Contribution of radiotherapy to function preservation and cancer outcome in primary treatment of nasopharyngeal carcinoma

Abstract

Development of primary treatment for nasopharyngeal carcinoma is summarized and the contribution of radiotherapy (RT) is reviewed. Accumulation of knowledge, together with technological advances, has led to significant improvement both for tumor control and organ preservation. With contemporary RT, it is possible to achieve a 10-year disease-specific survival of 47% with a severe late complication rate of 5%. Presenting stage is one of the most important prognostic factors, but unfortunately late presentation and delayed diagnosis remains a common problem. The average local control rate is 80% for tumor confined within the nasopharynx, but only 50% for those associated with erosion of the base of the skull or cranial nerve involvement. Nodal deposits from nasopharyngeal carcinoma are much more radiosensitive than those from other head and neck cancers. An average control rate of 75% can be achieved with RT alone, even in patients with nodes > 6 cm in diameter. Successful locoregional control is important, not only because it is crucial for survival but also because it is associated with a lower incidence of distant failure (29% versus 41%). Distant failure remains a sinister problem, especially for patients presenting with advanced T or N-stage cancers. Randomized trials exploring the value of additional chemotherapy are reviewed. The significant improvement in 3-year overall survival achieved by the addition of concurrent and adjuvant chemotherapy (78% versus 47%) recently reported is encouraging, but remaining uncertainties are also discussed.