Souichi Oka
University of Occupational and Environmental Health Japan
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Publication
Featured researches published by Souichi Oka.
Asian Journal of Surgery | 2010
Souichi Oka; Takeshi Hanagiri; Hidetaka Uramoto; Tetsuro Baba; Masaru Takenaka; Manabu Yasuda; Kenji Ono; Tomoko So; Mitsuhiro Takenoyama; Kosei Yasumoto
BACKGROUND The clinical features of mucinous bronchioloalveolar carcinoma (BAC) have remained unclear due to the low incidence of this disease. This study investigated the clinicopathological features and the surgical outcome in patients with mucinous BAC. METHODS We clinicopathologically evaluated 782 patients who underwent resection for nonsmall cell carcinoma between 1999 and 2008, of whom, 13 (1.6%) demonstrated to have mucinous BAC. RESULTS The patients with mucinous BAC included six men and seven women. The mean age was 69.1 years (range: 55-78 years). Eight patients (61.5%) had a smoking habit. No patients had any subjective symptoms. The tumour diameter ranged from 1.2 cm to 10 cm. The surgical procedures included 11 lobectomies, and two partial resections of affected lobes. The pathological stage was IA in eight patients, IB in two, IIA in two, and IIIA in one. None of the patients had lymph node metastases or lymphovascular invasion. The overall postoperative 5-year survival rate was 52.5%. The 5-year survival rate according to tumour diameter was 100% in patients with tumours ≤ 3 cm, and 25.1% in patients with tumours > 3 cm. Two patients died due to pulmonary metastases, and one died from carcinomatous pleuritis and pulmonary metastases. CONCLUSION Patients with small mucinous BAC (≤ 3 cm) in diameter showed excellent prognosis after surgical resection. However, mucinous BAC > 3 cm in diameter tended to recur with pulmonary metastasis.
Scandinavian Journal of Surgery | 2011
T. Baba; Hidetaka Uramoto; T. Kuwata; Souichi Oka; Y. Shigematsu; Y. Nagata; H. Shimokawa; M. Takenoyama; Takeshi Hanagiri; F. Tanaka
Background and Aims: The widespread use of high resolution computed tomography has increased the number of small peripheral lung cancers. This study reviewed the clinicopathological features of the patients with non-small cell lung cancer (NSCLC) with a tumor diameter of 1 cm or less, in order to explore the adequate management of such small sized lung cancers. Material and Methods: This study was a retrospective analysis of consecutive 58 patients (5.3% out of 1095 patients) who underwent a complete resection for a peripheral NSCLC with a diameter of 1.0 cm or less. The clinical features and outcomes were compared with 203 patients with NSCLC with a diameter between 1.1 and 2.0 cm. Results: The mean age was 64.5 years and there were 26 males and 32 females. Clinical stage was IA in 57 (98%) and IIIA in 1. Lobectomy was performed in 39 patients, segmentectomy in nine, and nonanatomic wedge resection in ten. Two patients, who underwent systemic lymph node dissection, had mediastinal lymph node metastasis and were diagnosed as pathological stage IIIA; however they did not relapse after surgery. One patient with pathological stage IA papillary adenocarcinoma died due to brain metastases. The five-year overall survival rate and disease free survival rate was 95.0% and 95.3%, respectively. Patients with NSCLC of 1.0 cm or less showed significantly better survival than those with tumors measuring 1.1–2.0 cm in size (p = 0.048). Discussion: The indications for avoiding systemic lymph node dissection for operable NSCLC should not be based on the size of the tumor. A small-sized lung cancer might be surgically treated before the tumor enlarges to more than 1.0 cm in size.
Scandinavian Journal of Surgery | 2011
Manabu Yasuda; Takeshi Hanagiri; Souichi Oka; Hidetaka Uramoto; Mitsuhiro Takenoyama; Kosei Yasumoto
Objectives: This study investigated the clinical features of patients with complete resection of thymic carcinoma. Patients and Methods: The clinical records from 11 patients who underwent a complete resection of thymic carcinoma were retrospectively reviewed. Results: Twelve of 22 patients underwent a resection (a complete resection in 11 and an incomplete in 1). Six of the 11 patients with complete had confirmed recurrent tumors. The 5-year survival rate was 45.4%, and the median survival time was 50.6 months. The patients who underwent complete resection showed significantly better prognosis than cases with incomplete resection and inoperable cases (p = 0.048). Three of the 6 patients had a recurrence within 1 year. Frequent sites of recurrence were the pleura, pericardium, and lung. Conclusions: A complete resection improved the prognosis of thymic carcinoma. Further prospective studies regarding postoperative adjuvant therapy are necessary to prevent local recurrence after a surgical resection for thymic carcinoma.
International Journal of Surgery | 2010
Takeshi Hanagiri; Souichi Oka; Satoru Takenaka; Tetsuro Baba; Manabu Yasuda; Kenji Ono; Tomoko So; Hidetaka Uramoto; Mitsuhiro Takenoyama; Kosei Yasumoto
PURPOSE The clinical features of large cell carcinoma (LCC) of the lung have remained unclear due to the low incidence of the disease. This study investigated the clinicopathological features and the surgical outcome in patients with LCC. SUBJECTS This study clinicopathologically evaluated 975 patients who had undergone a resection for non-small cell carcinoma between 1994 and 2007. There were 57 (5.8%) patients with LCC among them. RESULTS The LCC patients included 49 males and 8 females and included 9 patients with large cell neuroendocrine carcinoma. All patients excluding 1 had a smoking habit. The mean smoking pack-year index was 49.9 in the patients with LCC, 27.1 in 625 patients with adenocarcinoma, and 52.5 in 266 patients with squamous cell carcinoma, and this was significantly higher in the patients with LCC than in those with adenocarcinoma. The mean tumor diameter was 38 mm for LCC, 28 mm for adenocarcinoma, and 39 mm for squamous cell carcinoma. The pathological stage was IA in 11 patients, IB in 11, II in 12, IIIA in 16, IIIB in 5, and IV in 2. The post-operative 5-year survival rate was 60.5% for LCC, 64.3% for large cell neuroendocrine carcinoma, 67.0% for adenocarcinoma, and 50.1% for squamous cell carcinoma. CONCLUSION The tumor diameter was significantly larger for LCC than for adenocarcinoma at the time of diagnosis. The proportion of smokers and the smoking pack-year index in patients with LCC were significantly higher than those of adenocarcinoma. The surgical results were similar between LCC and other non-small cell lung carcinomas.
Interactive Cardiovascular and Thoracic Surgery | 2012
Tetsuro Baba; Hidetaka Uramoto; Masaru Takenaka; Souichi Oka; Yoshiki Shigematsu; Hidehiko Shimokawa; Takeshi Hanagiri; Fumihiro Tanaka
We evaluated the tumour shape as a potential prognostic indicator in lung adenocarcinoma patients. Among 994 patients who underwent curative surgery, 78 cases of adenocarcinoma (N0M0) with tumours ≥ 31 mm in diameter were reviewed. The patients were divided into two groups based on the ratio between the longest and the smallest axis length. The patients who had tumours whose ratios were > 0.5 were defined as the globular shape group (GL) and the others, whose ratio was 0.5 or less, were defined as the ellipse shape group (EL). The 78 patients were divided into two subgroups (57 in the GL and 21 in the EL). The tumour shape was related to the prognosis, and the 5-year overall survival (OS) rate in the GL was 51.5%, and that in the EL was 85.5% (P = 0.018). The 5-year disease-free survival rate of the GL was 46.6% and that of the EL patients was 85.0% (P = 0.04). The multivariate analysis showed that the shape of the tumour and the presence of pleural invasion were the independent and significant factors predicting the OS (P = 0.04 and P < 0.01, respectively). In adenocarcinoma patients, the shape of the tumour is related to the postoperative survival.
Journal of Thoracic Disease | 2015
Shuichi Shinohara; Kouji Kuroda; Hidehiko Shimokawa; Taiji Kuwata; Masaru Takenaka; Yasuhiro Chikaishi; Souichi Oka; Ayako Hirai; Naoko Imanishi; Hidetaka Uramoto; Fumihiro Tanaka
Pulmonary ground-glass opacity (GGO) nodules, which do not grow remarkably, are often observed without treatment. Lung tumors coexisting with inflammation and infection are difficult to diagnose. In this paper, we describe a very rare case of a pulmonary mixed GGO nodule with pleural dissemination. In 67-year-old female, chest computed tomography (CT) showed a mixed GGO nodule that had not grown remarkably in the right lung. For 6 years, the mixed GGO had been treated as nontuberculous mycobacterial infection. She was referred to our department for further investigation of the mixed GGO. We suspected lung cancer and performed lung segmentectomy. The tissue showed pleural dissemination. Coexisting nontuberculous mycobacteria (NTM) delayed the clinical diagnosis. Peripheral lung nodules should be resected or diagnosed as soon as possible, despite manifesting as a slow growth.
Surgery Today | 2013
Tetsuro Baba; Hidetaka Uramoto; Taiji Kuwata; Masaru Takenaka; Yasuhiro Chikaishi; Souichi Oka; Yoshika Nagata; Yoshiki Shigematsu; Hidehiko Shimokawa; Makoto Nakagawa; Tomoko So; Takeshi Hanagiri; Fumihiro Tanaka
Journal of UOEH | 2012
Sminohara S; Takeshi Hanagiri; Taiji Kuwata; Takcenaka M; Souichi Oka; Chikainsi Y; Yoshika Nagata; Hidehiko Shimokawa; Yoshiki Shigematsu; Makoto Nakagawa; Hidetaka Uramoto; Tomoko So; Fumihiro Tanaka
Interactive Cardiovascular and Thoracic Surgery | 2016
Masaru Takenaka; Rintarou Oyama; Kenichi Kobayashi; Sakiko Yura; Hiroki Matsumiya; Syuichi Shinohara; Taiji Kuwata; Souichi Oka; Yasuhiro Chikaishi; Ayako Hirai; Kazue Yoneda; Yuko Tashima; Kouji Kuroda; Naoko Imanishi; Yoshika Nagata; Fumihiro Tanaka
The Journal of The Japanese Association for Chest Surgery | 2015
Teruo Iwata; Masaru Takenaka; Souichi Oka; Tomoko Sou; Hidetaka Uramoto; Fumihiro Tanaka
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University of Occupational and Environmental Health Japan
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View shared research outputsUniversity of Occupational and Environmental Health Japan
View shared research outputsUniversity of Occupational and Environmental Health Japan
View shared research outputsUniversity of Occupational and Environmental Health Japan
View shared research outputsUniversity of Occupational and Environmental Health Japan
View shared research outputsUniversity of Occupational and Environmental Health Japan
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