Chisato Hamashima

The Japanese Guidelines for Gastric Cancer Screening

BACKGROUND Gastric cancer is the leading cause of death from cancer in Japan. In 2004, there were 50 562 deaths from gastric cancer; they accounted for 15.8% of the total number of cancer deaths. Since 1983, under the Health Service Law for the Aged, gastric cancer screening has been conducted nationwide for all residents aged 40 years and over. METHODS On the basis of the standardized method developed for the Japanese Guidelines for Cancer Screening, the efficacies of various methods for gastric cancer screening were evaluated and the guideline was developed. RESULTS Four methods for gastric cancer screening were evaluated: photofluorography, endoscopy, serum pepsinogen testing and Helicobacter pylori antibody testing. On the basis of the analytic framework involving key questions, 1715 articles, published from January 1985 to February 2005, were selected using MEDLINE, the Japanese Medical Research Database and other methods. After the systematic literature review, 10 articles were identified as direct evidence and 49 articles as indirect evidence. The studies that evaluated mortality reduction from gastric cancer included five case-control and two cohort studies for radiographic screening. On the basis of the balance of benefits and harms, the recommendations for population-based and opportunistic screening were formulated. Gastric cancer screening using photofluorography was recommended for both screening programs. The other methods were not recommended for population-based screening due to insufficient evidence. CONCLUSIONS The guideline for gastric cancer screening guideline was developed based on the previously established method. Gastric cancer screening using photofluorography is recommended for population-based and opportunistic screening in Japan.

Long-term quality of life of postoperative rectal cancer patients.

Abstract Background: The long‐term quality of life (QOL) of postoperative rectal cancer patients has not been previously investigated in Japan and may vary depending on the surgical technique used (i.e. with or without a stoma).

A community-based, case-control study evaluating mortality reduction from gastric cancer by endoscopic screening in Japan.

Aims Although the incidence of gastric cancer has decreased in the last 3 decades, it remains the second leading cause of cancer death worldwide. In Asian countries, the burden of gastric cancer has remained, and cancer screening is normally expected to reduce gastric cancer death. We conducted a community-based, case-control study to evaluate the reduction of mortality from gastric cancer by endoscopic screening. Methods Case subjects were defined as individuals who had died of gastric cancer between 2003 and 2006 in 4 cities in Tottori Prefecture, and between 2006 and 2010 in Niigata City, Japan. Up to 6 control subjects were matched by sex, birth year (±3 years), and the residence of each corresponding case subject from the population lists in the study areas. Control subjects were required to be disease-free at the time when the corresponding case subjects were diagnosed as having gastric cancer. The odds ratios (ORs) were calculated for those who had participated in endoscopic or radiographic screening before the reference date when the case subjects were diagnosed as having gastric cancer, compared with subjects who had never participated in any screening. Conditional logistic-regression models for matched sets were used to estimate the ORs and 95% confidence intervals (CIs). Results The case subjects consisted of 288 men and 122 women for case subjects, with 2,292 matched control subjects. Compared with those who had never been screened before the date of diagnosis of gastric cancer in the case subjects, the ORs within 36 months from the date of diagnosis were 0.695 (95% CI: 0.489–0.986) for endoscopic screening and 0.865 (95% CI : 0.631–1.185) for radiographic screening. Conclusions The results suggest a 30% reduction in gastric cancer mortality by endoscopic screening compared with no screening within 36 months before the date of diagnosis of gastric cancer.

The Japanese Guideline for Cervical Cancer Screening

Cervical cancer is the 11th leading cause of death from cancer for females in Japan. In 2005, there were 2486 deaths from cervical cancer, accounting for 1.8% of the total number of cancer deaths in Japan. Cervical cancer screening using conventional cytology has been conducted worldwide. The guideline for cervical cancer screening was developed based on the established method. The efficacies of conventional and liquid-based cytology, human papillomavirus testing alone and two combination methods were evaluated. On the basis of the balance of the benefits and harms, recommendations for population-based and opportunistic screening were formulated. Five methods of cervical cancer screening were evaluated. On the basis of the analytic framework involving key questions, 3450 articles published from January 1985 to October 2007 were selected using MEDLINE and other methods. After the systematic literature review, 66 articles were confirmed. The results of 33 studies were consistent, and the evidence was sufficient to evaluate the effect of conventional cytology screening. The accuracy of liquid-based cytology was almost equal to that of conventional cytology. Although human papillomavirus testing and combination methods showed high sensitivity, no study has evaluated the reduction in mortality from cervical cancer. Except for the possibility of overdiagnosis, no serious adverse effects of cervical cancer screening were found. Cervical cancer screening using conventional and liquid-based cytology is recommended for population-based and opportunistic screening due to sufficient evidence. Cervical cancer screening using either human papillomavirus testing alone or two combination methods is not recommended for population-based screening due to insufficient evidence.

Prediction of gastric cancer development by serum pepsinogen test and Helicobacter pylori seropositivity in Eastern Asians: a systematic review and meta-analysis.

Background To identify high-risk groups for gastric cancer in presumptively healthy populations, several studies have investigated the predictive ability of the pepsinogen test, H. Pylori antibodies, and a risk-prediction model based on these two tests. To investigate whether these tests accurately predict gastric cancer development, we conducted a systematic review and meta-analysis. Methods PubMed and other electronic databases were searched for cohort studies published in English or Japanese from January 1985 through December 2013. Six reviewers identified eligible studies, and at least two investigators extracted data on population and study-design characteristics, quality items, and outcomes of interest. Meta-analyses were performed on non-overlapping studies. Results Nine prospective cohorts from Eastern Asia reported in 12 publications, including 33,741 asymptomatic middle-aged participants of gastric cancer screening, were eligible. For discriminating between asymptomatic adults at high and low risk of gastric cancer, the pepsinogen test (summary hazard ratio [HR], 3.5; 95% confidence interval [CI], 2.7–4.7; I2 = 0%) and H. pylori antibodies (summary HR, 3.2; 95% CI, 2.0–5.2; I2 = 0%) were statistically significant predictors as standalone tests. Although the risk-prediction model was in general moderately accurate in separating asymptomatic adults into four risk groups (summary c-statistic, 0.71; 95% CI: 0.68–0.73; I2 = 7%), calibration seemed to be poor. The study validity was generally limited. Conclusions The serum pepsinogen test, H. pylori antibodies, and the four-risk-group model for predicting gastric cancer development seem to have the potential to stratify middle-aged presumptively healthy adults. Future research needs to focus on comparative studies to evaluate the impact of screening programs adopting these tests. Also, validation, preferably with model updating, is necessary to see whether the current model performance is transferable to different populations.

Projection of lung cancer mortality in Japan

According to the National Vital Statistics data, age‐standardized mortality rates (ASRs) of lung cancer have shown slightly declining trends in Japan for both men and women. In order to evaluate whether this tendency will continue, a Bayesian age‐period‐cohort (APC) model was applied using the National Vital Statistics data from 1952 to 2001. In the projection, a Gaussian autoregressive prior model was applied to smooth age, period, and cohort effects from its 2 immediate predecessors by extrapolation. Posterior distributions from which we drew inferences on mortality rates were derived from 15,000 iterations using 5000 burn‐in iterations. We defined the median of the iterated values as the overall summary mortality rate of the iterated results. Our results suggest that the number of deaths due to lung cancer will double for men and women during the next 3 decades due to the aging of the baby‐boomer generation (individuals who were born between 1947 and 1951). Currently declining trends in some age groups will reverse and start to increase again in the next decades. However, for recent birth cohorts, the results of the projection varied according to whether the data set included early age group mortality or not. Lung cancer mortality in the future depends on the risk factors engaged in by todays young people, especially smoking. Strong promotion of anti‐smoking measures and careful surveillance for lung cancer are needed.

Evaluation of 18F-2-deoxy-2-fluoro-glucose positron emission tomography for gastric cancer screening in asymptomatic individuals undergoing endoscopy

18F-2-deoxy-2-fluoro-glucose Positron Emission Tomography (FDG-PET) has been recently proposed as a promising cancer-screening test. However, the validity of FDG-PET in cancer screening has not been evaluated. We investigated the sensitivity of FDG-PET compared with upper gastric endoscopy in gastric cancer screening for asymptomatic individuals. A total of 2861 consecutive subjects (1600 men and 1261 women) who were asymptomatic and who underwent both FDG-PET and upper gastrointestinal endoscopy between 1 February 2004 and 31 January 2005 were included in this study. Both endoscopists and a radiologist were unaware of the results of the other diagnostic tests. The FDG-PET images were examined using criteria determined by the pattern of FDG accumulation. Sensitivity and specificity of FDG-PET were calculated compared with endoscopic diagnosis as the gold standard. Among 2861 subjects enrolled in the study, there were 20 subjects with gastric cancer, of whom 18 were T1 in depth of cancer invasion. Positive FDG-PET results were obtained only in 2 of the 20 cancer subjects. The calculated sensitivity and specificity for overall gastric cancers were 10.0% (95% confidence interval (CI): 1.2–31.7%) and 99.2% (95% CI: 98.8–99.5%), respectively. 18F-2-deoxy-2-fluoro-glucose Positron Emission Tomography was poorly sensitive for detection of gastric cancer in the early stages.

Evaluation of whole-body cancer screening using 18F-2-deoxy-2-fluoro-D-glucose positron emission tomography: a preliminary report.

Objective18F-2-deoxy-2-fluoro-d-glucose positron emission tomography (FDG-PET) is a promising screening modality targeting whole body. However, the validity of PET cancer screening remains to be assessed. Even the screening accuracy for whole-body screening using FDG-PET has not been evaluated. In this study, we investigated the screening accuracy of PET cancer screening.MethodsA total of 2911 asymptomatic participants (1629 men and 1282 women, mean age 59.79 years) underwent both FDG-PET and other thorough examinations for multiple organs (gastrofiberscopy, total colonofiberscopy or barium enema, low-dose thin section computed tomography and sputum cytology, abdominal ultrasonography, an assay of prostate-specific antigen, mammography, mammary ultrasonography, Pap smear for the uterine cervix, and magnetic resonance imaging for the endometrium and ovaries) between February 2004 and January 2005, and followed sufficiently. The detection rate, sensitivity, specificity, and positive predictive value of FDG-PET were calculated using cancer data obtained from all examinations along with a 1 year follow-up.ResultsFrom among 2911 participants FDG-PET found 28 cancers, 129 cancers were PET negative. PET-positive cancers comprised seven colorectal cancers, four lung cancers, four thyroid cancers, three breast cancers, two gastric cancers, two prostate cancers, two small intestinal sarcomas (gastrointestinal stromal tumors), one malignant lymphoma, one head and neck malignancy (nasopharyngeal carcinoid tumor), one thymoma, and one hepatocellular carcinoma. PET-negative cancers included 22 gastric cancers and 20 prostate cancers that were essentially difficult to detect using FDG-PET. The overall detection rate, sensitivity, specificity, and positive predictive value were estimated to be 0.96%, 17.83%, 95.15%, and 11.20%, respectively.ConclusionsFDG-PET can detect a variety of cancers at an early stage as part of a whole-body screening modality. The detection rate of PET cancer screening was higher than that of other screening modalities, which had already shown evidence of efficacy. However, the sensitivity of PET cancer screening was lower than that of other thorough examinations performed at our institute. FDG-PET has some limitations, and cancer screening using only FDG-PET is likely to miss some cancers.

Impact of endoscopic screening on mortality reduction from gastric cancer

AIM To investigate mortality reduction from gastric cancer based on the results of endoscopic screening. METHODS The study population consisted of participants of gastric cancer screening by endoscopy, regular radiography, and photofluorography at Niigata city in 2005. The observed numbers of cumulative deaths from gastric cancers and other cancers were accumulated by linkage with the Niigata Prefectural Cancer Registry. The standardized mortality ratio (SMR) of gastric cancer and other cancer deaths in each screening group was calculated by applying the mortality rate of the reference population. RESULTS Based on the results calculated from the mortality rate of the population of Niigata city, the SMRs of gastric cancer death were 0.43 (95%CI: 0.30-0.57) for the endoscopic screening group, 0.68 (95%CI: 0.55-0.79) for the regular radiographic screening group, and 0.85 (95%CI: 0.71-0.94) for the photofluorography screening group. The mortality reduction from gastric cancer was higher in the endoscopic screening group than in the regular radiographic screening group despite the nearly equal mortality rates of all cancers except gastric cancer. CONCLUSION The 57% mortality reduction from gastric cancer might indicate the effectiveness of endoscopic screening for gastric cancer. Further studies and prudent interpretation of results are needed.

Sensitivity of endoscopic screening for gastric cancer by the incidence method

Although radiographic screening for gastric cancer has been conducted in Japan, it is anticipated that endoscopy will become a new screening method because of its high detection rate. The sensitivities of endoscopic and radiographic screening were calculated by the detection method and the incidence method based on the results of community‐based screening in Japan. There were 56,676 screenings for gastric cancer using endoscopy and radiography from April 2002 to March 2007 in Yonago, Japan. The target age group was from 40 to 79 years. Screen‐detected and interval cancers were investigated based on a screening database linked to the Tottori Cancer Registry. All gastric cancers diagnosed within 1 year after a negative screen were considered interval cancers. Based on the screening history, these were divided into prevalence screening and incidence screening. Prevalence screenings included 7,388 for endoscopic screening and 5,410 for radiographic screening, whereas incidence screenings included 18,021 for endoscopic screening and 11,417 for radiographic screening. The sensitivity of prevalence screening calculated by the incidence method was 0.886 (95% confidence interval [CI] = 0.698–0.976) for endoscopic screening and 0.831 (95% CI = 0.586–0.964) for radiographic screening; however, the difference was not significant (p = 0.626). The sensitivity of incidence screening calculated by the incidence method was 0.954 (95% CI = 0.842–0.994) for endoscopic screening and 0.855 (95% CI = 0.637–0.970) for radiographic screening (p = 0.177). Endoscopic screening for gastric cancer had a higher sensitivity than radiographic screening by the incidence method in both screening rounds. However, further study is needed to evaluate mortality reduction and to estimate overdiagnosis with endoscopic screening for gastric cancer.