• Asian Pacific Journal of Cancer Prevention
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• v.13 no.9
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• pp.4661-4664
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• 2012

Mammographic breast density is a known risk factor for breast cancer. To conduct a survey to estimate the distribution of mammographic breast density in Korean women, appropriate sampling strategies for representative and efficient sampling design were evaluated through simulation. Using the target population from the National Cancer Screening Programme (NCSP) for breast cancer in 2009, we verified the distribution estimate by repeating the simulation 1,000 times using stratified random sampling to investigate the distribution of breast density of 1,340,362 women. According to the simulation results, using a sampling design stratifying the nation into three groups (metropolitan, urban, and rural), with a total sample size of 4,000, we estimated the distribution of breast density in Korean women at a level of 0.01% tolerance. Based on the results of our study, a nationwide survey for estimating the distribution of mammographic breast density among Korean women can be conducted efficiently.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.5
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• pp.1829-1831
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• 2012

Background: The generalized gamma distribution statistics constitute an extensive family that contains nearly all of the most commonly used distributions including the exponential, Weibull and log normal. A saturated version of the model allows covariates having effects through all the parameters of survival time distribution. Accelerated failure-time models assume that only one parameter of the distribution depends on the covariates. Methods: We fitted both the conventional GG model and the saturated form for each of its members including the Weibull and lognormal distribution; and compared them using likelihood ratios. To compare the selected parameter distribution with log logistic distribution which is a famous distribution in survival analysis that is not included in generalized gamma family, we used the Akaike information criterion (AIC; r=l(b)-2p). All models were fitted using data for 369 women age 50 years or more, diagnosed with stage IV breast cancer in BC during 1990-1999 and followed to 2010. Results: In both conventional and saturated parametric models, the lognormal was the best candidate among the GG family members; also, the lognormal fitted better than log-logistic distribution. By the conventional GG model, the variables "surgery", "radiotherapy", "hormone therapy", "erposneg" and interaction between "hormone therapy" and "erposneg" are significant. In the AFT model, we estimated the relative time for these variables. By the saturated GG model, similar significant variables are selected. Estimating the relative times in different percentiles of extended model illustrate the pattern in which the relative survival time change during the time. Conclusions: The advantage of using the generalized gamma distribution is that it facilitates estimating a model with improved fit over the standard Weibull or lognormal distributions. Alternatively, the generalized F family of distributions might be considered, of which the generalized gamma distribution is a member and also includes the commonly used log-logistic distribution.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.13
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• pp.5299-5303
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• 2014

Background: To explore etiology for providing scientific clues for the prevention of lung cancer. Materials and Methods: Data for lung cancer incidence and meteorological geographic factors from 25 counties in Zhejiang province of China during 2011 were studied. Stepwise multiple regression and correlation analysis were performed to analyze the geographic distribution and epidemiology of lung cancer. Results: 8,291 new cases (5,998 in males and 2,293 females) of lung cancer during 2011 in Zhejiang province were reported in the 25 studied counties. Reported and standardized incidence rates for lung cancer were 58.0 and 47.0 per 100,000 population, respectively. The incidence of lung cancer increased with age. Geographic distribution analysis shows that the standardized incidence rates of lung cancer in northeastern Zhejiang province were higher than in the southwestern part, such as in Nanhu, Fuyang, Wuxing and Yuyao counties, where the rates were more than 50 per 100,000 population. In the southwestern Zhejiang province, for instance, in Yueqing, Xianju and Jiande counties, the standardized incidence rates of lung cancer were lower than 37 per 100,000 population. Spearman correlation tests showed that forest coverage rate, air quality index (AQI), and annual precipitation level are associated with the incidence of lung cancer. Conclusions: Lung cancer in Zhejiang province shows obvious regional differences. High incidence appears associated with low forest coverage rate, poor air quality and low annual precipitation. Therefore, increasing the forest coverage rate and controlling air pollution may play an important role in lung cancer prevention.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.13
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• pp.5153-5158
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• 2015

Infection with high-risk human papillomavirus (HR-HPV) is an essential cause of cervical cancer. Because of substantial geographical variation in the HPV genotype distribution, data regarding HPV type-specific prevalence for a particular country are mandatory for providing baseline information to estimate effectiveness of currently implemented HPV-based cervical cancer prevention. Accordingly, this review was conducted to evaluate the HR-HPV genotype distribution among Thai women with precancerous cervical lesions i.e. cervical intraepithelial neoplasia grade 2-3 (CIN 2-3), adenocarcinoma in situ (AIS), and invasive cervical cancer by reviewing the available literature. The prevalence of HR-HPV infection among Thai women with CIN 2-3 ranged from 64.8% to 90.1% and the three most common genotypes were HPV 16 (38.5%), HPV 58 (20.0%), and HPV 18 (5.5%). There were high squamous cell carcinoma/CIN 2-3 prevalence ratios in women with CIN 2-3 infected with HPV 33 and HPV 58 (1.40 and 1.38, respectively), emphasizing the importance of these subtypes in the risk of progression to invasive cancer among Thai women. Data regarding the prevalence and genotype distribution of HR-HPV in Thai women with AIS remain unavailable. Interesting findings about the distribution of HPV genotype in cervical cancer among Thai women include: (1) a relatively high prevalence of HPV 52 and HPV 58 in invasive squamous cell carcinoma; (2) the prevalence of HPV 18-related adenocarcinoma is almost double thepreviously reported prevalence, and (3) 75% of neuroendocrine carcinomas are HPV18-positive when taking into account both single and multiple infections.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.16
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• pp.6889-6894
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• 2015

Gastric cancer (GC) is the fifth most common cancer in the world, with a wide variation in incidence rates across different geographical areas. In Iran GC is the most common cancer in males and it is reported to be the third most prevalent after breast and colorectal in females. A geographical information system (GIS) allows investigation of the geographical distribution of diseases. The purpose of the present study was to explore the relationship between gastric cancer and effective climatic factors using GIS. The dispersion distribution and the relationship between environmental factors effective on cancer were measured using Arc GIS. Of all cases, 672 (73.8%) were in males with a sex ratio of 3 to1. The highest incidence by cities was seen in Namin with 137.5 per 100,000. The results of this study showed that the distribution of GC around the Sabalan volcanic mountain was significantly higher than other places in the same province. These results can be considered as a window to future comprehensive research on gastric cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.5
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• pp.1959-1964
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• 2015

Purpose: To investigate the distribution of liver cancer mortality as well as its developing trend from 1991 to 2012, forecast the future five-year trend, and provide a basis for the comprehensive prevention and management. Materials and Methods: Mortality data for liver cancer in China from 1991 to 2012 were used to describe characteristics and distribution of liver cancer mortality. Trend surface analysis was used to study the geographical distribution of liver cancer mortality. Curve estimation, time series modeling, gray modeling (GM) and joinpoint regression were used to predict and forecast future trends. Results: The mortality rate of liver cancer has constantly increased in China since 1991. Rates in rural areas are higher than in urban areas, and in males are higher than in females. In addition, our data predicted that the trend will continue to increase in the next 5 years. The age-specific mortality of liver cancer increases with age and peaks in the group of 80-84 years old. Geographical analysis showed the liver mortality rate was higher in the southeast provinces, such as Jiangsu, Zhejiang and Guangdong, and southwest regions like Guangxi Province. Conclusions: The standardized mortality rate of liver cancer in China has consistently increased from 1991 to 2012, and the upward trend is predicted to continue in the future. Much better prevention and management of liver cancer is needed in high mortality areas (the southwestern and southeastern parts of China) and high mortality age groups (80- to 84-year-olds), especially in rural areas.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7737-7742
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• 2015

Background: Cancer is one of the common causes of disability and mortality in the world. The present study aimed to define the spatiotemporal distribution of gastrointestinal tract cancers using a geographic information system (GIS) over the time period of 2007-2012 in Kermanshah-Iran. Materials and Methods: The method of studying was descriptive-analytical as well as comparative with gastrointestinal tract cancer patients based in the City of Kermanshah over the time period covered. For data analysis, the GIS and SPSS 16.0 were applied. Results: According to the pathological reports within the space of 5 years, 283 cases of gastrointestinal tract cancer (157 in males, 156 in females) were reported. The performed tests in terms of spatial distribution in the environment of GIS indicated that the disease demonstrated a clustered pattern in the City of Kermanshah. More to the point, some loci of this disease have emerged in the City of Kermanshah that in the first level, 6 neighborhoods with 29-59 cases of this disease per square kilometer and in the second level, 15-29 cases. Conclusions: Gastrointestinal tract cancer demonstrated an ascending trend within the space of 5 years of research and the spatiotemporal distribution of cancer featured a concentrated and clustered pattern in the City of Kermanshah.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.3
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• pp.1197-1199
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• 2016

Background: This study aimed to facilitate decision-making in cases of breast cancer radiotherapy shifts by simulating millimetric shifts and analyzing their effects on dose distribution. Methods: The study included 30 patients with left side breast cancer who were treated with three dimensional conformal radiotherapy (3D-CRT) in the Radiation Oncology Department in Hatay Public Hospital, between January 2013 and April 2015. A treatment plan shifting at three axes with six different measures was simulated. Results: The biggest difference in values was (+3mm shift) 476cGy, with a 7.7 % change for heart and 25.6% for spinal cord. The shifts in values respectively for CTV min, mean, max were -4.8%, 2.5%, 4%. The differences for lymphatic min, mean, max were 21.3%, 20.3%, -12.2%. Conclusion: The most important thing is not the treatment plan quality, but its practicality. The treatment plan must be practical and its practice must be controlled rigidly.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2355-2359
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• 2013

Vulva cancer is rare among all gynecological cancer worldwide, including Thailand, and mainly affects older women. Persistent high risk type infection of human papillomavirus (HPV) is the one important factor for developing cancer. In this study, we focused on HPV DNA investigation and type-specific distribution of HPV in 25 formalin-fixed paraffin-embedded (FFPE) samples collected from Thai women with vulva cancer histologically confirmed by the National Cancer Institute, Thailand, during 2003-2011. HPV DNA detection and genotyping were undertaken with polymerase-chain reaction and enzyme-immunoassay using GP5+/bio6+ consensus specific primers and digoxigenin-labeled specific oligoprobes, respectively. Human ${\beta}$-globin genes was used as the internal control. Our results showed that 44% (11/25) of all vulva cancer samples were HPV-positive. All of them are high risk HPV type infection, detected as single (63.64%, 7/11) and/or double infections (4/11, 36.36%). HPV 16 was the most common type identified in vulva cancer, followed by HPV 35, 33, 18 and 58. In conclusion, this study presented that HPV-16 is observed at the highest frequency in this cancer, similar to cervical cancer, with HPV 18 being less frequent. Although the sample size was small and could not represent overall incidence and prevalence in Thai women, these preliminary data for vulva cancer are of interest since they reinforce the necessity for HPV screening or vaccination in Thailand.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.3
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• pp.2071-2077
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• 2013

Esophageal cancer is a mjaor health problems in many parts of the world. A geographical information system (GIS) allows investigation of the geographical distribution of diseases. The purpose of the present study was to explore the relationship between esophageal cancer and effective climatic factors using GIS. The dispersion distribution and the relationship between environmental factors effective on cancer were measured using Arc GIS. The highest degree of spread was in Germi town and the least was in Ardabil city. There was a significant relationship between effective environmental factors and esophageal cancer in Ardabil province. The results indicated that environmental factors probably are influential in determining the incidence of esophageal cancer. Also, these results can be considered as a window to future comprehensive research on esophageal cancer and related risk factors.