Krittika Suwanrungruang

Cancer survival in Africa, Asia, and Central America: a population-based study

BACKGROUND Population-based cancer survival data, a key indicator for monitoring progress against cancer, are not widely available from countries in Africa, Asia, and Central America. The aim of this study is to describe and discuss cancer survival in these regions. METHODS Survival analysis was done for 341 658 patients diagnosed with various cancers from 1990 to 2001 and followed up to 2003, from 25 population-based cancer registries in 12 countries in sub-Saharan Africa (The Gambia, Uganda), Central America (Costa Rica), and Asia (China, India, Pakistan, Philippines, Saudi Arabia, Singapore, South Korea, Thailand, Turkey). 5-year age-standardised relative survival (ASRS) and observed survival by clinical extent of disease were determined. FINDINGS For cancers in which prognosis depends on stage at diagnosis, survival was highest in China, South Korea, Singapore, and Turkey and lowest in Uganda and The Gambia. 5-year ASRS ranged from 76-82% for breast cancer, 63-79% for cervical cancer, 71-78% for bladder cancer, and 44-60% for large-bowel cancers in China, Singapore, South Korea, and Turkey. Survival did not exceed 22% for any cancer site in The Gambia; in Uganda, survival did not exceed 13% for any cancer site except breast (46%). Variations in survival correlated with early detection initiatives and level of development of health services. INTERPRETATION The wide variation in cancer survival between regions emphasises the need for urgent investments in improving awareness, population-based cancer registration, early detection programmes, health-services infrastructure, and human resources. FUNDING Association for International Cancer Research (AICR; St Andrews, UK), Association pour la Recherche sur le Cancer (ARC, Villejuif, France), and the Bill & Melinda Gates Foundation (Seattle, USA).

Prevalence of Opisthorchis viverrini infection and incidence of cholangiocarcinoma in Khon Kaen, Northeast Thailand

Liver cancer is the most common cancer in Khon Kaen, Northeast Thailand, because of the high incidence of cholangiocarcinoma (CHCA). Opisthorchis viverrini (OV), a liver fluke, is endemic in the area, and has been evaluated as a cause of CHCA by International Agency for Research on Cancer. Residents of 20 districts in the province were invited to attend a mobile screening programme between 1990 and 2001. Of 24 723 participants, 18 393 aged 35–69 years were tested for OV infection, by examining stools for the presence of eggs. Prevalence of infection in each district was estimated from the sample of the population who had been tested. The incidence of liver cancer in 1990–2001 was obtained for each district from the cancer registry. The average crude prevalence of OV infection in the sample subjects was 24.5%, ranging from 2.1% to 70.8% in different districts. Truncated age‐standardized incidence of CHCA at ages >35 years varied threefold between districts, from 93.8 to 317.6 per 100 000 person‐years. After adjustment for age group, sex and period of sampling, there was a positive association between prevalence of OV infection and incidence of CHCA at the population level. Associations between CHCA and active OV infection in individuals have become hard to demonstrate, because of effective anti‐OV treatment. The relationship may, however, be clear in comparisons between populations, which, for infectious diseases, take into account the contextual effects of group exposure in determining individual outcome. The cancer registry is an appropriate tool for disease monitoring in small areas.

Survival of Cholangiocarcinoma Patients in Northeastern Thailand after Supportive Treatment

BACKGROUND Cholangiocarcinoma (CCA) is a very common cancer in Northeastern Thailand. Most CCA patients see a physician at a late stage when curative surgery is not possible. After diagnosis, they generally are treated by partial surgery/percutaneous drainage, chemotherapy and supportive treatment. OBJECTIVE This study aimed to assess the survival rates of CCA patients after supportive treatment. METHODS A retrospective cohort design was applied in this study. Data for 746 CCA patients were extracted from the hospital-based cancer registry of Srinagarind Hospital, Khon Kaen University. The patients were diagnosed (at least by ultrasonography) between 1 January, 2009 and 31 December, 2009 and then followed up for current status until 30 June, 2011. The cumulative survival rate was calculated by the Kaplan-Meier method, and independent prognostic factors were investigated using Cox regression. RESULTS The total follow-up time was 5,878 person-months, and the total number of deaths was 637. The mortality rate was therefore 10.8 per 100 person-year (95%CI : 10.1-11.7). The cumulative 3, 6, 9, 12 and 24 month survival rates were 59%, 39%, 31%, 24% and 14%, respectively. The median survival time after supportive treatment was 4 months. After adjusting for gender, age, stage, distant metastasis, histological grading and treatment, stage was a significant predictor of survival of CCA patients. Those in stage III and stage IV had a 6.78 fold higher mortality than the stage I and stage II cases (95% CI : 1.6-28.7). CONCLUSION It is very important to encourage patients to see health personnel at an early stage.

Reproductive Risk Factors for Thyroid Cancer: A Prospective Cohort Study in Khon Kaen, Thailand

BACKGROUND Because of the gender disparity in the incidence of thyroid cancer, this study aimed to determine the association between reproductive factors and thyroid cancer. METHODS A total of 10,767 eligible women from the Khon Kaen Cohort, recruited and interviewed between 1990 and 2001, were followed up until 2011. The data were linked to the Khon Kaen Population-Based Cancer Registry to detect thyroid cancer cases. RESULTS There was 17 thyroid cancer cases detected, an incidence of 11.2 per 100,000 person-years, of which 70.6 % were papillary tumors. The incidence was apparently greater among those with an early age of menarche, nulligravida women, and oral contraceptive users. CONCLUSIONS There was a trend for thyroid cancer to develop in relation to longer estrogen exposure. This evidence is inconclusive but warrants further investigation.

Trends in Incidence of Hepatocellular Carcinoma, 1990 - 2009, Khon Kaen, Thailand

BACKGROUND Liver cancer is the most frequent cancer among Thais especially people in northeastern Thailand, but there has as yet been no assessment of trend. The data of all cancers in Khon Kaen can be retrieved from data base of the Khon Kaen Cancer Registry (KKCR) which was established in 1984. OBJECTIVE To assess the incidence trend of hepatocellular carcinoma in Khon Kaen, Thailand, between 1990 and 2009. METHODS Population-based cases of liver cancer registered between 1985 and 2009 were retrieved from the KKCR data base and cases with diagnosis of hepatocellular carcinoma (HCC) with the coding C22.0 according to ICD-O were selected. Incidence trends were calculated using the Jointpoint analysis. RESULTS There were 7,859 cases of HCC during the study period. Males were affected two times more frequently than females. The most common age group of cases was 50 and 69 years (60.3%). Most patients were diagnosed based on radiology imaging (40.6%) while the morphology verification was 7%. The age-standardized rates (ASR) were 13.1 to 49.8 per 100,000 among males and 4.8 to 38.4 per 100,000 among females depending on year of diagnosis since 1985. Remarkably, the ASRs were clearly low during first few years of starting the registration. The overall ASRs of HCC were 30.3 per 100,000 in males (95% CI: 25.9 to 34.6) and 13.1 per 100,000 (95% CI: 10.4 to 15.8) in females. During 1990-2009, the trends in incidences have been decreasing significantly with the annual percent change (APC) of 6.2% per year (95% CI: -7.6 to -4.8) in males and by 6.5% per year in females (95% CI: -8.4 to -4.9). CONCLUSIONS The incidence trends have been decreasing in both sexes. The recent decline in incidence may represent a falling risk.

XRCC1 gene polymorphism, diet and risk of colorectal cancer in Thailand.

BACKGROUND Colorectal cancer (CRC) is one of the most common cancers worldwide. This study aimed to investigate the interaction between the presence of a polymorphism of the XRCC1 gene and known risk factors for colorectal cancer in Thailand. MATERIALS AND METHODS A hospital-based case-control study was conducted in Thailand. The participants were 230 histologically confirmed new cases and 230 controls matched by sex and age and recruited from the same hospital. Information about demographic characteristics, life style, and dietary habits was collected using structured interviews, and blood samples were taken which were used for the detection of a homozygous and heterozygous polymorphisms of XRCC1. Associations were assessed using multiple conditional logistic regression. RESULTS In the univariate analysis, factors found to be significantly associated with an increased risk for CRC were the presence of the XRCC1 AA homozygote (OR= 4.95; 95% CI: 1.99-12.3), a first degree family history of cancer (OR= 1.74; 95% CI: 1.18-2.58), and a high frequency of pork consumption (OR= 1.49; 95% CI: 1.00-2.21). Intakes of fish fruit and vegetables appeared to be protective factors, but the associations were not statistically significant. In the multivariate analysis only the XRCC1 AA homozygote polymorphism and a family history of cancer emerged as risk factors (OR= 4.96; 95% CI: 1.90- 12.95 and OR=1.80; 95% CI: 1.18-2.72, respectively). CONCLUSIONS While the XRCC1 AA homozygote and a family history of cancer were found to be associated with an increased risk of CRC, none of the dietary intake variables were clearly identified as risk or protective factors. There is a need for further research to determine the reasons for this.

Childhood Cancer Incidence and Survival 1985-2009, Khon Kaen, Thailand

BACKGROUND The Khon Kaen Cancer Registry (KKCR) was established in 1984. Previous population-based incidences and survivals of childhood cancer in Thailand were determined using a short cancer registration period. MATERIALS AND METHODS Data were retrieved of all children residing in Khon Kaen, between 0-15 years, diagnosed as having cancer and registered in the KKCR (1985-2009). The follow-up censored date was December 31, 2012. The childhood cancers were classified into 12 diagnostic groups, according to the International Classification of Childhood Cancer. The incidence was calculated by the standard method. Survival of childhood cancer was investigated using the KKCR population-based registration data and overall survival calculated using the Kaplan Meier method. RESULTS In the study period, 912 newly diagnosed cases of childhood cancer were registered. The respective mean and median age was 6.4 (SD=4.6) and 6 (0-14) years. The age-peak for incidence was 0-4 years. The age-standardized rate (ASR) was 83 per million. Leukemia was the most common cancer (N=360, ASR 33.8) followed by neoplasms of the central nervous system (CNS, N=150, ASR 12.8) and lymphoma (N=79, ASR 7.0). The follow-up duration totaled 101,250 months. The death rate was 1.11 per 100 person-months (95%CI: 1.02 -1.20). The 5-year overall survival was 52% (95%CI: 53-56.9) for all cancers. The respective 5-year overall survival for (1) acute lymphoblastic leukemia (ALL), (2) acute non-lymphoblastic leukemia (ANLL), (3) lymphoma, (4) germ cell tumors, (5) renal tumors, (6) retinoblastoma, (7) soft tissue tumors, (8) CNS tumors, (9) bone tumors, (10) liver tumors, and (11) neuroblastoma was (1) 51%, (2) 37%, (3) 63%, (4) 74%, (5) 67%, (6) 55%, (7) 46%, (8) 44%, (9) 36%, (10) 34%, and (11) 25%. CONCLUSIONS The incidence of childhood cancer is lower than those of western countries. Respective overall survival for ALL, lymphoma, renal tumors, liver tumors, retinoblastoma, soft tissue tumors is lower than that reported in developed countries while survival for CNS tumors, neuroblastoma and germ cell tumors is comparable.

Retrospective Appraisal of Cancer Patients from Vientiane Capital City, Lao People's Democratic Republic (PDR), Seeking Treatment in Thailand

BACKGROUND Recent estimates suggest that in the Lao Peoples Democratic Republic (Lao PDR) the burden of cancer in terms of DALYs lost is amongst the highest in South East Asia. As such, increasingly cancer is becoming an important public health concern in the country. Lao PDR however has no population-based cancer registry and only one hospital-based registry. Cancer treatment within the country is extremely limited. Patients who can, may travel to neighboring countries for treatment, but little information about this is available in the country. The aim of this study was to estimate some of the otherwise largely unknown parameters of the cancer burden in Lao PDR. MATERIALS AND METHODS This is a retrospective, descriptive study based on the records of 847 Lao cancer cases treated with surgery, radiation and chemotherapy at Srinagarind Hospital, Khon Kaen University, in Thailand between 1988 and 2010. RESULTS The annual rate of registration of Lao cancer cases fluctuated, but showed an increasing trend. Most cancers were diagnosed by histology (65.2%), and a combination of endoscopy and radiology (15.6%). In most cases (70.2%) the stage of cancer at diagnosis could not be determined. In those whose stage could be identified, 54.0% were at the final stage (Stage IV). Among males, the commonest cancer sites were the liver (16.1%), blood (12.3%) and nasopharynx (10.6%). Those in female patients were the cervix (22.2%), breast (14.6%) and blood (8.1%). CONCLUSIONS This study indicates that despite some fluctuations, the number of Lao cancer patients presenting at Srinagarind Hospital, Khon Kaen, gradually increased between 1988 and 2010. The unfavorable pattern of late-stage cancer diagnosis among male and female patients suggests a need for cancer control interventions and the establishment of cancer registration and treatment facilities within Lao PDR.

National and Subnational Population-Based Incidence of Cancer in Thailand: Assessing Cancers with the Highest Burdens

In Thailand, five cancer types—breast, cervical, colorectal, liver and lung cancer—contribute to over half of the cancer burden. The magnitude of these cancers must be quantified over time to assess previous health policies and highlight future trajectories for targeted prevention efforts. We provide a comprehensive assessment of these five cancers nationally and subnationally, with trend analysis, projections, and number of cases expected for the year 2025 using cancer registry data. We found that breast (average annual percent change (AAPC): 3.1%) and colorectal cancer (female AAPC: 3.3%, male AAPC: 4.1%) are increasing while cervical cancer (AAPC: −4.4%) is decreasing nationwide. However, liver and lung cancers exhibit disproportionately higher burdens in the northeast and north regions, respectively. Lung cancer increased significantly in northeastern and southern women, despite low smoking rates. Liver cancers are expected to increase in the northern males and females. Liver cancer increased in the south, despite the absence of the liver fluke, a known factor, in this region. Our findings are presented in the context of health policy, population dynamics and serve to provide evidence for future prevention strategies. Our subnational estimates provide a basis for understanding variations in region-specific risk factor profiles that contribute to incidence trends over time.

Aberrant methylation of PCDH10 and RASSF1A genes in blood samples for non-invasive diagnosis and prognostic assessment of gastric cancer.

Background. Assessment of DNA methylation of specific genes is one approach to the diagnosis of cancer worldwide. Early stage detection is necessary to reduce the mortality rate of cancers, including those occurring in the stomach. For this purpose, tumor cells in circulating blood offer promising candidates for non-invasive diagnosis. Transcriptional inactivation of tumor suppressor genes, like PCDH10 and RASSF1A, by methylation is associated with progression of gastric cancer, and such methylation can therefore be utilized as a biomarker. Methods. The present research was conducted to evaluate DNA methylation in these two genes using blood samples of gastric cancer cases. Clinicopathological data were also analyzed and cumulative survival rates generated for comparison. Results. High frequencies of PCDH10 and RASSF1A methylations in the gastric cancer group were noted (94.1% and 83.2%, respectively, as compared to 2.97% and 5.45% in 202 matched controls). Most patients (53.4%) were in severe stage of the disease, with a median survival time of 8.4 months after diagnosis. Likewise, the patients with metastases, or RASSF1A and PCDH10 methylations, had median survival times of 7.3, 7.8, and 8.4 months, respectively. A Kaplan–Meier analysis showed that cumulative survival was significantly lower in those cases positive for methylation of RASSF1A than in their negative counterparts. Similarly, whereas almost 100% of patients positive for PCDH10 methylation had died after five years, none of the negative cases died over this period. Notably, the methylations of RASSF1A and PCDH10 were found to be higher in the late-stage patients and were also significantly correlated with metastasis and histology. Conclusions. PCDH10 and RASSF1A methylations in blood samples can serve as potential non-invasive diagnostic indicators in blood for gastric cancer. In addition to RASSF1A methylation, tumor stage proved to be a major prognostic factor in terms of survival rates.