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Background: Increases in recorded childhood cancer incidence are widely reported, but do not necessarily represent real increases in risk. Time trends might conceal underlying steps caused by changes in diagnosis and registration procedures., Methods: Using records from the National Registry of Childhood Tumours 1966-2005 (N=54650), the age-sex-standardised rate for residents of Great Britain aged under 15 years was calculated by individual year of diagnosis for each cancer subtype, and the average annual percentage change (trend) was assessed. The timing of assumed step changes in rate was estimated by iterative Poisson regression, and compared graphically with the approximate timing of innovations previously identified from published sources., Results: Estimated timing of underlying steps approximately coincided with the following relevant innovations: biochemical assays, mid-1980s (hepatic and germ-cell cancer); diagnostic imaging, mid-1980s to early 1990s (intracranial/intraspinal tumours, neuroblastoma, soft-tissue sarcoma); revised cancer registration scheme, 1971 (leukaemia, bone and soft-tissue sarcoma); mandatory registration, 1993 (intracranial/intraspinal tumours, retinoblastoma, melanoma/carcinoma); cancer registration improvements, 2001 (leukaemia, renal and hepatic cancer)., Conclusion: While the possibility of some real change in risk cannot be excluded, for many cancer subtypes the estimated timing of underlying step changes in rate appeared to correspond with changes in diagnosis or registration procedures. Childhood cancer may have been considerably under-recorded in the past.

Background: Completeness of ascertainment is a very important aspect of cancer registration. There is no recent published estimate for childhood cancer in Britain., Methods: We estimated completeness of ascertainment by the National Registry of Childhood Tumours for cancer diagnosed under age 15 years in residents of Britain during 2003-04. Stratified two-source capture-recapture was applied to notifications from general cancer registries (CRs) and specialist clinicians. Variation in notification patterns was assessed by logistic regression. Results were verified by cross-checking with Hospital Episode Statistics for leukaemia patients from England born in 1998 and diagnosed before 2005., Results: CRs notified 92-96% of registrations, and specialist clinicians 93%. Notification patterns varied slightly according to registry region, age at diagnosis, diagnostic group, socioeconomic status, and whether the patient had died. Irrespective of stratification by these factors, the overall completeness estimate was 99-100% (assuming independence of sources). Estimated completeness was at least 99% within all subgroups, except for one region (Thames 98-99%) and two small diagnostic groups (germ-cell and gonadal cancer 98-99%, melanoma and non-skin cancer 97-98%)., Interpretation: The independence assumption cannot be fully justified, as both sources used records from treatment centres. With this caveat, ascertainment of recently diagnosed childhood cancer in Britain appears to be virtually complete.

Objective: To determine cancer morbidity in members of the armed forces who took part in tests of chemical warfare agents from 1941 to 1989., Design: Historical cohort study, with cohort members followed up to December 2004., Data Source: Archive of UK government research facility at Porton Down, UK military personnel records, and national death and cancer records., Participants: All veterans included in the cohort study of mortality, excluding those known to have died or been lost to follow-up before 1 January 1971 when the UK cancer registration system commenced: 17,013 male members of the UK armed forces who took part in tests (Porton Down veterans) and a similar group of 16,520 men who did not (non-Porton Down veterans)., Main Outcome Measures: Cancer morbidity in each group of veterans; rate ratios, with 95% confidence intervals, adjusted for age group and calendar period., Results: 3457 cancers were reported in the Porton Down veterans compared with 3380 cancers in the non-Porton Down veterans. While overall cancer morbidity was the same in both groups (rate ratio 1.00, 95% confidence interval 0.95 to 1.05), Porton Down veterans had higher rates of ill defined malignant neoplasms (1.12, 1.02 to 1.22), in situ neoplasms (1.45, 1.06 to 2.00), and those of uncertain or unknown behaviour (1.32, 1.01 to 1.73)., Conclusion: Overall cancer morbidity in Porton Down veterans was no different from that in non-Porton Down veterans.

Aim: To examine cancer mortality by occupation among New Zealand women, 1988-1997., Method: Proportional mortality ratios (PMRs) were calculated for the six most common general occupations among women: clerical workers, health professionals, teachers, farmers, cleaners and textile workers. Age groups examined were those aged 20-59 and those > or =20 years. Data on occupation was obtained from death certificates., Results: From 1988-1997, annually 12-54% of women had a codeable occupation on their death certificate, leaving 3079 deaths among women 20-59 years, and 7236 in those > or =20 years for analysis. Leukaemia was significantly increased in health professionals aged > or =20 years (PMR=1.52; 95% CI: 1.08-2.09, n=38). In nurses alone, the PMR for leukaemia was 1.42; 95% CI: 0.96-2.01, n=31)., Conclusion: This study represents the first systematic examination of cancer mortality by occupation among women in New Zealand. These data should be examined routinely as part of regular surveillance of occupational cancer among women. Avenues for further research identified particularly include an analytical study of leukaemia and other cancers among female health professionals.

Associations between work in the electrical and electronic industry and cancer incidence were assessed using data for 371 890 cancers registered in England between 1981 and 1987, of which 7981 were in electrical workers. Proportional registration ratios (PRRs) were calculated, both with and without the commonest cancers, with adjustment for age, social class, cancer registry of origin and sex. Of four cancers previously linked with work in the electrical and electronic industry (leukaemia, brain, breast and melanoma), only two were significantly raised: leukaemia (PRR=124, 95% CI=109-142, based on 217 cases) and malignant brain cancer (PRR=118, 95% CI=103-136, based on 204 cases). A significantly increased risk was also observed for pleural cancer (PRR=201, 95% CI=167-241, based on 115 cases). The histology of almost 90% of pleural cancers was coded as mesothelioma, confirming the previously observed association between pleural cancer and exposure to asbestos in electrical workers. The extent to which workplace exposures to extremely low frequency electromagnetic fields explains the excesses seen here for leukaemia and brain cancer requires further study.

One hundred and fifty-two patients in whom a diagnosis of dermatitis herpetiformis was made at St John's Hospital for Diseases of the Skin, London, during 1950-85, were followed from the date of diagnosis to the end of 1989 for mortality, and from 1971, or the date of diagnosis if later, to 1986 for cancer incidence. Thirty-eight deaths occurred under the age of 85, slightly fewer than expected on the basis of national general population rates [standardized mortality ratio (SMR) = 87; 95% confidence interval (CI) 61-119]. All-cause mortality was somewhat lower in patients who had followed a gluten-free diet (SMR = 51; 17-120) than in those who had not (SMR = 97; 66-136), but the difference in SMRs was not significant (P = 0.3). Cancer mortality was non-significantly below expectations from national rates (SMR = 72; 31-142), but cancer incidence was significantly increased [standardized registration ratio (SRR) = 394; 180-749]. No particular cancer site accounted for the cancer incidence excess. One death occurred from cancer of the small intestine (SMR = 4953, P = 0.04), and one lymphoma was incident (SRR = 1555, P = 0.12). Increased risks of these malignancies have previously been found to be associated with coeliac disease (which is present in many patients with dermatitis herpetiformis), and with dermatitis herpetiformis, respectively. Mortality from ischaemic heart disease (IHD) was significantly below national rates (SMR = 37; 95% CI 12-86), and was similar in patients who had followed a gluten-free diet and those who had not.(ABSTRACT TRUNCATED AT 250 WORDS)