Genotype distribution of T cell receptor β gene in Indonesian nasopharyngeal carcinoma patients.

Background: Nasopharyngeal carcinoma (NPC) is a multifactorial genetic disease, characteristically endemic and shows considerable differences in its geographical distribution. Besides infection with EBV, genetic factors such as polymorphisms of TCR-β gene contribute to the incidence of NPC. This study investigates the association of TCR-β gene polymorphisms with individual susceptibility to develop NPC in Indonesian ethnic groups. Methods: The study was carried out by the PCR-RFLP method using Bgl II restriction enzyme to digest TCR-β gene. The PCR-RFLP analysis of TCR-β gene was used to determine allotypes of TCR-β gene in NPC patients and control among ethnic Chinese and indigenous groups in the population of Indonesia. Results: The results indicate that the distribution of TCR-β gene allotypes between NPC patients and controls are not significantly different (p > 0.05); however, the frequency of A allele tends to increase in NPC patients. The distribution of TCR-β gene allotypes between Chinese ethnic group was not signifi cantly different from indigenous groups (p > 0.05). Conclusion: The distribution of TCR-β gene allele between NPC group and control groups showed no difference. The distribution of TCR-β gene between ethnic Chinese and indigenous groups showed no difference. Polymorphisms of TCR-β gene are not associated with NPC and ethnic groups in Indonesian population.

Nasopharyngeal carcinoma: correlation of histopathology with radiation response.

Forty-nine cases of NPC were evaluated histopathologically and the radiation responses of the tumor types were assessed. The overall radiation response were as follows: CR 40.8%, PR 14.3%, NC 42.9%, PD 2.0%. The distribution of tumor types were: Squamous cell carcinoma (WHO type I) 4.08%; Non-keratinizing carcinoma (WHO type II) 4.08%; Undifferentiated carcinoma (WHO type III) 91.84% var. Lympho-epitheliomatous (LE), Anaplastic (A), Spindle cell (SC), Clear cell (CC). 94.38% of the cases were classified as clinical stage II, III and IV (tumor found beyond the nasopharyngeal space). The radiation response rate of the tumor in the lymphnode was reversed to the clinical stage and extent of node involvement, namely the higher stage and node involvement, the less rate of radiation response. Twelve cases received radiation dose of less than 4000 cGy, which comprised 11 NC cases and 1 PD case. Of the 37 cases who got 4000 cGy and over, the response rate was 72.97%. Of these WHO type I was not evaluated because of insufficient radiation dose; WHO type II showed 50% response rate; WHO type III showed 74.29% response rate. Radiation response (as assessed from the cervical lymphnode involvement) of NPC was influenced by tumor burden and histologic type of the tumor, namely the less differentiated tumor responded better than the more differentiated one. No definite conclusion can be drawn yet of the different behaviour (if any) of the variants of undifferentiated carcinoma (WHO type III) toward irradiation.