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In order to assess the efficacy of lung cancer screening using low-dose thoracic computed tomography, compared with chest roentgenography, in people aged 50-64 years with a smoking history of <30 pack-years, a randomized controlled trial is being conducted in Japan. The screening methods are randomly assigned individually. The duration of this trial is 10 years. In the intervention arm, low-dose thoracic computed tomography is performed for each participant in the first and the sixth years. In the control arm, chest roentgenography is performed for each participant in the first year. The participants in both arms are also encouraged to receive routine lung cancer screening using chest roentgenography annually. The interpretation of radiological findings and the follow-up of undiagnosed nodules are to be carried out according to the guidelines published in Japan. The required sample size is calculated to be 17 500 subjects for each arm.

The efficacy of lung cancer screening should not be evaluated by the survival rate of lung cancer patients but by lung cancer mortality in a certain population because the survival rate can be greatly affected by several types of bias. Randomized controlled trials that were conducted during the 1970s and 1980s in Europe and the United States failed to prove the efficacy of lung cancer screening in decreasing the mortality rate; but recently the results of case-control studies in Japan have revealed that undergoing currently available screening decreases the risk of lung cancer deaths by 30%-60%. A system is now being created in Japan whereby the guidelines regarding cancer screening will continue to be updated. The preliminary reports concerning lung cancer screening using thoracic computed tomography revealed that not only the detection rate of lung cancer but also the survival rate of detected lung cancer patients were surprisingly high. However, the presence of some potential bias in these studies cannot be ignored; therefore, it is still unknown whether there is actual efficacy. Several randomized controlled trials are presently in progress overseas, but the interim results were not favorable. A randomized controlled trial should therefore immediately be started in Japan as well.

In 2005, there were 9264 deaths from prostate cancer, accounting for 4.7% of the total number of cancer deaths in Japan. As the population continues to age, interest in prostate cancer screening has increased, and opportunistic screening for prostate cancer has been conducted worldwide. The guideline for prostate cancer screening was developed based on the established method. The efficacies of prostate-specific antigen (PSA) and digital rectal examination (DRE) were evaluated. Based on the balance of the benefits and harms, recommendations for population-based and opportunistic screening were formulated. Two methods of prostate cancer screening were evaluated. Based on the analytic framework involving key questions, 1186 articles published from January 1985 to October 2006 were selected using MEDLINE and other methods. After the systematic literature review, 28 articles were identified as providing evidence of mortality reduction from prostate cancer, including 5 observational studies for DRE screening, 1 meta-analysis, 3 randomized controlled trials and 19 observational studies for PSA screening. Although several studies showed that PSA screening had a beneficial effect, the results of the selected studies were inconsistent. Overall, the evidence that screening reduced mortality from prostate cancer was insufficient. Furthermore, prostate cancer screening is associated with serious harms, including overdiagnosis, adverse effects of needle biopsy and adverse effects of local prostatectomy. At present, the evidence for the effect of prostate cancer screening is insufficient. Both PSA and DRE were not recommended for population-based screening programs, but they could be conducted as individual-based screening if basic requirements were met.

Although quality control is essential in mass screening system for early detection of cancer, no global method for quality control has not been established, because the mass screening system in each country is quite different from each other. At present, we have to find appropriate method for each cancer and for each country. In 2000, The Lung Cancer Screening Division (LCSD) of the Miyagi Prefectural Committee for Management of the Cancer Screening System (Miyagi PCMCSS) decided to evaluate annually whether the local governments had appropriate information to evaluate the quality of lung cancer screening systems, announcing that the results would be informed to residents. On the basis of the manual developed by the Ministry of Health, Labor and Welfare, 45 items were selected as indicators for the survey, which could be obtained easily when the screening had been conducted according to the standard method. LCSD of Miyagi PCMCSS sent a questionnaire including the 45 items to the municipalities. According to the reply to the questionnaire, LCSD rated each municipality using a 5-rank classification depend on the number of insufficient items: A: 0; B: 1-4; C: 5-8; D: 9 or more; E: no reply. As the results, 58, 3, 6, 3, and 0 municipalities were categorized in 2002 as A, B, C, D, and E, respectively. In 2003, the number of municipalities changed to 60, 7, 2, 1, and 0. In 2005, the distribution improved more, such as 68, 2, 0, 0, and 0. The detection rate of lung cancer also improved. It is possible for PCMCSS to annually conduct surveys to determine whether the local government has appropriate information to evaluate the quality of lung cancer screening systems. Such surveys improve the distribution of response to better direction.

The efficacy of lung cancer screening is still controversial. In order to evaluate efficacy of mass screening for lung cancer in 1990s, the Japanese Ministry of Health and Welfare planned to conduct four independent case-control studies in four different regions; Miyagi, Gunma, Niigata, and Okayama Prefecture. The study design of all the four studies was a matched case-control study in which the decedents from lung cancer were defined as cases. In Gunma Prefecture, a screening examination is annual miniature chest X-ray only, whereas sputum cytology is added for high-risk screenees in others. Matching conditions were gender, year of birth, smoking histories (except Okayama), and municipality. Smoking adjusted odds ratio (OR) of dying from lung cancer for those screened within 12 months before case diagnosis compared with those not screened ranged 0.40-0.68. Three of four studies revealed statistically significant reduction of the risk for lung cancer death. OR of pooled analysis, where all sets were combined and analyzed, was 0.56 (95% confidence interval: 0.48-0.65). Recent mass screening program for lung cancer in Japan could reduce the risk for lung cancer death. However, the possibility exists that some confounding factors affected the results. In order to elucidate whether the results can be applied to Western countries, further studies will be required.

Background: In order to evaluate the efficacy of sputum cytology in lung cancer screening, we re-analyzed the data obtained in our previous case-control study., Materials and Methods: The source population was defined as the previous screenees for reducing self-selection bias. Matching conditions were: gender, year of birth, municipality and smoking history., Results: Smoking adjusted odds ratio (SAOR) of dying from lung cancer for those screened by chest roentgenogram (CXp) only vs. not screened was 0.47, and that for those screened by sputum cytology (SpC) & CXp vs. not screened was 0.36, which was approximately three-fourths of the former. In another analysis, SAOR for those screened by SpC & CXp vs. those screened by CXp only was 0.63., Conclusion: Although statistical significance was not obtained, there might be some possibility that the risk of lung cancer death in smokers would decrease by additional SpC, compared with CXp only.

In order to evaluate the efficacy of annual chest X-ray screening for lung cancer, a case-control study was conducted in Gunma Prefecture, Japan. Population-based annual lung cancer screening programmes have been conducted by the local government in Gunma Prefecture since the mid-1970s. A total of 121 case subjects, including 91 high-risk males and 30 non-high-risk females between the ages of 40 and 79 years who died of lung cancer from 1992 to 1997 were evaluated. A total of 536 controls (3-5 controls for each case) were matched to case subjects by gender, year of birth, address and smoking habits. Controls were selected from screening programme lists provided by the local governments. All case subjects were also included on these lists. The smoking-adjusted odds ratio (OR) of lung cancer death for those subjects screened within 12 months prior to diagnosis versus those not screened was 0.68 (95% confidence interval (CI): 0.44-1.05; P=0.084). When the analysis was conducted without matching case and control subjects by smoking habits, the OR was 0.79 (95% CI: 0.53-1.18). When stratified by histological type, the OR was 0.62 (95% CI: 0.31-1.24) for adenocarcinoma, and 1.01 (95% CI: 0.44-2.31) for squamous cell carcinoma. The results of this study suggest 20-30% of deaths attributable to lung cancer, especially adenocarcinoma, might be prevented by annual chest X-rays.

Although an annual screening programme for lung cancer has been carried out widely in Japan since 1987, there is insufficient evidence to confirm its efficacy in terms of reducing mortality. In order to evaluate the efficacy of the lung cancer screening which has been widely carried out in Japan since 1987, a case-control study was conducted in Niigata Prefecture, Japan. In the study area, chest X-ray examinations for all participants and sputum cytology for high-risk participants were offered annually. Case subjects, who had died from lung cancer (174), and control subjects matched by sex, year of birth, residence and smoking status (801), who had been alive at the time of diagnosis of the corresponding case, were selected from the National Health Insurance holders. Screening histories of the subjects were compared between cases and matched controls for the identical calendar period before the time of diagnosis of the cases. The odds ratio of death from lung cancer for those screened within 12 months vs those not screened was 0.401 (95% CI: 0.272-0.591) with adjustment by smoking index. Our results suggest that annual lung cancer screening might reduce mortality from lung cancer by approximately 60%., (Copyright 2001 Cancer Research Campaign)

Background: In Miyagi Prefecture, Japan, a mass screening program for lung cancer has been conducted since 1982 (miniature chest X-ray for all screenees and sputum cytology for those with a smoking index > or = 600) [smoking index 600 = 30 pack years, the average number of cigarettes smoked per day multiplied by the number of years of regular smoking]. Over 1500 lung carcinomas, including 250 roentgenographically occult lung tumors, were detected and treated up to 1999. In the current study, a nested case-control study was conducted in the population that was screened in 1989 to evaluate the efficacy of the screening program for lung cancer., Methods: To reduce self-selection bias, the source population was defined as screenees with negative results in 1989 (284,226 individuals). In the population, 474 individuals died of lung carcinoma during 1992-1994. After exclusion, 328 patients who died of primary lung carcinoma at between ages 40 years and 79 years were defined as the cases. Six controls were supposed to be selected in the source population for each case and matched by gender, year of birth, municipality, and smoking habits. Controls who had died or moved before the matched case was diagnosed were excluded. Finally, 328 cases and 1886 controls were selected. Screening histories were compared, and odds ratios were calculated using conditional logistic regression analysis., Results: Within the 12 months before diagnosis, 241 of 328 cases (73.5%) had attended the screening compared with 1557 of 1886 controls (82.6%). The smoking-adjusted odds ratio was 0.54 (95% confidence interval, 0.41-0.73)., Conclusions: The mass screening program for lung cancer in Miyagi Prefecture was capable of reducing by 46% the risk of death from carcinoma of the lung., (Copyright 2001 American Cancer Society.)

For the purpose of early detection, we have conducted population-based mass screening for lung cancer by sputum cytology since 1982. Although detection of lung cancer in its early stage is important for a good prognosis, it is often difficult to localize lesions in roentgenographically occult cancer. To clarify the role of autofluorescence bronchoscopy in localizing tumors in patients with roentgenographically occult cancer, we analyzed our diagnostic results. Fifty patients who had been detected by sputum cytology were screened by the light-induced fluorescence endoscope (LIFE)-Lung System from November 1997 to April 1999. We compared the results according to the screening methods: conventional bronchoscopy alone versus LIFE with conventional white-light bronchoscopy (November 1997 to April 1999). Twenty-eight cancerous lesions and 39 borderline lesions were detected by LIFE. Of the 39 borderline lesions, nine were detected only by LIFE. Multicentric lesions including cancer or dysplasia were also detected in 21 of the 50 patients by LIFE. The sensitivity by white-light bronchoscopy alone was 85.3%, whereas that of the LIFE-Lung System with white-light bronchoscopy was 94.1% (P=0.078). There were no cancerous lesions in the area observed as normal by LIFE. We also compared the diagnostic results of two localization methods: brushing of all bronchi (September 1986 to December 1990) and the LIFE-Lung System (November 1997 to April 1999). Although this was a historical comparison, the number of detected borderline lesions increased, which led to a high detection rate in patients with suspected-positive sputum (P=0.0006) by the LIFE-Lung System. In conclusion, the LIFE-Lung System is a safe and non-invasive system for detecting small intraepithelial lesions of the tracheobronchial tree. Autofluorescence bronchoscopy is more efficacious for localizing intraepithelial lesions and places fewer burdens on the patient than brushing of all bronchi.

A total of 1,615,010 person-years in 64 local municipalities were screened from April 1982 through March 1990. All participants were screened annually by chest X-ray, and participants of high risk group were screened by both chest X-ray and sputum cytology. 76,522 person-years(4.7%) were screened by sputum cytology. Among 148 lung cancer patients(0.194%) detected by sputum cytology, 132 were squamous cell carcinoma, and 116(78%) were chest X-ray negative. 90 patients were proved to be Stage 0 or I after resection, and 47 were less than 10 mm in diameter. On the contrary, 166 out of 432 detected patients detected by chest X-ray only, were proved to be Stage I after resection, and 4 patients were less than 10 mm in diameter. Thus, sputum cytology for high risk group were effective to detect early lung cancer.

Eighty-one patients of roentgenologically occult lung cancer (all men, and squamous cell carcinoma) were detected by sputum cytology in lung cancer screening of "Miyagi Program". Sixty-seven patients were resected surgically, and sixty-four of them underwent absolutely curative resection. In fifty-six patients, carcinoma did not penetrate the bronchial wall, and all of them were free from lymph node involvement. In eleven patients, carcinoma penetrated the bronchial wall, and three of them were proved to have lymph node involvement. For that reason, carcinoma which did not penetrate the bronchial wall and was free from lymph node involvement, was defined as early squamous cell carcinoma. Fourty-two early squamous cell carcinoma were located on segmental or more proximal bronchi, but twelve were located on subsegmental or more peripheral bronchi. Five-year survival of fifty-six patients with early squamous cell carcinoma were 91.8%, seven of fifty-six early squamous cell carcinoma patients were multicentric, which were detected synchronously in four cases, postoperatively in two cases, and both synchronously and postoperatively in one case. Two of three postoperatively detected cases were resected surgically and alive without cancer. These results indicate the validity of surgical treatment for roentgenologically occult squamous cell carcinoma. As the most serious prognostic problem is multicentricity, careful localization of primary lesion and postoperative intensive follow-up should be considered.

Mass screening for early detection of lung cancer has been in practice from 1982. Up to 1985, 583,549 persons-years have been screened. Screening was done by examining miniature X-rays taken of the chest for all those tested, and by sputum cytology for those thought to be high-risk, 34,044 persons-years. Heavy smokers over 50 years of age comprised much of the high-risk cases and persons evidencing hemoptysis. In a total of 207 detected cases of lung cancer, 120 cases were found by chest X-ray only, 69 cases were uncovered by sputum cytology only, and 18 cases were discovered by both X-ray and cytology. In one hundred and forty-four cases the cancers were resected and in 69 cases the cancers were determined to be in an early stage.