Kanjana Shotelersuk

Human papillomavirus DNA in plasma of patients with cervical cancer

BackgroundHuman papillomavirus (HPV) is a crucial etiological factor for cervical cancer (CC) development. From a diagnostic view-point, the consistent presence of HPV in CC allows the viral DNA to be used as a genetic marker. The aims of this study were to evaluate the presence, physical status and clinical significant of HPV DNA in circulation of CC patients.ResultsWhereas 6 out of 50 (12%) HPV positive CC patients revealed plasma HPV DNA, it was detected in none of 20 normal controls or 13 HPV negative CC cases. The plasma DNA exhibited an HPV type identical to the HPV in the primary tumors and the DNA from both sources was integrated into host genome. Interestingly, several findings suggested an association between plasma HPV DNA and metastasis. First, three of the HPV DNA positive cases were CC patients with clinical stage IVB or recurrence with distance metastases (P = 0.001, RR = 15.67). Second, the amount of plasma HPV DNA from metastatic patients to be three times more than three other patients without metastases. Finally, the later cases had tendency to develop recurrence distant metastases within one year after complete treatment when compared with other HPV associated CC patients with the same stage but without the present of plasma HPV DNA.ConclusionsThe plasma HPV DNA originated from the CC, was associated with metastasis and could be used as a marker representing the circulating free CC DNA.

Polymeric immunoglobulin receptor polymorphisms and risk of nasopharyngeal cancer

BackgroundEpstein-Barr virus (EBV) associated nasopharyngeal cancer (NPC) is an important squamous cell cancer endemic in Southeast Asia and the Far East and can be considered a multifactorial genetic disease. This research explores potential associations between nasopharyngeal epithelial EBV receptor and NPC susceptibility. To prove the hypothesis, we evaluated two candidate genes, complement receptor 2 (CR2) and polymeric immunoglobulin receptor (PIGR) by using 4 SNPs, CR2 IVS2-848C→T, PIGR IVS3-156G→T, PIGR 1093G→A and PIGR 1739C→T, to genotype 175 cases and 317 controls, divided into Thai, Chinese and Thai-Chinese based on their respective ethnic origins.ResultsThe results obtained indicated that PIGR is an NPC susceptibility gene. The risk association pertaining to each ethnic group was detected for homozygous PIGR 1739C with a significant ethnic group adjusted OR (95%CI) of 2.71(1.72–4.23) and p < 0.00001. Haplotype of the two missense PIGR SNPs, 1093G→A and 1739C→T, and sequence analyses have confirmed the role of the nucleotide PIGR 1739 and excluded possibility of an additional significant nonsynonymous NPC susceptibility SNP.ConclusionsWe present genetic evidence leading to hypothesize a possibility of PIGR to function as the EBV nasopharyngeal epithelium receptor via IgA-EBV complex transcytosis failure. The PIGR 1739C→T is a missense mutation changing alanine to valine near endoproteolytic cleavage site. This variant could alter the efficiency of PIGR to release IgA-EBV complex and consequently increase the susceptibility of populations in endemic areas to develop NPC.

Dosimetry of conformal dynamic arc radiotherapy and intensity modulated radiotherapy in unresectable cholangiocarcinoma

Background: Radiotherapy in cholangiocrcinoma has to overcome organ tolerance of the upper abdomen. Hi-technology radiotherapy may improve conformity and reduce dose to those organ. Objective: Quantitatively compare the dosimetry of conformal dynamic arc radiotherapy (CD-arcRT) and intensity modulated radiotherapy (IMRT) in unresectable cholangiocarcinoma. Material and methods: Eleven cases of unresectable cholangiocarcinoma were re-planned with IMRT and CDarcRT at King Chulalongkhorn Memorial Hospital between 20 September 2004 and 31 December 2005. Both the planning techniques were evaluated using the dose volume histogram of the planning target volume and organ at risk. The conformation number and dose to critical normal structures were used to determine the techniques. Results: IMRT technique was significantly conformed to the planning target volume than CD-arcRT in term of conformation number. For critical structure, IMRT significantly reduced the radiation dose to liver in terms of mean liver dose, V30Gy and V20Gy of the right kidney. Conclusion: The advantage of IMRT was more conformity and reduced dose to critical structure compared with CD-arcRT, but there was no difference between these techniques in terms of V20Gy of left kidney and maximum dose to the spinal cord.

Clinical Outcomes of Stereotactic Body Radiation Therapy Using Flattening Filter Free (FFF) in Early Non–Small Cell Lung Cancers and Metastatic Lung Cancers

improved OS (HR 0.379; 95% CI 0.16-0.93; PZ.033). This was not observed in patients with higher GPA scores. Conclusion: Brain radiation therapy plus EGFR-TKI, whether upfront or delayed, may improve intracranial disease control compared with TKI alone in EGFR mutant NSCLC with BM. The addition of brain irradiation to EGFR-TKI did not appear to improve survival in unselected patients, but low GPA scores may be a useful clinical predictor for early brain irradiation. Further prospective studies are needed to determine the optimal timing and appropriate patient group who need upfront brain radiation therapy. Author Disclosure: Y. Liu: None. L. Deng: None. X. Zhou: None. L. Zhou: None. Y. Xu: None. Y. Gong: None. J. Wang: None. Y. Lu: None.