Detection of Stage I nasopharyngeal carcinoma by serologic screening and clinical examination / 癌症

In a prospective study, 42 048 adults residing in Zhongshan City, Guangdong, China, were followed for 16 years, and 171 of them developed nasopharyngeal carcinoma (NPC). Although Epstein-Barr virus (EBV) antibody levels of the cohort fluctuated, the antibody levels of 93% of the patients with NPC were raised and maintained at high levels for up to 10 years prior to diagnosis. This suggests that the serologic window affords an opportunity to monitor tumor progression during the preclinical stage of NPC development, facilitating early NPC detection. We reviewed the clinical records of the 171 patients with NPC in the prospective study to assess the efficacy of early NPC detection by serologic screening and clinical examination. Of the 171 patients, 51 had Stage I tumor (44 were among the 73 patients detected by clinical examination and 7 were among the 98 patients presented to outpatient department). Initial serologic screening predicted 58 (95.1%) of the 61 patients detected within 2 years. The risk of the screened population (58/3093) raised 13 times relative to cohort (61/42 048) during this period. Clinical examination detected all the 58 predicted cases, and 35 (60.3%) of which were diagnosed with Stage I tumor. The serologic prediction rate fell to 33.6% (37/110) 2 to 16 years after screening. The proportion of cases detected by clinical examination fell to 40.5% (15/37). The proportion of Stage I tumors among the cases detected by clinical examination during both periods remained at about 60%. We concluded that early detection of NPC can be accomplished by repeated serologic screening to maintain high prediction rates and by promptly examining screened subjects to detect tumors before the symptoms develop.

Study of sequence variations of Epstein-Barr virus LMP1 gene in nasopharyngeal carcinoma / 中华病理学杂志

<p><b>OBJECTIVE</b>To detect the sequence variations frequently found within the N- and C-terminal regions of Epstein-Barr virus (EBV) LMP1 gene in nasopharyngeal carcinoma (NPC) and to study the underlying mechanisms.</p><p><b>METHODS</b>Fresh tumor tissues were sampled from 63 patients with untreated NPC encountered in Affiliated Tumor Hospital of Sun Yat-sen University, Guangzhou. The N-terminal region of EBV LMP1 gene was amplified with nested polymerase chain reaction (PCR), followed by XhoI enzyme digestion. Nested PCR was also employed to detect the 30 base pairs deletion within the C-terminal region. Four-colored fluorescence terminator sequencing method was applied for bi-directional solid-phase sequencing of the 8 representative PCR products in 4 cases of NPC. The DNA sequence within the N- and C-terminal regions of LMP1 gene was then analyzed.</p><p><b>RESULTS</b>There were 4 patterns of sequence variations, namely, wt-XhoI/wt-LMP1 (4 cases, 6.3%), wt-XhoI and XhoI-loss/del-LMP1 (4 cases, 6.3%), wt-XhoI/del-LMP1 (5 cases, 7.9%) and XhoI-loss/del-LMP1 (50 cases, 79.5%), detected in the 63 studied cases. Sequence analysis showed that the EBV LMP1 gene had underwent non-synonymous and synonymous substitutions, as compared with the prototype of B95-8 cells. The ratio of non-synonymous to synonymous substitutions was 2.25.</p><p><b>CONCLUSIONS</b>XhoI-loss/del-LMP1 is the predominant sequence variation pattern of EBV LMP1 gene in NPC from Guangzhou. The XhoI-loss variation seems to develop on top of del-LMP1. When compared with the EBV LMP1 gene in peripheral blood B-lymphocytes of virus carriers and in preinvasive epithelial lesions (reported previously), it is likely that the sequence variation patterns of LMP1 gene may represent 4 different phases of intrahost evolution of EBV during nasopharyngeal carcinogenesis.</p>

Value of EBNA1-IgA and EA-IgG in serological diagnosis of nasopharyngeal carcinoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To evaluate the value of EBNA1-IgA and EA-IgG in serological diagnosis of nasopharyngeal carcinoma (NPC).</p><p><b>METHODS</b>The serum EBNA1-IgA and EA-IgG of 56 patients with NPC and 58 healthy adults were detected by ELISA. The sensitivity, specificity, positive predictive value, accuracy rate and odds ratio of the two tests used singly or in combination were compared with each other.</p><p><b>RESULTS</b>The sensitivity of EBNA1-IgA (91.07%) was higher than that of EA-IgG (87.50%), while the specificity of EA-IgG (87.93%) was higher than that of EBNA1-IgA (84.48%). The combination of EBNA1-IgA and EA-IgG could enhance the specificity (94.83%), positive predictive value (0.9375), likelihood ratio (15.5435) and odds ratio (75.0000) for serological diagnosis of NPC. Forty-five patients showed both positive EBNA1-IgA and positive EA-IgG. A positive EA-IgG was detected in 4 out of 5 patients with negative EBNA1-IgA and a positive EBNA1-IgA was founded in 6 out of 7 patients with negative EA-IgG.</p><p><b>CONCLUSION</b>Although relatively high sensitivity and specificity could be obtained by either EBNA1-IgA or EA-IgG test alone, the combination of these two tests with a complementary effect is able to enhance the reliability of serological diagnosis of NPC as most patients have positive ENBA1-IgA and EA-IgG concurrently.</p>

Primary adenoid cystic carcinoma of the nasopharynx and its relation to Epstein-Barr virus infection / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the clinicopathologic characteristics of primary nasopharyngeal adenoid cystic carcinoma (NPACC) and its relation to Epstein-Barr virus (EBV) infection in Guangzhou where is a high-incidence area of EBV-associated nasopharyngeal carcinoma (NPC).</p><p><b>METHODS</b>17 cases of NPACC with clinical record and biopsy samples were collected in Guangzhou and their clinical manifestations were reviewed. Besides HE, Alcian blue and PAS, LSAB immunohistochemistry was performed for detecting the expression of a variety of epithelial markers, CD21 and EBV encoded LMP1. EBV encoded early RNAs (EBER) was detected by using in-situ hybridization. Nested PCR was applied for studying the presence of EBV W-fragment in tissues.</p><p><b>RESULTS</b>The ratio of male to female was 7:10. The patients' age ranged from 30 to 63 years, and the median age was 46 years. 14 out of 17 tumors showed markedly local aggressive growth, presenting as T3 or T4. However, only 1 patient had metastasis of an ipsilateral cervical lymph node. The majority of neoplastic cells were basal-cell like in shape and with scanty cytoplasm and a deeply stained nucleus. Intercellular hyaline or mucinous substance was always present in between the carcinoma cells. Cribriform structure formed by the neoplastic cells could be found in 16 out of these 17 biopsies. The NPACC always express the wide-spectrum cytokeratin and the epithelium membrane antigen. Only a few or a small number of carcinoma cells showed nuclear EBER-signals in 9 cases (9/17). Concurrently, these 9 NPACCs showed a 192 bp W-fragment positive band on electrophoresis gel by nested PCR. LMP1 expression had been found in 5 out of the 9 NPACCs (55.6%) accompanying with EBER-positive carcinoma cells. The EBER-positive infiltrating lymphocytes could also be found in the stroma of 3 out of the 9 EBER-stained NPACC slides. All the tumor cells, including the EBER-positive cell of the 17 NPACCs showed no CD21 expression.</p><p><b>CONCLUSIONS</b>The female is predominant over the male in development of NPACC, which often accompanied with a markedly invasive capacity at the nasopharynx and its neighboring sites. Only a small number of tumor cells, nearly a half of the studied cases were infected with EBV. Therefore, it's postulated that there seems no close relation present between NPACC and EBV infection.</p>

Comparison of the Epstein-Barr virus infection and 30 bp-deleted LMP1 gene among 4 histologic types of nasopharyngeal carcinoma / 中华病理学杂志

<p><b>OBJECTIVE</b>To compare the Epstein-Barr virus (EBV) infection rates and the frequencies of wt-LMP1 and del-LMP1 EBV variants detected singly or dually among the four types of nasopharyngeal carcinoma (NPC) and to illustrate the possible role of del-LMP1 gene in nasopharyngeal carcinogenesis.</p><p><b>METHODS</b>EBER in situ hybridization was performed in 117 NPCs, including 48 non-keratinizing carcinomas (NKCs), 25 keratinizing squamous cell carcinomas (KSCCs), 5 adenosquamous carcinomas (ASCs), 6 mucoepidermoid carcinomas (MECs) and 33 adenocarcinomas (ACs). Nested PCR for demonstration of EBV LMP1 gene was performed on the tissue samples collected from 99 EBER-positive carcinoma cases and the peripheral blood mononuclear cells (PBMCs) of 53 healthy adults (HAs).</p><p><b>RESULTS</b>As indicated by EBER in-situ hybridization, the EBV infection rates in both of 48 NKCs and 25 KSCCs were 100%; and the infection rates of 11 ASCs/MECs and 33 ACs were 9/11 and 51.5% (17/33), respectively. Worthy to note was that most of the NKC cells were EBER-positive while only a small number of EBER-positive neoplastic cells could be found in 17 ACs. The percentage of del-LMP1 EBV variant detected singly in NKCs (85.4%, 41/48) was not only significantly higher than that in PBMCs of 46 HAs (8.7%, 4/46) but also significantly higher than those detected in KSCCs (16.0%, 4/25). The dual infection rate of wt-LMP1 and del-LMP1 variants detected in KSCCs (56.0%, 14/25) was significantly higher than that of NKCs (12.5%, 6/48). The majority of the EBV detected in AC tissues (12/17) and HAs' PBMCs (34/46, 73.7%) were of dual wt-LMP1 and del-LMP1 variants.</p><p><b>CONCLUSIONS</b>The EBV infection rates are significantly different among 3 major histological categories, namely, NKC/KSCC, ASC/MEC and AC. Though NKCs and KSCCs are always consistently associated with EBV, the single del-LMP1 EBV variant detected in NKCs is predominant over that in KSCCs and most of the KSCCs contain dual wt-LMP1 and del-LMP1 EBV variants. The EBV of the del-LMP1 variant might play a crucial role in carcinogenesis of NKC.</p>

Analysis of Epstein-Barr virus with BamHI "f" variant and XhoI-loss of LMP1 gene in nasopharyngeal carcinoma / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the genomic variation of Epstein-Barr virus (EBV) and its significance in nasopharyngeal carcinogenesis.</p><p><b>METHODS</b>Forty nasopharyngeal carcinoma (NPC) biopsy tissues were used for detection of EBV BamHI f variant and LMP1 XhoI-loss by polymerase chain reaction (PCR), nested PCR, and RFLP (restriction fragment length polymorphism). Forty-eight samples of peripheral blood mononuclear cells (PBMC) taken from apparently healthy adult individuals were used for detection of LMP1 XhoI-loss. Three samples of amplified LMP1 exon 1 DNA from B95-8 cell line and 2 NPC tissues (one having XhoI-loss and the other having Wt-XhoI/XhoI-loss) were sequenced.</p><p><b>RESULTS</b>Thirty out of the 40 NPC cases (30/40, 75%) harbored EBV BamHI f variant and the remaining 10 (10/40, 25%) harbored BamHI F prototype. Thirty out of the 39 NPCs (30/39, 76.9%) showed single EBV LMP1 XhoI-loss, 7 (7/39, 18.0%) showed single LMP1 Wt-XhoI (presence of a XhoI site in exon 1 of LMP1 gene, as in B95-8 cell line), and 2 (2/39, 5.1%) showed both LMP1 Wt-XhoI and XhoI-loss. Thirty-eight of the 39 NPCs (97.4%) showed EBV LMP1 XhoI-loss or/and BamHI F variant. In the NPC tissue (1 case only) showing the prototype of Wt-XhoI/BamHI "f", there were several base substitutions, including 5 missense mutations and 2 silent mutations present in LMP1 exon 3, on DNA sequencing. On the other hand, 10 out of the 48 samples of PBMC taken from apparently healthy individuals could be amplified successfully by nested PCR for detection of LMP1 XhoI site. All of these 10 samples carried the prototype of EBV LMP1 Wt-XhoI.</p><p><b>CONCLUSIONS</b>The majority of EBV present in neoplastic cells of NPC is of BamHI "f" variant and/or possesses LMP1 XhoI-loss, as compared with that in healthy individuals. This genomic variation of EBV may bear some roles in the development and progression of NPC.</p>