2002-2011年上海市浦东新区居民大肠癌发病情况及其趋势分析

目的分析上海市浦东新区居民2002-2011年大肠癌(colorectal cancer,CRC)发病情况并预测其发展趋势,为CRC防治策略提供参考。方法以2002-2011年上海市浦东新区常住户籍居民为研究对象,按世界标准人口标化率(age-standardized rate,ASR)计算CRC标化发病率,采用泊松近似法比较年龄和性别率值间的差异,并应用年均变化百分率(annual percent change,APC)计算其年均率值并进行趋势分析。结果浦东新区2002-2011年CRC新发10 779例,其中男5 749例,女5 030例;男性世界标化发病率(24.60/10万人年)高于女性(19.05/10万人年),标化发病比例为1.29∶1。男性CRC标化发病率上升趋势明显,APC=1.31%,P=0.021;女性CRC标化发病率有下降趋势,APC=-1.29%,P=0.018;男女合计标化发病率趋势差异无统计学意义,APC=0.20%,P=0.235。居民≤35岁CRC发病率相对较低,>35岁粗发病率呈明显上升趋势,z=77.94,P<0.01。结论 CRC防控应关注重点人群,并采取有效措施积极探讨CRC发病相关危险因素,从而降低CRC的发病率。     

上海市浦东新区居民2002-2014年胃癌发病情况及其趋势分析

目的 随着生活行为方式和环境的改变,居民恶性肿瘤发病率呈现不同发展趋势.本研究拟分析上海市浦东新区居民胃癌发病情况及其发展趋势,为制订胃癌防治策略提供参考.方法 以2002-2014年上海市浦东新区常住户籍居民为研究对象,按1985年世界标准人口计算胃癌标化发病率(age-standardized rate,ASR),并应用Join-point regression program线性回归分析率值的变化百分比(percent changes,PC)和年均变化百分比(annual percent change,APC)并进行趋势分析.结果 2002-2014年浦东新区新发胃癌13 795例,男8 740例,女5 055例,合计粗发病率为40.04/10万人年,其中男性粗发病率为50.75/10万人年,女性粗发病率为29.34/10万人年.男性世界标化发病率(29.70/10万人年)高于女性(13.92/10万人年),标化发病比例为2.13:1.男性胃癌世界标化发病率下降趋势明显;APC=-4.28％,Z=17.92,P＜0.001,女性胃癌世界标化发病率下降趋势明显,APC=-4.22％,Z=7.91,P＜0.001,合计标化发病率下降趋势明显,APC=-4.13％,Z=14.87,P＜0.001.居民胃癌发病率从40岁开始随年龄增加上升趋势明显(PC=9.42％,Z=7.79,P＜0.001),发病高峰位于80～84岁.结论 浦东新区胃癌发病率呈明显下降趋势,在胃癌防治工作中应重点关注中老年男性居民的胃健康,争取胃病早诊早治,降低胃癌发病率.     

Trends in incidence and overdiagnosis of thyroid cancer in China,Japan, and South Korea

We used data from 13 cancer registries in China, Japan, and South Korea to analyze time trends in overdiagnosis of thyroid cancer between 1998 and 2012. Age-standardized and age-specific incidence and annual percentage changes were calculated. The number of thyroid cancers diagnosed and the proportion attributable to overdiagnosis were estimated, with calculations stratified by sex and age group. The Spearman method was used to analyze the correlation between thyroid cancer incidence and overdiagnosis. From 1998 to 2012, both the incidence and proportions of overdiagnoses of thyroid cancer in China, Japan, and South Korea showed an increasing trend, with higher rates in women than men. South Korea had both the highest incidence for men (10.1/10⁵) and women (46.7/10⁵) and the highest proportions of overdiagnosis (men, 90.3%; women, 94.9%). The fastest growth in overdiagnosis was in Chinese men and women (annual percentage changes 6.1 and 4.6, respectively). We found significant positive correlations between age-standardized incidence and proportions of overdiagnosis for both men (Spearman r = 0.98, p < 0.05) and women (Spearman r = 0.99, p < 0.05) in the three countries. Age-specific incidence curves in Chinese and South Korean individuals were of an inverted U-shape. Overdiagnosis of thyroid cancer in Japan was mainly concentrated in middle-aged and older patients, whereas in China and South Korea, it occurred primarily in the middle-aged. The incidence and overdiagnosis of thyroid cancer in China, Japan, and South Korea are increasing, necessitating the implementation of comprehensive measures to reduce these overdiagnoses.     

Trends in childhood cancer incidence in the U.S. (1992-2004)

BACKGROUND: The etiology of most pediatric neoplasms remains elusive. Examination of population-based incidence data provides insight regarding etiology among various demographic groups and may result in new hypotheses. The objective of the current study was to present updated information regarding childhood cancer incidence and trends in the U.S. overall and among demographic subgroups, including Asian/Pacific Islanders and Hispanics, for whom to the authors' knowledge trends have not been previously examined. METHODS: Data obtained by 13 registries of the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program were evaluated to assess incidence and trends of common primary cancers diagnosed between 1992 and 2004 among children aged birth to 19 years. Frequencies, age-adjusted incidence rates, and joinpoint regression results, including annual percent change (APC) in incidence rates (and 95% confidence intervals [95% CI]), were calculated. RESULTS: Between 1992 and 2004, a modest, nonsignificant increase in the average annual incidence rate (APC, 0.4%; 95% CI, -0.1%-0.8%) was observed for all pediatric cancer diagnoses combined. There was a suggestion of an increase in leukemia (APC, 0.7%; 95% CI, -0.1%-1.5%), and acute lymphoblastic leukemia in particular (APC, 0.8%; 95% CI, -0.4%-1.9%), whereas rates for central nervous system tumors overall were stable (APC, -0.1%; 95% CI, -1.1%-1.0%); 2 joinpoints were observed for astrocytoma. Rate increases were noted for hepatoblastoma (APC, 4.3%; 95% CI, 0.2%-8.7%) and melanoma (APC, 2.8%; 95% CI, 0.5%-5.1%). Differences by demographic group (sex, age, and race/ethnicity) are also described. CONCLUSIONS: The observed trends reinforce an ongoing need for population-based surveillance and further etiologic studies.     

Characteristics and trends in incidence of childhood cancer in Beijing,China, 2000-2009

Objective： To investigate the characteristics and incidence trends of childhood cancer in Beijing, China, from 2000 to 2009. Methods： A total of 1,274 cases with childhood cancer in Beijing from 2000 to 2009 were included in the study. All rates were age-standardized using the direct method to the world standard population and expressed per million person-years. Incidence trends were characterized by calculating annual percent change （APC） usingJoinpoint Regression Program. Results： The crude incidence rate was 106.47 per million [age-standardized rate （ASR） 113.34] between 2000 and 2009 in Beijing with the most common diagnoses, leukemia （N=505, 39.64%, ASR 45.20）, followed by central nervous system （CNS） tumors （N=228, 17.90%, ASR 19.28） and lyrnphoma （N=91, 7.14%, ASR 6.97）. The incidence for all childhood cancers combined has increased during the study period, with an APC of 5.84% [95% confidence interval （95% CI）： 1.0-10.9] after adjusted by world population. The ASR of all combined cancers in boys showed a slight, but no significant increase, with an APC of 5.33 % （95 % CI： -0.6- 11.6）; for girls, the trends increased significantly, with an APC of 6.54% （95% CI： 1.5-11.8）. Conclusions： The incidence rate of childhood cancer in Beijing was higher than the average level of China and lower than that of western countries. The incidence trends of childhood cancer, especially leukemia among girls showed a significantly increase from 2000 to 2009. While among boys, no substantially change was seen during the observed time period. Some sex-specific trends by subcategories and trends of major cancers in different age groups by cancer site merit further investigation.     

Trends in testicular cancer incidence and mortality in 22 European countries: continuing increases in incidence and declines in mortality

This study profiles testicular cancer incidence and mortality across Europe, and the effects of age, period and generational influences, using age-period-cohort modeling. Despite a 5-fold variation in incidence rates, there were consistent mean increases in incidence in each of the 12 European countries studied, ranging from around 6% per annum (Spain and Slovenia) to 1-2% (Norway). In contrast, declines in testicular cancer mortality of 3-6% per annum were observed in the 1980s and 1990s for the majority of the 22 countries studied, particularly in Northern and Western Europe. The mortality trends in several European countries were rather stable (Romania and Bulgaria) or increasing (Portugal and Croatia). Short-term attenuations in increasing cohort-specific risk of incidence were indicated among men born between 1940 and 1945 in 7 European countries. In Switzerland, successive generations born from the mid 1960s may have experienced a steadily declining risk of disease occurrence. While the underlying risk factors responsible remain elusive, the temporal and geographical variability in incidence may point to an epidemic in different phases in different countries-the result of country-specific differences in the prevalence of one or several ubiquitous and highly prevalent environmental determinants of the disease. Advances in treatment have led to major declines in mortality in many European countries from the mid 1970s, which has translated to cohorts of men at successively lower risk of death from the disease. Slower progress in the delivery of optimal care is however evident from the mortality trends in several lower-resource countries in Southern and Eastern Europe. The first beneficiaries of therapy in these populations may be those men born--rather than diagnosed--in the era of major breakthrough in testicular cancer care.     

Trends in incidence of anal cancer and high-grade anal intraepithelial neoplasia in Denmark, 1978-2008

The aim of the study was to determine the incidences of anal cancer and high-grade anal intraepithelial neoplasia (AIN2/3) over time in Danish women and men. Describing the burden of anal cancer and AIN may be valuable in future evaluations of the human papillomavirus (HPV) vaccine. We included all anal cancers in the Danish Cancer Register in the period 1978-2008 and all cases of AIN2/3 in the Danish Registry of Pathology. Overall and age-, period- and histology-specific incidence rates were estimated. During the 30-year period, 2,187 anal cancers were identified, two thirds of which were in women. Between 1978-1982 and 2003-2008, the age-standardized incidence rate of anal cancer increased from 0.68 to 1.48 per 100,000 person-years in women and from 0.45 to 0.80 per 100,000 person-years in men. Although there is no systematic screening for AIN in Denmark, we nevertheless identified 608 cases of AIN2/3 during the study period. The average annual percentage change of 5% between 1998 and 2008 represents a steep increase in the incidence of AIN in both genders. Furthermore, the incidence rate of HPV-associated anal cancers increased significantly, whereas that of non-HPV-associated histological types levelled out or even declined during the 30 years of observation. In women, the increase in HPV-associated cancers was more pronounced among those under 60 years of age. Our findings indicate that vaccines against HPV might play an important role in the prevention of anal cancer and its precursor lesions.     

Cambodian cancer incidence rates in California and Washington, 1998-2002

BACKGROUND.

Among the many diverse Asian ethnic groups living in the US, Cambodian immigrants comprise a small fraction (1.8%) of the total Asian population. Because of their small numbers, Cambodian vital statistics are often combined into Southeast Asian (SA) cancer data consisting of Vietnamese, Thais, Laotians, and Hmong.

METHODS.

The 2000 Census counts were used for 2 Cambodian populations, Cambodians alone and Cambodians alone and in combination with any other racial/ethnic group for California and for Seattle (Puget Sound area), Washington. Then the cancer incidence rates were calculated using cancer cases from the California and Puget Sound cancer registries between 1998–2002. The 1998–2002 annual age‐adjusted incidence rates, upper bound rates (based on the Cambodian alone population), lower bound rates (based on the Cambodians alone or in combination population) are reported and compared with the rates in the non‐Hispanic White (NHW) population in these regions.

RESULTS.

The top 5 cancers in Cambodian males are lung and bronchus, liver, prostate, colorectal, and stomach cancers. The sites where the rates are higher in male Cambodians than NHW males are (in ascending rank) nasopharynx, liver, stomach, myeloma, and lung and bronchus. The top 5 cancers for female Cambodians are breast, lung, colon and rectum, cervix, and thyroid. The sites where female rates are greater than NHW female rates are (in ascending rank) nasopharynx, liver, stomach, cervix uteri, oral cavity, and thyroid.

CONCLUSIONS.

The challenges to address the health issues of Cambodians are complicated by historical events that caused their emigration to the US. Many of the immigrants are survivors of the holocaust in Cambodia. Health programs for Cambodians must deal with the consequences of these issues as well as cultural issues of language and religion in helping Cambodians to reduce their cancer disparities. Cancer 2007. © 2007 American Cancer Society.     

Time trend analysis of gastric cancer incidence in Japan by histological types, 1975-1989

Since different histological types (HT) of gastric cancer (GC) may differ in their aetiology, time trend analysis by HT may afford an insight into aetiology. From the Gastric Cancer Registry of Japan, 161 067 cases diagnosed were retrieved between 1975 and 1989 to calculate the annual relative frequencies, stratified by age group and sex, of HT according to the Lauren and the Japanese Research Society for Gastric Cancer (JRSGC) classifications. Age- and sex-specific incidence rates by HT were estimated by multiplying the corresponding national cancer incidence rates of GC by the relative frequencies. Logistic regression models stratified by sex and age group were fitted to determine the time trends of HT. Using the Lauren classification, a decreasing trend of the intestinal type and a stable trend of the diffuse type were found. By the JRSGC classification, significant decreasing trends for most age groups were found for papillary and mucinous adenocarcinomas. Tubular adenocarcinomas (well differentiated type) showed a decreasing trend only in younger age groups. Tubular (moderately differentiated type), poorly differentiated adenocarcinomas, and signet ring cell carcinoma were statistically stable during the period. Considering changes in lifestyles of the Japanese, the result suggests that there are three aetiological types of GC.     

2012年至2016年陕西省商洛市商州区肺癌发病及时间趋势分析

目的:分析2012年至2016年陕西省商洛市商州区肺癌发病情况及时间趋势,了解商州区肺癌年龄别发病率的变化趋势。方法:收集陕西省商洛市商州区2012年至2016年肿瘤登记数据中ICD10编码为C33-C34的全部肺癌患者和同期人口数据。采用Excel 2007计算分析2012年至2016年商州区肺癌发病率、标化发病率、累计率、截缩率以及性别别、年龄别发病率。采用SPSS 25.0分析各年份肺癌不同性别发病率。采用Joinpoint regression program 4.8.01软件进行2012年至2016年肺癌粗率、标化率、年龄别率的年度变化百分比（APC）以及95%可信区间。结果:2012年至2016年商州区累计报告肺癌新发病例1 295例,发病率为46.29/10万,中标率为39.75/10万,截缩率为60.98%,0~74岁累计率为5.30%。2012年至2016年商州区肺癌男性与女性发病率性别比为3.56∶1,男女肺癌发病率差异有统计学差异（P=0.00）。2012年至2016年商州区总体年龄别肺癌发病率整体呈上升趋势,APC为9.6%（95%CI:8.5%~10.7%）,有3个Joinpoint点,30岁以下APC为9.9%（95%CI:8.4%~11.4%）,30~44岁APC为24.2%（95%CI:16.0%~33.1%）,45~64岁APC为10.3%（95%CI:6.6%~14.2%）,65岁以上APC为-1.2%（95%CI:-3.3%~1.0%）。2012 年至2016年,商州区肺癌发病率APC为1.3%(95%CI:-17.9%~25.1%),趋势检验无统计学差异。结论:2012年至2016年商州区肺癌发病趋势较为平稳。总体肺癌发病率处于全国平均水平,男性肺癌发病率高于女性,45~64岁陕西省商洛市男性肺癌应作为陕西省商洛市商州区肺癌防控的重点人群。     

启东市1972~2011年肺癌发病趋势分析

[目的]分析启东市1972-2011年肺癌发病趋势,为制定肺癌预防控制措施与策略提供依据。[方法]肺癌发病资料来自启东肿瘤登记处,计算粗发病率、中国人口标化率（中标率）、世界人口标化率（世标率）、35-64岁截缩率、0-74岁累积率、累积风险、变化百分比（PC）、年均变化百分比（APC）、各时期发病率及出生队列发病率等指标。[结果]启东1972-2011年肺癌发病15 340例,其中男性11 028例,女性4312例。肺癌粗发病率为34.12/10万,中标率为15.74/10万,世标率为25.41/10万。35-64岁截缩发病率为36.96/10万,0-74岁累积发病率为3.27%,肺癌发病的累积风险为3.22%。肺癌的发病率从1972年的12.09/10万上升到2011年76.09/10万,PC为626.68%,APC为4.92%。[结论]40年中,启东肺癌的发病率约上升了6倍;加强肺癌预防与控制已成为当务之急。     

启东市1972~2011年胃癌发病趋势分析

[目的]探讨启东市1972-2011年胃癌发病率变化趋势。[方法]基于启东市1972-2011年癌症发病登记数据库,对胃癌发病率作性别、年龄别、时间趋势分析,计算指标包括粗发病率、中国人口标化率（中标率）、世界人口标化率（世标率）、35-64岁截缩率、0-74岁累积率、累积风险、变化百分比（PC）及年均变化百分比（APC）等。[结果]1972-2011年启东胃癌发病15 401例（男性9804例,女性5597例）,粗发病率为34.26/10万,占全部癌症发病的16.60%,位居癌症发病第2位。中标率和世标率分别为16.25/10万和25.59/10万;35-64岁截缩发病率为40.03/10万;0-74岁累积发病率为3.15%,累积风险为3.10%。40年间胃癌发病的粗率、中标率和世标率的变化百分比（PC）分别为＋21.90%、-55.32%与-51.20%,年均变化百分比（APC）分别为＋0.49%、-2.12%、-2.06%。各时期胃癌发病率显示25-74岁各年龄组的发病率有下降趋势。年龄—出生队列方法分析显示,25-79岁各年龄组出生队列发病率有下降趋势。[结论]启东胃癌40年粗发病率总体维持在较高水平,但标化发病率已呈下降趋势。启东人群中胃癌的进一步下降,是可以预期的。     

启东市1972~2011年结直肠癌发病趋势分析

[目的]探讨启东市1972-2011年结直肠癌发病变化趋势,为制定结直肠癌预防控制措施与策略提供依据。[方法]采用启东市1972-2011年癌症发病登记数据库,对结直肠癌发病率作性别、年龄、时间趋势分析,计算指标包括粗发病率、中国人口标化率（中标率）、世界人口标化率（世标率）、35-64岁截缩率、0-74岁累积率、累积风险率、变化百分比（PC）及年均变化百分比（APC）等。[结果]1972-2011年启东结直肠癌发病6035例（男性2926例,女性3109例）,粗发率为13.43/10万,占全部癌症发病的6.50%,位居癌症发病第4位。中标率和世标率分别为6.20/10万和9.80/10万;35-64岁截缩发病率为14.36/10万;0-74岁累积发病率为1.16%;结直肠癌发病的累积风险为1.15%。40年间结直肠癌发病的粗率、中标率和世标率的变化百分比（PC）分别为373.63%、67.42%与88.38%,年均变化百分比（APC）分别为4.21%、1.38%、1.58%。各时期结直肠癌发病率显示55岁以上各年龄组发病率有显著的上升趋势。年龄—出生队列方法分析显示,45岁以后的各年龄组出生队列发病率有明显的上升趋势。40年中结肠癌、直肠癌的粗率分别为3.93/10万、9.49/10万,中标率分别为1.81/10万、4.39/10万,世标率分别为2.87/10万、6.94/10万。40年中直肠癌在结直肠癌的占比为70.72%,近期直肠癌的占比有所下降。[结论]启东40年来结直肠癌发病率有明显上升趋势,应加强结直肠癌的防控。     

江苏省昆山市2006-2014年恶性肿瘤发病趋势分析

目的 恶性肿瘤发病率相关的研究较多,但是较长时期分年龄组恶性肿瘤发病率趋势和顺位变化的研究不多.本研究主要分析江苏省昆山市2006-2014年分年龄组肿瘤发病率和顺位变化趋势.方法 2006-2014年恶性肿瘤发病病例来源于昆山市肿瘤登记,用中国2000年第5次人口普查年龄结构计算分性别的年龄标化发病率(中标率),使用年度变化百分比(annual change percentage,APC)评价发病率在年份之间变化趋势.结果 男性人群恶性肿瘤中标率从2006年的218.77/10万上升到2014年的222.67/10万(APC=0.3％,95％CI:-0.4％～1.0％);女性人群中标率从2006年的146.53/10万上升到2014年的217.86/10万(APC=4.5％,95％CI:3.3％～5.7％).男性人群中,0～29岁人群(APC=5.4％,95％CI:0.3％～10.5％)标化发病率随着时间明显上升,30～69岁及≥70岁年龄组标化发病率无明显变化趋势.女性人群中,0～29岁(APC=3.7％,95％CI:0.7％～6.7％)和30～69岁(APC=5.9％,95％CI:4.1％～7.7％)年龄组标化发病率随着时间明显上升,而≥70岁年龄组标化发病率无明显变化趋势.男性人群中,发病顺位上升明显的有肺癌、结直肠癌、前列腺癌和甲状腺癌;在女性人群中,发病顺位上升的有甲状腺癌和卵巢癌.结论 江苏省昆山市2006-2014年女性人群恶性肿瘤标化发病率在0～69岁年龄组均明显上升,而男性人群标化发病率在0～29岁年龄组明显上升.发病顺位以肺癌和甲状腺癌最为明显,在高危人群探究践行癌症防控具有重要意义.     

中国部分市县1998～2002年肺癌的发病与死亡

[目的]探讨中国居民肺癌的发病、死亡流行特征。[方法]分析中国30个肿瘤登记处1998-2002年肺癌登记资料。[结果]肺癌新病例69597例，死亡病例61090例。肺癌世界人口调整发病率介于116．9／10万～9．9／10万之间。肺癌世界人口调整死亡率介于43．9／10万～8．1／10万之间。[结论]肺癌是威胁我国居民身体健康的主要恶性肿瘤，应作为当前肿瘤防治工作的重点。     

中国部分市县1998～2002年食管癌发病与死亡

[目的]探讨中国居民食管癌的发病和死亡特征。[方法]分析中国30个肿瘤登记处1998～2002年食管癌登记资料。[结果]食管癌新病例38339例，死亡30116例。食管癌粗发病率在0.3/10万～115.1/10万之间，世界人口调整发病率在0.3/10万～132.7/10万之间。食管癌粗死亡率在1.3/10万～90.9/10万之间，世界人口调整死亡率在2.7/10万～110.6/10万之间。[结论]各地的食管癌发病率差异较大。在不少地区尤其是农村，食管癌是严重威胁居民健康的主要恶性肿瘤，应积极开展防治工作。     

广州市2000～2002年大肠癌的发病率分析

背景与目的：随着饮食习惯的改变,大肠癌的发病率逐年上升。本研究分析广州市大肠癌的发病率。为大肠癌的防治研究提供科学依据。方法：收集广州市肿瘤登记处2000～2002年大肠癌的发病资料和死亡资料,统计和分析大肠癌的粗发病率和死亡率、世界标化发病率和死亡率等指标。结果：广州市2000—2002年结肠癌的粗发病率和死亡率分别为13．4／10万（其中男性13．5／10万,女性13．3／10万）和7．1／10万（其中男性7．3／10万,女性6．9／10万）。广州市2000—2002年直肠癌的粗发病率和死亡率分别为9．6／10万（其中男性10．8／10万,女性8．2／10万）和5．0／10万（其中男性5．5／10万,女性4．5／10万）。结肠癌和直肠癌的发病率分别位居全部恶性肿瘤的第5位和第7位。大肠癌的发病率随着年龄的增长而上升。结论：广州市大肠癌发病率较高,应加强防治研究。     

Increasing incidence of childhood leukemia in Northwest Italy, 1975-98

Although some childhood cancer registries reported increasing incidence, the evidence and magnitude of time trends in the incidence of childhood leukemia are debated and the scientific evidence is conflicting. Only limited data have so far been supplied from Southern European countries. We present an analysis of the incidence trend of childhood leukemia in Piedmont (NW Italy) in 1975-98, based on data from the population-based childhood cancer registry. The Childhood Cancer Registry of Piedmont has been recording cases of childhood neoplasms since 1967. Procedures have been uniform and are based on an active search for cases and relevant information. Only cases with confirmed residence in Piedmont at diagnosis are included. Eight hundred cases of leukemia (622 acute lymphoblastic [ALL], 133 acute nonlymphoblastic [AnLL], 45 other and unspecified) were recorded in the period 1975-98 considered in our study. Incidence trends were analyzed using piecewise regression and Poisson regression, based on annual incidence rates. As results from the 2 analyses were similar, only the former were reported. In the age group 1-4 years, a statistically significant annual 2.6% increase in incidence rate of ALL (adjusted by age and gender; 95% confidence interval [CI] 1.13-4.13) was estimated. There was no evidence of increase in other age groups. During 1980-98, a statistically significant 4.4% annual increase (95% CI 1.86-6.90) was seen for pre-B-All in the age group 1-4 years. An increase was also seen for T-ALL that was not statistically significant. Sensitivity analyses were conducted, with no relevant differences from the main results. Our data suggest an increasing trend in ALL incidence for children between the ages of 1 and 4 years. These results are unlikely to be explained by changes in quality of data or exhaustiveness in reporting in the study period. The results were not changed in the sensitivity analyses we conducted. Possible causes to be investigated include environmental factors, changes in family size and parental age, socioeconomic conditions and geographical distribution of cases.