancers reaching or crossing the midline. Materials and Methods: All patients of oral cavity cancer where the primary cancer was reaching or crossing the midline, operated during 3 years in a single institute were taken up for the study. All patients underwent surgery of primary cancer and bilateral neck dissection. Patients with truly lateral disease not approaching midline, history of any previous oncologic treatment, and recurrent cancers, and patients with two or more primaries were excluded from the study. Results: Out of 93 patients, 43% of the buccal mucosa – gingivobuccal sulcus region and 57% of the tongue – floor of mouth region. Out of 46 patients having nodal metastasis (50%), 26.8% of patients had bilateral nodal metastasis, but none had isolated contralateral nodal metastasis. On univariate and bivariate analysis, we found tumor grade, stage, site of ENE, and presence of multiple ipsilateral positive nodes were significant factors predicting contralateral nodal metastasis. Conclusion: Surgical management of the contralateral neck in oral cavity cancer is a complex issue. The simplistic approach of doing contralateral neck dissection in all oral cavity cancers when disease crosses midline is not sufficient. The presence of contralateral neck node metastasis in the absence of positive ipsilateral neck is very rare (0% in our study). There are other important clinic radiological factors such as DOI >10 mm, involvement of skin and bone, and presence of extranodal extension and location of primary tumor which also need to be considered in decision-making algorithm.

Keywords: Contralateral neck dissection, oral cancer, oral cavity cancer, oral squamous cell carcinoma

How to cite this article:
Wani S, Modi N, Srinitya M, Bhatt R, Shah S, Shah A, Choksi N. Contralateral neck dissection in oral cavity cancers crossing midline: A look in the mirror. J Head Neck Physicians Surg 2022;10:148-51

How to cite this URL:
Wani S, Modi N, Srinitya M, Bhatt R, Shah S, Shah A, Choksi N. Contralateral neck dissection in oral cavity cancers crossing midline: A look in the mirror. J Head Neck Physicians Surg [serial online] 2022 [cited 2023 Jun 4];10:148-51. Available from: https://www.jhnps.org/text.asp?2022/10/2/148/363922

Introduction

Oral cavity cancer is the most common cancer in our country. In patients with oral cavity squamous cell carcinoma (OCSCC), elective neck dissection results in increased overall survival and disease-free survival.^[1] Nodal metastasis in OCSCC is associated with poor prognosis.^[2] Elective ipsilateral node dissection is recommended in all patients.^[1] Contralateral nodal metastasis is associated with poorer prognosis.^[3] The incidence of contralateral nodal metastases is 0.9%–36%.^[4] In view of the low incidence of contralateral nodal metastases and morbidity associated with empirical contralateral neck dissection, it is not routinely practiced. In cases, where primary disease reaches or crosses midline, there is a higher incidence of contralateral nodal metastases. In such instances, it is a routine surgical practice to do contralateral neck dissection.^[5] Lin et al. in their original work have shown that tumors invading floor of mouth (FOM), midline crossing tumors, and poorly differentiated tumors had high risk of contralateral neck metastasis.^[6] It is the current routine clinical practice to address the contralateral neck when primary disease reaches or crosses midline. The question we seek answer for is: Is this approach by a surgeon appropriate? We also intend to study other risk factors (other than reaching or crossing the midline) which will give indications to address the contralateral neck surgically when primary tumor is reaching or crossing the midline. The purpose of our study is to identify the predictors and factors associated with bilateral or contralateral nodal metastasis in oral cavity cancers reaching or crossing the midline.

Materials and Methods

Study Population: All patients of oral cavity cancer, where the primary cancer was reaching or crossing the midline, operated during 3 years in our institute were taken up for the study. All patients underwent surgery of primary cancer and bilateral neck dissection.

Exclusion Criteria: Patients with truly lateral disease not approaching midline, history of any previous oncologic treatment, recurrent cancers, and patients with two or more primaries were excluded from the study.

A total of 93 patients were taken up for the study. Out of them, 40 cases (43%) were of the buccal mucosa (BM) – gingivobuccal sulcus (GBS) region and 53 cases (57%) of the tongue –FOM region [Table 1]. Seventy-six were males (81.7%) and 17 were females (18.3%) with a male-to-female ratio of 4.47:1. The youngest patient was 24 and the oldest patient was 77 with a median age of 52 years.

Table 1: Clinicopathological factors

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Study design: It is a single-institution observational study. Data were collected retrospectively from a prospectively kept Excel sheet. All patients included in the study were operated from December 2016 to December 2019 at our center.

Radiological studies preoperative were either CECT or MRI depending on the site of disease and surgeon preference. All the surgeries involved resection of the primary tumor with adequate margins.^[6] The types of neck dissections performed were combinations of selective neck dissection, modified radical neck dissection, or radical neck dissection. Sentinel lymph node biopsy was not done, and neck dissection specimens were not sent for frozen section. All surgical specimens were reported by a single full-time surgical pathologist.

All patients completed adjuvant treatment as per MDT recommendation based on TNM staging as per AJCC 8^th edition.

Statistical analysis: Statistical analysis was done based on the software Statistical Package for the Social Sciences (SPSS) version 17. A Chi-square test was done for analyzing the variables predicting bilateral nodal metastasis for squamous cancers crossing the midline. Various clinicopathological factors such as gender of the patient, site of disease, tumor grade, nodal status, pathological stage, histology of cancer, depth of invasion (DOI), presence of extranodal extension (ENE), presence of multiple ipsilateral nodes were correlated with bilateral positivity of lymph nodes using univariate and bivariate analysis. The P < 0.05 was considered statistically significant.

Results

Among 93 patients who underwent bilateral neck dissection, 46 patients had either unilateral or bilateral nodal metastases. Forty-seven patients had node negative on the final histopathology report. Ipsilateral nodal metastasis was seen in 21/93 patients and bilateral nodal metastases were seen in 25/93 patients. No patient had isolated contralateral metastases.

40/93 cases (43%) were of BM – GBS region and 53/93 cases (57%) of the tongue–FOM region.

In BM – GBS region 12/40 (30%) had nodal metastases, 4/40 had ipsilateral nodal metastases, and 8/40 (20%) had contralateral nodal metastases. In the tongue FOM region, 34/53 (64%) had nodal metastases. Moreover, 17/53 (32%) had contralateral nodal metastases [Table 1].

Correlating with T stage, out of total BM – GBS cancer, 18/40 were T1 and T2 and none had any contralateral nodal metastases. Moreover, out of 53 tongue – FOM cases had 18/53 were T1 and T2 and 5/18 had contralateral lymph node metastasis. Out of total 25 positive contralateral nodes, five patients had DOI=/<10 mm. 20/25 patients either had DOI >10 mm or involvement of skin or bone.

Looking at the presence or absence of ENE, 19/25 patients had ENE present and 6/25 patients had ENE absent. A total of 35/46 node-positive patients had ENE present. 19/35 patients had positive contralateral neck nodes and 16/35 patients had a negative contralateral neck [Table 2].

Table 2: Relationship between clinicopathological factors and bilateral nodal metastasis

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Discussion

Oral cavity cancers are the most common cancers in our country and primary cancer often reaches or crosses the midline to involve the opposite side. The neck is electively operated in oral cavity cancers due to survival advantages.^[1] It is common practice to surgically address the opposite neck when cancer is reaching or crossing the midline. In this study, it is clear that when ipsilateral nodes are not involved in such cancers, it is very rare (0% in the present study) to have contralateral nodal involvement. There are other important risk factors which would increase the chances of contralateral nodal involvement such as the site of primary cancer (tongue – FOM), DOI more than 10 mm, involvement of overlying skin or underlying bone, and presence of ENE. All the factors studied in this study such as the presence or absence of ipsilateral nodal metastases, site of primary, T stage, and ENE can be evaluated clinicoradiologically.

We had 12/40 (30%) chances of neck nodal metastases in primary of BM – gingivobuccal complex tumors as compared to 34/53 (64%) chances for the tongue – FOM primaries. The incidence of contralateral nodal metastases in BM – GBS primary is 20%. Mair et al.^[7] in a study of 125 patients with BM – GBS primary had an incidence of 22.4%. Isolated contralateral nodal metastasis in the absence of ipsilateral positive nodes in our study of 93 patients was zero. Chaturvedi et al. in a study of 125 patients of BM – GBS, primary had isolated contralateral metastases of 2/125 (1.6%) patients. In the absence of positive ipsilateral nodes, contralateral nodal metastasis is extremely rare. Rao et al.^[8] showed that frozen sections of neck dissection specimens are accurate in predicting nodal status. Hence, frozen section analysis of ipsilateral nodes can be an important indicator to decide whether to operate contralateral neck or not.

T stage of primary is also an important indicator for contralateral nodal metastases. Out of total BM – GBS cancer, 18/40 were T1 and T2 and none had any contralateral nodal metastases. Moreover, out of 53 tongue – FOM cases 18/53 were T1 and T2 and 5/18 had contralateral lymph node metastasis. Out of total 25 positive contralateral nodes, 5/25 patients had DOI ≤10 mm. 20/25 patients either had DOI >10 mm or involvement of the skin or bone. Kurita et al. in a study of 202 patients with lateral oral cavity cancer (not crossing the midline) have shown T-stage as an important predictor for contralateral neck nodal involvement. Chaturvedi et al. also have shown skin involvement as an important independent predictor for contralateral neck nodal involvement. Kurita et al.^[9] on multivariate analysis also demonstrated that ipsilateral lymph node metastasis (P < 0.01) along with T-stage (P < 0.01) and histopathology grading (P < 0.05) were significant independent predictors for contralateral lymph node metastasis. T Vegneshvaran et al.^[10] on a small retrospective study concluded that skin involvement and frozen section of ipsilateral neck dissection specimen can be an important pointer for addressing contralateral neck.

ENE is an important addition in N stage of TNM manual in the AJCC 8^th edition. There are clinical as well as radiological signs to identify and report ENE. In our study, we found ENE to be an important and independent predictor for contralateral neck nodal involvement.

Clinical implications of our findings are that, while operating on oral cavity cancer which crosses the midline, the operating surgeon should take into account T-stage, involvement of the skin and bone, presence of ipsilateral nodal metastasis, and presence of ENE while deciding to address the opposite neck. Not every patient with a disease crossing midline would need contralateral neck dissection.

In our study, the presence of ipsilateral nodal metastasis, DOI >10 mm, involvement of the skin and bone, and presence of ENE are independent risk factors for contralateral lymph node metastases. Whether this data can be extrapolated to lateral oral cavity cancer or not would be an important study to be conducted in future. This is a single institute study with very specific subgroup of patients with oral cancers where disease crosses midline and surgery is performed on bilateral neck. This is a retrospective study of data kept prospectively with less numbers of patients so subgroup analysis is not valuable. No follow-up data are presented to evaluate outcomes in patients.

Conclusion

Surgical management of contralateral neck in oral cavity cancer is a complex issue. The simplistic approach of doing contralateral neck dissection in all oral cavity cancers when disease crosses midline is not sufficient. The presence of contralateral neck node metastasis in the absence of positive ipsilateral neck is very rare (0% in our study). There are other important clinic radiological factors such as DOI >10 mm, involvement of the skin and bone, presence of ENE, and location of primary tumor which also need to be considered in the decision-making algorithm.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

Disclosure

This material has never been published and is not currently under evaluation in any other peer-reviewed publication.

Ethical approval

The permission was taken from the Institutional Ethics Committee before starting the project. All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Informed consent

Informed consent was obtained from all individual participants included in the study.

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