Development of paediatric non-stage prognosticator guidelines for population-based cancer registries and updates to the 2014 Toronto Paediatric Cancer Stage Guidelines

Population-based cancer registries (PBCRs) generate measures of cancer incidence and survival that are essential for cancer surveillance, research, and cancer control strategies. In 2014, the Toronto Paediatric Cancer Stage Guidelines were developed to standardise how PBCRs collect data on the stage at diagnosis for childhood cancer cases. These guidelines have been implemented in multiple jurisdictions worldwide to facilitate international comparative studies of incidence and outcome. Robust stratification by risk also requires data on key non-stage prognosticators (NSPs). Key experts and stakeholders used a modified Delphi approach to establish principles guiding paediatric cancer NSP data collection. With the use of these principles, recommendations were made on which NSPs should be collected for the major malignancies in children. The 2014 Toronto Stage Guidelines were also reviewed and updated where necessary. Wide adoption of the resultant Paediatric NSP Guidelines and updated Toronto Stage Guidelines will enhance the harmonisation and use of childhood cancer data provided by PBCRs.

Estimating the global cancer incidence and mortality in 2018: GLOBOCAN sources and methods

Estimates of the worldwide incidence and mortality from 36 cancers and for all cancers combined for the year 2018 are now available in the GLOBOCAN 2018 database, compiled and disseminated by the International Agency for Research on Cancer (IARC). This paper reviews the sources and methods used in compiling the cancer statistics in 185 countries. The validity of the national estimates depends upon the representativeness of the source information, and to take into account possible sources of bias, uncertainty intervals are now provided for the estimated sex- and site-specific all-ages number of new cancer cases and cancer deaths. We briefly describe the key results globally and by world region. There were an estimated 18.1 million (95% UI: 17.5-18.7 million) new cases of cancer (17 million excluding non-melanoma skin cancer) and 9.6 million (95% UI: 9.3-9.8 million) deaths from cancer (9.5 million excluding non-melanoma skin cancer) worldwide in 2018.

Cancer Mortality in Italian Migrants to Canada

The present study reports on the analysis of cancer mortality in Italian first-generation migrants resident in Canada, deceased in the period between 1964-1985 (5,801 males: 3,267 females). Mortality in migrants is compared to that of the host population as well as to that in the migrants’ country of origin. This is carried out both on a national level (Italy), and on a regional level with those regions that have made the greatest contribution to the Italian migratory flow (Southern Italy). Compared with the Canada-born population, significantly higher risks were evident for nasopharynx, stomach, liver and gallbladder tumors in migrants. Lower risks were observed for the oral cavity, esophagus, colon, rectum, pancreas (females), larynx, lung, melanoma, breast, ovary, prostate, bladder (females), and non-Hodgkin's lymphoma in migrants. This is consistent with that evidenced in the comparison between Italy and Canada. The data are discussed in relation to the results of other studies on Italian migrants and the prevalence of main risk factors.

Screening for liver cancer: results of a randomised controlled trial in Qidong, China

Objectives: To investigate the effectiveness of screening for liver cancer in reducing mortality from the disease in a high-risk population in China.

Setting: A randomised controlled trial was carried out among men aged 30-69 who were chronic carriers of hepatitis-B virus (HBsAg positive) during the period 1989-1995 in Qidong county, Jiangsu Province, China.

Methods: 5581 HBsAg carriers were identified by population screening and randomly assigned to a screening group (group A, 3712 men), and controls (group B, 1869 men). Screening was planned to be six monthly alpha-fetoprotein (AFP) assays, with follow-up of subjects having an abnormal (≥20 μg/l) test. All subjects were followed up for liver cancer and/or death until 31 December 1995.

Results: The overall sensitivity and specificity of the programme was 55.3% and 86.5%, respectively; in subjects who complied with all scheduled screening tests, the values were 80.0% and 80.9%. Three hundred and seventy-four primary liver cancer (PLC) cases were diagnosed. The percentage of cases in stage I was significantly higher in group A (29.6%) than in group B (6.0%). The one-, three-, and five-year relative survival rates were 23.7%, 7.0%, and 4.0% in group A, and 9.7%, 4.0%, and 4.1% in group B respectively, with no difference in five-year survival between the groups. The mortality rate in the screened group (1138 per 100,000 person-years) was not significantly different from that in the controls (1114 per 100,000). A Poisson regression model showed that the probability of death (rate ratio) in the screening group was 0.83 (95% CI 0.68-1.03) relative to the control group.

Conclusions: Screening with AFP resulted in earlier diagnosis of liver cancer, but the gain in lead time did not result in any overall reduction in mortality, because therapy for the patients found by screening was ineffective. Further studies using improved methods of screening, diagnosis and treatment are indicated.

Trends in the incidence of cancer in the black population of Harare, Zimbabwe 1991-2010

Incidence rates of different cancers have been calculated for the black population of Harare, Zimbabwe for a 20-year period (1991-2010) coinciding with continuing social and lifestyle changes, and the peak, and subsequent wane, of the HIV-AIDS epidemic. The overall risk of cancer increased during the period in both sexes, with rates of cervix and prostate cancers showing particularly dramatic increases (3.3% and 6.4% annually, respectively). By 2004, prostate cancer had become the most common cancer of men. The incidence of cancer of the esophagus, formerly the most common cancer of men, has remained relatively constant, whereas rates of breast and cervix cancers, the most common malignancies of women, have shown significant increases (4.9% and 3.3% annually, respectively). The incidence of Kaposi sarcoma increased to a maximum around 1998-2000 and then declined in all age groups, and in both sexes The incidence of squamous cell cancers of the conjunctiva is relatively high, with temporal trends similar to those of Kaposi sarcoma. Non-Hodgkin lymphoma, the fifth most common cancer of men and fourth of women, showed a steady increase in incidence throughout the period (6.7-6.9% annually), although rates in young adults (15-39) have decreased since 2001. Cancer control in Zimbabwe, as elsewhere in sub-Saharan Africa, involves meeting the challenge of emerging cancers associated with westernization of lifestyles (large bowel, breast and prostate), while the incidence of cancers associated with poverty and infection (liver, cervix and esophagus) shows little decline, and the residual burden of the AIDS-associated cancers remains significant.

1. The fraction of cancer attributable to lifestyle and environmental factors in the UK in 2010

The overall objective of the study is to estimate the percentage of cancers (excluding non-melanoma skin cancer) in the UK in 2010 that were the result of exposure to 14 major lifestyle, dietary and environmental risk factors: tobacco, alcohol, four elements of diet (consumption of meat, fruit and vegetables, fibre and salt), overweight, lack of physical exercise, occupation, infections, radiation (ionising and solar), use of hormones and reproductive history (breast feeding). The number of new cases attributable to suboptimal exposure levels in the past, relative to a theoretical optimum exposure distribution, is evaluated. For most of the exposures, the attributable fraction was calculated based on the distribution of exposure prevalence (around 2000), the difference from the theoretical optimum (by age group and sex) and the relative risk per unit difference. For tobacco smoking, the method developed by Peto et al (1992) was used, which relies on the ratio between observed incidence of lung cancer in smokers and that in non-smokers, to calibrate the risk. This article outlines the structure of the supplement – a section for each of the 14 exposures, followed by a Summary chapter, which considers the relative contributions of each factor to the total number of cancers diagnosed in the UK in 2010 that were, in theory, avoidable.

16. The fraction of cancer attributable to lifestyle and environmental factors in the UK in 2010

This chapter summarises the results of the preceding sections, which estimate the fraction of cancers occurring in the UK in 2010 that can be attributed to sub-optimal, past exposures of 14 lifestyle and environmental risk factors. For each of 18 cancer types, we present the percentage of cases attributable to one or all of the risk factors considered (tobacco, alcohol, four elements of diet (consumption of meat, fruit and vegetables, fibre, and salt), overweight, lack of physical exercise, occupation, infections, radiation (ionising and solar), use of hormones, and reproductive history (breast feeding)).Exposure to less than optimum levels of the 14 factors was responsible for 42.7% of cancers in the UK in 2010 (45.3% in men, 40.1% in women)--a total of about 134,000 cases.Tobacco smoking is by far the most important risk factor for cancer in the UK, responsible for 60, 000 cases (19.4% of all new cancer cases) in 2010. The relative importance of other exposures differs by sex. In men, deficient intake of fruits and vegetables (6.1%), occupational exposures (4.9%) and alcohol consumption (4.6%) are next in importance, while in women, it is overweight and obesity (because of the effect on breast cancer)--responsible for 6.9% of cancers, followed by infectious agents (3.7%).Population-attributable fractions provide a valuable quantitative appraisal of the impact of different factors in cancer causation, and are thus helpful in prioritising cancer control strategies. However, quantifying the likely impact of preventive interventions requires rather complex scenario modelling, including specification of realistically achievable population distributions of risk factors, and the timescale of change, as well as the latent periods between exposure and outcome, and the rate of change following modification in exposure level.

Cancer incidence in the United Kingdom: projections to the year 2030

Background:

Projections of cancer incidence are important for planning health services and to provide a baseline for assessing the impact of public health interventions.

Methods:

Rates estimated from smooth function age–period–cohort modelling of cancer incidence data from Great Britain 1975 to 2007 are extrapolated to 2030 and applied to UK population projections. Prostate and breast cancer projections take into account the effect of screening.

Results:

Overall rates of cancer are projected to be stable over the next 20 years, but this masks individual changes. In both sexes, age-standardised rates of cancers of the stomach, larynx, bladder and leukaemia are projected to fall by ⩾1% per year, whereas cancers of the lip, mouth and pharynx (ICD-10 C00-C14) and melanoma are projected to increase by ⩾1% per year. The growing and aging populations will have a substantial impact: numbers of cancers in men and women are projected to increase by 55% (from 149 169 to 231 026) and 35% (from 148 716 to 200 929), respectively, between 2007 and 2030. The model used yields similar results to those of Nordpred, but is more flexible.

Conclusion:

Without new initiatives for smoking and obesity reduction, the number of cancers in the United Kingdom will increase substantially reflecting the growing and aging populations.

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.

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.

A chemically modified alpha-amylase with a molten-globule state has entropically driven enhanced thermal stability

The thermostability properties of TAA were investigated by chemically modifying carboxyl groups on the surface of the enzyme with AMEs. The TAA(MOD) exhibited a 200% improvement in starch-hydrolyzing productivity at 60 degrees C. By studying the kinetic, thermodynamic and biophysical properties, we found that TAA(MOD) had formed a thermostable, MG state, in which the unfolding of the tertiary structure preceded that of the secondary structure by at least 20 degrees C. The X-ray crystal structure of TAA(MOD) revealed no new permanent interactions (electrostatic or other) resulting from the modification. By deriving thermodynamic activation parameters of TAA(MOD), we rationalised that thermostabilisation have been caused by a decrease in the entropy of the transition state, rather than being enthalpically driven. Far-UV CD shows that the origin of decreased entropy may have arisen from a higher helical content of TAA(MOD). This study provides new insight into the intriguing properties of an MG state resulting from the chemical modification of TAA.

Estimates of cancer incidence and mortality in Europe in 2008

Up-to-date statistics on cancer occurrence and outcome are essential for the planning and evaluation of programmes for cancer control. Since the relevant information for 2008 is not generally available as yet, we used statistical models to estimate incidence and mortality data for 25 cancers in 40 European countries (grouped and individually) in 2008. The calculations are based on published data. If not collected, national rates were estimated from national mortality data and incidence and mortality data provided by local cancer registries of the same or neighbouring country. The estimated 2008 rates were applied to the corresponding country population estimates for 2008 to obtain an estimate of the numbers of cancer cases and deaths in Europe in 2008. There were an estimated 3.2 million new cases of cancer and 1.7 million deaths from cancer in 2008. The most common cancers were colorectal cancers (436,000 cases, 13.6% of the total), breast cancer (421,000, 13.1%), lung cancer (391,000, 12.2%) and prostate cancer (382,000, 11.9%). The most common causes of death from cancer were lung cancer (342,000 deaths, 19.9% of the total), colorectal cancer (212,000 deaths, 12.3%), breast cancer (129,000, 7.5%) and stomach cancer (117,000, 6.8%).

A novel approach for enhancing the catalytic efficiency of a protease at low temperature: reduction in substrate inhibition by chemical modification

The alkaline protease, savinase was chemically modified to enhance the productivity of the enzyme at low temperatures on a complex polymeric protein (azocasein) substrate. At 5 and 15 degrees C, savinase modified with ficol or dextran hydrolyzed fivefold more azocasein than the unmodified savinase. Kinetic studies showed that the catalytic improvements are associated with changes in uncompetitive substrate inhibition with K(i) values of modified savinases sixfold higher than the unmodified savinase. Modeling of small-angle scattering data indicates that two substrate molecules bind on opposing sides of the enzyme. The combined kinetic and structural data indicate that the polysaccharide modifier sterically blocks the allosteric site and reduces substrate inhibition. In contrast to the properties of cold-active enzymes that generally manifest as low activation enthalpy and high flexibility, this study shows that increased activity and productivity at low temperature can be achieved by reducing uncompetitive substrate inhibition, and that this can be achieved using chemical modification with an enzyme in a commercial enzyme-formulation.

Predicting the impact of the screening programme for colorectal cancer in the UK

Objectives

Screening for colorectal cancer by biennial testing for faecal occult blood is being introduced in the UK from 2007. We examine the likely impact of the programme, in terms of reduced mortality, lives saved and changes in incidence, over the next 20 years.

Setting

Projections of incidence and mortality of colorectal cancer in England, and the policy that has been adopted for screening in England (biennial at ages 60–69 from 2007, then 60–74 in 2010).

Methods

The results are based on the output of a simulation model that has been used to examine cost-effectiveness of screening policy options, with two scenarios regarding compliance with screening; both assume that 20% of the population will never attend for screening, but attendance of those who do is modelled either as a random 60% or 80%, at each screening round.

Results

The decrease in mortality rates expected 20 years after introducing screening is 13–17% in men and 12–15% in women (depending on the attendance levels). The model predicts an initial rise in incidence, followed (after six to seven years) by a fall, so that there is little net change in the number of cases detected over a 20-year period.

Conclusion

Percentage changes in mortality seem modest, but the projected saving in terms of numbers of lives is not negligible – 1800–2400 per year by 2025 in England (equivalent numbers are 2200–2700 in all over the UK). Newer screening modalities may improve on these projected results.

Cancer mortality in the United Kingdom: projections to the year 2025

The purpose of this study was to project mortality rates in the United Kingdom for the period 2006-2025 for 21 major cancers on the basis of the observed trends in mortality rates during 1971-2005, and to estimate the implication in terms of expected deaths. Age-period-cohort models were applied to official statistics. The projected decrease in age-standardised mortality rates for all cancers from 2003 to 2023 was 17% in men and 16% in women. Future mortality rates were projected to decline for most cancer sites. In men, there were small projected increases in mortality rates from cancers of the oral cavity, oesophagus and melanoma, with a larger projected increase (14% over 20 years) in mortality of liver cancer. In women, the only projected increase (18%) was for corpus uteri. The numbers of deaths will increase for most cancers, with a 30% increase in all cancers projected for men and a 12% increase projected for women. Mortality rates from cancer as a whole have been falling in the United Kingdom since 1990, and this decline was projected to continue into the future as well as the declining rates in both sexes for most cancers. Actual numbers of deaths will increase for most cancers.

Up-to-date monitoring of childhood cancer long-term survival in Europe: leukaemias and lymphomas

BACKGROUND

In recent decades, following the introduction of effective chemotherapy, the prognosis of children with leukaemia and lymphoma has dramatically improved, but data reflecting further possible improvement achieved in the 1990s are scarce.

METHODS

Using the Automated Childhood Cancer Information (ACCIS) database, we carried out a period analysis of 10-year survival for the 1995-99 period. Analyses were carried out by diagnostic groups, age-group at diagnosis, sex and four European regions.

RESULTS

Ten-year survival estimates for the 1995-99 period were 73% for any type of leukaemia, 78% for acute lymphoid leukaemia and 52% for acute non-lymphocytic leukaemia. The corresponding 10-year survival rates for all types of lymphomas, Hodgkin lymphoma, and non-Hodgkin lymphoma were 84, 91 and 79%, respectively. These figures are much higher than those obtained by traditional (cohort-based) methods of survival analysis. A large difference in prognosis is still observed between the East and other parts of Europe.

CONCLUSION

Major improvement in prognosis for children with leukaemia or lymphoma has been ongoing in Europe during the 1990s, but further monitoring and investments are required to remove the large regional differences between European regions.

Timely disclosure of progress in childhood cancer survival by 'period' analysis in the Automated Childhood Cancer Information System

BACKGROUND

A few years ago, a new method of survival analysis, denoted 'period' analysis, was introduced to provide more up-to-date survival estimates of cancer patients.

PATIENTS AND METHODS

We evaluated the period survival method using the large database of the Automated Childhood Cancer Information System (ACCIS). Our evaluation is based on data from 35 191 children diagnosed with cancer in 13 European countries between 1975 and 1989 and followed for vital status until around 1999.

RESULTS

Using the follow-up data available in 1989, 10-year survival for all children with cancer calculated by the period method for the 1985-89 period was 58%, while it was 43% when calculated by traditional 'cohort' life-table analysis (based on children diagnosed in 1975-79). The period method provided a better estimate of the true 10-year survival of 62%, observed 10 years later in the cohort of patients diagnosed in 1985-89. Similar results were observed for each of the common groups of childhood cancer.

CONCLUSION

Period analysis is especially useful for monitoring childhood cancer survival, because at a given point in time it provides more timely estimates of long-term survival expectations than the cohort life-table method. Using the ACCIS database, up-to-date estimates of period survival for childhood cancer are derived in subsequent papers in this journal.

Thyroid cancer incidence and survival among European children and adolescents (1978-1997): report from the Automated Childhood Cancer Information System project

Data on 1690 childhood and adolescent cases of thyroid cancer registered in 61 European cancer registries were extracted from the database of the Automated Childhood Cancer Information System (ACCIS) and included in analyses of incidence and survival. In 1988-1997, the age-standardised incidence rates (ASR) for children aged 0-14 years varied in European regions from 0.5 to 1.2 per million and the age-specific incidence in adolescents aged 15-19 years ranged from 4.4 to 11.0 per million. Over the age-span 0-19 years, the female to male ratio increased from 1 to around 3. Papillary thyroid cancer accounted for almost 65% of cases in children and 77% in adolescents. In the childhood population of Belarus, the ASR for 1989-1997 was 23.6 per million and the proportion of papillary tumours was 87%. No association was found between thyroid cancer risk and national dietary iodine status across 16 countries. Incidence of thyroid carcinoma among children and adolescents in Europe (excluding Belarus) increased during 1978-1997 by 3% per year, largely due to papillary carcinoma. Survival of children and adolescents was high over the entire study period and in all regions of Europe. Children with medullary carcinoma had slightly lower 5-year survival (95%, 95% CI 81-99), than those with papillary carcinoma (99%, 95% CI 95-100). More than 90% of patients survived 20 years after diagnosis. Further standardisation of diagnostic, classification and registration criteria will be fundamental for future studies of thyroid carcinomas in young people.

Quality, comparability and methods of analysis of data on childhood cancer in Europe (1978–1997): Report from the Automated Childhood Cancer Information System project

In collaboration with 62 population-based cancer registries contributing to the Automated Childhood Cancer Information System (ACCIS), we built a database to study incidence and survival of children and adolescents with cancer in Europe. We describe the methods and evaluate the quality and internal comparability of the database, by geographical region, period of registration, type of registry and other characteristics. Data on 88,465 childhood and 15,369 adolescent tumours registered during 1978-1997 were available. Geographical differences in incidence are caused partly by differences in definition of eligible cases. The observed increase in incidence rates cannot be explained by biases due to the selection of datasets for analyses, and only partially by the registration of non-malignant or multiple primary tumours. Part of the observed differences in survival between the regions may be due to variable completeness of follow-up, but most is probably explained by resource availability and organisation of care. Further standardisation of data and collection of additional variables are required so that this study may continue to yield valuable results with reliable interpretation.

[Time trends, estimates and projects for breast cancer incidence and mortality in China]

OBJECTIVE

Using comprehensive available data on women breast cancer in China, to describe the mortality trends from late 1970s, estimate and project the profile in 2000 and 2005, and to aim to provide a reference for clinic, basic research and prevention and control strategy making for breast cancer in China.

METHODS

Using Joinpoint model, the mortality trends were analyzed on the basis of routine surveillance data. Combining with the data from the second national mortality survey and several cancer registries, using the log-linear model (based on Poisson distribution), the breast cancer profile in 2000 and 2005 were estimated and projected.

RESULTS

Although there was a slight decline in mortality between early 1970s and 1990s, the age-specific mortality rates among young and middle age women increased dramatically which followed a continuing increase trend on both rates and absolute numbers, in both urban and rural areas in recent 15 years. Compared with 2000, there are 470 thousands more new breast cancer cases and 130 thousands more deaths from breast cancer in 2005.

CONCLUSION

Due to the double effects of both increasing risk factors and population growth and ageing, breast cancer will be one of the most extensively increasing cancers in Chinese women. The prevention and control of breast cancer will be of great emphasis for future cancer control strategy in China.

Calculating age-adjusted cancer survival estimates when age-specific data are sparse: an empirical evaluation of various methods

We evaluated empirically the performance of various methods of calculating age-adjusted survival estimates when age-specific data are sparse. We have illustrated that a recently proposed alternative method of age adjustment involving the use of balanced age groups or age truncation may be useful for enhancing calculability and reliability of adjusted survival estimates.

Human papillomavirus and cervical cancer from a prospective study in Khon Kaen, Northeast Thailand

The risk of developing carcinoma of the cervix in women infected with human papillomavirus (HPV) was estimated in a nested case-control analysis of 33 cancers (invasive and in situ) and 113 controls, matched by age and sex, from an ongoing cohort study of lifestyle and cancer in a rural population of Northeast Thailand. Oncogenic HPV types were present in 10.8% of control women and in 31/33 of the carcinoma cases, corresponding to an odds ratio of 130.6 (95% CI 11.7-1457.0). There was no significant difference in risk between prevalent cancer cases (diagnosed less than 3 months after HPV testing) and incident cases (diagnosed an average of 2.1 years later). HPV 16 and 18 were the most prevalent oncogenic HPV types present. The results confirm that some two of three of cervical cancer cases in this population of Northeast Thailand are caused by HPV 16 and 18.

Outcome of screening by clinical examination of the breast in a trial in the Philippines

The value of screening by Clinical Examination of the Breast (CBE) as a means of reducing mortality from breast cancer (BC) is not established. The issue is relevant, as CBE may be a suitable option for countries in economic transition, where incidence rates are on the increase but limited resources do not permit screening by mammography. Our aims were to assess whether mass screening by CBE carried out by trained para-medical personnel is feasible in an urban population of a low-income country, and its efficacy in reducing BC mortality. Our study was designed as a randomised controlled trial of the effect on BC mortality of 5 annual CBE carried out by trained nurses. The target population was women aged 35-64 years, resident in 12 municipalities of the National Capital Region of Manila, Philippines. The units of randomization were the 202 health centres (HC) within the selected municipalities. During 1995 nurses and midwives were recruited and trained in performing CBE. The first round of screening took place in 1996-1997. The intervention however showed a refractory attitude of the population with respect to clinical follow-up and was discontinued after the completion of the first screening round. Cases of breast cancer occurring in the study population during 1996-1999 were identified by the 2 local population-based registries. In the single screening round 151,168 women were interviewed and offered CBE, 92% accepted (138,392), 3,479 were detected positive for a lump and referred for diagnosis. Of these only 1220 women (35%) completed diagnostic follow-up, whereas 42.4% actively refused further investigation even with home visits, and 22.5% were not traced. Of 53 cases that occurred among screen-positive women in the 2 years after CBE only 34 were diagnosed through the intervention. Eighty cases occurred among screen-negative women. The test sensitivity for CBE repeated annually was 53.2%. The actual sensitivity of the programme was 25.6% and positive predictive value 1%. Screen-detected cases were non-significantly less advanced than the others. Previous studies have shown that most breast cancer cases in the Philippines present at advanced stages and have an unfavourable outcome. Although CBE undertaken by health workers seems to offer a cost-effective approach to reducing mortality, the sensitivity of the screening programme in the real context was low. Moreover, in this relatively well-educated population, cultural and logistic barriers to seeking diagnosis and treatment persist and need to be addressed before any screening programme is introduced.

Statistics on cancer in China: cancer registration in 2002

The objective of this study was to determine how many population-based cancer registries exist in China, what methods are being used, and the statistical data that are available from them, and to identify future needs with respect to technical support. A two-stage survey was conducted in 2002 at provincial and cancer registry level. Based on the questionnaire used in these two stages, the basic distribution and descriptive information on population-based cancer registry practices in China are addressed. There are 48 cancer registries in China, covering 73 million people (5.7% of the total population of China in 2000). The oldest three registries are LinZhou, ShangHai and QiDong. There are marked variations in practice between registries, with respect to data collection, data management and coding. Differences are also found in administrative aspects and sources of financial support. In conclusion, this first national survey of Chinese cancer registry practice provides a benchmark against which development and standardization can be evaluated in the future. The survey suggests that lack of qualified personnel, insufficient funding support and lack of stability of the population are major problems in carrying out registration work in China. It also indicates several ways in which registry practice, and hence availability and quality of incidence and survival data can be improved.

Tobacco associated mortality in Mumbai (Bombay) India. Results of the Bombay Cohort Study

BACKGROUND

Little is known about the excess mortality from forms of tobacco use other than cigarette smoking that are widely prevalent in India, such as bidi smoking and the various forms of smokeless tobacco use. We report on absolute and relative risks of mortality among various kinds of ever tobacco users vs never-users in the city of Mumbai, India.

METHODS

Using the Mumbai voters' list as the selection frame, 99 570 individuals aged > or = 35 years were interviewed at their homes during 1992-94. At active follow-up (during 1997-99) after 5.5 years, 97 244 (97.7%) were traced. Among these, 7531 deaths (4119 men, 3412 women) were recorded, of which 89% died within study area. It was possible to abstract cause of death information from the records of the municipal corporation for 5470 deaths. These were coded using ICD 10.

RESULTS

The adjusted relative risk was 1.37 (95% CI 1.23-1.53) for (men) cigarette smokers and 1.64 (95% CI 1.47-1.81) for bidi smokers, with a significant dose-response relationship for number of bidis or cigarettes smoked. Women were essentially smokeless tobacco users; the adjusted relative risk was 1.25 (95% CI 1.15-1.35). The risk of deaths from respiratory diseases (RR 2.12, 95% CI 1.57-2.87), tuberculosis (RR 2.30, 95% CI 1.68-3.15), and neoplasms (RR 2.60, 95% CI 1.78-3.80) were significantly high in male smokers than never tobacco users.

CONCLUSIONS

Bidi is no less hazardous than cigarette smoking, and smokeless tobacco use may also result in significantly increased mortality.

A prospective study of diet, lifestyle, and genetic factors and the risk of cancer in Khon Kaen Province, northeast Thailand: description of the cohort

Cohort studies are the preferred design in observational epidemiology, but few involving the general population have been performed in Asia, and most concern affluent urban populations. The Khon Kaen study has recruited about 25,000 subjects, aged mainly 35-64, from villages in the relatively underdeveloped north-east of Thailand. All subjects underwent simple physical examination, completed an interviewer-administered questionnaire (including sections on lifestyle, habits, and diet) and donated specimens of blood, which were processed and stored in a biological bank at -20 degrees C. Female subjects (about 16,500) were offered screening by Pap smear, and specimens of cells from the cervix were stored at -20 degrees C. This paper describes the methodology of the study, and the characteristics of the participants. Almost all subjects are peasant farmers, with low annual income and body mass, although 14.6% of women had a BMI in the obese range (>30 kg/m(2)). Smoking was common among men (78% regular smokers, most of whom used home-produced cigarettes), but rare among women. Fertility levels were relatively high, with a more than half the women having four or more live births. 23.4% of subjects were infected with the liver fluke Opisthorchis viverrini, known to be highly endemic in this region. Follow-up of the cohort is by record-linkage to the provincial cancer registry. By 2003, 762 cancer cases had occurred, the most common being cancers of the liver (363 cases) and cervix uteri (44 cases). The antecedents of these cancers are being investigated using a nested case-control approach. The cohort will yield increasing numbers of cancers for study in the next decade, giving important information on the relative importance of dietary and lifestyle factors in a rural population, undergoing gradual transition to a more westernised lifestyle.

Cancer survival in Kampala, Uganda

Epidemiological data on the occurrence of cancer in sub-Saharan Africa are sparse, and population-based cancer survival data are even more difficult to obtain due to various logistic difficulties. The population-based Cancer Registry of Kampala, Uganda, has followed up the vital status of all registered cancer patients with one of the 14 most common forms of cancer, who were diagnosed and registered between 1993 and 1997 in the study area. We report 5-year absolute and relative survival estimates of the Ugandan patients and compare them with those of black American patients diagnosed in the same years and included in the SEER Program of the United States. In general, the prognosis of cancer patients in Uganda was very poor. Differences in survival between the two patient populations were particularly dramatic for those cancer types for which early diagnosis and effective treatment is possible. For example, 5-year relative survival was as low as 8.3% for colorectal cancer and 17.7% for cervical cancer in Uganda, compared with 54.2 and 63.9%, respectively, for black American patients. The collection of good-quality follow-up data was possible in the African environment. The very poor prognosis of Ugandan patients is most likely explained by the lack of access to early diagnosis and treatment options in the country. On the policy level, the results underscore the importance of the consistent application of the national cancer control programme guidelines as outlined by the World Health Organization.

Consistency of cytology diagnosis for cervical cancer between two laboratories

The principal approach to the prevention of cancer of the cervix uteri has been through screening programmes, using the cervical smear (Pap test) to detect precursor lesions. The sensitivity and specificity of Pap smears depend on the skill of the observer in recognizing and classifying a variety of cellular abnormalities. We have studied the reproducibility of cytological diagnosis, according the Bethesda classification, made by cytologists in Khon Kaen, north-east Thailand, and in Helsinki, Finland, on smears taken from rural women undergoing screening during 1994-2001. A total of 313 slides were reviewed. The prevalence of abnormalities was relatively high, since the series included smears judged abnormal in Khon Kaen or from women who developed cancer during follow-up, as well as a group whose smears were negative. In general, the reviewing cytologist in Finland evaluated more slides as abnormal than in the initial report. The level of agreement between the two observers was evaluated by calculating the coefficient of concordance (Kappa). The kappa score depended upon the degree of detail in the diagnosis; it was 0.43 for the presence or not of an epithelial abnormality (the General Categorization of the Bethesda system), and rather higher (0.5) for separating low grade from high grade (HSIL or worse) abnormalities or glandular lesions. Agreement was only fair (0.37) when the more detailed Bethesda categories (seven) were used. The reproducibility of cervical cytology evaluations is critical to the success of screening programmes, and in this programme in a moderate-high risk population of women in rural Thailand, we found that agreement between skilled observers, at the level of tests requiring diagnostic follow-up or not, was only moderate. The women in this study are being traced to evaluate the true sensitivity of screening in terms of the lesions found on histology, during a prolonged follow up of 4 or more years.

Sheep and goats: separating cervix and corpus uteri from imprecisely coded uterine cancer deaths, for studies of geographical and temporal variations in mortality

Analysing time trends in mortality from cancers of the cervix and corpus uteri using routine data sources (such as the World Health Organisation mortality database) involves two major problems: deaths certified as "uterus, unspecified site", and the presence of a combined category comprising unspecified and corpus uteri cancer deaths. To avoid misleading interpretations, the unspecified and the misclassified data must be incorporated into the analysis to produce rates that allow meaningful comparisons between populations and over time. Reallocation methods based on age- and time-specific distributions of cervix and corpus uteri cancer are applied to the unspecified deaths, while for those in the combined category, the age- and time-specific distributions of unspecified and corpus uteri cancer are considered. Adjustments of the general strategies for reallocation were developed to take into account the different quality of the data. Results from eight European countries with different degrees of coding precision are presented. The reallocation methods bring the cervix and corpus uteri mortality trends more in line with the trends for countries with more precise data while keeping the country-specific characteristics. In addition, the methods ensured the availability of time trends for corpus uteri cancer in women age 50 years and older, which were completely missing without reallocation. We propose generally applicable reallocation methods that allow valid time trend analysis of cervix and corpus uteri cancer mortality using datasets of varying precision. Our results show that any sensible analysis of time trends must involve procedures for correcting for unspecified and misclassified uterine cancer deaths. The modified data are available at .

Premalignant lesions of the esophagogastric mucosa

Premalignant esophagogastric (EG) lesions develop against a background of chronic inflammation, called a premalignant condition. For esophageal squamous cell cancer, causal factors include alcohol, tobacco, hot beverages, oral consumption of opioids, and probably infectious agents. For adenocarcinoma in the Barrett's esophagus (BE), gastroesophageal reflux disease (GERD) is the principal causal factor. At the EG junction, adenocarcinoma arises either from the esophagus or from the proximal stomach (cardia). In the distal stomach, chronic gastritis with atrophy is the premalignant condition related to Helicobacter pylori infection. A high intake of salt and low intake of antioxidants also play a role. The histopathology of EG premalignant lesions is now included in the groups low-grade and high-grade intraepithelial neoplasia (IEN) of the revised Vienna classification. Endoscopy is the gold standard for detection of the lesions at the preclinical stage and their appearance is described in subtypes of the type 0 of the Japanese classification, with a distinction between protruding and nonprotruding lesions. There is a priority for primary prevention of causal factors rather than for mass screening, which is justified only in Japan for the prevention of stomach cancer. The trend to early detection of premalignant lesions justifies the development of mini-invasive endoscopic procedures of treatment.

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.

Estimation and projection of the national profile of cancer mortality in China: 1991-2005

There are no national-level data on cancer mortality in China since two surveys in 1973–1975 and 1990–1992 (a 10% sample), but ongoing surveillance systems, based on nonrandom selected populations, give an indication as to the trends for major cancers. Based on a log-linear regression model with Poisson errors, the annual rates of change for 10 cancers and all other cancers combined, by age, sex and urban/rural residence were estimated from the data of the surveillance system of the Center for Health Information and Statistics, covering about 10% of the national population. These rates of change were applied to the survey data of 1990–1992 to estimate national mortality in the year 2000, and to make projections for 2005. Mortality rates for all cancers combined, adjusted for age, are predicted to change little between 1991 and 2005 (−0.8% in men and +2.5% in women), but population growth and ageing will result in an increasing number of deaths, from 1.2 to 1.8 million. The largest predicted increases are for the numbers of female breast (+155.4%) and lung cancers (+112.1% in men, +153.5% in women). For these two sites, mortality rates will almost double. Cancer will make an increasing contribution to the burden of diseases in China in the 21st century. The marked increases in risk of cancers of the lung, female breast and large bowel indicate priorities for prevention and control. The increasing trends in young age groups for cancers of the cervix, lung and female breast suggest that their predicted increases may be underestimated, and that more attention should be paid to strategies for their prevention and control.

Estimation and projection of the national profile of cancer mortality in China: 1991-2005

There are no national-level data on cancer mortality in China since two surveys in 1973-1975 and 1990-1992 (a 10% sample), but ongoing surveillance systems, based on nonrandom selected populations, give an indication as to the trends for major cancers. Based on a log-linear regression model with Poisson errors, the annual rates of change for 10 cancers and all other cancers combined, by age, sex and urban/rural residence were estimated from the data of the surveillance system of the Center for Health Information and Statistics, covering about 10% of the national population. These rates of change were applied to the survey data of 1990-1992 to estimate national mortality in the year 2000, and to make projections for 2005. Mortality rates for all cancers combined, adjusted for age, are predicted to change little between 1991 and 2005 (-0.8% in men and +2.5% in women), but population growth and ageing will result in an increasing number of deaths, from 1.2 to 1.8 million. The largest predicted increases are for the numbers of female breast (+155.4%) and lung cancers (+112.1% in men, +153.5% in women). For these two sites, mortality rates will almost double. Cancer will make an increasing contribution to the burden of diseases in China in the 21st century. The marked increases in risk of cancers of the lung, female breast and large bowel indicate priorities for prevention and control. The increasing trends in young age groups for cancers of the cervix, lung and female breast suggest that their predicted increases may be underestimated, and that more attention should be paid to strategies for their prevention and control.

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.