Prognostic factors and outcome for nasopharyngeal carcinoma

Nasopharyngeal cancer (NPC) is a distinct form of cancer of the upper respiratory or digestive tract in which the epidemiologic features, origin, histopathologic types, treatment, and prognosis are different from those associated with other malignant neoplasms of this anatomical area. Recent publications have demonstrated the advantage of aggressive multimodality treatment for advanced NPC.

To evaluate the results of standardized treatment of NPC during 11 years and to identify pertinent factors for clinical outcome.

Between January 1, 1989, and December 31, 2000, 173 patients with newly diagnosed NPC were treated at Instituto Nacional de Cancer. Clinical records and radiographic studies of the patients were retrospectively reviewed. Documented data of the initial presenting symptoms, head and neck examination, radiotherapy protocols, chemotherapy regimens, and surgical technique were analyzed. To determine important prognostic factors, we correlated survival rates with age, clinical stage, tumor extent, histopathological type, and therapeutic approach. The major end point used for assessment was relapse-free survival. Survival curves were estimated by the Kaplan-Meier product-limit method. Multivariate analysis was performed using the Wilcoxon signed rank and Cox proportional hazards regression tests.

Most patients (88.5%) had locoregional advanced disease, mostly (53.4%) of the nonkeratinizing subtype. Forty-seven percent of patients had clinical cervical nodal metastases at first consultation. Gross extension of the primary tumor involving the facial bones and skull base was observed in 39.3% and 20.8%, respectively. Just under 75% of patients were treated with radiotherapy (median dose, 6600 cGy), and 25.4% underwent concomitant chemoradiotherapy with adjuvant chemotherapy (cisplatin plus 5-fluorouracil) (median dose, 6800 cGy). The 5-year disease-specific survival for the 173 patients was 32.3%. The disease-specific survival for the radiotherapy group was 22.5%, compared with 61.4% for the chemoradiotherapy plus adjuvant chemotherapy group (P =.004). Factors associated with adverse outcomes were age older than 40 years at treatment (P =.001), advanced TNM stage (P =.002), skull base invasion (P =.004), and facial bone invasion (P<.001).

Compared with radiotherapy alone, concomitant chemoradiotherapy with adjuvant chemotherapy improved the treatment outcome of patients with NPC treated in our institution. Advanced age, local extension, and stage of the disease adversely affected the prognosis in our patients. Compared with reirradiation, salvage brachytherapy and radical neck dissection for local and regional residual or recurrent NPC were associated with increased rates of locoregional control and survival.