Objectives: The highly polymorphic nature of the CYP2D6 gene and its central role in the metabolism of commonly used drugs make it an ideal candidate for pharmacogenetic screening. This study aims to determine the prevalence of CYP2D6 polymorphisms among Filipinos and their association to lung cancer. Method: Forty seven single nucleotide polymorphisms (SNPs) of the CYP2D6 gene were genotyped from DNA samples of 115 cases with lung cancer and age- and sex-matched 115 controls. Results: Results show that 18 out of 47 polymorphisms have significant genotypic variability (>1% for at least 2 genotypes). No variant is associated with lung cancer. However, rs1135840, rs16947 and rs28360521, were found to be highly variable among Filipinos. Conclusion This study demonstrated that CYP2D6 polymorphisms are present among Filipinos, which, although not found to be associated with lung cancer, can be useful biomarkers for future pharmacogenetic studies. The SNP rs16947 is found to be associated with cancer and timolol-induced bradycardia; the SNP rs1135840, on the other hand, is only shown to be linked with cancer. The genetic variant rs28360521 is known to be associated with low-dose aspirin-induced lower gastrointestinal bleeding.
Pharmacogenetics ; Cytochrome P-450 CYP2D6 ; Lung Neoplasms ; Biomarkers

Objectives. Polymorphisms in metabolic genes which alter rates of bioactivation and detoxification have been shown to modulate susceptibility to colorectal cancer. This study sought to evaluate the colorectal cancer risk from environmental factors and to do polymorphism studies on genes that code for Phase I and II xenobiotic metabolic enzymes among Filipino colorectal cancer patients and matched controls. Methods. A total of 224 colorectal cancer cases and 276 controls from the Filipino population were genotyped for selected polymorphisms in GSTM1, GSTP1, GSTT1, NAT1 and NAT2. Medical and diet histories, occupational exposure and demographic data were also collected for all subject participants.Results. Univariate logistic regression of non-genetic factors identified exposure to UV (sunlight) (OR 1.99, 95% CI: 1.16-3.39) and wood dust (OR 2.66, 95% CI: 1.21-5.83) and moldy food exposure (OR 1.61, 95% CI:1.11-2.35) as risk factors; while the NAT2*6B allele (recessive model OR 1.51, 95% CI :1.06-2.16; dominant model OR 1.87, 95% CI: 1.05-3.33) and homozygous genotype (OR 2.19, 95% CI: 1.19-4.03) were found to be significant among the genetic factors. After multivariate logistic regression of both environmental and genetic factors, only UV radiation exposure (OR 2.08, 95% CI: 1.21-3.58) and wood dust exposure (OR 2.08, 95% CI: 0.95-5.30) remained to be significantly associated with increasing colorectal cancer risk in the study population.Conclusion. This study demonstrated that UV sunlight and wood dust exposure play a greater role in influencing colorectal cancer susceptibility than genotype status from genetic polymorphisms of the GST and the NAT` genes.
Colorectal Neoplasms ; Polymorphism, Genetic

OBJECTIVE: This study aimed to evaluate the clinical utility of power Doppler ultrasonography (PDUS) in the detection of prostate cancer and determine its predictive ability compared to digital rectal examination, serum PSA levels and gray-scale transrectal ultrasonography, using biopsy as the reference standard.

MATERIALS AND METHODS: This is a prospective cross-sectional study of 100 consecutive patients, who underwent prostate needle biopsies at the National Kidney and Transplant Institute. All patients were seen at the Out-patient Department, suspected of having prostate cancer because of abnormally high serum PSA levels (>4 ng/ml) and/or abnormal digital rectal examination. Patients previously diagnosed with prostate cancer were excluded in the study. All patients underwent gry-scale TRUS before power Doppler imaging of the prostate using the Siemens Sonoline Elegra high resolution digital ultrasound with a 6.5 MHz endocavitary probe. After power Doppler imaging, a systematic 12-core and lesion-directed TRUS-guided biopsy of the prostate was performed.

RESULTS: A total of 100 patients (mean age 65, SD 7, range 41-83) were included in this study. Prostate needle biopsy confirmed 37 prostate cancer cases. Of the 37 patients diagnosed with prostate cancer, 18 had an abnormal DRE, 26 had abnormal TRUS findings, and 14 had positive power Doppler flow. PDUS has a positive predictive value of 66.7% and a specificity of 88.9%. Logistic regression analysis with the odds ratio computed at 95% C.I. showed that the probability of having prostate cancer when DRE is positive, PSA is elevated, hypoechoic lesion is present on Gray-scale TRUS and hypervascularity of the peripheral zone is present on PDUS are significantly higher than if all of these tests were negative with PDUS in combination with DRE showing the highest predictive ability for prostate cancer.

CONCLUSION: Power Doppler imaging increases the specificity and positive predictive value of Gray-scale transrectal ultrasound in prostate cancer detection. The addition of PDUS to the screening tool of digital rectal exam increases the probability of the patient having cancer when both tests are positive, thus increasing its predictive power.

AIM

This study aims to evaluate the clinical utility of Power Doppler Ultrasonography (PDUS) in the detection of prostate cancer and determine its predictive ability compared to digital rectal examination, serum PSA levels and gray-scale transrectal ultrasonography, using biopsy as the reference standard.

This is a prospective cross-sectional study of 49 consecutive patients, who underwent prostate needle biopsies at the National Kidney and Transplant Institute. All patients were seen at the out-patient department and suspected of having prostate cancer because of abnormally high serum PSA levels (>4 ng/ml) and/or abnormal digital rectal examination. Patients previously diagnosed with prostate cancer were excluded in the study. All patients underwent gray-scale TRUS before power Doppler imaging of the prostate using the Siemens Sonoline Elegra high resolution digital ultrasound with a 6.5 MHz endocavitary probe. After power Doppler imaging, a systematic 1 2-core and lesion-directed TRUS-guided biopsy of the prostate was performed.

A total of 49 patients (mean age 64.45, SD 7.53, range 41-79) were included in this study. Prostate needle biopsy confirmed 15 (30.6%) to have prostate cancer. Of the 15 patients diagnosed with prostate cancer, 5 (33.3%) had an abnormal DRE, 10 (66.7%) had abnormal TRUS findings, 3 (20%) had positive power Doppler flow. PDU had a positive predictive value of 60% and a specificity of 94.1 %. Multivariate logistic regression analysis with the odds ratio computed at 95% C.l. showed that the addition of PDUS to the standard procedure for prostate cancer detection using DRE, serum PSA, and TRUS resulted in a higher sensitivity and better overall predictive performance.

The overall prostate cancer detection rate was 30.6% with a sensitivity of 66.7% for gray-scale TRUS and 20% for power Doppler ultrasonography. PDUS increased the predictive value and specificity of Gray-scale TRUS. The addition of PDUS to the standard procedure for prostate cancer detection using DRE, serum PSA, and TRUS resulted in a higher sensitivity and better overall predictive performance.