Biomedical subjects

Shinn-Yn Lin

Publications and source records attributed to Shinn-Yn Lin.

5 recordsLinked to original sources

PubMed2006

Complex mutation patterns of epidermal growth factor receptor gene associated with variable responses to gefitinib treatment in patients with non-small cell lung cancer.

Mutational analysis was performed in the kinase domain (exons 18-21) of the EGFR gene on tumor tissues of 65 non-small cell lung cancer (NSCLC) patients who had received gefitinib monotherapy. The association between EGFR gene mutation, gefitinib treatment response, and the overall survival were evaluated. In total, EGFR mutations with complex patterns were identified in 32 tumors. The overall mutation rate was 49.2% (32/65). Twenty of the 32 patients were responders, 10 non-responders, and 2 not assessable. The most common mutation in non-responders was L858R. Gefitinib responsiveness was only significantly associated with EGFR mutation and adenocarcinoma. The median survival for responder (15.5 months) was much longer than non-responder (9.23 months), though the difference only had marginal significance (p=0.056). The difference of overall survival between patients with and without EGFR mutation was non-significant (p=0.7819), mainly due to the short survival of the non-responders with EGFR mutations (median survival=6.2 months). Our study revealed that the response to gefitinib treatment in NSCLC patients with EGFR mutations could be quite variable even for the same EGFR mutation type. An analysis of the various EGFR mutations and the response patterns was also performed and compared with recently published reports on EGFR mutation and gefitinib responsiveness.

Adenocarcinoma↗

PubMed2006

The 30-bp deletion of Epstein-Barr virus latent membrane protein-1 gene has no effect in nasopharyngeal carcinoma.

OBJECTIVE: The specific 30-bp deletion of the Epstein-Barr virus (EBV)-derived latent membrane protein-1 gene has been suggested to be associated with the pathogenesis of nasopharyngeal carcinoma (NPC) and a more aggressive phenotype of some EBV-associated malignancies. METHODS: The authors conducted a retrospective cohort study. Between 1995 and 2001, 542 patients who had received complete courses of radiotherapy followed by at least 3 years of follow up were enrolled. Patients were divided into two groups according to the presence or absence of the 30-bp deletion in their tumor samples. RESULTS: A total of 446 (82.3%) patients were found to feature the 30-bp deletion, whereas 88 (16.2%) did not. Interestingly, dual infection was found in eight (1.5%) patients. No statistical significance was found in age, gender, NPC-presenting stage, radiosensitivity, and pathologic classification between the two groups. The actuarial 5-year overall survival rate and the distant metastasis-free rate for the 30-bp deletion and nondeletion group were not statistically different (61.3% vs. 65.4% and 68.1% vs. 73.1%; P = .132 and .135, respectively). In multivariate analysis, older age, nasopharyngeal recurrence, advanced tumor stage, and the development of distant metastasis were shown to be poorer prognosticators for overall survival, whereas the presence of 30-bp deletion was not. For distant metastasis, only advanced tumor stage was shown to be a poor prognosticator, whereas other variables, including the presence of 30-bp deletion, had no statistical significance. CONCLUSIONS: In this retrospective cohort, we have demonstrated that this specific 30-bp sequence deletion might be only the predominant variant rather than an NPC phenotype-associated polymorphism. Additionally, dual infection is a rare but possible phenomenon in the endemic NPC tumors.

Adolescent↗

PubMed2005

The time frame of Epstein-Barr virus latent membrane protein-1 gene to disappear in nasopharyngeal swabs after initiation of primary radiotherapy is an independently significant prognostic factor predicting local control for patients with nasopharyngeal carcinoma.

PURPOSE: The presence of Epstein-Barr virus latent membrane protein-1 (LMP-1) gene in nasopharyngeal swabs indicates the presence of nasopharyngeal carcinoma (NPC) mucosal tumor cells. This study was undertaken to investigate whether the time taken for LMP-1 to disappear after initiation of primary radiotherapy (RT) was inversely associated with NPC local control. METHODS AND MATERIALS: During July 1999 and October 2002, there were 127 nondisseminated NPC patients receiving serial examinations of nasopharyngeal swabbing with detection of LMP-1 during the RT course. The time for LMP-1 regression was defined as the number of days after initiation of RT for LMP-1 results to turn negative. The primary outcome was local control, which was represented by freedom from local recurrence. RESULTS: The time for LMP-1 regression showed a statistically significant influence on NPC local control both univariately (p < 0.0001) and multivariately (p = 0.004). In multivariate analysis, the administration of chemotherapy conferred a significantly more favorable local control (p = 0.03). Advanced T status (> or = T2b), overall treatment time of external photon radiotherapy longer than 55 days, and older age showed trends toward being poor prognosticators. The time for LMP-1 regression was very heterogeneous. According to the quartiles of the time for LMP-1 regression, we defined the pattern of LMP-1 regression as late regression if it required 40 days or more. Kaplan-Meier plots indicated that the patients with late regression had a significantly worse local control than those with intermediate or early regression (p = 0.0129). CONCLUSION: Among the potential prognostic factors examined in this study, the time for LMP-1 regression was the most independently significant factor that was inversely associated with NPC local control.

Adult↗

PubMed2003

Detection of Epstein-Barr virus-derived latent membrane protein-1 gene in various head and neck cancers: is it specific for nasopharyngeal carcinoma?

OBJECTIVE: The object of the study was to determine the incidence of the presence of Epstein-Barr virus-derived latent membrane protein-1 (LMP-1) gene in various head and neck cancers by polymerase chain reaction method. STUDY DESIGN: Prospective study. METHODS: During a 5-year period, polymerase chain reaction was used to investigate the presence of LMP-1 gene in various head and neck cancers from different locations and histopathological types, noncancerous nasopharyngeal biopsy samples, and tonsillectomy specimens from patients with chronic hypertrophic tonsillitis. RESULTS: Of 202 patients enrolled in the study, 53 were diagnosed by pathological study with oropharyngeal carcinoma, 45 with nasopharyngeal carcinoma, 26 with oral cavity carcinoma, 26 with laryngohypopharyngeal carcinoma, 31 with nasopharyngeal lymphoid hyperplasia, and 21 with tonsils with lymphoid hyperplasia. After the application of polymerase chain reaction, the LMP-1 gene was not detected in any sample from oral cavity carcinoma, laryngohypopharyngeal carcinoma, or nasopharyngeal lymphoid hyperplasia or from tonsillectomy specimens but was detected in only one case of tonsillar carcinoma. On the contrary, the LMP-1 gene was detected in 43 (95.6%) of 45 samples from patients with nasopharyngeal carcinoma. The statistical analysis shows a significant association (P <.001) between the presence of LMP-1 gene and tumor localization in the nasopharynx. CONCLUSIONS: The study shows that the presence of LMP-1 gene detected by polymerase chain reaction in the tumor cell is only significantly associated with tumor located in the nasopharynx, implying that Epstein-Barr virus plays a trifling role in the tumorigenesis of carcinomas arising from other head and neck locations. The polymerase chain reaction method that was used is a potential tool for screening nasopharyngeal carcinoma.

Adenocarcinoma↗

PubMed2002

A lack of association between p53 mutations and recurrent nasopharyngeal carcinomas refractory to radiotherapy.

OBJECTIVE: The object of this study was to determine the incidence of p53 mutation in recurrent nasopharyngeal carcinoma refractory to radiotherapy. STUDY DESIGN: Prospective study. METHODS: There were 31 patients enrolled in this study between 1995 and 1998. All patients had received radiotherapy but none of them had undergone chemotherapy or local salvage surgery previously. RESULTS: The p53 status of each tumor was analyzed by polymerase chain reaction and by sequencing of exons 5 to 8 (codons 126-306). Five (16.1%) of 31 patients had mutations in the p53 gene, of which 2 were non-sense mutations, 2 were transition mutations, and 1 was a frameshift deletion mutation. The majority of the p53 mutations were found in exon 5. There is no significant difference in the incidence of p53 mutation compared with that of the previous reports for the primary disease. Based on the clinicopathologic data, there was no specific difference found between these 5 patients and the others. CONCLUSIONS: This study shows that p53 mutation is an infrequent event and may have no essential role in recurrent nasopharyngeal carcinomas.

Adolescent↗