The assessment of oral squamous cell carcinoma: A study on sentinel lymph node biopsy, lymphatic drainage patterns and prognostic markers in tumor and saliva

Abstract

Around 20-30% of the patients with a small tumor of the oral mucosa will have metastasis to one of the lymph nodes in the neck. It is important to predict the presence or absence of lymph node metastases to choose the optimal neck treatment for the individual patient. Lymph node metastases are frequently too small to detect by MRI or CT scan. In the past, a substantial number of lymph nodes of the neck were removed by surgery and microscopically examined postoperatively to find these lymph node metastases. However, the majority of the patients receive prophylactic surgery of the neck and consequently risk the morbidities related to this surgery without having lymph node involvement. Therefore, the less invasive sentinel lymph node biopsy (SLNB) procedure was introduced in head and neck cancer. The sentinel lymph node (SLN) is the first lymph node affected with metastases. With the SLNB procedure, only the SLN is removed and microscopically examined. Only in patients with a metastasis-positive SLN, the other lymph nodes in the neck are removed by second surgery. Koos Boeve studied the SLNB procedure in small oral cavity tumors and concluded that this technique is a reliable procedure to detect lymph node metastasis in the neck. He concluded also that the SLNB procedure is useful in patients with previous treatment of the neck, in whom it is most likely that lymphatic drainage patterns are altered. The SLNB procedure provides important information about individual drainage patterns. Moreover, Boeve studied also the possibility to predict lymph node metastasis using molecular characteristics of the oral cavity tumor. His research showed that the expression of several proteins might predict the presence of metastases in both sentinel lymph nodes and non-sentinel lymph nodes. In the end, Boeve detected the presence of tumor specific DNA in saliva of patients with an oral cavity tumor. This is a potential technique to use saliva for screening for oral cavity tumors or to detect recurrences of oral cavity tumors after initial treatment.