**6. Mortality and survival**

### **6.1 Mortality of NPC**

Global mortality rates of NPCestimated 51,000 deaths in 2012 among females and males were 0.04 per 10, 000 and 0.1 per 10,000, respectively.

The mortality rate were high in Southeast Asia, East Asia, East Africa North Africa and Micronesia. Nasopharyngeal carcinoma is the native cancer of Southeast Asia and the countries with the highest mortality were Malaysia, Singapore, Indonesia, Vietnam, and Brunei [26] (**Figure 2**).

#### **6.2 Survival patterns of NPC**

Early diagnosed NPC patients respond very well to radiation, and this treatment shows promise. Radiation therapy is the strategy treatment for treating NPC. However, approximately 70% of stage III or IV NPC patients are exposed to a local and/or regional condition of distant metastases or recurrences after radiation therapy [86]. Treatment with combination of chemotherapy and radiation therapy often required for advanced NPC [87].

Studies have shown that intensity modulated radiation therapy (IMRT) often produces larger radiation dose distributions corresponding to improved tumor exposure and allows for lower doses of normal tissue for a variety of cancers that

**Figure 2.** *Mortality rate of nasopharyngeal carcinoma in Asia in 2012 (GLOBOCAN 2012) [26].*

occur in the head and neck area [88]. In addition, the prognosis of NPC associated with many factors are, including age, sex, TNM stage, histology, radiation dose, leukopenia and anemia, and the type of combined chemotherapy [89]. Therefore, minimizing the risk of late complication and distant metastasis and maximizing the local control should be the key objects in designing future treatment.
