Trend analysis of cancer incidence in Japan using data from selected population-based cancer registries.

Population-based cancer registries are operated by over 80% of prefectures in Japan. However, only a limited proportion of the registries can provide long-term incidence data. Here, we aimed to establish a method for monitoring cancer incidence trends in Japan using data from selected prefectures. Based on the availability of long-term (≥ 20 years) high-quality data, we collected incidence data from five prefectures (Miyagi, Yamagata, Fukui, Osaka, and Nagasaki), which included an annual average of 54,539 primary cancer cases diagnosed between 1985 and 2004. Cancer mortality data for 1995-2004 were obtained from the vital statistics. Representativeness and homogeneity of the trends were examined by funnel plot analysis of log-linear regression coefficients calculated for the most recent 10 years of data (1995-2004) of age-standardized rates (ASR). The ASR of incidence for five prefectures in total (5-pref total) showed a significant decrease, with an annual percent change (APC) of -1.0 (95% confidence interval [CI] -1.4: -0.6) for males and -0.4 (95% CI -0.8: -0.1) for females. Excluding data from Osaka (4-pref total) reversed the decreasing trend; the corresponding APC was +0.4 (95% CI -0.2: +1.0) for males and +0.7 (95% CI +0.5: +0.9) for females. The APCs for the ASR of mortality for the 4-pref total (males, -1.5; females, -1.3) were more representative of nationwide data (males, -1.4 [95% CI -1.7: -1.2]; females, -1.1 [95% CI -1.4: -0.9]) than those for the 5-pref total (males, -1.7; females, -1.4). We conclude that using data from Miyagi, Yamagata, Fukui, and Nagasaki prefectures, with continuous monitoring of the representativeness of the data, is a provisionally relevant way to evaluate cancer incidence trends in Japan.

Cancer incidence and incidence rates in Japan in 2006: based on data from 15 population-based cancer registries in the monitoring of cancer incidence in Japan (MCIJ) project.

The Japan Cancer Surveillance Research Group estimated the cancer incidence in 2006 as part of the Monitoring of Cancer Incidence in Japan (MCIJ) project, on the basis of data collected from 15 of 32 population-based cancer registries. The total number of incidences in Japan for 2006 was estimated as 664 398 (C00-C96). The leading cancer site was stomach for men and breast for women. Age-standardized incidence rates remained at almost the same level as for the previous 3 years.

Population-based survival of cancer patients diagnosed between 1993 and 1999 in Japan: a chronological and international comparative study.

OBJECTIVE: The purpose of the present study was to collect data from population-based cancer registries and to calculate relative 5-year survival of cancer patients in Japan. We also sought to determine time trends and to compare the results with international studies. METHODS: We asked 11 population-based cancer registries to submit individual data for patients diagnosed from 1993 to 1999, together with data on outcome after 5 years. Although all these registries submitted data (491 772 cases), only six met the required standards for the quality of registration data and follow-up investigation. The relative 5-year survival calculated by pooling data from 151 061 cases from six registries was taken as the survival for cancer patients in Japan. RESULTS: Relative 5-year survival (1997-99) was 54.3% for all cancers (males: 50.0%, females: 59.8%). Survival figures for all sites changed slightly over the 7-year period, from 53.2% for the first 4 years of the study (1993-96) to 54.3% for the last 3 years (1997-99), however, a major improvement was observed in several primary sites. Some overall survival was lower in Japan than in the USA, but similar to that in European countries. Specifically, survival for uterine cancer, prostate cancer, testis cancer, lymphoma and leukemia was much lower in Japan than in other countries. However, survival was better in Japan mainly for cancers of the esophagus, stomach, colon, liver and gallbladder. CONCLUSION: The study suggests an improvement in cancer survival in several primary sites in Japan, which is consistent with the development of treatments and early detection.

Cancer incidence and incidence rates in Japan in 2005: based on data from 12 population-based cancer registries in the Monitoring of Cancer Incidence in Japan (MCIJ) project.

The Japan Cancer Surveillance Research Group estimated the cancer incidence in 2005 as part of the Monitoring of Cancer Incidence in Japan (MCIJ) project, on the basis of data collected from 12 of 30 population-based cancer registries. The total number of incidences in Japan for 2005 was estimated as 646,802 (C00-C96). The leading cancer site was the stomach for men and the breast for women. Age-standardized incidence rates remained almost the same level as the previous 2 years.

Cancer incidence and incidence rates in Japan in 2004: based on data from 14 population-based cancer registries in the Monitoring of Cancer Incidence in Japan (MCIJ) Project.

The Japan Cancer Surveillance Research Group estimated the cancer incidence in 2004 as part of the Monitoring of Cancer Incidence in Japan (MCIJ) project, on the basis of data collected from 14 of 31 population-based cancer registries. The total number of incidences in Japan for 2004 was estimated as 623,275 (C00-C96). The leading cancer site according to the crude and age-standardized incidence rates was the stomach for men and breast for women. The apparent increase in age-standardized incidence rates in 2003 was calmed down in 2004.

Do the Japanese feel more suspicious about cancer registration than the British?

BACKGROUND: Cancer registration is indispensable, providing useful statistical measures for the appropriate evaluation of cancer control programs and medical treatment or screening. METHODS: Following the British national survey on attitudes toward cancer registration, we conducted an investigation to correctly evaluate the general opinion of the Japanese population in this regard. We randomly recruited 3000 men and women aged 20-69 years from a research database. RESULTS: Only 4% of all respondents had heard about the cancer registry system before the investigation. However, 77% of respondents thought that cancer registration was useful. Forty-three percent of respondents answered, regardless of the strictness of the data protection, that privacy had been violated if the registration occurred without an individual explanation. Compared with the British survey results, Japanese people seemed to be more suspicious about the largely unknown system of cancer registry. Nonetheless, it is noteworthy that Japanese respondents did not show active opposition to cancer registration; they tended to choose "I don't know" instead of "no" to questions asking if they supported the registry system. Multivariate analysis showed that male sex, older age, and living in the southern region were the factors significantly associated with support for cancer registration. CONCLUSIONS: We can seek society's understanding toward cancer registration by actively utilizing information from cancer registries, by using examples of how data are actually used that have wide appeal, and by educating the public on how the data are treated under the complete privacy policy.

Incidence and survival trends for childhood cancer in Osaka, Japan, 1973-2001.

Mortality for childhood cancer has declined in Osaka, as well as all over Japan, since the 1970s, but whether this decline can be explained by trends of incidence or survival of childhood cancer has not been examined. A total of 5960 malignant tumors diagnosed between 1973 and 2001 in children <15 years of age were registered at the Osaka Cancer Registry in Japan. The time trends for childhood cancer were analyzed over 29 years for incidence and 20 years for survival. Leukemia was the most common among childhood cancer for both sexes and accounted for one-third of all cases. The age-standardized annual incidence rate of all tumors was highest in 1988-1992: 155.1 per million for males and 135.9 for females. Five-year survival for all tumors improved from 50.1% in 1978-1982 to 73.0% in 1993-1997 for males and from 52.3% to 76.3% for females. Thus, the constant decline in mortality in childhood cancer was primarily due to improved survival between the 1970s and 1980s and reduced incidence after the 1990s.

Regional differences in population-based cancer survival between six prefectures in Japan: application of relative survival models with funnel plots.

We used new methods to examine differences in population-based cancer survival between six prefectures in Japan, after adjustment for age and stage at diagnosis. We applied regression models for relative survival to data from population-based cancer registries covering each prefecture for patients diagnosed with stomach, lung, or breast cancer during 1993-1996. Funnel plots were used to display the excess hazard ratio (EHR) for each prefecture, defined as the excess hazard of death from each cancer within 5 years of diagnosis relative to the mean excess hazard (in excess of national background mortality by age and sex) in all six prefectures combined. The contribution of age and stage to the EHR in each prefecture was assessed from differences in deviance-based R(2) between the various models. No significant differences were seen between prefectures in 5-year survival from breast cancer. For cancers of the stomach and lung, EHR in Osaka prefecture were above the upper 95% control limits. For stomach cancer, the age- and stage-adjusted EHR in Osaka were 1.29 for men and 1.43 for women, compared with Fukui and Yamagata. Differences in the stage at diagnosis of stomach cancer appeared to explain most of this excess hazard (61.3% for men, 56.8% for women), whereas differences in age at diagnosis explained very little (0.8%, 1.3%). This approach offers the potential to quantify the impact of differences in stage at diagnosis on time trends and regional differences in cancer survival. It underlines the utility of population-based cancer registries for improving cancer control.

Proposal for a cooperative study on population-based cancer survival in selected registries in East Asia.

Reliable population-based cancer survival data are essential for assessment of the effectiveness of cancer screening programs, distribution of cancer therapy and prevalent cancer cases. International comparisons are useful to allow societies, mass media and health authorities to gain a real appreciation of the cancer problem in their own country and provide an impetus to improve registration and cancer control planning. Since directly comparable survival data among East Asian countries are presently very limited, a comparative study on population-based cancer survival involving China, Indonesia, Japan, Korea, the Philippines and Taiwan, with Nepal as an observer, was proposed. At the 1st Working Group meeting in Tokyo on March 18th, 2009, it was decided to publish the present Commentary as a step towards realization of truly comparable cancer survival statistics in the region. Included are general information and quality of data of cancer registration at each participating registry and five-year relative survival rates of cancer of the stomach, colo-rectum, liver, lung, breast and cervix.

Cancer incidence and incidence rates in Japan in 2002: based on data from 11 population-based cancer registries.

The number of cancer incidences, crude incidence rates, age-standardized incidence rates in 2002 in Japan are estimated. The estimated total number of incidences was 570,598.

Lifetime and age-conditional probabilities of developing or dying of cancer in Japan.

The concepts of lifetime and age-conditional probabilities of developing and dying of cancer are introduced as indexes to understand the risk of cancer. In this paper, we estimated the lifetime and age-conditional probabilities of developing and dying of cancer in 2001 and 2005, respectively, in Japan. It is estimated that one in two Japanese males and one in three females will develop cancer, and one in four Japanese males and one in six females will die of cancer. Moreover, the probabilities of developing cancer within specific decades of age are obtained as the short-term risks.

Trend in incidence of adenocarcinoma of the esophagus in Japan, 1993-2001.

BACKGROUND: Several studies with population-based cancer registry data have suggested that incidence of adenocarcinoma of the esophagus has been increasing since 1970 in some European and North American countries and Australia. However, data from Asian countries with regard to the incidence of esophageal cancer by histological type based on the population-based cancer registry are lacking. The aim of this study was to describe the incidence of esophageal cancer by histological type in a Japanese population. METHODS: Cancer incidence data for 1993-2001 from 15 population-based cancer registries were collected by the Japan Cancer Surveillance Research Group in 2005. We used data from eight registries corresponding to inclusion criteria for data quality. RESULTS: Squamous cell carcinoma remains the predominant type in all esophageal cancers in Japan. The ratio of squamous cell carcinoma to adenocarcinoma is 26:1. For adenocarcinoma, estimated average annual percentage change was 4.7% (95% confidence interval: 0.7, 8.9) in men and 6.0% (2.4, 9.8) in women. Age-adjusted incidence rate (the world standard population) per 100 000 for 2001 was 0.3 in men and 0.05 in women. Incidence of squamous cell carcinoma was increasing slightly in men and nearly constant in women. Age-adjusted incidence rate for 2001 was 8.2 in men and 1.0 in women. CONCLUSION: No dramatic increase in adenocarcinoma has occurred, and absolute incidence remains low in Japan.

Hospital procedure volume and survival of cancer patients in Osaka, Japan: a population-based study with latest cases.

BACKGROUND: Recent studies reported that hospital procedure volume (i.e. volume of patients per hospital receiving a particular treatment)was directly proportional to cancer survival; however the degree of association might be different according to the primary tumor site, extent of disease and year of diagnosis. We performed a systematical examination of survivals by hospital procedure volume according to the primary site with inclusion of latest cases in Osaka, Japan. METHODS: Individual data on reported cancer cases with active follow-up information and diagnosis between 1994 and 1998 were retrieved from Osaka Cancer Registry's database. The analysed primary sites included oesophagus, stomach, large bowel, liver, gall bladder, pancreas, lung, breast, uterus, ovary, prostate, bladder and lymphoma. Hospitals were ranked as high-, medium-, low- and very low-volume hospitals for every primary site by dividing the number of cancer patients who received treatment in hospitals into four quartiles. RESULTS: The primary sites could be classified into three categories based on the association between hospital procedure volume and cancer survival: In type 1, a better survival was associated with a higher procedure volume as for oesophagus, liver, lung, ovary, prostate, or lymphoma; in type 2, a better survival was associated with a higher procedure volume but there was no significant difference in survival between high- and medium-volume hospitals as for uterus; and in type 3, there was no significant difference in survival among high-, medium- and low-volume hospitals as for stomach, large bowel, gall bladder, pancreas, breast, or bladder sites. CONCLUSIONS: A higher procedure volume was generally associated with a better survival; however, this association could be classified into three types according to the primary site.

Survival of male breast cancer patients: a population-based study in Osaka, Japan.

BACKGROUND: Little information is available on the survival of male breast cancer patients because the disease is extremely rare in men. Recent studies indicated there were no gender-differences in the 5-year survival if patients' age and stage were matched. However, this problem has rarely been studied in Japan. METHODS: Using the Osaka Cancer Registry's data, the 5-year survival was analyzed based on the reported 19,869 cases who lived in Osaka Prefecture excluding Osaka City and were diagnosed in 1975-1997, or who resided in Osaka City and were diagnosed in 1993-1997, because reliable follow-up information was available for them. RESULTS: Breast cancer in males accounted for 0.49% of all cases during 1975-1997. The 5-year relative survivals were 71.1% in men and 81.6% in women. The survival in males decreased over older groups due to a lower proportion of localized stage, but not in females. The survival of males in the regional stage was significantly lower than that of females (49.1 versus 73.7%, P<0.05). Survival of males has increased since 1980-1984, while it has been stable in females. Compared with the survival of patients diagnosed in 1975-1979, male patients diagnosed in 1995-1997 had a noticeably lower risk of death after adjusting for age and cancer stage. CONCLUSIONS: The results suggest male breast cancer patients at the regional stage had a worse 5-year survival rate compared to females. However, this gender-related difference seems to have disappeared with the increased survival of males during the 1990s. Further population-based studies are required with a greater number of male patients diagnosed after 1990.

Pravastatin use and the five-year incidence of cancer in coronary heart disease patients: from the prevention of coronary sclerosis study.

BACKGROUND: Although the short-term safety of statins is well established, their potential carcinogenicity in the long term is still being debated. The aim of this study was to investigate the association between statin-therapy and the incidence of cancer in coronary heart disease patients. METHODS: The subjects were 263 patients with coronary heart disease who were from Osaka prefecture and who were admitted to the Osaka Medical Center for Cancer and Cardiovascular Diseases between September 28, 1991 and March 31, 1995. The five-year cancer incidence among the subjects was checked using the database of the institution-based cancer registry of the hospital as well as the population-based Osaka Cancer Registry. The Cox's proportional hazards ratios (HRs) of all cancer incidence and observed/expected (O/E) ratios by cancer site were calculated. RESULTS: Cancer incidence was observed in 17 patients during the follow-up period. Age (HR=1.16 per one year of age) and continuous smoking during the period (HR=5.82 compared to not smoking during the period) were significantly associated with cancer incidence using multivariable analysis. After being adjusted for sex, age, total serum cholesterol level and smoking habit, the HR of cancer incidence with pravastatin use was 0.78 (95% confidence interval: 0.18-3.46). In the O/E analysis, significantly elevated risks were found for bladder cancer in all the subjects (HR=8.93), as well as in the pravastatin use patients (HR=13.76). CONCLUSIONS: Pravastatin use for 5 years did not indicate an increase in over all cancer risk.

Survival of cancer patients diagnosed between 1993 and 1996: a collaborative study of population-based cancer registries in Japan.

BACKGROUND: Survival of cancer patients has been measured only in some limited areas in Japan until recently. The purpose of the present study was to collect data of fairly high quality on the population-based cancer registries and to estimate relative 5-year survival of cancer patients in Japan. METHODS: We requested 11 population-based cancer registries within the research group to submit individual data of the patients diagnosed from 1993 to 1996, together with the prognosis after 5 years, to the collaborative study secretariat. Ten population-based cancer registries (Miyagi, Yamagata, Niigata, Chiba, Kanagawa, Fukui, Aichi, Osaka, Tottori and Nagasaki) then accepted data submission (373,000 data). Among 10 registries, only 7 registries met the required standards for the quality of registration data and prognosis investigation. The relative 5-year survival calculated by pooling 279,000 data from seven registries was taken as the national estimate of that of cancer patients in Japan. RESULTS: The relative 5-year survival was 53.6% for all cancers (males: 49.2%, females: 59.4%); the survivals of stomach, large bowel, prostate and kidney cancer patients were from 62 to 68%; those of breast, uterus, larynx, skin, testis, bladder and thyroid cancer patients were from 74 to 92%; those of liver, gall bladder and bile duct, pancreas and lung cancer patients ranged from 6 to 23%. CONCLUSION: On the basis of the data from seven population-based cancer registries in Japan, we calculated the relative 5-year survival of cancer patients diagnosed from 1993 to 1996 for the first time.