• Title/Summary/Keyword: Bias control

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Breast Cancer Trend in Iran from 2000 to 2009 and Prediction till 2020 using a Trend Analysis Method

  • Zahmatkesh, Bibihajar;Keramat, Afsaneh;Alavi, Nasrinossadat;Khosravi, Ahmad;Kousha, Ahmad;Motlagh, Ali Ghanbari;Darman, Mahboobeh;Partovipour, Elham;Chaman, Reza
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.3
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    • pp.1493-1498
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    • 2016
  • Background: Breast cancer is the most common cancer in women worldwide with a rising incidence rate in most countries. Considering the increase in life expectancy and change in lifestyle of Iranian women, this study investigated the age-adjusted trend of breast cancer incidence during 2000-2009 and predicted its incidence to 2020. Materials and Methods: The 1997 and 2006 census results were used for the projection of female population by age through the cohort-component method over the studied years. Data from the Iranian cancer registration system were used to calculate the annual incidence rate of breast cancer. The age-adjusted incidence rate was then calculated using the WHO standard population distribution. The five-year-age-specific incidence rates were also obtained for each year and future incidence was determined using the trend analysis method. Annual percentage change (APC) was calculated through the joinpoint regression method. Results: The bias adjusted incidence rate of breast cancer increased from 16.7 per 100,000 women in 2000 to 33.6 per 100,000 women in 2009. The incidence of breast cancer had a growing trend in almost all age groups above 30 years over the studied years. In this period, the age groups of 45-65 years had the highest incidence. Investigation into the joinpoint curve showed that the curve had a steep slope with an APC of 23.4% before the first joinpoint, but became milder after this. From 2005 to 2009, the APC was calculated as 2.7%, through which the incidence of breast cancer in 2020 was predicted as 63.0 per 100,000 women. Conclusions: The age-adjusted incidence rate of breast cancer continues to increas in Iranian women. It is predicted that this trend will continue until 2020. Therefore, it seems necessary to prioritize the prevention, control and care for breast cancer in Iran.

Postmenopausal Hormone Therapy is Associated with in Situ Breast Cancer Risk

  • Ni, Xiao-Jian;Xia, Tian-Song;Zhao, Ying-Chun;Ma, Jing-Jing;Zhao, Jie;Liu, Xiao-An;Ding, Qiang;Zha, Xiao-Ming;Wang, Shui
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.8
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    • pp.3917-3925
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    • 2012
  • Background: The relationship between postmenopausal hormone therapy (HT) and invasive breast cancer has been extensively investigated, but that with breast carcinoma in situ (BCIS) has received relatively little attention. The aim of our present study was to review and summarize the evidence provided by longitudinal studies on the association between postmenopausal HT use and BCIS risk. Methods: A comprehensive literature search for articles published up to May 2012 was performed. Prior to performing a meta-analysis, the studies were evaluated for publication bias and heterogeneity. Relative risk (RR) or odds ratio (OR) values were calculated using 14 reports (8 case-control studies and 6 cohort studies), published between 1986 and 2012. Results: There was evidence of an association between ever postmenopausal estrogen use and BCIS based on a random-effects model (RR = 1.25, 95% confidence interval (CI) = 1.01, 1.55). However, we found no strong evidence of an association between ever postmenopausal estrogen combined with progesterone use and BCIS using a randomeffects model (RR = 1.55, 95% CI = 0.95, 2.51). Furthermore, our analysis showed a strong association between "> 5 years duration" of estrogen or estrogen combined with progesterone use and BCIS. Furthermore, current use of any HT is associated with increased risk of BCIS in cohort studies. Additional well-designed large studies are now required to validate this association in different populations.

Association between Pax8-PPARγ1 Rearrangement and Follicular Thyroid Cancer: a Meta-Analysis

  • Li, Hang-Yu;Xie, Zhi-Hao;Xu, Cong-Hui;Pu, Mei-Ling;Chen, Zi-Yan;Yu, Miao;Wang, Heng-Shu;Zhou, Chen-Ming;Pu, Chao-Yu;Liu, Wei
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.9
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    • pp.4247-4250
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    • 2016
  • Background: Pax8 and peroxisome proliferator-activated receptor gamma 1 gene (Pax8-$PPAR{\gamma}1$) are important factors in tumors. Several studies have suggested that follicular thyroid cancer may arise from Pax8- $PPAR{\gamma}1$ rearrangement. In order to have a better understanding of the association between Pax8-$PPAR{\gamma}1$ rearrangement and follicular thyroid cancer, we conducted the presenmt meta-analysis. Materials and Methods: The information was extracted from PubMed, EMBASE and Web of Science. Statistic analysis was performed with Stata12.0 software. Odds ratios (ORs) were calculated using a fixed-effects model. We also performed heterogeneity and publication bias analyses. Results: Nine studies including 198 follicular thyroid cancer patients and 268 controls were considered eligible. The frequency of Pax8-$PPAR{\gamma}1$ rearrangement was significantly higher in the follicular thyroid cancer group than in the control group, with a pooled OR of 6.63 (95%CI=3.50-12.7). In addition, through subgroup analysis, the OR between Pax8-$PPAR{\gamma}1$ rearrangement and follicular thyroid cancer was 6.04 (95%CI = 3.18-11.5) when using benign tumor tissues as controls. The OR for the method subgroup was 9.99 (95% CI =4.86-20.5) in the RT-PCR. Conclusions: The final results demonstrated that Pax8-$PPAR{\gamma}1$ rearrangement has significant association with follicular thyroid cancer.

Methodologic Lessons Learned from Multicenter, Randomized, Controlled Clinical Trial of Acupuncture for Hot Flashes in Peri- and Postmenopausal Women (갱년 및 폐경 후 여성의 안면홍조에 대한 침 치료 다기관 임상연구 : 수행보고 및 방법론적 교훈)

  • Kim, Kun-Hyung;Kim, Dong-Il;Hwang, Deok-Sang;Lee, Jin-Moo;Kim, Hyung-Jun;Yoon, Hyun-Min;Jung, Hee-Jung;Kang, Kyung-Won;Lee, Myeong-Soo;Choi, Sun-Mi
    • The Journal of Korean Obstetrics and Gynecology
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    • v.23 no.1
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    • pp.42-52
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    • 2010
  • Purpose: This report aims to administer methodologic issues around recently conducted multicenter study for evaluating the effects of acupuncture on menopusal hot flashes and discuss practical issues for further implementation of acupuncture clinical trial for hot flashes. Methods: Study process were mentioned, and issues related to avoiding risk of bias, designing appropriate control group, optimal outcome measurement, potential different effects of menopausal status on study outcomes, and suggestions for developing future clinical trials are discussed. Results: Shortcomings of our multicenter study include lack of allocation concealment and assessor blinding, subjective outcome measurement, short-term follow-up, and fixed acupuncture regimen despite pragmatic purpose of this study. Improving trial design, using objective or validated outcomes, assessing long-term effects of acupuncture, and individualizing acupuncture regimen are needed in future clinical trials. Conclusion: We expect these practical discussions to enable researchers to plan and develop future well-designed clinical trials for evaluating the effects of acupuncture on hot flashes or other women's health issues.

Design and Fabrication of APD-FET Module for 2.5 Gbps Optical Communicating System (광통신용 APD-FET 광수신모듈 설계 및 제작)

  • 강승구;송민규;윤형진;박경현;박찬용;박형무;윤태열;이창희;심창섭
    • Korean Journal of Optics and Photonics
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    • v.5 no.1
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    • pp.166-172
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    • 1994
  • The fiber optic receiver, ETRI APD-FET 1.0, is developed for the application of optical communication. This fiber optic receiver includes PD sub-module and pre-amplifier case. A single lens system is introduced for the PD sub-module. The sub-module consists of the avalenche photodiode(APD), GRIN rod lens, and a single mode fiber. The above components are enclosed into the stainless steel 304L housings. By bevelling the fiber end, the single mode fiber provides less than ~ 28 dB of optical return loss. The area of image focus is controlled by adjusting the length of spacer located in-between the fiber and the GRIN rod lens. The laser welding technique is applied to achieve the maximum coupling efficiency for the joining of each housing. In the pre-amplifier case, GaAs FET pre-amplifier workes for photocurrent amplification and the thermister is mounted to control the APD bias. The performance of ETRI APD-FET1.0 shows the sensitivity of - 30.3 dBm at $10^{-10}$ BER(bit error rate) and 2.5 Gbps optical random signal of $2^{23}-1$ word length. The fiber optic receiver is one of the essensial parts of the transmission module for B-ISDN. Also, the above optical packaging technology will be adapted for the developement of 10 Gbps transmission application 2.5 Gbps 5 Gbps

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No Association of the TGF-β1 29T/C Polymorphism with Breast Cancer Risk in Caucasian and Asian Populations: Evidence from a Meta-Analysis Involving 55, 841 Subjects

  • Alqumber, Mohammed A.A.;Dar, Sajad Ahmad;Haque, Shafiul;Wahid, Mohd;Singh, Rohit;Akhter, Naseem
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.20
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    • pp.8725-8734
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    • 2014
  • The transforming growth factor-${\beta}1$ (TGF-${\beta}1$) gene 29 T/C polymorphism is thought to be associated with breast cancer risk. However, reports are largely conflicting and underpowered. We therefore conducted a meta-analysis of all available case-control studies relating the TGF-${\beta}1$ 29T/C polymorphism to the risk of developing breast cancer by including a total of 31 articles involving 24,021 cases and 31,820 controls. Pooled ORs were generated for the allele contrasts, with additive genetic, dominant genetic and recessive genetic models. Subgroup analysis was also performed by ethnicity for the TGF-${\beta}1$ 29T/C polymorphism. No association was found in the overall analysis (C vs T: OR=1.028, 95% CI=0.949-1.114, p-value 0.500; CC vs TC: OR= 1.022, 95% CI=0.963-1.085, p-value 0.478; CC vs TT: OR= 1.054, 95% CI=0.898-1.236, p-value 0.522; CC vs TT+ TC: OR= 1.031, 95% CI=0.946-1.124, p-value 0.482; TT vs CC+TC: OR= 0.945, 95% CI=0.827-1.080, p-value 0.403). Similarly, in the subgroup analysis by ethnicity, no association was found in Caucasian (C vs T: OR= 1.041, 95% CI=0.932-1.162, p-value 0.475; CC vs TC: OR= 1.031, 95% CI=0.951-1.118, p-value 0.464; CC vs TT: OR= 1.081, 95% CI=0.865-1.351, p-value 0.493; CC vs TT+TC: OR= 1.047, 95% CI=0.929-1.180, p-value 0.453; TT vs CC+TC: OR= 0.929, 95% CI=0.775-1.114, p-value 0.429;) and Asian populations (C vs T: OR= 1.004, 95% CI=0.908-1.111, p-value 0.931; CC vs TC: OR= 0.991, 95% CI=0.896-1.097, p-value 0.865; CC vs TT: OR= 1.015, 95% CI=0.848-1.214, p-value 0.871; CC vs TT+TC: OR= 1.000, 95% CI=0.909-1.101, p-value 0.994; TT vs CC+TC: OR= 0.967, 95% CI=0.808-1.159, p-value 0.720;). No evidence of publication bias was detected during the analysis. No significant association with breast cancer risk was demonstrated overall or on subgroup (Caucasian and Asian) analysis. It can be concluded that TGF-${\beta}1$ 29T/C polymorphism does not play a role in breast cancer susceptibility in overall or ethnicity-specific manner.

Lack of Any Association of GST Genetic Polymorphisms with Susceptibility to Ovarian Cancer - a Meta-analysis

  • Han, Li-Yuan;Liu, Kui;Lin, Xia-Lu;Zou, Bao-Bo;Zhao, Jin-Shun
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.15
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    • pp.6131-6136
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    • 2014
  • Objective: Epidemiology studies have reported conflicting results between glutathione S-transferase Mu-1 (GSTM1), glutathione S-transferase theta-1 (GSTT1) and glutathione S-transferase pi-1 (GSTP1) and ovarian cancer (OC) susceptibility. In this study, an updated meta-analysis was applied to determine whether the deletion of GSTM1, GSTT1 and GSTP1 has an influence on OC susceptibility. Methods: A published literature search was performed through PubMed, Embase, Cochrane Library, and Science Citation Index Expanded database for articles published in English. Pooled odds ratios (ORs) and 95% confidence intervals (95%CIs) were calculated using random or fixed effects models. Heterogeneity between studies was assessed using the Cochrane Q test and $I^2$ statistics. Sub-group analysis was conducted to explore the sources of heterogeneity. Sensitivity analysis was employed to evaluate the respective influence of each study on the overall estimate. Results: In total, 10 published studies were included in the final analysis. The combined analysis revealed that there was no significant association between GSTM1 null genotype and OC risk (OR=1.01, 95%CI: 0.91-1.12). Additionally, there was no significant association between GSTT1 genetic polymorphisms and OC risk (OR=0.98, 95% CI: 0.85-1.13). Similalry, no significant associations were found concerning the GSTP1 rs1695 locus and OC risk. Meanwhile, subgroup analysis did not show a significant increase in eligible studies with low heterogeneity. However, sensitivity analysis, publication bias and cumulative analysis demonstrated the reliability and stability of the current meta-analysis. Conclusions: These findings suggest that GSTs genetic polymorphisms may not contribute to OC susceptibility. Large epidemiological studies with the combination of GSTM1 null, GSTT1 null and GSTP1 Ile105Val polymorphisms and more specific histological subtypes of OC are needed to prove our findings.

The XRCC1 Arg399Gln Genetic Polymorphism Contributes to Hepatocellular Carcinoma Susceptibility: An Updated Meta-analysis

  • Pan, Yan;Zhao, Lei;Chen, Xing-Miao;Gu, Yong;Shen, Jian-Gang;Liu, Lu-Ming
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.10
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    • pp.5761-5767
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    • 2013
  • The potential correlation of X-ray repair cross-complementing group 1 (XRCC1) Arg399Gln polymorphism with hepatocellular carcinoma (HCC) susceptibility is ambiguous. Taking account of inconsistent results of previous meta-analyses and new emerging literatures, we conducted a meta-analysis covering 15 case-control datasets to evaluate the relationship. Relevant studies from Medline, Embase and CNKI were retrieved. A fixed-effect model or a random-effect model, depending on between-study heterogeneity, were applied to estimate the association between XRCC1 polymorphism Arg399Gln and HCC risk with the results presented as odds ratios (ORs) and 95% confidence intervals (95% CIs). In accordance with Hardy-Weinberg equilibrium, 15 studies with data for 6,556 individuals were enrolled in this systematic review. For overall HCC,thr XRCC1 polymorphism Arg399Gln was significantly associated with HCC susceptibility in a homozygote model as well as in a dominant model (G/G vs. A/A, OR=1.253, p=0.028; G/G+A/G vs. A/A, OR= 1.281, p=0.047, respectively), but not in a heterozygote model (A/G vs. A/A, OR=1.271, p=0.066) or a recessive model (G/G vs. A/G + A/A, OR= 1.049, p=0.542). Similar results were also observed on stratification analysis by ethnicity (A/G vs. A/A, OR=1.357, p=0.025; G/G vs. A/A, OR=1.310, p=0.011; G/G+A/G vs. A/A, OR= 1.371, p=0.013). However, no potential contribution of XRCC1 Arg399Gln polymorphism to HCC susceptibility in HBV/HCV subgroups was identified. No publication bias was found in this study. In conclusion, the XRCC1 Arg399Gln polymorphism contributes to HCC susceptibility. Due to the lack of studies in Western countries, further large-sample and rigorous studies are needed to validate the findings.

Matrix Metalloproteinase-2 -1306 C>T Gene Polymorphism is Associated with Reduced Risk of Cancer: a Meta-analysis

  • Haque, Shafiul;Akhter, Naseem;Lohani, Mohtashim;Ali, Arif;Mandal, Raju K.
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.3
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    • pp.889-896
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    • 2015
  • Matrix metalloproteinase-2 (MMP2) is an endopeptidase, mainly responsible for degradation of extracellular matrix components, which plays an important role in cancer disease. A single nucleotide polymorphism (SNP) at -1306 disrupts a Sp1-type promoter site. The results from the published studies on the association between MMP2 -1306 C>T polymorphism and cancer risk are contradictory and inconclusive. In the present study, a meta-analysis was therefore performed to evaluate the strength of any association between the MMP2 -1306 C>T polymorphism and risk of cancer. We searched all eligible studies published on association between MMP2 -1306 C>T polymorphism and cancer risk in PubMed (Medline), EMBASE and Google Scholar online web databases until December 2013. Genotype distribution data were collected to calculate the pooled odds ratios (ORs) and 95% confidence intervals (95%CIs) to examine the strength of the association. A total of 8,590 cancer cases and 9,601 controls were included from twenty nine eligible case control studies. Overall pooled analysis suggested significantly reduced risk associated with heterozygous genotype (CT vs CC: OR=0.758, 95%CI=0.637 to 0.902, p=0.002) and dominant model (TT+CT vs CC: OR=0.816, 95%CI=0.678 to 0.982, p=0.032) genetic models. However, allelic (T vs C: OR=0.882, 95%CI=0.738 to 1.055, p=0.169), homozygous (TT vs CC: OR=1.185, 95%CI=0.825 to 1.700, p=0.358) and recessive (TT vs CC+CT: OR=1.268, 95%CI=0.897 to 1.793, p=0.179) models did not show any risk. No evidence of publication bias was detected during the analysis. The results of present meta-analysis suggest that the MMP2 -1306 C>T polymorphism is significantly associated with reduced risk of cancer. However, further studies with consideration of different populations will be required to evaluate this relationship in more detail.

Random Balance between Monte Carlo and Temporal Difference in off-policy Reinforcement Learning for Less Sample-Complexity (오프 폴리시 강화학습에서 몬테 칼로와 시간차 학습의 균형을 사용한 적은 샘플 복잡도)

  • Kim, Chayoung;Park, Seohee;Lee, Woosik
    • Journal of Internet Computing and Services
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    • v.21 no.5
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    • pp.1-7
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    • 2020
  • Deep neural networks(DNN), which are used as approximation functions in reinforcement learning (RN), theoretically can be attributed to realistic results. In empirical benchmark works, time difference learning (TD) shows better results than Monte-Carlo learning (MC). However, among some previous works show that MC is better than TD when the reward is very rare or delayed. Also, another recent research shows when the information observed by the agent from the environment is partial on complex control works, it indicates that the MC prediction is superior to the TD-based methods. Most of these environments can be regarded as 5-step Q-learning or 20-step Q-learning, where the experiment continues without long roll-outs for alleviating reduce performance degradation. In other words, for networks with a noise, a representative network that is regardless of the controlled roll-outs, it is better to learn MC, which is robust to noisy rewards than TD, or almost identical to MC. These studies provide a break with that TD is better than MC. These recent research results show that the way combining MC and TD is better than the theoretical one. Therefore, in this study, based on the results shown in previous studies, we attempt to exploit a random balance with a mixture of TD and MC in RL without any complicated formulas by rewards used in those studies do. Compared to the DQN using the MC and TD random mixture and the well-known DQN using only the TD-based learning, we demonstrate that a well-performed TD learning are also granted special favor of the mixture of TD and MC through an experiments in OpenAI Gym.