Occult Nodal Metastasis in Oral Cavity Cancers

Introduction:  In squamous cell carcinoma (SCC) of the oral cavity, there is always a risk of occult metastasis to neck nodes in the clinically and radiologically negative neck (N0). Therefore, elective neck dissection (END) has ever been under discussion since the beginning of their routine use for the management of neck for oral carcinomas. The purpose of the current study is to identify the percentage of occult nodal metastasis to neck levels I-V in the cases of oral carcinoma who were treated for the N0 with END.

Methods:  Patients who were treated between June 2005 and May 2010 with END from neck levels I to V for the management of N0 with oral SCC had been identified from the database of Aga Khan University Hospital. Those who met the inclusion and exclusion criteria were included in the study. Data were analyzed using SPSS 16 software. Using descriptive statistics, the mean was computed for the quantitative variable (age). Frequencies and percentages were calculated for gender, site, tumor grade, and lymph node involvement for each neck level.

Results:  A total of 50 patients were included in the study. There were 38 males and 12 females. The mean age was 47 (range 25-72). The most common site of the tumor was buccal mucosa in 50% of the cases followed by tongue 20%, then floor of mouth 14%, dentoalveolar ridge 8%, retromolar area 4%, lip 2%, and hard palate 2%. Histopathological grading of tumors showed well-differentiated 28%, moderately differentiated 33%, and poorly differentiated 6%. Twenty-seven out of 50 patients were found positive for nodal metastasis on final postoperative histopathology. Neck node metastasis at level I was found in 22 patients, at level II in 16 patients, at level III in seven patients, and at level IV in two patients. The level V was found free of metastasis in all of the cases.

Conclusion:  The rate of occult metastatic disease to the neck nodes was similar to that found in the literature. Both early and advanced local disease is associated with a risk of occult metastasis. END for neck levels I-V is, therefore, recommended for the management of the N0 in all cases of oral SCCs. Spread to levels IV and V is rare and these levels should not be a part of routine END.