Lymph node status assessment in head and neck squamous cell carcinoma in patients with clinically non palpable lymph nodes

Abstract

Squamous cell carcinoma is the most common malignant neoplasm of the upper aerodigestive tract. One of the most important influences on the prognosis is the presence of cervical lymph node metastasis. The prevalence of occult cervical LN metastasis is known to range from 12% to 50% depending on the location and the size of the primary cancer. The presence of a solitary ipsilateral metastatic lymph node reduces expected survival by almost 50%. Watchful waiting should be considered when the risk of occult cervical LN metastases is estimated to be 20% or less. If the risk thought to be greater than 15-20%, sugery or irradiation should be considered. Neck dissection is too morbid to be used as a staging tool in patients with cN0HNSCC. Also, because of the high morbidity and the cost of the procedure, optimal diagnostic tools should be used to improve the preoperative assessment of the cervical LN involvement to avoid unnecessary operations. Unfortunatly this optimal method remains controversial. Previous studies demonstrated benefit with PET/CT, while others recorded no benefit for some patients. Some studies recorded USFNAC to be the most accurate modality to detect cervical LN metastases, whereas others recorded USFNAC has no role in detection of occult metastases in early oral cancer. It was nessesary to analyze all previous studies about diagnostic modalities of cN0HNSCC. But when we gathered them we found some studies consider every patient as one unit (patient who have single LN similar to other patients with multiple LN in different level). In other studies each level considered a unit (even this level contain more than one LN). Others deal with each side (right or left) as their unit.