The Incidence of Nasopharyngeal Carcinoma in Pahang State of Malaysia from 2012 to 2017

Background

Nasopharyngeal carcinoma (NPC) is the fifth most common cancer among Malaysians. While several studies have reported the trend of NPC in other states in Malaysia, no studies have reported the trend of NPC in Pahang state. This study was designed to report the number and distribution of newly diagnosed NPC cases in Pahang.

Methods

NPC cases that were diagnosed between 2012 and 2017 in two referral hospitals in Pahang were traced. The crude incidence rate (CR) and age-standardised rate (ASR) were calculated to investigate the NPC incidence.

Results

There were 143 new cases of NPC reported from the two hospitals. The mean age at diagnosis was 52.0 ± 13.7 years old. The majority of cases involved males (74.1%) with a male to female ratio of 2.9:1. Chinese males were found to have the highest incidence with a mean ASR of 4.7 per 100,000 population. Overall, the mean ASR for Pahang was 2.4 per 100,000 population for males and 0.9 per 100,000 population for females.

Conclusion

The total number of NPC cases reveals an increasing trend from 2012 to 2014 and then a slightly decreasing trend from 2015 to 2017. The incidence of NPC in Pahang was intermediate in males and low in females.

A Solo Dance or a Tango?

Previous studies have identified genetic factors and Epstein-Barr virus underlying nasopharyngeal carcinoma. A hypothesis postulated that the local buildup of HCl, mediated by hydrogen bond donors and acceptors and basic amino acids, causes cancer. Nasopharyngeal carcinoma incidences are high in the humid southern coastal China, Southeast Asia, and Mediterranean regions, but not in the noncoastal and nonhumid southern Yunnan Province, China, and nonhumid Central China. The nearly saturated humidity in the Huinan period in Guangdong can trigger the expression of proteins with extensive hydrogen bonding to protons, augmenting the formation of HCl that is mutagenic. Given that the Epstein-Barr virus carries high content of hydrogen bond donors and acceptors, the moist environment in the nasal cavity may enable the virus to colonize the site, compounding pertinent investigations as both virus and high humidity are likely to trigger carcinogenesis. Therefore, the phenomena of exceptionally high humidity in regions with high nasopharyngeal cancer rates warrant further investigations.

Tissue P16 is Associated with Smoking Status among Indonesian Nasopharyngeal Carcinoma Subjects

Background: Nasopharyngeal carcinoma (NPC) is a malignancy with high incidence in Southern China and South-East Asia. NPC incidence among males in Indonesia is estimated around 8.3/100,000 populations. Tobacco smoking is a common risk factor for cancer, including NPC. P16 is one of the key proteins related to the activation of apoptotic pathways, that commonly change during carcinogenesis. Carcinogenesis is often related to environmental exposure, including tobacco smoke. Objective: To analyze the association between P16 protein and smoking status among NPC subjects in Indonesia. Methods: Forty formalin fixed-paraffin embedded NPC tissue samples of known smoking status (20 smokers, 20 non-smokers) were collected from the Department of Anatomical Pathology, Dr. Sardjito Hospital, Yogyakarta. P16 was detected by immunohistochemistry staining. German semi-quantitative scoring system was applied to the P16 staining. Expression index with the score of 0 to 3 was classified as negative staining, meanwhile 4 to 12 was classified as positive staining. The association between P16 (score) and smoking status among NPC patients was analyzed using Fischer exact test. One-sided p ≤ 0.05 was considered as statistically significant. Results: All samples were Javanese males, with age range 25-76 years old. P16 positive staining among smokers was 5% (1/20), while among non-smokers was 40% (8/20). P16 among smokers was significantly lower than non-smokers patients (p=0.010). No difference was found between quantity of smoke and P16 score. Conclusion : A significant association between P16 and smoking status in Indonesian NPC patients has been revealed. The result of this study may be used to improve prevention and management of NPC cases related to smoking habit in Indonesia.

Identification of fatal outcome in a childhood nasopharyngeal carcinoma patient by protein expression profiling

Nasopharyngeal carcinoma (NPC) is a rare disease in children with good prognosis and high cure rate. Nevertheless, certain patients have an unfavorable prognosis due to development of refractory NPC that is unresponsive to any therapeutic strategies. The current study studies a case of a 17 years-old female with non-keratinizing NPC type IIb (T2N0M0), who passed away as a consequence of resistance to chemo-, radio- and β-interferon therapy, and to an allogenic stem cell transplantation. In order to identify factors that lead to treatment failure and fatal outcome, immunohistochemical analyses of different tumor biomarkers and hierarchical cluster analysis were performed and compared with those of eight other patients with NPC who experienced complete remission following conventional therapy. Hierarchical cluster analysis of the immunohistochemical results clearly demonstrated that staining for immunological factors (CD4, CD8 and CD56) distinguished this patient from the others. To further investigate a potential role of the immune system, lymphocytic infiltration was assessed in tumor tissue by evaluation of hematoxylin and eosin-stained tumor sections. Indeed, no tumor infiltrating lymphocytes (TILs) were observed in this NPC case, while 7 out of 8 of the other NPC samples contained variable TIL amounts. The view that immunodeficiency of the patient may be a factor in the fatal outcome of treatment is supported by the fact that this patient with NPC was not positive for Epstein-Barr virus markers and also infected by several other viruses and fungi (herpes simplex virus, human herpes virus 6, Varicella zoster virus, and Candida). In conclusion, the investigation of rare NPC cases with poor prognosis may provide an improved understanding of the molecular mechanisms involved in refractory tumors and identification of novel potential therapeutic targets for NPC in the future.