Clinical features and prognostic factors in patients with nasopharyngeal carcinoma relapse after primary treatment

Nasopharyngeal carcinoma (NPC) relapse after primary treatment is a major cause of cancer-related deaths. There is little comprehensive information on long-term outcomes particularly pertaining to the site of relapse. Therefore, the aim of this study was to determine the clinicopathological features of NPC relapse after primary treatment of 1424 patients referred to our institution from 2000 to 2006. After initial treatment, patients were reviewed at 3–6 month intervals. Information was collected on demographics, preand post-management and patient outcomes. The median age was 48 years (range 3–77), with complete data for 82% patients. In total, 152 patients (13%) had a local relapse and 193 patients (16.5%) had a distant relapse. Among patients with distant metastasis, the most common site of first relapse was the bone (in 56 patients), followed by multiple organ involvement (50), lung (37) and liver (30). The median interval from primary treatment until recurrence was 28 months, and diseasefree intervals correlated to survival (P < 0.0001). If a relapse occurred, the 3-year survival was 51% for local recurrence and 29.2% for distant recurrence (P < 0.0001). There were four dominant prognostic variables that predicted the patient’s clinical course: (1) stage of cancer (P = 0.008), (2) remission duration (�24 months vs. >24 months, P = 0.043), (3) location of metastases (local recurrence vs. distant recurrence, P = 0.043) and (4) nodal status (P = 0.048). Factors that were not significant in the univariate analysis included the patients’ age and sex, tumour size and histology. This data provided information on treatment outcomes in NPC patients along with statistical information to inform NPC patients about their expectations after the diagnosis of a relapse. Introduction Nasopharyngeal carcinoma (NPC) is the most common malignancy in the head and neck and has unique histological features, epidemiology, progression behaviours and management approaches. It also has a high prevalence in Southeast Asia and southern China1. With the introduction of new treatment modalities and earlier detection, survival has steadily improved over recent decades2. However, cancer relapse is still the leading cause of cancer-related deaths in patients with NPC. The most common cause of death after radiotherapy is distant metastasis, followed by nasopharyngeal and cervical recurrence3. Although much is known on the treatment and prognostic factors for this cancer, there has not been a systematic study on patterns of relapse and long-term outcomes after relapse occurs. Data from other cancers suggest that patients with bone metastasis have a better prognosis than those with visceral metastasis4. Whether the same is applicable for NPC remains to be investigated. Additionally, we attempted to find any factors that best predict the clinical course of metastatic NPC. In this paper, we describe the occurrence, survival time and prognosis of relapsed NPC. Patients after initial treatment were followed prospectively for up to 12 years. This information is especially important for NPC because the high propensity for spreading to more sites has a more variable clinical course than most other head and neck cancers. Knowledge about the dominant prognostic variables is also important in designing optimal patient treatment. Methods and materials