STUDY DESIGN: Eighty-six postnasal biopsy samples and 71 fine-needle aspirate samples of neck masses were obtained from patients who were clinically suspect for NPC. Genomic DNA was extracted from the samples, and EBNA1, EBNA2, and LMP genes of EBV were detected by PCR. PCR results were compared with NPC histopathology findings.
RESULTS: The sensitivity of PCR to detect EBNA1 (97.14%), EBNA2 (88.57%), and LMP (91.43%) genes of EBV in nasopharyngeal biopsy samples were higher than those in fine-needle aspirate samples.
CONCLUSION: Detection of EBV by PCR in tissue obtained from nasopharyngeal biopsy and fine-needle aspirate samples of neck masses is a relatively inexpensive, reliable, and accurate method of diagnosing NPC. Detection of EBV genes is on par with histopathological examination (HPE) and superior to fine-needle aspirate cytology.
SIGNIFICANCE: PCR is an ideal tool for suggesting NPC and guiding the diagnostic workup in occult primary tumors, facilitating earlier diagnosis and reducing morbidity and mortality.
MATERIALS AND METHODS: From 1997 to 1999, 55 patients with FIGO stage Ib1 lymph nodes-negative cervical carcinoma limited to the cervix were prescribed RT following radical surgery, based on their RS, as follows: RS <40, RT is omitted; RS >40 to <120, modified (smaller) field RT; and RS >120, standard field pelvic RT. Their incidence and site of recurrence were compared with a similar cohort of 40 patients who were treated prior to 1997.
RESULTS: Prior to 1997, of the 40 patients, 10 patients were given standard field RT. There were 2 (5%) recurrent diseases. The mean duration of follow-up was 61.6 months (range, 1 to 103 months). The RS of 23 of the 30 patients who were not given RT were available. The mean RS was 22 with 5 patients having a score of >40. From 1997 onwards, of the 55 patients, 28 (51%) did not require RT, 13 (23%) were treated with modified (smaller) field RT and 14 (26%) were given standard field RT. There were 2 (3.6%) cases of relapse. The mean duration of follow-up was 36.4 months (range, 5 to 60 months). All patients with a RS of <40 did not suffer any relapse. Their survival outcomes were better when compared to patients who did not have any RT in the GOG Study.
CONCLUSIONS: The results of this study indicated that postoperative adjuvant RT given to patients with a high GOG RS of >120, significantly improved their 5-year recurrence rate and disease-free survival, as compared with the similar group of patients who were without adjuvant therapy in the GOG study. Patients with a GOG risk-score of <40 may be safely spared from adjuvant pelvic RT. The current treatment protocol did not compromise the outcome in patients, compared with the use of a less precise treatment protocol in the past.
METHODS: Paraffin-embedded tissue from 38 lymphomas (17 Hodgkin's, 14 Burkitt's, four T cell and 3 B cell non-Hodgkin's lymphomas) and 14 nasopharyngeal carcinomas (NPC) were studied, with 12 reactive lymph nodes and tonsils as normal control. EBER in situ hybridisation was performed to confirm EBV association in the tumour cells. A nested polymerase chain reaction (PCR) protocol was employed using two pairs of consensus primers which flanked a 105-bp deletion in the type A virus. U2 region encoding for EBNA-2 was chosen as the target of amplification, with cell lines B95.8 and AG876 serving as positive controls for types A and B virus, respectively.
RESULTS: All cases showed presence of type A virus, consistently detected with nested PCR protocol but not with single step PCR. There was no type B virus or mix infections detected.
CONCLUSIONS: Nested PCR technique has successfully increased the sensitivity of EBV subtype detection, and type A virus is the prevalent strain associated with human diseases in Malaysia.