Effectiveness of catch-up and routine program of the 9-valent vaccine on cervical cancer risk reduction in Japan.

In 2013, the national human papillomavirus (HPV) immunization program began. However, in June 2013, Japan's Ministry of Health, Labor and Welfare (MHLW) announced a "temporary" suspension of its recommendation for the human papillomavirus vaccine. Finally, in November 2021, the MHLW ended its suspension of the recommendation of the HPV vaccine. To address the 9-year gap in HPV vaccinations the suspension had caused, the MHLW conducted a program of catch-up vaccinations from April 2022 to March 2025. Finally, in April 2023, the 9-valent HPV vaccine was approved for both the routine and catch-up vaccination programs in Japan. In this study, we investigated the potential effects of the introduction of the 9-valent vaccine on the increased risk of cervical cancer in females born after fiscal year (FY) 2000. We estimated the lifetime relative risk of cervical cancer incidence and death using the improved routine and catch-up vaccination rates after the recent resumption of the governmental recommendation for women and girls to have the HPV vaccination. These relative risks were calculated using a lifetime risk of 1.000 for cervical cancer incidence and death for females born in FY 1993. We predicted that even if a 90% vaccination rate were to be achieved by FY 2024 with the 9-valent vaccine among women born between FY 2000 and FY 2005, the risk would remain higher than for the vaccination generation. Therefore, for women born between FY 2000 and FY 2005, it will be necessary to significantly improve the cervical cancer screening rate to compensate for this increased risk.

Intentions for catch-up HPV vaccination in Japan: an internet survey.

PURPOSE: In Japan, Japan's Ministry of Health, Labor, and Welfare decided to suspend govermental recommendation for HPV vaccination in FY 2013. The HPV vaccination rate for those born in FY 2000 or thereafter declined dramatically. In 2021, the "suspension of recommendation" ended. The catch-up vaccinations for the unvaccinated have been offered nationwide from FY 2022 to FY 2024. We aimed to quantify the vaccination intentions and characteristics of those young women now eligible for catch-up vaccination.  METHODS: In February of 2022, we conducted an internet survey targeted women who were born in 1997-2004 but who had not yet been HPV vaccinated. RESULTS: We received 1,648 valid responses. 41.6% of the respondents wanted to uptake the catch-up HPV vaccination, 29.7% were undecided, and 28.7% did not want to be vaccinated. The intention to uptake catch-up HPV vaccination was associated with a good history of gynecological visits, intention to receive cervical cancer screening, sexual activity, degree of anxiety about cervical cancer, familiarity with problems associated with cervical cancer, experience with vaccination recommendations, and knowledge about cervical cancer (p < 0.05, respectively). In the vaccinated generation, the proportion of the group that did not want to be vaccinated was significantly higher (p < 0.05). In the vaccine-suspended generation, the proportion of the group that wanted to be vaccinated was significantly higher (p < 0.05). CONCLUSION: Our survey revealed that catch-up vaccination intentions differed depending on the vaccination environment. It is necessary for all organizations involved with HPV vaccination, such as government, medical institutions, and educational institutions, to make recommendations based on an understanding of the characteristics of the "vaccinated generation" and the "vaccine-suspended generation".

Trends in lung cancer incidence by gender, histological type and stage at diagnosis in Japan, 1993 to 2015: A multiple imputation approach.

Continued decrease in smoking prevalence and increasing use of sensitive diagnostic procedures necessitate updated monitoring of trends in lung cancer incidence in Japan. We analyzed histology- and stage-specific trends in 1993 to 2015 using data from 62 870 diagnosed cases from the Monitoring of Cancer Incidence in Japan project. After applying a multiple imputation approach to impute missing/unknown values of stage and histology, we estimated age-standardized incidence rates and applied joinpoint regression analyses. We observed long-term growth trends in adenocarcinoma (ADC) and localized cancer among both genders, long-term declining trends among men and leveling-off trends among women in small-cell carcinoma (SMC) and squamous cell carcinoma (SQC). Stratifying by gender, we observed an increase in localized ADC with average annual percentage changes (AAPC) of 4.5 (95% confidence interval: 3.9 to 5.0) and 5.7 (5.0 to 6.4), a decrease in regional ADC with AAPC of -1.5 (-2.5 to -0.6) and -2.3 (-4.6 to 0.0), but an increase in distant ADC with AAPC of 1.5 (1.1 to 1.9) and 1.6 (0.9 to 2.3) among males and females, respectively. Additionally, increasing trends in female-to-male incidence rate ratios were observed in localized ADC with significantly above one in the most recent diagnosis period. Our results revealed evidence for a partial shift from advanced to early cancer stage, which may suggest the modest effectiveness of nationwide organized screening programs. The observed increasing localized and distant ADC may be linked to improved diagnostic procedures, especially for metastasis detection. Further investigation is needed for more accurate quantification of these factors.

Improved long-term survival of corpus cancer in Japan: A 40-year population-based analysis.

The incidence of uterine corpus cancer has been increasing globally due to increase in obesity. However, a detailed analysis of long-term epidemiological trends of corpus cancer in Japan, where obesity is relatively minimal, has not been conducted. In this retrospective, population-based study using the Osaka Cancer Registry, we analyzed 15 255 cases of corpus neoplasia registered between 1977 and 2016. We determined the age-standardized incidence, mortality, relative survival and conditional survival rates, and the treatment trends for corpus cancer over the last 40 years in Japan. The age-standardized incidence rate of corpus neoplasia increased sharply in 2000-2011 (APC = 9.9, 95% CI: 8.4-11.3), whereas the mortality rate trended to a much more modest increase (APC = 3.3, 95% CI: 2.7-3.8). Compared to 1977-2000, 10-year survival rates for post-2000 cases of localized and regional corpus cancers significantly improved (from 87.7% [95% CI: 85.8-89.4] to 94.2% [95% CI: 92.7-95.7] and from 47.5% [95% CI: 43.3-51.6] to 64.4% [95% CI: 61.0-67.6], respectively). This was largely associated with the significant increase in the percentage of localized and regional patients who received chemotherapy instead of radiation as an adjuvant therapy combined to surgery (P < .001 for both). We found that each histological type (endometrioid carcinoma, serous carcinoma, clear cell carcinoma and carcinosarcoma) has different characteristics of trend of age-standardized incidence rate, relative survival and distribution of extent of disease. In endometrioid carcinoma, the age-standardized incidence rate increased consistently after 1990, but the rate of increase was decreasing after 1997.

How much can screening reduce colorectal cancer mortality in Japan? Scenario-based estimation by microsimulation.

BACKGROUND: Screening is one of the effective interventions for the reduction of colorectal cancer mortality. Though the Japanese government recommends faecal occult blood test and colonoscopy as a follow-up examination following a diagnosis, both participation rates have not been so high and the national mortality rate has not shown a clear decreasing trend. METHODS: Microsimulation models simulate the life histories of a large population of individuals under various scenarios. In this study, we applied a microsimulation model to estimate the reduction of colorectal cancer mortality based on screening scenarios. RESULTS: The effect of reducing the age-standardized mortality rate for colorectal cancer was estimated at 9.4% for men and 6.0% for women under the scenario which calls for 50% participation in faecal occult blood test and 90% participation of follow-up examination. This scenario corresponds to the goal setting for screening in the third-term of the Basic Plan to Promote Cancer Control Programs in Japan. CONCLUSIONS: Our microsimulation model was found to be useful in estimating the mortality reduction effect of cancer control policy. Such modelling techniques can be utilized to develop effective and optimal cancer control programs.

Change of HPV vaccination rates in Japan: the effect of individual notifications implemented by local governments.

BACKGROUND: In Japan, in June 2013, The Ministry of Health, Labor and Welfare (MHLW) decided to temporarily suspend its official recommendation for the participation of girls in the national immunization program. The HPV vaccination rate in Japan soon declined to below 1%. In October 2020, the MHLW notified that the municipalities could and should begin to individually notify girls and their parents targeted for routine vaccination. We have examined how that type of individual notification has affected the number of vaccinations. METHODS: From 12 municipalities (with a combined total population of approximately 4.06 million), we collected vaccination data for all girls who attended grades 6 through 10 from April 2019 to March 2021. We analyzed the number of initial-round vaccinations that occurred by month and the timing and the subjects of the individual notifications. RESULTS: The annual vaccination rate for tenth-grade students in 2020 in the six municipalities that had implemented individual notification was 9.46% (342/3618), which was significantly higher than the rate of 3.22% (54/1676) in the three municipalities that had not implemented individual notification (p < 0.001). On the other hand, the annual vaccination rate for the sixth to ninth-grade students in 2020 in the six municipalities that had implemented individual notification was not significantly (p = 0.56) higher than the rate in the three municipalities that did not: 1.43% (197/13,785) versus 1.33% (83/6260), respectively. CONCLUSION: This study clearly demonstrates the importance of providing information for routine vaccination directly to the targets and their parents.

A nationwide birth year-by-year analysis of effectiveness of HPV vaccine in Japan.

In Japan, the age-adjusted incidence of cervical cancer has been increasing constantly and rapidly among younger women. We set out to accurately confirm the effectiveness of the HPV vaccine in Japan. Data were collected for women born in the fiscal year (FY) 1990 to 1997, who became eligible for their 20-y-old cervical cancer screening between the FY 2010 to 2017. The adjusted incidence of cervical intraepithelial neoplasia (CIN)1+ in women born in FY 1990 to 1993, that is those who reached the national vaccination target age prior to the introduction of publicly subsidized HPV vaccinations, referred here after as "the pre-introduction generation", was 1.42% (242/17 040). The incidence in the "vaccination generation" (women born in FY 1994 to 1997, that is those who were heavily vaccinated as a group when they were of the nationally targeted age of 13-16) was 1.66% (135/8020). There was no significant difference between these incidence rates. However, our FY birth year-by-year analysis revealed that the incidence of CIN1+ was obviously lower than that predicted based on just the trend for CIN1+ seen in the pre-introduction generation. Our analysis revealed that the incidence of CIN3+ was obviously lower in the vaccination generation than in the pre-introduction generation (P = .0008). The incidence of CIN was already tending to increase in both the pre-introduction and vaccination generations. The changes in CIN incidence by individual birth FY must be examined to accurately determine the actual effects of the HPV vaccine for reducing mild cervical lesions.

Complications of colonoscopy in Japan: An analysis using large-scale health insurance claims data.

BACKGROUND AND AIM: In Japan, screening colonoscopy for colorectal cancer is expected to reduce colorectal cancer mortality, although its complication rate has not been sufficiently examined. The aim of this study is to analyze severe complications due to colonoscopy. METHODS: As a study population, we retrospectively used commercially anonymized health insurance claims data covering 5.71 million patients from January 2005 to August 2018. We extracted patients who received colonoscopy with lesions resection or without treatment. Main outcomes were rates of hemorrhage, perforation, fatal events, and their risk factors. RESULTS: Among 341 852 colonoscopy without treatment in 260 128 patients (mean age: 49.6 ± 11.7 years), the rates of hemorrhage, perforation, and fatal events were 0.0059% (95% confidence interval [CI] 0.0031-0.0085), 0.0032% (95% CI 0.0011-0.0052), and 0.00029% (95% CI 0-0.0012), respectively. Regarding hemorrhage, compared with the rate for patients <50 years old (0.0050%), the rates for those 50-59, 60-69, and ≥70 years old were 0.0095% (P = 0.17), 0.0031% (P = 0.17), and 0%, respectively. Regarding perforation, compared with patients <50 years old (0.0056%), the rates for those 50-59, 60-69, and ≥70 years old were 0%, 0.0015% (P = 0.99), and 0.0102% (P = 0.99), respectively. A multivariate analysis for risk factors showed no significant findings for hemorrhage and perforation without treatment. Among 123 087 colonoscopy with lesions resection in 102 058 patients (mean age: 53.7 ± 9.3 years), the rates of hemorrhage, perforation, and fatal events were 0.136% (95% CI 0.1157-0.1572), 0.033% (95% CI 0.0228-0.0437), and 0.00081% (95% CI 0-0.0035), respectively. CONCLUSIONS: The analysis using health insurance claims data demonstrated the safety of colonoscopy.

Alcohol Drinking and Bladder Cancer Risk From a Pooled Analysis of Ten Cohort Studies in Japan.

BACKGROUND: The association of alcohol drinking with bladder cancer risk remains unclear in East Asian populations. Aldehyde dehydrogenase 2 (ALDH2) enzyme oxidizes alcohol-metabolized carcinogenic acetaldehyde into acetate. It is well known that the inactive ALDH2 carriers, specific to East Asian populations, have an increased risk of several cancer types because of increased exposure to acetaldehyde after alcohol consumption. The aim of this study was to examine the association between alcohol drinking and bladder cancer risk using data from ten population-based prospective cohort studies in Japan, where approximately 40% of the population has inactive ALDH2 enzyme. METHODS: We analyzed 340,497 Japanese participants with average follow-up of 13.4 years. The association between alcohol drinking and bladder cancer risk was evaluated using Cox regression models within each study, and random-effects models were used to estimate pooled hazard ratios (HRs) with corresponding 95% confidence intervals (CIs). RESULTS: During 4,729,071 person-years, 936 men and 325 women were newly diagnosed with bladder cancer. Our results showed no evidence of significant association between alcohol drinking and bladder cancer risk even among men who consumed alcohol of ≥69 g/week, with HR of 1.02 (95% CI, 0.79-1.33). The null result was observed consistently among women. CONCLUSIONS: Our findings do not support an association between alcohol drinking and bladder cancer risk in the Japanese, at least without consideration of the polymorphisms of alcohol-metabolizing enzymes.

Coffee Consumption and All-Cause and Cardiovascular Mortality　- Three-Prefecture Cohort in Japan.

BACKGROUND: Coffee, which contains various bioactive compounds, is one of the most popular beverages. Further accumulation of evidence is needed, however, to confirm whether coffee consumption would be effective in preventing cardiovascular disease in the general Japanese population. Methods and Results: We evaluated the association between coffee consumption frequency (never, sometimes, 1-2 cups/day, 3-4 cups/day and ≥5 cups/day) and mortality from all causes, heart disease, and cerebrovascular disease, in 39,685 men and 43,124 women aged 40-79 years at baseline, in a 3-prefecture cohort study. The coffee consumption frequency was assessed on questionnaire. Cox proportional hazards regression modeling was used to assess the association between coffee consumption frequency and all-cause and cardiovascular disease mortality with adjustment for potential confounders. During 411,341 and 472,433 person-years in men and women, respectively, a total of 7,955 men and 5,725 women died. Coffee consumption frequency was inversely associated with all-cause mortality in both genders (P for trend<0.001). In addition, the risks of mortality from cerebrovascular disease in men (P for trend<0.001), and heart disease in women (P for trend=0.031) were inversely associated with coffee consumption. CONCLUSIONS: In this Japanese population, coffee drinking has a preventive effect on all-cause and on cardiovascular mortality in men and/or women.

Trends and projections of cancer mortality in Osaka, Japan from 1977 to 2032.

Projecting cancer mortality is fundamental to the process of planning cancer control. Although the prefecture is one of the main units for the implementation and evaluation of cancer control in Japan, a long-term detailed future projection of cancer mortality has not been conducted by prefecture. The main objective of this paper is to estimate the future number of cancer deaths in Osaka prefecture. Projections were made using the Nordpred model to estimate future trends in cancer mortality. The projected age-standardized mortality rate decreased by 24.5% in males and 16.8% in females from 2012-16 to 2032-36. However, the number of deaths showed a small decrease in males (1.3%) and an increase in females (13.1%). The largest contributor to the increasing number of cancer deaths is the aging population. In Japan, cancer control programmes are implemented by prefecture; our report can therefore be used for prefecture-level cancer control planning.

A population-based cohort study to evaluate the effectiveness of lung cancer screening using low-dose CT in Hitachi city, Japan.

OBJECTIVES: To evaluate the effectiveness of lung cancer screening using low-dose computed tomography for the general population, we conducted a retrospective cohort study of screening for participants among Hitachi residents. MATERIALS AND METHODS: Citizens aged 50-74 who underwent low-dose computed tomography screening at least once during 1998-2006 were defined as the computed tomography group, and those who underwent X-ray screening at least once during the same period, but did not receive low-dose computed tomography screening throughout the follow-up period, were defined as the XP group. We investigated the lung cancer incidence rate, mortality rate and all-cause mortality rate for both groups from the first lung cancer screening to the end of 2012. RESULTS: In the computed tomography group (17 935 residents; 9790 males and 8145 females), 273 cases of lung cancer (1.5%), 72 cases of lung cancer death (0.4%), and 885 cases of all-cause death (4.9%) were observed. On the other hand, 164 cases (1.1%) of lung cancer, 80 cases (0.5%) of lung cancer death and 1188 cases (7.6%) of all-cause death were observed in the XP group (15 548 residents; 6526 males and 9022 females). The hazard ratios of the computed tomography group to the XP group adjusted for gender, age and smoking history were 1.23 for lung cancer incidence rate, 0.49 for lung cancer mortality rate and 0.57 for all-cause mortality rate. Non-smokers and light smokers (<30 pack-years) had a significantly lower lung cancer mortality (0.41 and 0.21, respectively). CONCLUSION: low-dose computed tomography screening for a population including non-smokers and light smokers may be effective.

Trends in Small-Cell Lung Cancer Survival in 1993-2006 Based on Population-Based Cancer Registry Data in Japan.

BACKGROUND: Lung cancers are classified into small-cell lung cancer (SCLC) and non-small-cell lung cancer due to their different treatment and prognosis. Although many studies have reported the specific survival of SCLC patients treated at cancer hospitals, survival from population-based data has rarely been reported. METHODS: We analyzed survival of SCLC cases diagnosed from 1993 through 2006 from a population-based cancer registry of six prefectures. To assess trends in SCLC survival, we defined three periods that mirrored developments in SCLC treatment: period 1, 1993-1998; period 2, 1999-2001; and period 3, 2002-2006. Assessments were based on relative survival (RS), excess hazard, and conditional survival. RESULTS: A total of 10,911 SCLC patients were analyzed. Five-year RS among limited disease SCLC (LD-SCLC) in periods 1 to 3 was 16.8%, 21.1%, and 21.4%, respectively. Five-year RS among extensive disease SCLC (ED-SCLC) in periods 1 to 3 was 2.3%, 2.8%, and 2.7%, respectively. Improvement in 5-year RS in periods 2 and 3 compared with period 1 was significant among both LD- and ED-SCLC patients (all P < 0.001). Conditional 5-year RS of LD-SCLC increased from 21% at year 0 to 73% at year 5, while that of ED-SCLC was 3% at year 0 and 53% at year 5. CONCLUSIONS: The prognosis of SCLC patients improved from 1999-2001 but plateaued in 2002-2006, after which no further significant improvement was seen. Continuous survey based on population-based data is helpful in monitoring the impact of developments in treatment.

Trends in incidence and long-term survival of Japanese women with vulvar cancer: a population-based analysis.

OBJECTIVE: The incidence and long-term survival analysis for vulvar cancer, due to its rarity, has not been fully described in Asian population. The objective of the study is to determine the trends in incidence and long-term survival for vulvar cancer in a Japanese population, using a population-based cancer registry data in Osaka, Japan. METHODS: The age-standardized incidence rate of 389 cases of vulvar squamous cell carcinoma (SCC) diagnosed between 1976 and 2010 was calculated, using the 1985 model population of Japan. The annual percentage change (APC) of the age-standardized incidence was estimated by the joinpoint regression models. The 5- and 10-year relative survival of 290 cases with vulvar SCC diagnosed between 1976 and 2008 were analyzed, using a cohort or period approach. Using the 10-year relative survival, the conditional 5-year survival for patients who lived for some years after diagnosis was also calculated. RESULTS: We have found that the age-standardized incidence rate for vulvar cancer trended downward during the period of 1979-1992 (APC - 6.3%; 95% confidence interval (CI) [- 11.3% to - 1.0%]), whereas it trended upward from 1993 to 2010 (APC 1.9%; 95% CI [- 0.7% to 4.6%]). There was no statistically significant difference for the 5- and 10-year relative survival between the two periods of 1976-2000 and 2001-2008. A statistically significant increase in the conditional 5-year survival at 2 years after diagnosis was observed (48.4%; 95% CI [41.1-55.3] versus 75.6%; 95% CI [64.0-83.9]). CONCLUSION: Despite an increasing trend in vulvar cancer incidence among Japanese population, the relative survival rate for vulvar cancer did not change over the 35 years of this study. We found that the conditional 5-year survival for vulvar cancer, as patients survived additional years, approached within reach of 100%. These data can provide valuable information for both patients and clinicians.

Coffee drinking and colorectal cancer and its subsites: A pooled analysis of 8 cohort studies in Japan.

Coffee is a rich source of bioactive compounds that have potential anticarcinogenic effects. However, it remains unclear whether coffee drinking is associated with colorectal cancer. Also, despite different etiological factors involved in gut physiology, few studies have investigated this association by anatomical site of the lesion. To address these issues, this study examined the association between coffee drinking and colorectal cancer in a pooled analysis from 8 cohort studies conducted in Japan. Among 320,322 participants followed up for 4,503,274 person-years, 6,711 incident colorectal cancer cases were identified. Study-specific hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models and then pooled using the random effects model. Coffee drinking was not materially associated with colorectal cancer risk in men or women (pooled HR 0.92, 95% CI 0.82-1.03 in men and pooled HR 0.90, 95% CI 0.76-1.07 in women). Analysis by subsite showed a lower risk of colon cancer among female drinkers of ≥3 cups coffee/day (pooled HR 0.80, 95% CI 0.64-0.99). There was no such association in men. Coffee drinking was not associated with risk of rectal cancer in men or women. Results were virtually the same among never smokers except for an increased risk of rectal cancer associated with frequent coffee consumption. Coffee drinking may be associated with lower risk of colon cancer in Japanese women.

Increase in incidental detection of thyroid cancer in Osaka, Japan.

Using Osaka Cancer Registry data, we examined age-specific and age-adjusted incidence rates of thyroid cancer according to the route of thyroid cancer detection from 1992 to 2012. The detection routes were categorized into "symptomatic" and "incidental detection." Age-specific incidence rates of incidentally-detected thyroid cancer consistently increased during the study period, especially after 2001, for all sex and age groups other than childhood. The rate of symptomatic thyroid cancer did not largely differ among groups. Age-adjusted incidence rates of symptomatic thyroid cancer were around 1.5 and 4.5 per 100 000 among men and women, respectively. The rate of incidentally-detected thyroid cancer increased from 0.1 and 0.1 per 100 000 person-years among men and women in 1992-1994 to 2.0 and 4.9, respectively, in 2010-2012. Age-adjusted mortality rates among both sexes during the study period leveled off. This finding suggests that the thyroid cancer incidence rate in Osaka increased with incidental detection. We need to continue careful monitoring to confirm these findings.

Smoking and subsequent risk of acute myeloid leukaemia: A pooled analysis of 9 cohort studies in Japan.

Smoking has been identified as a significant risk factor for acute myeloid leukaemia (AML). However, epidemiological evidence for the effect of smoking on the risk of AML among Asians is scarce. Here, we investigated the impact of smoking habits on the risk of AML by conducting a pooled analysis of 9 population-based prospective cohort studies in Japan. We analysed original data on smoking habits at baseline from 9 cohort studies. Hazard ratios (HRs) in the individual studies were calculated using a Cox proportional hazard model adjusted for potential confounders and combined using a random-effects model. During 4 808 175 person-years of follow-up for a total of 344 676 participants (165 567 men and 179 109 women), 245 AML cases (139 men and 106 women) were identified. For both sexes combined, current smokers had a marginally significant increased risk of AML compared to never smokers (HR = 1.44, 95% confidence interval [CI], 0.97-2.14). Ever smokers with more than 30 pack-years had a statistically significant increased risk of AML compared to never smokers among both sexes combined (HR = 1.66, 95% CI, 1.06-2.63). By sex, this significant association was observed only among men, with an HR of 1.69 (95% CI, 1.00-2.87) for ever smokers with more than 30 pack-years relative to never smokers. In conclusion, this study confirmed that cigarette smoking increases the risk of AML in Japanese. This study provides important evidence that smoking increases the risk of AML among Asians, which has already been shown in Western populations.

Improvement in 5-Year Relative Survival in Cancer of the Corpus Uteri From 1993-2000 to 2001-2006 in Japan.

BACKGROUND: Medical circumstances in Japanese patients with cancer of the corpus uteri have greatly changed since the late 1990s, including the introduction of concomitant therapy with taxane and platinum. We evaluated changes in survival rates for this cancer following these advances by analyzing data from population-based cancer registries in Japan. METHODS: Data were available for 8562 cases of cancer of the corpus uteri from six prefectural cancer registries. We defined the two periods of 1993-2000 (1st period) and 2001-2006 (2nd period). Relative survival (RS) in each period was calculated to assess changes using an excess mortality model, with adjustment for age group (15-54, 55-69, and 70-99 years), extent of disease (localized, regional, and distant), and histological subtype. RESULTS: Overall 5-year RS improved from 77.7% in the 1st period to 80.2% in the 2nd period, with an excess hazard ratio (EHR) of 0.785 (95% confidence interval [CI], 0.705-0.873). Five-year RS significantly improved in the group aged 55-69 years, in all groups by extent of disease, and in the endometrioid adenocarcinoma group. In particular, 5-year RS significantly improved in patients with endometrioid adenocarcinoma, from 84.5% to 89.7%, with an EHR of 0.698 (95% CI, 0.560-0.870). CONCLUSION: Overall 5-year RS for cancer of the corpus uteri in Japan improved from the 1990s to early 2000s. These improvements might have been aided by the comprehensive medical development of management for this cancer, including the spread of concomitant therapy with taxane and platinum as a standard adjuvant chemotherapy in the early 2000s.

Recent Improvement in the Long-term Survival of Breast Cancer Patients by Age and Stage in Japan.

BACKGROUND: Recent improvements in 5-year survival of breast cancer have been reported in Japan and other countries. Though the number of long-term breast cancer survivors has been increasing, recent improvements in 10-year survival have not been reported. Moreover, the degree of improvement according to age and disease stage remains unclear. METHODS: We calculated long-term survival using data on breast cancer diagnosed from 1993 through 2006 from six prefectural population-based cancer registries in Japan. The recent increase in 10-year relative survival was assessed by comparing the results of period analysis in 2002-2006 with the results of cohort analysis in 1993-1997. We also conducted stratified analyses by age group (15-34, 35-49, 50-69, and 70-99 years) and disease stage (localized, regional, and distant). RESULTS: A total of 63,348 patients were analysed. Ten-year relative survival improved by 2.4% (76.9% vs 79.3%) from 1993 through 2006. By age and stage, 10-year relative survival clearly improved in the age 35-49 years (+2.9%; 78.1% vs 81.0%), 50-69 years (+2.8%; 75.2% vs 78.0%) and regional disease (+3.4%; 64.9% vs 68.3%). In contrast, the degree of improvement was small in the age 15-34 years (+0.1%; 68.2% vs 68.3%), 70-99 years (+1.0%; 87.6% vs 88.6%), localized disease (+1.1%; 92.6% vs 93.7%) and distant metastasis (+0.9%; 13.8% vs 14.7%). CONCLUSIONS: These population-based cancer registry data show that 10-year relative survival improved 2.4% over this period in Japan. By age and stage, improvement in the age 15-34 years and distant metastasis was very small, which suggests the need for new therapeutic strategies in these patients.

Body-Mass Index and Pancreatic Cancer Incidence: A Pooled Analysis of Nine Population-Based Cohort Studies With More Than 340,000 Japanese Subjects.

BACKGROUND: A high body mass index (BMI) has been proposed as an important risk factor for pancreatic cancer. However, this association of BMI with pancreatic cancer risk has not been confirmed in Asian populations. METHODS: We evaluated the association between BMI (either at baseline or during early adulthood) and pancreatic cancer risk by conducting a pooled analysis of nine population-based prospective cohort studies in Japan with more than 340,000 subjects. Summary hazard ratios (HRs) were estimated by pooling study-specific HRs for unified BMI categories with a random-effects model. RESULTS: Among Japanese men, being obese at baseline was associated with a higher risk of pancreatic cancer incidence (≥30 kg/m2 compared with 23 to <25 kg/m2, adjusted HR 1.71; 95% confidence interval [CI], 1.03-2.86). A J-shaped association between BMI during early adulthood and pancreatic cancer incidence was seen in men. In contrast, we observed no clear association among women, although there may be a positive linear association between BMI at baseline and the risk of pancreatic cancer (per 1 kg/m2, adjusted HR 1.02; 95% CI, 1.00-1.05). CONCLUSIONS: Pooling of data from cohort studies with a considerable number of Japanese subjects revealed a significant positive association between obesity and pancreatic cancer risk among men. This information indicates that strategies that effectively prevent obesity among men might lead to a reduced burden of pancreatic cancer, especially in Asian populations.