OBJECTIVE
To improve the treatment outcomes in patients with oropharyngeal cancer after a radical chemoradiotherapy (CRT) by optimizing their management.
MATERIAL AND METHODS
The study is based on the treatment results of 120 patients with locally advanced oropharyngeal cancer (cT1-4N1-3M0). All patients initially underwent CRT according to a radical treatment protocol. In the prospective group (50 patients), neck lymphadenectomy was performed only if cytological confirmation of residual tumor in lymph nodes was present. In the retrospective group (70 patients), neck lymphadenectomy was performed for all patients regardless of the tumor’s response to CRT. The groups were comparable in terms of patient characteristics, tumor spread, localization, and CRT methods.
RESULTS
In the prospective group, modified unilateral neck lymphadenectomy was performed in 5 patients. Two patients showed a pathologic response grade III, and three showed grade II. In the retrospective group of 70 patients, 46 (65.7%) had pathologic response grade IV, 16 (22.8%) of grade III, 7 (11.4%) of grade II, and 1 (1.4%) of grade I. Analysis of long-term results in the prospective group showed an overall two-year survival rate of 92% compared to 88.6% in the retrospective group (p=0.918). In the prospective group, the two-year disease-free survival rate was 78% compared to 80% in the retrospective group (p=0.613). Neck lymphadenectomy often negatively affected the quality of life of patients (p<0.01). Predictors of a high risk of regional recurrence include absence of p16 protein expression in oropharyngeal tumors (p=0.04), smoking history of more than 5 pack-years (p=0.03), regional tumor volume exceeding 20 cm3, primary tumor extension into the oral cavity, and extension into the hypopharynx (p=0.04).
CONCLUSION
Mandatory neck lymphadenectomy after CRT for oropharyngeal cancer does not significantly improve two-year overall and disease-free survival rates. Performing lymphadenectomy based on clinical and instrumental data in combination with morphological confirmation of residual tumor in lymph nodes is the most justified approach.