TP53 and EGFR Mutational Status in Thymoma: A Genetic Sequencing Study.

BACKGROUND AND OBJECTIVE: Thymoma is a rare malignant tumor that usually with an indolent presentation, which was falsely assumed to be benign previously. The tumor suppressor P53 (TP53) and EGFR gene mutate most frequently in human cancers. We tried to investigate the presence of TP53 and EGFR mutations among thymoma patients referred to an Indonesian referral respiratory hospital and to discuss its potential role in thymoma management and prognosis. MATERIAL AND METHODS: Surgically resected tumor tissues were collected from thymoma patients and then underwent genomic analysis. PCR was performed on the extracted Paraffinized  DNA to amplify exon 6 of TP53 and exons 18, 19, and 21 of EGFR. The evaluation of mutational status was done using direct sequencing and sequence analysis of purified PCR products. RESULTS: Among 27 collected samples, TP53 exon 6 mutation, namely  missense mutation and nonsense mutation, was observed in two samples (7.4%). EGFR exon 18 mutation, namely E709K and nonsense mutation, was found in 2 samples (7.4%). An intronic mutation in EGFR exon 19 (3.7%) and exon 21 (3.7%) was observed in one sample. CONCLUSION: TP53 and EGFR mutations were not most frequent, so it seems that these genes are not involved in the pathogenesis of thymoma in Indonesian patients. Nevertheless, we found two samples with a significant mutation in p53 and EGFR genes, suggesting further research on thymoma prognostification and targeted therapy.

Single and multiple high-risk and low-risk Human Papillomavirus association with cervical lesions of 11,224 women in Jakarta.

PURPOSE: We sought to evaluate prevalence, age-adjusted distribution, and impact of single and multiple high- and low-risk human papillomavirus (HPV) subtypes and their associations with cervical lesions. METHODS: Data were extracted from 11,224 women who underwent routine screening of HPV genotyping and liquid-based cytology co-testing. Fifteen high-risk (HR) and six low-risk (LR) HPV types were genotyped. RESULTS: Overall HPV prevalence was 10.7 %, and young women (under 21 years old) harbored highest HPV infection rate (40.38 %). The rate declined in old women 9.49 % (age 30-49) and 6.89 % (age 50 and above). Normal cytology had lowest HPV (5.66 %) compared to low-grade (60.49 %), high-grade (71.96 %) squamous intraepithelial lesions (LSIL and HSIL) and squamous cell carcinoma SCC (86.9 %). LR HPV subtypes were absent in SCC and were consistently lower than HR HPV in LSIL (6.74 vs. 33.54 %) and HSIL (2.12 vs. 51.32 %). Multiple HPV infection was more frequent in young women under 30 years old (10 %) than older women (2 %) and in LSIL (20.2 %), HSIL (18.5 %) than SCC (4.4 %). HR HPV 52, 16, 18, and 58 were the most frequent subtypes in normal, LSIL, and HSIL. Greater or equal proportion of HPV 16, 18, 45, and 52 was found in SCC compared to normal cytology (SCC/normal ratios 4.8, 1.2, 1.6, and 1.7). While important in LSIL and HSIL, HPV58 was not detected in SCC. CONCLUSION: Taken together, identification of these HPV types, especially HPV 16, 18, 45, and 52, and their associated cervical lesions may improve cervical cancer preventive strategies in Indonesia.