Paternal occupational contact level and childhood leukaemia in rural Scotland: a case-control study

In a national Scottish study of 809 cases of leukaemia and non-Hodgkins lymphoma diagnosed in 1950-89 among children aged 0-4 years who were born in Scotland, together with 2363 matched population controls, we investigated one aspect of the infective hypothesis. This concerns whether in rural areas (where the prevalence of susceptible individuals is likely to be higher) the risk is greater among the young children of men whose work involves contacts with many different people, particularly children, as noted in certain childhood infections. A positive trend was found in rural areas across 3 levels of increasing paternal occupational contact (as recorded at birth) by each of 2 previously defined classifications; no such effect was found in urban areas. The rural trend was more marked in that part of the study period with greater population mixing, but the difference from the period with less mixing was not itself significant, leaving open whether these rural findings reflect the extreme isolation of much of rural Scotland, or the effects in such areas of a degree of population mixing. In marked contrast, among the 850 cases and 2492 controls aged 5-14, those in rural areas in the higher population mixing period showed a significantly decreasing trend with increasing paternal occupational contact level. This would be consistent with immunity produced either by earlier infection at ages 0-4 years, or directly by low doses of the infective agent that were largely immunizing at these older ages. The findings overall provide further support for infection underlying childhood leukaemia and for the role of adults.     

High-contact paternal occupations, infection and childhood leukaemia: five studies of unusual population-mixing of adults.

The hypothesis has been tested that, among excesses of childhood leukaemia associated with extreme population-mixing, the incidence is higher for the children of men in occupations involving contact with many individuals (particularly children), as noted in certain childhood infections. Data on childhood leukaemia were examined from five previous studies of the author in which significant excesses had been found associated with population-mixing involving adults. Occupational titles were categorized according to the estimated level of work contacts as medium, high, very high or indeterminate. Occupations involving frequent contact with children were categorized as having a very high contact level given the high frequency of exposure to the infection postulated as underlying childhood leukaemia. There was a significant positive trend (P < 0.001) in childhood leukaemia risk at ages 0-14 years across the occupational contact categories from the reference group (comprising the medium and low plus indeterminate categories) through high to very high (i.e. high-child) contact categories in the combined data from the author''s five studies of adult population-mixing; this significant trend also applied at ages 0-4 (P < 0.001) and 5-14 (P < 0.01) years. The excess in the high category was mainly because of paternal occupations connected with the construction industry and transport, suggesting a broader definition of the ''very high'' contact category. No sign of these excesses was found in a limited examination of the question outside areas of population-mixing using mortality data for childhood leukaemia in the general population of England and Wales. The findings represent the first individual-based support for infection underlying childhood leukaemia that is promoted by population-mixing, as well as further support for the role of adults in transmission of the infection.     

Population mixing, socioeconomic status and incidence of childhood acute lymphoblastic leukaemia in England and Wales: analysis by census ward

In this population-based study of acute lymphoblastic leukaemia (ALL) diagnosed among children aged under 15 years in England and Wales during 1986-1995, we analysed incidence at census ward level in relation to a range of variables from the 1991 census, which could be relevant to theories of infectious aetiology. 'Population-mixing' measures, used as surrogates for quantity and diversity of infections entering the community, were calculated from census data on the origins and destinations of migrants in the year before the census. Incidence at ages 1-4 years tended independently to be higher in rural wards, to increase with the diversity of origin wards from which in-migrants had moved during the year before the census, and to be lower in the most deprived areas as categorised by the Carstairs index. This last association was much weaker when urban/rural status and in-migrants' diversity were allowed for. There was no evidence of association with population mixing or deprivation for ALL diagnosed at ages 0 or 5-14 years. The apparent specificity to the young childhood age group suggests that these associations are particularly marked for precursor B-cell ALL, with the disease more likely to occur when delayed exposure to infection leads to increased immunological stress, as predicted by Greaves. The association with diversity of incomers, especially in rural areas, is also consistent with the higher incidence of leukaemia predicted by Kinlen, where population mixing results in below average herd immunity to an infectious agent.     

Parental social contact in the work place and the risk of childhood acute lymphoblastic leukaemia

To study the possible relation between parental social contact through occupation, a marker for a child's risk of infection, and childhood acute lymphoblastic leukaemia (ALL), the parents of 294 children with ALL aged 0-14.9 years and 376 matched controls were interviewed about their jobs after their child's birth up to the age of 3 years. Job titles were assigned to a level of social contact, and an index of occupational social contact months was created using the level and the job duration. Positive interactions between this index and rural residence associated with an increased risk of childhood ALL and common ALL (c-ALL) were observed (interaction P-value=0.02 for both, using tertiles of contact months; interaction P-value=0.05 and 0.02 for ALL and c-ALL, respectively, using continuous contact months); such findings were not observed when job durations were ignored. Our data suggest that duration of parental occupation may be important when examining the association between parental social contact in the workplace and childhood leukaemia.     

Recent trends in breast cancer incidence in Sweden.

Breast cancer incidence in Sweden during the period 1984-93 shows no clear trend in women aged below 40 years but a transient increase at ages 50-69 years, probably as a result of mammography screening. Our data give no indication that use of oral contraceptives or replacement hormones have affected nationwide breast cancer incidence rates.     

1988-2002年中国10个市县大肠癌的流行特征

目的 了解中国人群中大肠癌的发病、死亡情况及流行特征.方法 从<中国试点市、县恶性肿瘤的发病与死亡>第1～3卷中,提取1988--2002年肿瘤登记资料完整的10个市县的大肠癌数据资料,统计分析1988--1992年、1993--1997年、1998--2002年3个时期大肠癌的发病率和死亡率,评价大肠癌1988--2002年15年问的流行趋势.结果 1988--2002年中国10个市县共登记大肠癌新发病例62 793例,占全部恶性肿瘤新发病例的9.27%,居第4位.粗发病率为20.10/10万,中国人口调整率(简称中调率)为11.75/10万,世界人口调整率(简称世调率)为15.63/10万.大肠癌死亡35 545例,占全部恶性肿瘤死亡病例的7.37%,居第5位.粗死亡率为11.38/10万,中调率为6.35/10万,世调率为8.70/10万.1988--2002年大肠癌发病率和死亡率均呈上升趋势,发病率增长38.56%,死亡率增长15.30%;呈现男性高于女性、城市高于农村的流行特征.结肠癌的发病率(10.77/10万)高于直肠癌(9.33/10万).1988--1992年和1993--1999年2个时期,直肠癌死亡率均高于结肠癌,而1998--2002年结肠癌死亡率高于直肠癌.结论 1988--2002年中国10个市县大肠癌发病率和死亡率均呈上升趋势,应进一步加强全人群大肠癌的预防和诊治工作.     

Incidence of childhood leukaemia in The Netherlands (1973-1980).

The childhood leukaemia incidence rate for the Netherlands was estimated at 3.11 per 100.000 children (aged 0-15 year) per year, based on a complete nation-wide childhood leukaemia registry comprising the period 1973-1980. Acute lymphocytic leukaemia (ALL) accounted for 82.4% of the patients, acute non-lymphocytic leukaemia for 13.6% and chronic myeloid leukaemia for 2.9%. ALL occurred more frequently in boys (sex ratio 1.2). The highest ALL rate was observed in the 3-4 year age group. These figures corresponded with the data of the Manchester Children''s Tumour Registry. Neither the incidence rates according to year of diagnosis nor the incidence rates according to year of birth showed a significant trend with time. The total leukaemia incidence rate in urban areas was somewhat higher than in rural areas. While the direct comparison of the incidence rate between these areas is not significant, the trend over the three categories of urbanisation is significant.     

2006-2020年中国食管癌死亡趋势及其年龄-时期-队列模型分析

目的:分析2006-2020年全国食管癌死亡趋势。方法:收集并整理中国卫生和计划生育统计年鉴中2006-2020年全国城市和农村食管癌死亡率数据,利用Joinpoint 回归模型分析食管癌死亡率的变化趋势,并计算平均年度变化百分比（average annual percent change,AAPC）值。运用年龄-时期-队列模型(age-period-cohort model,APC模型)分析年龄、时期、队列对死亡率变化的影响。结果:2006-2020年全国食管癌世标死亡率总体上呈下降趋势,城市男性、城市女性、农村男性、农村女性AAPC分别为-3.04（P=0.119）、-3.43%（P=0.041）、-5.58%（P<0.001）、-9.80%（P<0.001）,农村下降趋势更加明显。APC模型结果显示:年龄效应:食管癌死亡风险随着年龄的增加而升高,除农村男性80~84年龄段最高外,其余均在85+年龄段最高;时期效应:城市居民没有明显变化,农村居民呈下降趋势;队列效应:城市和农村出生队列越晚死亡风险越低,其中城市男性和农村男性在1921-1925年死亡风险最高,城市女性和农村女性1931-1950年最高。结论:2006-2020年全国食管癌死亡率呈下降趋势,农村和城市死亡率差异在缩小。人群食管癌死亡风险受年龄与出生队列影响较大,控制危险因素、扩大早癌筛查覆盖面有助于降低食管癌的死亡风险。     

2010—2016年广西肿瘤登记地区肝癌发病和死亡分析及变化趋势

目的 分析2010—2016年广西肿瘤登记地区肝癌发病和死亡特征及其变化趋势,为广西制定肝癌防控措施提供依据.方法 收集2010—2016年广西肿瘤登记地区上报的恶性肿瘤发病与死亡资料,计算肝癌发病率、死亡率、构成比、0～74岁累积率、35～64岁截缩率,按地区(城市/农村)、性别和年龄分层.采用2000年中国人口普查...     

Childhood leukaemia and ordnance factories in west Cumbria during the Second World War

Much evidence has accumulated that childhood leukaemia (CL) is a rare response to a common, but unidentified, infection and in particular that situations involving the unusual mixing of urban and rural groups (approximating to, respectively, groups infected with, and susceptible to, the relevant microorganism) can produce localised epidemics with consequent increases of the infrequent leukaemic complication. During the Second World War, explosives production factories were built and operated at Drigg and Sellafield, and a shell filling factory at Bootle, in west Cumbria, England, requiring substantial numbers of construction workers to be brought into this remote and isolated area. Following the design of an earlier study of CL near large (post-war) rural construction sites, mortality from this disease was investigated with the help of the Office of National Statistics, in the area around these Cumbrian factories where local workers largely lived, during the construction period and with particular reference to the overlapping construction and operational phase when the mixing of local and migrant workers would have been greatest. An excess of leukaemia deaths at ages 1-14 was found during the construction period (observed 3; observed/expected (O/E) 2.2, 95% confidence interval (CI): 0.6, 6.0), which was more marked and statistically significant during the overlap with operations (O 3; O/E 4.5, 95% CI: 1.1, 12.2), especially at ages 1-4 (O 2; O/E 7.1, CI: 1.2, 23.6). A previous investigation did not detect this excess because it considered only a small part of west Cumbria that omitted the communities where most of the workforce lived, having incorrectly attributed the post-war expansion of the village of Seascale (situated between Drigg and Sellafield) to the wartime ordnance factories. The present findings are consistent with the results of the earlier study of rural construction projects and with the general evidence that marked rural-urban population mixing increases the risk of CL.     

Service screening with mammography in Sweden--evaluation of effects of screening on breast cancer mortality in age group 40-49 years

The aim of the study was to develop a model for estimating the effect of the nation-wide service screening program with mammography on breast cancer mortality in Sweden. In 1997, the introduction of population-based service screening had been completed in all 26 counties. In approximately half of the counties suitable for evaluation, the lower age limit for invitation was 40 years (study population) and in the other half the age limit was 50 years (control population). The numbers of females aged 40-49 years for the two populations were 202 152 and 237 279, respectively (1988). The study and control populations were compared for the period 1986-1996 with regard to refined breast cancer mortality. To adjust for geographical differences, the period 1976-1986 was used as reference. With a mean follow-up time of 8 years, the estimated relative risk of breast cancer death in relation to invitation to service screening among women aged 40-49 years at breast cancer diagnosis was 0.91 (95% confidence interval 0.72-1.15). These findings were compatible with those presented in the previous overview of the Swedish randomized studies.     

中国膀胱癌发病现状及流行趋势分析

目的探讨我国膀胱癌发病现状及流行趋势。方法收集整理全国肿瘤登记中心1998～2008年登记的膀胱癌数据,包括膀胱癌发病率、发病构成、0～74岁发病累积率和年龄别发病率。分别按性别及城乡差异进行统计,分析中国男性与女性,城市与农村膀胱癌的发病现状和流行趋势。结果 2008年,全国肿瘤登记地区膀胱癌发病率为7.49/10万,占中国恶性肿瘤发病构成的2.50%,0～74岁中国膀胱癌发病累积率为0.52%。分性别统计,2008年中国男性膀胱癌的发病率为11.41/10万,是中国女性膀胱癌发病率(3.51/10万)的3.3倍。分城乡统计,2008年中国城市人口膀胱癌的发病率为8.55/10万,是中国农村人口膀胱癌发病率(3.55/10万)的2.4倍。1998～2008年全国肿瘤登记人口膀胱癌发病率呈现逐年增长趋势,10年间的年均增长率为4.60%。中国男性膀胱癌发病率在10年间的年均增长率为4.76%,略高于女性的4.32%。中国城市人口膀胱癌发病率在10年间的年均增长率为3.90%,低于农村人口的5.64%。膀胱癌发病率随年龄的增长而增加。2008年,中国人膀胱癌发病率在60岁以后超过肾肿瘤,居中国泌尿系恶性肿瘤发病第1位;至85岁以上年龄组膀胱癌发病率达到69.77/10万的峰值。在1998～2008年的10年间,中国膀胱癌年龄别发病率变化趋势不明显。结论中国相对于其他国家而言,膀胱癌发病水平中等。但近10年间,不论是男性还是女性,也不论城市或农村,膀胱癌发病率均呈现逐年增长趋势,应引起重视。     

中国肿瘤登记地区人群骨肿瘤发病分析

  目的  分析我国城市和农村恶性骨肿瘤的发病趋势和特点。  方法  根据全国32个肿瘤登记地区的2003年至2007年和部分1988年至2007年恶性骨肿瘤的发病数据库, 其中城市点14个, 农村点18个, 覆盖总人口255 430 909。肿瘤登记采用ICD-10和ICD-O-3编码。发病趋势分别应用变化百分比（PC）和年度变化百分比（APC）分析。  结果  2003年至2007年我国骨肿瘤粗发病率1.79/105, 其中城市1.72/105, 农村2.01/105; 中标率分别是1.39/105、1.21/105, 1.40/105, 骨肿瘤占全部恶性肿瘤发病的0.67%, 发病顺位居第24位。2003年至2007年骨肿瘤发病下降9.6%, 其中城市下降13.03%, 农村上升4.06%;分析1988年至2007年上海市、北京市、江苏启东市和河南林州市的发病趋势, 仅上海市骨肿瘤发病出现有统计学差异的下降, APC为-1.76（P=0.042）。  结论  中国农村骨肿瘤的发病高于城市, 并且农村发病呈现上升趋势, 城市呈下降趋势      

Sex hormones in women in rural China and in Britain

Plasma concentrations of certain hormones linked to breast cancer risk were measured in age-pooled samples from 3,250 rural Chinese women in 65 counties, and 300 British women, all aged 35-64. In age-groups 35-44, 45-54 and 55-64 respectively, mean oestradiol concentrations were 36% (P = 0.043), 90% (P less than 0.001) and 171% (P = 0.001) higher in the British than in the Chinese women, and mean testosterone concentrations were 48% (P less than 0.001), 68% (P less than 0.001) and 53% (P = 0.001) higher in the British than in the Chinese women. The difference in testosterone concentrations between the two countries appeared to be due largely to the lower average body weight in the Chinese women. Sex hormone binding globulin did not differ significantly between the two countries in age groups 35-44 and 45-54, but was 15% (P = 0.002) lower in the British than in the Chinese women at ages 55-64. Prolactin concentrations did not differ significantly between the two countries in any age group.     

Reversed urban-rural differences in breast cancer mortality (China, 2002-2008)

The purpose of this study was to examine the urban–rural difference in breast cancer mortality between 2002 and 2008 in China. A longitudinal analysis of mortality data was performed. Mortality data were extracted from Chinese Health Statistics Yearbook. Linear regression was used to examine the statistical significance of linear trend in mortality rates. The percent change in rates was used to measure the linear trend, which was calculated as regression coefficient × 100 × 6 divided by the rate of 2002. Between 2002 and 2008, the mortality from breast cancer increased by 201% among urban women (P < 0.05) while among rural women the rate did not show the significant increase, thus resulting in a reversed urban–rural difference (from −2.3/100,000 population in 2002 to 3.6 in 2008). Subgroup analysis showed that the reversed urban–rural difference was completely due to substantial increases among urban women aged 55–59 years and aged 75 years and above. In addition, significant decreases of breast cancer mortality were observed in urban women aged 35–49 years and in rural women aged 35–39 years (P < 0.05). The reversed urban–rural difference in breast cancer mortality during 2002–2008 is primarily caused by the increases among elderly urban women. Further studies are needed to understand the increases and to develop cost-effective interventions for elderly urban women in China.     

Increasing incidence of non-Hodgkin's lymphomas in Sweden 1958-1992

In recent years, there have been many reports from Europe and North-America describing non-Hodgkin's-lymphoma (NHL) as one of the most rapidly increasing malignancies. The reasons for this are poorly understood. This study describes the incidence pattern of NHL in Sweden during 1958-1992. A total of 26,925 cases (14,854 males and 12 071 females aged 15 years or older reported to the Swedish Cancer Registry between 1958 and 1992 were analysed. The increase in the age-adjusted incidence during this period was 433% among men and 386% among women, a mean yearly increase of 3.6% in men and 2.9% in women. The highest rates were seen during the most recent years and in the oldest age group, although there was a clear trend with increased age-adjusted incidence over time in both the male and the female groups in ages over 35. The incidence was low in the ages below 35 years. Known etiologic factors including viruses, environmental exposures and immunosuppression of different types are discussed. It is concluded that there has been a true increase in the age-adjusted incidence of non-Hodgkin's lymphomas in Sweden during the years 1958-1992.     

An ecologic study of childhood leukemia and population mixing in Ontario, Canada

Objective: To examine the association between population mixing and the incidence of childhood leukemia, specifically the acute lymphocytic leukemia (ALL) subtype among young children. Methods: This ecologic study was based on incidence rates of leukemia in children aged 0–14 years. The Ontario Cancer Registry was used to identify the residence of 1394 leukemia cases between 1978 and 1992. Ecologic units were composed of census subdivisions in a 5-year period. Percent population change, determined from the Census of Canada, was employed as a measure of population mixing. The relationship between population mixing and childhood leukemia was examined separately after stratifying by the level of geographic isolation, defined according to urban–rural status. Analyses were also conducted separately in specific age groups and for the ALL subtype. Results: Population growth in rural areas was associated with an increased incidence of leukemia, particularly for the ALL subtype in children aged 0–4 years (rate ratio = 1.8, 95% confidence interval 1.1–2.8, for a greater than 20% population change relative to no increase in population). In contrast, an elevated risk due to population mixing was not observed in urban areas. Conclusions: Results from this study are consistent with results from similar studies conducted in the United Kingdom, which are suggestive of a role for an infectious agent in the etiology of childhood leukemia, as proposed in the Kinlen hypothesis.     

Childhood leukaemia incidence and the population mixing hypothesis in US SEER data

We evaluated the infectious aetiology hypothesis of childhood leukaemia that rapid population influx into rural areas is associated with increased risk. Using data from the US SEER program, we found that in changes in rural county population sizes from 1980 to 1989 were associated with incidence rates for childhood acute lymphocytic leukaemia (ALL). The observed associations were strongest among children 0-4 years of age, born in the same state as diagnosis, in extremely rural counties, and when counties adjacent to nonrural counties were excluded. Similar analyses for brain and central nervous system (CNS) cancer in children, a disease less linked to this infectious hypothesis, provide evidence against methodologic bias. Similar evaluations for other decades were not meaningful due to limited sample sizes and, perhaps, increased population mobility.     

2004—2018年中国大陆地区城乡居民结直肠癌死亡趋势分析

目的 分析我国城乡2004—2018年结直肠癌死亡流行病学特征,为预防控制结直肠癌发病与死亡提供科学依据。方法 分析中国疾病预防控制中心发布的全国605个监测点的2004—2018年结直肠癌死亡病例,根据年龄、性别和地区进行分层,计算结直肠癌粗死亡率（crude mortality rate,CMR）、年龄标化死亡率（age-standardized mortality rate,ASMR）及其年度变化百分比（annual percent change,APC）。结果 2004—2018年我国结直肠癌死亡病例共213 513例,CMR为9.67/10万,ASMR为6.52/10万。15年间我国结直肠癌CMR呈上升趋势（APC=3.30%,P<0.001）。城市地区结直肠癌ASMR无明显变化,但东、西部农村地区结直肠癌ASMR呈上升趋势（APC=1.13%,P=0.020;APC=1.80%,P=0.004）,中部农村地区结直肠癌ASMR呈下降趋势（APC=-1.22%,P=0.010）。城乡地区男性结直肠癌CMR均高于女性（P<0.001）,城市地区女性结直肠癌ASMR呈下降趋势（APC=-1.10%,P<0.001）。城市地区20~39岁和40~59岁年龄组的结直肠癌ASMR呈下降趋势（APC=-3.04%,P=0.007;APC=-1.98%,P=0.002）;农村地区≥60岁年龄组结直肠癌ASMR呈上升趋势（APC=0.86%,P=0.030）。结论 我国结直肠癌死亡率逐年上升,城乡地区人群结直肠癌死亡率在年龄、性别、地区等各层均存在显著差异,未来应加大对农村地区人群结直肠癌的防控,以早期发现、诊断和治疗。     

1991-2011年中国肝癌死亡趋势的APC模型分析

目的 随着生活方式和环境的改变,居民恶性肿瘤呈现不同的发展趋势.本研究分析1991-2011年中国居民肝癌死亡率的流行变化趋势,为制订肝癌防治策略提供参考.方法 以1991-2011年中国15～84岁居民为研究对象,根据《中国卫生统计年鉴》的数据,采用年龄-时期-出生队列(age-period-cohort,APC)模型和Intrinsic Estimator算法估计肝癌死亡率的年龄效应、时期效应和出生队列效应.结果 1991-2011年,中国居民肝癌死亡率整体呈上升趋势,城市、农村全人群肝癌死亡率分别由1 991年的19.63/10万和22.25/10万上升至2011年的23.61/10万和27.12/10万.APC模型结果显示,中国居民肝癌死亡风险的年龄效应总体上随年龄增加而增大,城市和农村80～84岁居民的死亡风险分别比15～19岁增加了74倍和44倍.时期效应随年代缓慢上升,城市和农村总死亡风险分别增加了38.54％和25.86％.出生队列效应波动较大,整体呈下降趋势.结论 中国居民肝癌死亡风险的时期效应占主导地位,人口老龄化、代谢性疾病和不健康生活方式可能是肝癌死亡率时期效应上升的重要原因,在肝癌防治工作中重视这些方面的改善,有助于从整体上降低居民肝癌死亡率.