Nasopharyngeal carcinoma in Slovenia, 1990-2003 (results of treatment with conventional two-dimensional radiotherapy)

Abstract

Aim: To review the treatment results and identify prognostic factors for disease control and survival in a cohort of nasopharyngeal carcinoma (NPC) patients from a non-endemic population in Slovenia, diagnosed between 1990 and 2003.

Background: In Caucasians, nasopharyngeal carcinoma is a rare malignant tumor. Its diagnosis and treatment are complex and have been dramatically impacted by recent technological advances.

Materials and methods: In the Cancer Registry of Slovenia database, a total of 126 patients with NPC were identified, 93 of whom were available for analysis. All patients were treated with conventional two-dimensional radiotherapy (RT) and 29.3% underwent chemotherapy (ChT).

Results: The median follow-up time for those alive at the last follow-up examination was 74.5 months. Disease recurred locally in 17 patients, regionally in 4 patients and at distant sites in 18 patients, resulting in 5-year locoregional control (LRC), distant failure-free survival (DFFS) and disease-free survival (DFS) of 73.7%, 78.6% and 59.3%, respectively. Disease-specific survival at 5 years was 59% and overall survival (OS) was 49.7%. In a multivariate analysis, LRC was favorably affected (P < 0.05) by an undifferentiated histology (hazard ratio [HR] = 2.86), DFFS through the absence of neck metastases (HR = 0.28), DFS by younger age (HR = 0.46), and more intensive RT (expressed as the isoeffective dose, EQD2,T ; HR = 2.08). The independent prognosticator for OS was age (≤55 years vs. >55 years, HR = 0.39); in the ≤55 years subgroup, an improved OS was connected to a more intensive RT regimen of EQD2,T ≥ 66 Gy (HR = 4.17).

Conclusions: Our results confirm an independent and favorable effect from an undifferentiated histology, the absence of neck metastases, a younger patient age at diagnosis, and more intensive RT regimens for disease control and survival.

Keywords: Chemotherapy; Nasopharyngeal carcinoma; Prognostic factors; Radiotherapy; Survival.

Fig. 1

Local, regional and distant control.

Fig. 2

Patients ≤55 years of age: effect of intensity of radiotherapy (EQD_2,T): A, disease-free survival; B, overall survival.

Fig. 3

Salvage therapy for disease recurrence and outcome.

Fig. 4

Disease-specific and overall survival.