Lung cancer kills more people than any other cancer worldwide. Studies of screening for lung cancer using low-dose CT have been carried out at many institutions in different countries from 1993 through 2007. Over 100,000 asymptomatic persons, mainly those at risk for lung cancer were screened. All of the studies showed a high proportion of stage I diagnosis ranging from 77-100%. International Early Lung Cancer Action Program Investigators (I-ELCAP) screened 31,567 persons. The screening resulted in a diagnosis lung cancer in 484 participants. Of these participants, 412 (85%) had clinical stage I lung cancer, and the estimated 10-year survival rate was 88%. Case studies by the Anti-Lung Cancer Association (ALCA) and Hitachi investigators demonstrated the presence of a stage shift. The stage shift suggests a decrease in lung cancer mortality. ALCA and Hitachi investigators carried out the repeat screening over 14 years and 7 years respectively. Only after the fourth year of screening does the mortality rate start to decrease. Iinuma reported that the mortality reduction of the screened cancer is to be measured, the cumulative number of deaths should be observed and confirmed between the study group and control group and the ratio of the 2 groups are calculated in order to obtain the relative risk (RR) of death between the 2 groups. A mathematical simulation model was employed to calculate the values of RR after the prevalence screening using data from ALCA. The cumulative number of deaths should be counted from only those found in the repeated screening following the initial, prevalence screening. Iinuma predicts the reduction of lung cancer mortality in Japan in the year 2025 employing lung cancer screening CT (LSCT) and proposes a realistic method to achieve this goal. It is possible to reduce the lung cancer mortality in Japan by 22%, if we can perform LSCT screening in more than 50% of population aged 40-85 years old in 2025. We do not yet have sufficient data from well designed randomized controlled trials or cohort studies for CT lung cancer screening. However, the results of case studies have shown that repeat CT screening over 5 years can detect lung cancer which is curable. It is a very important task for us to study the effectiveness of CT screening for asbestos-related diseases. Cost-effectiveness analyses have shown that CT screening for lung cancer is very cost-effective.

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Background. We investigated the current status of multi-modality treatment for malignant pleural mesothelioma in Japan as part of the campaign entitled "Comprehensive Strategy Against Asbestos-related Diseases", which was funded by the 2006 Special Coordination Fund for Promoting Science and Technology from the Japan Science and Technology Agency. Methods. We evaluated cases of extrapleural pneumonectomy (EPP) for malignant pleural mesothelioma between January 2002 and December 2006. A questionnaire was sent to a total of 69 institutions, and was returned by 61 of them. Results. A total of 171 patients underwent EPP for malignant pleural mesothelioma during the study period. They consisted of 154 males and 17 females, and the age ranged between 14 and 78 with the average of 59. The side of EPP was on the right in 91 and on the left in 80 cases. One postoperative death due to interstitial pneumonia and 6 in-hospital deaths due to tumor recurrence (n=4), MRSA empyema (n=1), and pulmonary infarction (n=1) were noted. Preoperative chemotherapy with cisplatin was given in 38 patients, and 12 out of 38 underwent postoperative hemithorax radiation therapy. The median survival was 23 months. Conclusions. The present study showed an increase of cases and also improvement of surgical mortality of EPP for malignant pleural mesothelioma in comparison with former studies. However, we still do not have clinical evidence regarding the feasibility of multi-modality treatment for malignant pleural mesothelioma.

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Purpose. To determine factors affecting the prognosis of primary lung cancers, overall survival rate of patients with cancers found in local community medical organizations was measured. Methods. A total of 1120 hospitalized patients who had been given a pathological diagnosis of primary lung cancer in 7 local community hospitals in Tokyo within 10-year period from 1991 were included in this study. To determine prognostic factors, a multivariate analysis method was employed. Reasons for diagnosis of the patients were categorized into 3 groups, such as the symptoms group (614 patients in whom a diagnosis was based on symptoms of lung cancers), mass survey group (205 cases detected by medical examination) and other diseases group (301 patients in whom lung cancer was diagnosed during treatment of other diseases), and comparative analysis were done between these 3 groups. Results. The overall 5-year survival rate was 24.7%. Factors affecting survival rate were gender, stage of diseases, reasons for diagnosis and therapeutic methods. Difference of hospitals was also recognized as another factor. Comparing the symptoms group, mass survey group and other diseases group, patients of the symptoms group were found mostly in disease stages IIIB and IV, and as small cell lung cancers originating in the hilum of lung. The surgical operation rate of the group was 18.9% and the 5-year survival rate was 13.1%. Most patients of the mass survey group and other diseases group were diagnosed in stage I, or were adenocarcinomas originating in the lung field. The surgical operation rates of the 2 groups were 66.8% and 52.5%, and the 5-year survival rates were 44.7% and 32.8%, respectively. Conclusion. This study showed that it is possible to raise the overall survival rate of primary lung cancer patients if diagnosis is established in local community medical organizations before symptoms of lung cancer appear.

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Objective. We performed a clinicopathological analysis on 7 patients with pleomorphic carcinoma of the lung. Furthermore, we also evaluated the chemosensitivity of their tumors using a histoculture drug response assay (HDRA). Materials and Methods. Seven patients with pleomorphic carcinoma underwent a pulmonary lobectomy between January 1999 and December 2006. Surgical specimens were evaluated by HDRA. Results. The average age of the patients was 70.4 years (6 men, 1 woman), and all patients were smokers. The mean tumor diameter was 7.0 cm, and all tumors originated from the peripheral lung parenchyma, and the postoperative TN factors were as follows: T2/T3, 5/2; N0/N1, 2/5. A histopathological analysis revealed that all patients had adenocarcinoma and spindle cell/giant cell elements. In 6 of them, the proportion of spindle cells/giant cells was greater than that of adenocarcinoma in those tumors. All patients had vascular invasion. Two patients showed distant metastases to the intestinal tract and brain, etc. and locoregional recurrence during the 2-year follow up. According to the results of HDRA in 4 patients, anticancer agents of the taxan series also showed a good sensitivity for those tumors. Furthermore, single-agent chemotherapy using docetaxel (60 mg/m², 3 times weekly) showed a pathologically complete response in 1 patient with tumor recurrence. Conclusion. The patients with pleomorphic carcinomas all tended to have similar clinicopathological characteristics. Docetaxel was therefore suggested to show a good response against pleomorphic carcinoma of the lung based on the results of HDRA and its clinical application is thus considered to be effective.

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Background. Spontaneous remission of non-small cell lung cancer is rare, and the mechanism of remission remains unknown. Case. A 45-year-old man was referred to our hospital in June 2005 because of an abnormality on his chest X-ray. Computed tomography of the chest revealed a 17-mm nodule in the left S⁹. Transbronchial biopsy failed to detect any malignant findings, and further examination was not performed because significant reduction in size of the nodule, to 7 mm in diameter, was seen. In December 2005, he suddenly suffered from right leg paralysis, and a 16-mm mass in the left frontal lobe was detected on brain MRI. He underwent a craniotomy for diagnostic biopsy, and the tumor was histologically confirmed to be a metastatic brain tumor with positive thyroid transcription factor-1 (TTF-1) immunostaining. After irradiation therapy for the brain tumor, partial resection of his left lower lung was performed by video-assisted thoracosurgery. The pathological examination revealed large-cell carcinoma of the lung. Positive expression of HLA class I on tumor cells and a high grade of infiltration of CD8-positive cells within cancer cell nests, were seen both in brain and lung specimens. Conclusion. We encountered a case of spontaneous remission of large cell carcinoma of the lung with brain metastasis. An immune response characterized via infiltration of CD8-positive cells may be involved in the spontaneous remission of lung cancer in this case.

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Background. Metastasis from non-small cell lung cancer to the omentum is rare. Cases. Case 1: A 60-year-old man underwent left lower lobectomy for poorly differentiated adenocarcinoma. Thereafter, he underwent resection of a tumor in the abdominal cavity. Histological examination demonstrated metastasis to the omentum from lung cancer. Gastrointestinal fiberscopic examination detected metastasis to the stomach as well. Postoperative chemotherapy was performed, and he is currently alive apparently disease-free 14 months after the initial surgery. Case 2: A 44-year-old man was hospitalized by the Department of Surgery because of ileus. He underwent resection of a tumor of the omentum. Thereafter, resection of mediastinal tumor and partial resection of the left lung was performed. Histological examination demonstrated large cell carcinoma of the lung and metastases to the mediastinal lymph node and omentum. Postoperative chemotherapy was performed, and he is currently alive apparently disease-free 14 months after the initial surgery. Conclusion. Although metastasis to the omentum from lung cancer is rare, it must be considered when solitary tumor around the stomach is observed in a lung cancer patient.

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Background. Choroidal metastasis of lung cancer is a rare event. Case. A 69-year-old woman visited a hospital complaining of visual disturbance of right eye. Upon diagnosis of choroidal tumor and retinal detachment, she admitted to our hospital. In systemic examination, CT scan of chest disclosed a nodule in the left lung S³, a transbronchial lung biopsy revealed adenocarcinoma. Primary lung cancer with choroidal metastasis was diagnosed (cT4N0M1, stage IV). The cancer cells had a mutation of epidermal growth factor receptor (EGFR) gene in exon 21, and she desired therapy with gefitinib, so she was treated with gefitinib as a first line therapy. As a result, the visual disturbance was improved and the primary tumor lesion was reduced. Conclusion. Gefitinib was effective for choroidal metastases of lung adenocarcinoma associated with genetic mutation of EGFR.

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Background. Cancer of unknown origin with mediastinal lymph node metastases is relatively rare. In most of reported cases, the primary lesions were unknown. We encountered an interesting case in which the primary lesion appeared on CT scan taken 30 months after resection of mediastinal lymph node metastases. Case. A 76-year-old man underwent left lower lobectomy+ND2a for adenocarcinoma. He had a solitary lymph node swelling in the contralateral mediastinal space and underwent biopsy via mediastinoscopy, which was diagnosed as a squamous cell carcinoma. Finally, squamous cell carcinoma was seen in 2 lymph nodes resected by mediastinal lymph node dissection via median sternotomy. CYFRA also dropped to near the normal cut-off line. CT scans were taken every half year, and a new lesion was developing in the right upper lobe along with an increase in CYFRA, 30 months after the mediastinal lymph node dissection. Assuming primary lung cancer, right upper lobectomy+ND1 were done. Pathologically, it was squamous cell carcinomas similar to the previously resected mediastinal lymph node metastases. Conclusion. Surgical resection is adequate strategy for cancer of unknown origin with mediastinal lymph node metastases, because the prognosis is good compared with other unknown origin cancers or N2 primary lung cancers. It is necessary to carefully observe cancer of unknown origin with mediastinal lymph node metastases for appearance of the primary lesion.

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Background. Small bowel metastases from lung cancer are uncommon. Early diagnosis of small bowel metastases is said to be difficult, and the prognosis has been reported to be poor. The recently developed double-balloon enteroscopy (DBE) allows diagnosis and therapeutic interventions in all segments of the small bowel. Cases. We treated 2 cases who were found to have small bowel metastases secondary to lung cancer, using DBE. Case 1 was a 49-year-old man who complained of right chest pain and was given a diagnosis of large cell carcinoma of the lung. He frequently passed black, tarry stools. DBE was done, and histological examination revealed multiple small bowel metastases. The patient died despite aggressive treatment, which included palliative surgical resection (i.e. partial resection) of the small bowel. Case 2 was a 75-year-old man whose chief complaints were general malaise and melena. DBE was done, and histological examination showed multiple small bowel metastases from lung adenocarcinoma. The metastases bled so easily that even temporary hemostasis could not be achieved. Despite repeated red blood cell transfusions, the patient died. Conclusion. DBE is a useful tool for assessing small bowel lesions, because it allows direct observation of the state of small bowel, and it permits a histological diagnosis to be made in a relatively early phase of the disease. However, since DBE can be associated with pain and discomfort, and does not lead to a cure in all patients, candidates for DBE should be assessed for their suitability for the procedure on an individual basis.

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