Cancer survival in Khon Kaen province,Thailand

Thailand is one of the few developing countries for which population-based cancer survival data are available. Using clinical follow-up information and reply-paid postal enquiries, 10,333 residents of Khon Kaen province registered with cancer in the period 1985–1992 were followed-up to the end of 1993. The sites of the most common cancers in the province were liver (5-year relative survival rate 9.2%), cervix (60.1%), lung (15.4%), breast (48.1%) and large bowel (41.9%). Results for Khon Kaen were compared with age-standardized survival data for the US and Scotland. Survival was consistently higher for US whites compared to Khon Kaen residents for those cancers whose prognosis is associated with early diagnosis (breast, cervix and large bowel) or the availability of intensive therapy (leukaemia and lymphoma). The main implication of these results for cancer control in Thailand is that the interventions of greatest potential benefit are those designed to promote early detection. More than one-third of all cancers in Thailand are liver tumours: primary prevention through control of hepatitis-B infection and liver fluke infestation is the only effective strategy for their control. © 1995 Wiley-Liss, Inc.     

Cervix Cancer in Khon Kaen,Northeast Thailand, 1985-1999

The incidence of cancer of the cervix uteri in Khon Kaen Province is moderately high (age-standardised rate 16.8 ‍per 100 000 person-years), with about a two-fold variation in incidence between different districts. Stage at presentation ‍is considerably more advanced than in the United States and Europe, and there has been little change in incidence ‍over the last 15 years. Currently, control of cervix cancer is through early detection and treatment. Screening ‍programmes have, to date, been opportunistic, but a new national plan anticipates that all women will be screened ‍six times during their lifetime. The results from Khon Kaen provide a benchmark against which the success of this ‍policy can be evaluated.     

Cancer survival in Chiang Mai, Thailand, 1993-1997

The Chiang Mai tumour registry was established in 1978 as a hospital-based cancer registry, and population-based cancer registration started in 1986, with retrospective data collection on cancer incidence and mortality since 1983. Registration of cases is done by active methods. Data on survival for 36 cancer sites or types registered during 1993-1997 are reported here. Follow-up has been carried out predominantly by active methods, with median follow-up ranging between 1-39 months for different cancers. The proportion of histologically verified diagnosis for various cancers ranged between 28-100%; death certificate only (DCO) cases comprised 0-56%; 33-92% of total registered cases were included for survival analysis. Complete followup at five years ranged from 59-100% for different cancers. The 5-year age-standardized relative survival rates was the highest for Hodgkin lymphoma (70%) followed by thyroid (65%), cervix (57%), breast (56%) and corpus uteri (49%). The 5-year relative survival by age group showed either an inverse relationship or was fluctuating. An overwhelmingly high proportion of cases were diagnosed with a regional spread of disease, ranging between 44-82% for different cancers and survival decreased with increasing extent of disease for all cancers studied.     

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

Background: The Khon Kaen Cancer Registry (KKCR) was established in 1984. Previous population-basedincidences 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, diagnosedas 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 Classificationof Childhood Cancer. The incidence was calculated by the standard method. Survival of childhood cancer wasinvestigated using the KKCR population-based registration data and overall survival calculated using the KaplanMeier 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 0–4years. 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-yearoverall 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 canceris lower than those of western countries. Respective overall survival for ALL, lymphoma, renal tumors, livertumors, retinoblastoma, soft tissue tumors is lower than that reported in developed countries while survival forCNS tumors, neuroblastoma and germ cell tumors is comparable.     

Survival of Stomach Cancer Cases in Khon Kaen,Thailand 2000-2012

Background: Stomach cancer is an aggressive malignancy that is difficult to detect at an early stage and therefore is characterized by poor survival rates. Over the last two decades, there has been no report of gastric cancer survival in Khon Kaen province, Thailand. The aim of this retrospective cohort study was to provide up-to-date information about the survival of gastric cancer patients in this province. Materials and Methods: Data from Khon Kaen population-based cancer registry, Faculty of Medicine, Khon Kaen University were newly obtained on 650 patients who were diagnosed with stomach cancer during the period 1 January, 2000 to 31 December, 2012. These were then followed up until death or the end of the study (31 December 2014). We calculated the observed survival with the actuarial life table method, and relative survival, defined as the ratio of observed survival in the group of the stomach cancer patients to the expected survival in the entire Thai population from the estimated generation life tables for Thailand of five-year birth cohorts from 1900 - 2000. Results: The 5 year observed and 5 year relative survival rates were 17.2 % (95% CI: 13.54-21.14) and 18.2 % (95% CI: 14.3-22.4), respectively. The highest 5 year relative survival rates were demonstrated among patients aged 45-65, with stage I or II lesions, with adenocarcinomas, with a body of stomach location, well differentiated and receiving surgery and/or chemotherapy. Conclusions: The observed and relative survival rates were close to each other. Our findings provide basic information beneficial to development of an effective treatment system and appropriately improved population-based cancer registration.     

Loss-adjusted survival of cervix cancer in Khon Kaen, Northeast Thailand

For incident cancers of the cervix uteri (601 cases) registered in the population-based cancer registry of Khon Kaen province, Northeast Thailand, in 1985-1990 loss-adjusted survival probabilities were estimated by a logistic regression model with four prognostic factors (age at diagnosis, stage of disease, place of residence and treatment), and compared with observed survival, estimated by the actuarial method. All patients were followed up for a minimum of 5 years, using both passive and active methods. In all, 27.6% of patients were lost to follow-up within 5 years of the index date. The overall observed survival at 5 years was 56.8% and loss-adjusted survival was 54.7%. The difference between the loss-adjusted and observed survival at 5 years was small: 2.1% overall, varying between 0.8 and 3.5 percent units for any prognostic group. The assumption of independence of loss to follow-up and death in the calculation of survival by the actuarial method in this, and probably in other, population-based series, is reasonable and leads to no material bias in the estimates.     

Data Quality of Childhood Cancer in Khon Kaen,Thailand, 1990-2007

Introduction: Khon Kaen Cancer Registry (KKCR) was established in 1984. KKCR aims to collect allcancer cases in Khon Kaen Province. The poorly qualified data may lead to distort the cancer burden andmisinterpretation of policy maker. Objective: To assess data quality in childhood cancer between 1990 and 2007in Khon Kaen Province, Thailand. Materials and Methods: Data of childhood cancer cases aged less than 20 yearsdiagnosed during 1990-2007 were retrieved from the population-based data set of KKCR. All childhood cancerdata were verified before data entry. Internal consistency, percentage of morphological verification (MV%) andcancer cased of the basis of diagnosis by death certificate only (DCO%) were evaluated. The age-adjusted rate(ASR) was calculated by standard method. Results: The data of childhood cancer from KKCR is acceptablyqualified which reflects the quality of the whole registration.     

Health Insurance and Colorectal Cancer Survival in Khon Kaen,Thailand

Background: Evidence from healthcare studies demonstrates that patients’ health insurance affects serviceaccessibility and the outcome of treatment. However, assessment on how colorectal cancer survival relates to healthinsurance is limited. Objective: The study examined the association between health insurance and colorectal cancersurvival in Khon Kaen, Thailand. Methods: The retrospective cohort study was conducted with 1,931 colorectal cancerpatients from Khon Kaen cancer registry between January 1, 2003 and December 31, 2012, and was followed-up untilDecember 31, 2015. Relative survival was used to estimate the survival rate. Cox proportional hazard regression wasused to estimate the relationship between health insurance and colorectal cancer survival, represented with the hazardratio. Result: Most of the participants were males, and the median age was 62 years. The median survival time was2.25 years (95% CI: 2.00-2.51). The five-year observed survival rate and relative survival rate were 36.87 (95% CI:34.66-39.08) and, 42.28 (95% CI: 39.75-44.81), respectively. The factors that showed significant associations withpoorer survival after adjustment for gender and age were non-surgical treatments (HRadj=1.88;95%CI=1.45-2.45),advanced stage (III+IV) (HRadj=2.50; 95%CI=2.00-3.12), histological grading in poorly differentiated (HRadj=1.84;95%CI=1.32-2.56), and Universal Coverage Scheme (HRadj=1.37;95%CI=1.09-1.72). Conclusion: The survival ofcolorectal cancer patients in the Universal Coverage Scheme was likely to be poorer than in the Civil Servant MedicalBenefit Scheme. This indicates an urgent need for a national program for colorectal cancer screening in the generalpopulation and access to health insurance.     

Trends in Incidences of Stomach and Colorectal Cancer in Khon Kaen,Thailand 1985-2004

Background: The life styles of Thai people are changing with westernization and this would be expected to havean impact on the prevalence of cancer and other non-communicable diseases. For planning control programmes it isnecessary to monitor change over time and the present study was conducted to provide information on stomach andcolorectal cancer incidence rates in Khon Kaen Cancer Registry (KKCR), established in 1984 at the Faculty ofMedicine, Srinagarind Hospital, Khon Kaen University. Objective: To assess trends in urban and rural areas ofKhon Kaen province during 1985 - 2004. Methods: Data for stomach and colorectal cancer with an ICD-O diagnosis(coding C16 , C18 – C20) from the population-based cases of the KKCR, registered between 1985 and 2004, wereretrieved and incidence trends were calculated using the Generalized Linear Model method (GLM), which generatesincidence-rate-based logarithms. Results: The study population comprised 2,530 cases, 721 of stomach (males 449,females 272) and 1809 of colorectal (males 976, females 833) cancer. Most cases were aged 35-75 years. Accordingto the histopathological diagnosis, the most common was adenocarcinoma with over 90 percent. The overall agestandardizedincidence rates (ASR) for stomach cancer were 4.5 and 1.4 per 100 000 in males and females, respectively,during 1985-1989, 3.7 and 2.0 during 1990-1994, 3.0 and 2.2 during 1995-1999 and 3.6 and 1.8 during 2000-2004 .The respective figures for colorectal cancer were 3.3 and 2.6, 4.6 and 3.1, 5.4 and 3.5 and finally 5.8 and 5.3. In bothurban and rural areas males were affected more frequently than females, although a shift was evident towardsdecrease in the se ratio was evident for colorectal cancers over time. Discussion: The results of this study showedslight increase in the incidence of colorectal cancer in Khon Kaen province, while rates for stomach cancer remainedquite stable. The findings indicate a need for continuing research in stomach and colorectal cancer epidemiology,with subdivision into particular sites within these two sections of the gut.     

Cancer survival in Singapore, 1993-1997

The Singapore cancer registry is a national registry established in 1968. Cancer registration is done by passive methods. The registry contributed survival data on 45 cancer sites or types registered during 1993-1997. Data on 34 cancers registered during 1968-1997 were utilized for survival trend by period and cohort approaches. Follow-up was done by passive methods, with median follow-up ranging between 2-72 months for different cancers. The proportion with histologically verified diagnosis for various cancers ranged between 27-100%; death certificates only (DCOs) comprised 0-7%; 76-100% of total registered cases were included for the survival analysis. The top-ranking cancers on 5-year age-standardized relative survival rates were nonmelanoma skin (96%), thyroid (90%), testis (88%), corpus uteri (77%), breast (74%), Hodgkin lymphoma (73%) and penis (70%). Five-year relative survival by age group showed either a decreasing trend with increasing age groups or was fluctuating. Localized stage of disease ranged between 18-65% for various cancers and survival decreased with increasing extent of disease. Period survival closely predicted survival experience of cancers diagnosed in that period, and an increasing trend in period survival over different periods indicated an improved prognosis for cancers diagnosed in those calendar periods.     

Numbers of New Cases and Trends of Cancer 1993-2012: Srinagarind Hospital Based Population,Khon Kaen,North-East Thailand

Background: Cancer is the most common cause of death in Thailand, where treatment outcomes andprognosis are poor and mortality rates remain high. This study reports new cancer cases and trends of allcancers registered in Srinagarind Hospital from 1993 to 2012 and also provides a picture of the cancer situationin Northeast Thailand. Materials and Methods: All new cases of cancer registered in the hospital-based cancerregistry at Faculty of Medicine, Srinagarind Hospital, Khon Kaen University during 1993-2012 were included inthe study. Results and Conclusions: The number of new cancer cases has gradually increased each year duringthe last 20 years. The three most common cancers at present in males are liver and bile duct cancer, lung cancerand colorectal cancer, respectively. In females, liver and bile duct, breast and thyroid cancers are now the mostfrequent. Interestingly, the number of cases of both liver and bile duct cancer and colorectal cancer in malesnoticeably increased during the second decade of the study. Additionally, breast cancer greatly increased in thesame decade and lung cancer in females climbed into the top five most common cancers. Thyroid cancer hasalso risen steadily in the last decade. Trends of common cancers are similar to those throughout Thailand.     

Cancer survival in the Gambia, 1993-1997

The national cancer registry of the Gambia was established in 1986 as part of the Gambia Hepatitis Intervention Study in collaboration with IARC, France; Medical Research Council (MRC) Laboratories of the UK; and the Government of the Gambia at MRC, Banjul. Registration of incident cancer cases is done by active and passive methods. For this study, the registry contributed data on survival for six cancer sites or types registered during 1993-1997. Follow-up has been carried out predominantly by active methods with median follow-up ranging between 1-6 months. The proportion of histologically verified diagnosis for various cancers ranged between 1-45%, and 54-82% of total registered cases were included for survival analysis. Complete follow-up at five years from the incidence date ranged between 81-98% for different cancers. The 5-year age-standardized relative survival for selected cancers were cervix (23%), non-Hodgkin lymphoma (22%), breast (10%), stomach (4%) and liver (3%). The 5-year relative survival by age group showed fluctuations with no definite pattern or trend emerging, and with no survivors in many age intervals.     

Cancer survival in Harare, Zimbabwe, 1993-1997

The Zimbabwe national cancer registry was established in 1985 as a population-based cancer registry covering Harare city. Cancer is not a notifiable disease, and registration of cases is done by active methods. The registry contributed data on randomly drawn sub-samples of Harare resident cases among 17 common cancer sites or types registered during 1993-1997 from black and white populations. Follow-up was carried out predominantly by active methods with median follow-up ranging from 1-54 months for different cancers. The proportion with histologically verified diagnosis for various cancers ranged from 20-100%; death certificate only (DCO) cases comprised 0-34%; 58-97% of total registered cases were included for survival analysis. Complete follow-up at five years ranged from 94-100%. Five-year age-standardized relative survival rates of selected cancers among both races combined were cervix (42%), breast (68%), Kaposi sarcoma (4%), liver (3%), oesophagus (12%), stomach (20%) and lung (14%). Survival was markedly higher among white than black populations for most cancers with adequate cases. Five-year relative survival by age group was fluctuating, with no definite pattern or trend.     

Cancer survival in Kampala, Uganda, 1993-1997

The Kampala cancer registry was established in 1954 as a population-based cancer registry, and registration of cases is done by active methods. The registry contributed data on survival for 15 cancer sites or types registered in 1993-1997. For Kaposi sarcoma, only a random sample of the total incident cases was provided for survival study. Follow-up has been carried out predominantly by active methods, with median follow-up ranging from 4-26 months. The proportion with histologically verified diagnosis for various cancers ranged between 36-83%; death certificate only (DCO) cases were negligible; 58-92% of total registered cases were included for survival analysis. Complete follow-up at five years ranged between 47-87% for different cancers. Five-year age-standardized relative survival rates for selected cancers were Kaposi sarcoma (22%), cervix (19%), oesophagus (5%), non-Hodgkin lymphoma (26%), breast (36%) and prostate (46%). None survived beyond 5 years for cancers of the stomach and lung. Five-year relative survival by age group was fluctuating with no definite pattern or trend emerging and no survivors in many age intervals.     

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.     

Trends in Incidence of Childhood Lymphoma in Khon Kaen,Thailand, 1985-2008

Background: Lymphoma is the second most common of childhood cancer in Thailand, but data on trendsover time are limited. Objective: To perform a statistic assessment of the incidence trend of childhood lymphomain Khon Kaen, Thailand, between 1985 and 2008. Method: All children aged < 15 years newly diagnosed withlymphoma according to International Childhood Cancer Classification (ICCC) during January 1, 1985- December31, 2008 were collected from data base of Khon Kaen Provincial Registry. Aged-adjusted incidence rates (ASRs)were calculated by standard method and trends were calculated using the generalized linear model method, which utilizes incidence-rate-base logarithms. Results: During 1985-2008 there were 72 children (47boys and 25 girls) who were diagnosed with lymphoma in Khon Kaen province. The peak age-group of diseasewas in the 5-9 year olds for both sexes. All cases were pathologically proven. Non-Hodgkin lymphoma (NHL)was more common than Hodgkin disease (ratio 7:1). The overall ASR was 6.04 per million (95%CI: 4.64 to 7.45)and the ASR was 7.64 per million (95%CI: 5.44 to 9.84) in boys and 4.37 per million (95%CI: 2.64 to 6.10) ingirls. Significant increases were observed for boys, since the 2006 to 2008 ASR was 15.3 per million (95%CI:5.73 to 25.0). Trend analyses during 1985 - 2008 showed that incidence among boys for lymphoma increasedby 1.38 percent per year (95%CI:- 4.6-8.3) while the incidence among girl decreased by 2.6 percent per year(95%CI:- 12-6.8). Conclusions: Our data showed that the incidence of childhood lymphoma in Khon Kaenprovince was similar to the one of Thailand but lower than those of western countries. During the past 24 years,the incidence trend seems to be increasing in boys but decreasing in girls. Interpretation is difficult without abetter understanding of what underlies the reported changes.     

Trends in Incidence of Childhood Leukemia,Khon Kaen,Thailand, 1985-2002

Background: The Khon Kaen Cancer Registry (KKCR), providing both hospital and population-based ‍registration, was established in 1984 in the Faculty of Medicine, Khon Kaen University. Leukemia is the most ‍common cancer among Thai children in Thailand, including both curable and preventable types, but no assessment ‍of trends has hitherto been performed. Objective: To perform a statistical assessment of the incidence trend of ‍childhood leukemia in Khon Kaen, Thailand, between 1985 and 2002. Methods: Population-based cases of childhood ‍leukemia registered between 1985 and 2002 were retrieved from the KKCR and cases with an ICD-O diagnosis ‍(coding C42) in children under 15 were selected. Incidence trends were calculated using the Generalized Linear ‍Model method (GLM), which generates incidence-rate-based logarithms. Results: Of the 277 cases of leukemia, ‍boys were affected two times more frequently than girls and half of the cases were 0-4 years of age. Most diagnoses ‍were histologically- or cytologically-proven and the most common type (affecting two-thirds, 65.7%) was acute ‍lymphoblastic leukemia (ALL). The overall, age-standardized rate (ASR) for leukemia was 31.9 per million (95%CI: ‍28.1 to 35.7); 40.3 per million (95%CI: 34.2 to 46.4) in boys and 27.0 (95%CI: 21.8 to 32.2) in girls. Incidence has ‍been increasing by 2.4% per year in boys (95% CI: -0.5 to 5.3) and 4.1% per year in girls (95% CI: 1.1 to 7.2). ‍Conclusions: This incidence-rate-based logarithm indicates that childhood leukemia has been increasing, suggesting ‍further epidemiological research on causes and possible prevention is needed.     

Trends in Liver Cancer Incidence between 1985 and 2009, Khon Kaen,Thailand: Cholangiocarcinoma

Background: The Khon Kaen Cancer Registry (KKCR), having both hospital and population-based registration, was established in 1984 at the Faculty of Medicine, Khon Kaen University. Liver cancer is the most frequent malignancy among Thais from northeastern Thailand, but there has hitherto been no assessment of trends over time. Objective: To perform a statistical assessment of the incidence trends between 1985 and 2009 of liver cancer, specifically focusing on cholangiocarcinoma (CHCA). Methods: Cases of CHCA, registered between 1985 and 2009, were retrieved from the KKCR and all those with a specific ICD-O-3rd diagnosis with a coding of C22.1, C24.0, C24.8 and C24.9 were selected. Incidence trends were calculated using the generalized linear model method (GLM), which generates incidence rate based logarithms. Jointpoint analysis was used to identify the best fitting model. Results: Of the 18,589 cases of liver cancer 42% (7,859) were hepatocellular carcinoma and 58% (10,731) were CHCA. Among persons with CHCA, males were affected two times more frequently than females. Three-quarters of the cases were between 55 and 69 years of age. Morphology verified through a cytological or histological examination of tissue from the primary site (%MV) was only 10.8 % (1,141). The respective overall Age Standardized Rate (ASR) for CHCA from 1985 to 2009 was 16.8 to 62.0 per 100,000 among males and 4.8 to 25.6 per 100,000 among females. The respective, overall, ASR of CHCA among males vs. females was 44.3 per 100,000 (95% CI: 38.9 to 49.7) vs. 17.6 (95% CI: 14.5 to 20.7). Among males vs. females, the respective incidence from 1990 to 2009 has been significantly decreasing by –0.7% per year (annual percent change, APC: –0.7%, 95%CI: –2.1% to +0.8%) vs. –0.4% per year (APC: –0.4%, 95% CI: –2.1% to +1.4%).Conclusions: The rate increase in the first 5 to 6 years may be due to improved completeness of the registry, since in the subsequent 10 to 12 years there is a rather stable rate. It may be, however, that the recent decline in incidence represents a real fall in risk.     

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 determinethe association between reproductive factors and thyroid cancer. Methods: A total of 10,767 eligible women fromthe Khon Kaen Cohort, recruited and interviewed between 1990 and 2001, were followed up until 2011. Thedata 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 % werepapillary tumors. The incidence was apparently greater among those with an early age of menarche, nulligravidawomen, and oral contraceptive users. Conlusions: There was a trend for thyroid cancer to develop in relationto longer estrogen exposure. This evidence is inconclusive but warrants further investigation.