Efficacy of Clinical Palpation to Detect Cervical Lymph Node Metastasis of Oropharyngeal Cancer

Background and Objectives: Before excision of the primary tumor in oropharyngealcancer, a decision must be made to treat the cervical lymph nodes (LN) or not. The study aimed to assess the role of clinical palpation (CP) for preoperative detection of LN metastasis. Methods: Twenty patients withoropharyngeal squamous cell carcinoma (OSCC), managed by excision of the primary tumor andneck dissection. The histopathological examination results compared to the preoperative assessment of the nodes by CP. Results: There were 20 patients involved, 11 males and nine females. The mean age was 54.5 years. Twenty neck dissections were performed; there was 14 LN metastasis as proved by histopathological examination. On CP, true positive was 12, false negative was two, true negative was two and false positive was four. Conclusion: Clinical palpation performed preoperatively is highly advised as it has high diagnostic capabilities to reach a decision to do neck dissection or not.


Introduction
The deformity results from the management of oropharyngeal cancer is the main concern facing the head and neck surgeon during the treatment plan. In addition to this esthetic concern, there are functional problemssuch as speech and mastication. These factors make oropharyngeal cancer management differs from other types of cancer, also differs from the management of benign tumors (1)(2)(3) .
The first correct step of the treatment plan to manage patients with oropharyngeal cancer is an early diagnosis, which eventually decreases morbidity and mortality (4) .
Before the definite diagnosis of the excised primary tumor and its associated LN by histopathological examination, clinical examination by palpation and different imaging techniques provide a provisional or almost definite diagnosis especially if they are handled by an expert surgeon (5)(6)(7) .
More than 95% of oropharyngeal cancer is squamous cell carcinoma (SCC) (8) .The prognosis of the SCC depends on the size, site, thickness, and histopathological staging of the primary tumor.
However, the most significant prognostic factor is the metastasis to the cervical LN (9,10) .Metastasis to cervical LN reduces the five years survival rate by 50% (1,11) .The controversy of managing N 0 neck probably goes with elective neck dissection as the risk of occult metastasis is higher than 20% (12) .
Although the clinical examination of the neck may be difficult especially after radiotherapy or patients with a short neck, it acts as a first screening tool to detect LN metastasis, this is why a well-trained and experienced surgeon who can differentiate between reactionary and metastatic LN must do the examination.However, a decision to operate on the metastatic LN has to be made for all patients whether they are palpable clinically or not (1,13) .
The aim of the study was to assess the validity of the CPto reach a defi nite diagnosis by comparing the results with the histopathological examination of the excised nodes.

Methods
The study involved 20 patients; all of them were presented with OSCC. The data were collected over two years. Staging of the primary lesion and neck was according to the American Joint Committee on Cancer (14) .
Inclusion criteria included patients with OSCCwho required both surgical excision of the primary tumor along with neck dissection. Exclusion criteria included patients who required only excision of the primary tumor without neck dissection, patients previously treated by surgery, radiotherapy and/or chemotherapy, and patients who presented with inoperable tumors (beyond surgery).

Clinical Examination of the Neck
All the levels of the neck were examined systematically on both sides. If there was palpable LN (Fig1), the assessment of its site, size, consistency and tenderness or any associated signs and symptoms were recorded. The criteria to consider the node as metastatic on CP were palpable, fi rm to hard and /or fi xed node, while the criteria to consider the LN reactive were soft, tender or when there was a history of infl ammation.

Radiographic Examination
As a protocol, patients were examined by CT (with contrast/2mm sections) of the neck from the base of the skull to the clavicle.

Preparation For Pathological Examination
During surgery, the neck dissection specimens were divided into levels and sublevels; each level must be cautiously labeled and presented in a separate container to provide better information for the pathologist.

Statistical Analysis
Clinical palpation fi ndings were compared with the histopathologic results. The outcomes were presented in terms of sensitivity, specifi city, accuracy, positive and negative predictive values. IBM SPSS statistics for windows, version 24.0 was used for statistical analysis(P < 0.05 considered statistically signifi cant) (15) .

Results
There were 20 patients involved, 11 males (55%) and nine females (45%). The age range was 25-79 years, the mean age was 54.5 years, the sixth decade (50-59) was the most commonly involved (35%), the male to female ratio was 1.2-1. The most common site of the primary lesion was the tongue (45%) (Fig 2). The most frequent histopathological grade was well-differentiated SCC (60%). The most common size of the primary tumors was T4 (65%). Stage IV was the most common stage (Table 1).  On CP, true positive was 12, false negative was 2, true negative was 2 and false positive was 4. The sensitivity, specificity, accuracy, positive and negative predictive values were summarized in Table2.

Discussion
There is a debate about the role of the CP before the definite diagnosis of LN metastasis is given by histopathology, those who go with high sensitivity and specificity and those who conclude that there is a "not sufficient" sensitivity and specificity for the clinical and imaging examination to predict the LN metastasis (1,11) .
Oropharyngeal cancer is a disease of elderly; the peak incidence is usually during the sixth and seventh decades. The probable explanation is that the activity of the natural killer cells falls with increasing age. The incidence of cancer in the younger age group is uprising due to the diet that poor in antioxidant, genetic factor and exposure to different types of carcinogen (16) .In our study, the peak incidence was in the sixth decade(35%) and 25% for the younger age group 30-39.
Most of the patients (16 patients, 80%) were in stage IV this is mostly due to ignorance of patients to seek treatment of the primary tumors (delayed diagnosis).
This will allow the tumor to increase in size and metastasize to the LN.
The cervical LN metastasis occurs in a successive pattern except in the tongue, floor of the mouth, and anterior area of the oral cavity (17) . When the nodal stage increases the prognosis decrease, overall the rate of cure is halved with the nodal spread (18) .
The sensitivity of CP in our study was 85.7%, which is comparable to various studies (19,20) . While the accuracy of CP in our study was 70%, which is in line with previous studies (19,21) .

Conclusion
It is hard to conclude whether a diagnosis of cervical LN metastasis based on CP can be compared with histopathology because histopathological examination can show metastatic involvement as small as 1mm, which cannot be detected by CP or by imaging techniques.
However, the CP can provide a cornerstone role in taking a decision to do or not an elective neck dissection.

Source of Funding: Nil
Ethical Clearance: This research has exemption as it a routine treatment (no new materials were used).