Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Kenichi Gemba is active.

Publication


Featured researches published by Kenichi Gemba.


Cancer Journal | 2005

Interstitial lung disease in Japanese patients with non-small cell lung cancer receiving gefitinib : An analysis of risk factors and treatment outcomes in okayama lung cancer study group

Katsuyuki Hotta; Katsuyuki Kiura; Masahiro Tabata; Shingo Harita; Kenichi Gemba; Toshiro Yonei; Akihiro Bessho; Tadashi Maeda; Tomonori Moritaka; Takuo Shibayama; Keisuke Matsuo; Katsuya Kato; Arihiko Kanehiro; Yasushi Tanimoto; Keitaro Matsuo; Hiroshi Ueoka; Mitsune Tanimoto

ABSTRACTRisk factors for the development of interstitial lung disease in patients with non-small cell lung cancer receiving gefitinib and the prognostic factors after interstitial lung disease development have not been established. The aim of this study was to retrospectively identify and evaluate these possible factors. PATIENTS AND METHODSWe reviewed the clinical records and radiographs of 365 consecutive patients with non-small cell lung cancer who received gefitinib in West Japan between 2000 and 2003. RESULTSIn total, 330 patients were eligible for interstitial lung disease evaluation, and 15 patients (4.5%) were finally confirmed to have developed interstitial lung disease by blinded expert review. Multivariate analysis revealed that preexisting pulmonary fibrosis, poor performance status, and prior thoracic irradiation were independent risk factors for interstitial lung disease, with odds ratios of 21.0 (95% confidence interval, 5.12–86.3, P < 0.0001), 9.70 (2.27–41.4, P= 0.001), and 4.33 (1.27–14.8, P= 0.019), respectively. Among the 15 patients who developed interstitial lung disease, eight have died of the condition. Short interval from the initiation of gefitinib treatment to the onset of interstitial lung disease, acute interstitial pneumonia pattern, and the presence of pre-existing pulmonary fibrosis were associated with poor prognosis. DISCUSSIONOur results suggest the importance of patient selection for gefitinib treatment based on interstitial lung disease risk factors in the Japanese population identified.


Lung Cancer | 2000

A case-control study of lung cancer screening in Okayama Prefecture, Japan

Kenji Nishii; Hiroshi Ueoka; Katsuyuki Kiura; Tsuyoshi Kodani; Masahiro Tabata; Takuo Shibayama; Kenichi Gemba; Takushi Kitajima; Akio Hiraki; Masashi Kawaraya; Tomio Nakayama; Mine Harada

The effectiveness of lung cancer screening in reducing mortality still remains uncertain. In order to evaluate the efficacy of lung cancer screening, a case-control study was conducted in Okayama Prefecture, Japan. The study area consisted of 34 municipalities where a population-based lung cancer screening had been conducted. Chest X-ray examinations for all participants and sputum cytology for high-risk participants were offered annually. The cases analyzed in this study consisted of 412 individuals aged between 40 and 79 who died of lung cancer. A total of 3490 controls, two to ten for each case matched by gender, year of birth, and living district were randomly collected. Screening histories of cases were compared with those of and matched controls for the identical calendar period prio to diagnosis of the case. Smoking adjusted odds ratio (OR) of death from lung cancer for screened individuals versus unscreened, within 12 months before diagnosis, was calculated as 0.59 (95% confidence interval: 0.46-0.74; P=0.0001). The OR for women (0.39, 95% confidence interval: 0.24-0.64) was lower than that for men (0.67, 95% confidence interval: 0.51-0.87), although both were statistically significant. These results suggest that lung cancer screening contributes to reducing lung cancer mortality by 41%.


Japanese Journal of Clinical Oncology | 2011

Survival and Prognostic Factors in Malignant Pleural Mesothelioma: A Retrospective Study of 314 patients in the West Part of Japan

Shuko Nojiri; Kenichi Gemba; Keisuke Aoe; Katsuya Kato; Takuhiro Yamaguchi; Tsugumichi Sato; Kiyoshi Kubota; Takumi Kishimoto

OBJECTIVE The objective in our study was to examine baseline and other characteristics associated with survival in patients with malignant pleural mesothelioma in Japan. METHODS Three hundred and fourteen patients with an adjudicated diagnosis of mesothelioma were examined. Survival was evaluated by the Kaplan-Meier method with the log-rank test. The Cox model was used to estimate the hazard ratio for the possible prognostic factors. RESULTS Of 314 patients, 223 (71%) died and only 40 (13%) were still alive at the end of the observation period starting from the day of diagnosis, while 51 (16%) were transferred to other hospitals or had the last health service contact before the end of the study period yielding the median survival of 308 days. In the multivariate analysis, age older than 70 years (hazard ratio = 2.17; 95% confidence interval, 1.36-3.46), non-epithelioid type (hazard ratio = 1.58; 95% confidence interval, 1.15-2.18), poor performance status (hazard ratio = 3.22; 95% confidence interval, 1.19-8.74), high white blood cell count (hazard ratio = 1.49; 95% confidence interval, 0.99-2.26) and high C-reactive protein level (hazard ratio = 1.80; 95% confidence interval, 1.06-3.06) were negatively associated with survival, after adjustment for other factors. CONCLUSIONS Some baseline conditions including old age, poor performance status, non-epithelioid type, high white blood cell count and high C-reactive protein level were determinants of poor survival of patients with malignant mesothelioma.


Cancer Science | 2012

National survey of malignant mesothelioma and asbestos exposure in Japan

Kenichi Gemba; Nobukazu Fujimoto; Katsuya Kato; Keisuke Aoe; Yukio Takeshima; Kouki Inai; Takumi Kishimoto

In the present study, malignant mesothelioma (MM) cases in Japan were investigated retrospectively. We extracted records for 6030 cases of death due to MM between 2003 and 2008 to clarify the clinical features of MM, including its association with asbestos exposure (AE). Of all these cases, a clinical diagnosis of MM was confirmed for 929. The origin of MM included the pleura in 794 cases (85.5%), the peritoneum in 123 cases (13.2%), the pericardium in seven cases (0.8%), and the testicular tunica vaginalis in five cases (0.5%). The histological subtypes of MM included 396 epithelioid (55.9%), 154 sarcomatoid (21.7%), 126 biphasic (17.8%), and 33 cases (4.7%) classified as “other types”. Of all the MM cases, AE was indicated in 76.8% and pleural plaques were detected in 34.2%. The number of asbestos particles was determined in 103 cases of MM. More than 1000 asbestos particles per gram dried lung tissue were detected in 74.8% of cases and more than 5000 particles were detected in 43.7% of cases. We compared patient characteristics and the diagnostic procedures for MM before and after the “Kubota shock”. Compared with the early phase of this study (2003–2005), the median age at diagnosis of MM was higher, the number of cases without definite diagnosis of MM was lower, the proportion of cases diagnosed by thoracoscopy was higher, and the percentage of cases in which the occupational history was described in the medical records was significantly higher in the later phase (2006–2008). Our study confirmed that more than 70% of MM cases in Japan are associated with AE. The “Kubota shock” may affect some features pertaining to MM. (Cancer Sci 2012; 103: 483–490)


British Journal of Cancer | 2003

Evaluation of various cytological examinations by bronchoscopy in the diagnosis of peripheral lung cancer

Masashi Kawaraya; Kenichi Gemba; Hiroshi Ueoka; Kenji Nishii; Katsuyuki Kiura; T Kodani; Masahiro Tabata; Takuo Shibayama; Takuji Kitajima; Mitsune Tanimoto

To improve the efficacy of fibreoptic bronchoscopy in the diagnosis of peripheral lung cancer, we evaluated the effectiveness of various techniques for obtaining samples for cytological examination. Between January 1984 and December 2000, flexible fibreoptic bronchoscopy under fluoroscopic guidance was performed in 1372 patients with lung cancer having no visible endoscopic findings. Histological examination of specimens obtained by forceps biopsy and cytological examinations on imprints of biopsy specimens, brushing, selective bronchial lavage, curettage, transbronchial needle aspiration, rinse fluids of the forceps, brush, curette, and aspiration needle, and all fluids aspirated during the bronchoscopic examinations were evaluated for diagnostic power. Using these techniques, the overall diagnostic rate with bronchoscopy was 93.4%. The sensitivity of the histological examination was 76.9%; additional imprint cytology increased the sensitivity to 84.8% (P<0.0001), while additional cytology on the rinse fluid of the forceps increased the sensitivity to 83.7% (P<0.0001). The addition of both imprint cytology and cytology on the rinse fluid of the forceps increased the diagnostic rate to 86.2% (P<0.0001). Our results indicate that cytological examinations of the imprints of biopsy samples and the rinse fluids of the forceps and the brush improve the efficacy of fibreoptic bronchoscopy in the diagnosis of peripheral lung cancer.


Cancer Science | 2012

Aberrant DNA methylation profile in pleural fluid for differential diagnosis of malignant pleural mesothelioma.

Masanori Fujii; Nobukazu Fujimoto; Akio Hiraki; Kenichi Gemba; Keisuke Aoe; Shigeki Umemura; Hideki Katayama; Nagio Takigawa; Katsuyuki Kiura; Mitsune Tanimoto; Takumi Kishimoto

Malignant pleural mesothelioma (MPM) usually develops pleural fluid. We investigated the value of DNA methylation in the pleural fluid for differentiating MPM from lung cancer (LC). Pleural fluid was collected from 39 patients with MPM, 46 with LC, 25 with benign asbestos pleurisy (BAP) and 30 with other causes. The methylation of O6‐methylguanine‐DNA methyltransferase (MGMT), p16INK4a, ras association domain family 1A (RASSF1A), death‐associated protein kinase (DAPK), and retinoic acid receptor β (RARβ) was examined using quantitative real‐time PCR. DNA methylation of RASSF1A, p16INK4a, RARβ, MGMT and DAPK was detected in 12 (30.8%), 3 (7.7%), 11 (28.2%), 0 (0.0%) and five patients (12.8%) with MPM, and in 22 (47.8%), 14 (30.4%), 24 (52.2%), 1 (2.2%) and six patients (13.0%) with LC, respectively. The mean methylation ratios of RASSF1A, p16INK4a and RARβ were 0.37 (range 0.0–2.84), 0.11 (0.0–2.67) and 0.44 (0.0–3.32) in MPM, and 0.87 (0.0–3.14), 1.16 (0.0–5.35) and 1.69 (0.0–6.49) in LC, respectively. The methylation ratios for the three genes were significantly higher in LC than in MPM (RASSF1A, P = 0.039; p16INK4a, P = 0.005; and RARβ, P = 0.002). Patients with methylation in at least one gene were 3.51 (95% confidence interval, 1.09–11.34) times more likely to have LC. Hypermethylation seemed no greater with MPM than with BAP. Extended exposure to asbestos (≧30 years) was correlated with an increased methylation frequency (P = 0.020). Hypermethylation of tumor suppressor genes in pleural fluid DNA has the potential to be a valuable marker for differentiating MPM from LC. (Cancer Sci 2012; 103: 510–514)


British Journal of Cancer | 1999

Fractionated administration of irinotecan and cisplatin for treatment of lung cancer : a phase I study

Hiroshi Ueoka; Masahiro Tabata; Katsuyuki Kiura; Takuo Shibayama; Kenichi Gemba; Yoshihiko Segawa; Kenichi Chikamori; Toshiro Yonei; Shunkichi Hiraki; Mine Harada

SummaryA combination chemotherapy of irinotecan (CPT-11) and cisplatin (CDDP) has been reported to be active for lung cancer. In the previous trial, however, diarrhoea and leucopenia became the major obstacle for sufficient dose escalation of CPT-11 to improve the treatment outcome. We conducted a phase I study to investigate whether the fractionated administration of CDDP and CPT-11 at escalated dose was feasible and could improve the treatment outcome. Twenty-four previously untreated patients with unresectable non-small-cell lung cancer (NSCLC) or extensive disease of small-cell lung cancer (SCLC) were eligible. Both CDDP and CPT-11 were given on days 1 and 8, and repeated every 4 weeks. The dose of CDDP was fixed at 60 mg m–2 and given by 1-h infusion before CPT-11 administration. The starting dose of CPT-11 was 40 mg m–2, and the dose was escalated by an increase of 10 mg m–2. The maximally tolerated dose of CPT-11 was determined as 60 mg m–2 because grade 4 haematological or grade 3 or 4 non-haematological toxicities developed in six patients out of 11 patients evaluated. Diarrhoea became a dose-limiting toxicity. The objective response rates were 76% for NSCLC and 100% for SCLC. The recommended dose of CPT-11 and CDDP in a phase II study will be 50 mg m–2 and 60 mg m–2 respectively.


Acta Oncologica | 2013

Treatment and survival analyses of malignant mesothelioma in Japan.

Kenichi Gemba; Nobukazu Fujimoto; Keisuke Aoe; Katsuya Kato; Yukio Takeshima; Kouki Inai; Takumi Kishimoto

Abstract Background. There are few reports concerning treatment strategies and their contributions to survival of patients with malignant mesothelioma (MM) in Japan. Material and methods. We extracted all death cases due to MM between 2003 and 2008. The diagnosis of MM was confirmed in 929 cases. Histological subtypes was determined in 709 cases, including 396 (55.9%) epithelioid, 154 (21.7%) sarcomatoid, 126 (17.8%) biphasic, and 33 (4.7%) other types. Results and conclusion. Median overall survival (OS) of all MM cases was 7.7 months (95% confidence interval, 7.1–8.3). Median OS of patients with epithelioid MM was significantly longer than that of patients with biphasic (p = 0.030) or sarcomatoid (p < 0.001) MM. Surgical resection was performed in 172 patients (18.5%) and 449 (48.3%) received systemic chemotherapy. Survival of patients treated with both surgery and systemic chemotherapy was favorable. Median OS of patients in the late phase of the study period (2006–2008) was significantly longer than that in the early phase (2003–2005) (8.1 vs. 7.5 months, p = 0.008). Independent favorable prognostic factors included age younger than 70 years, female gender, epithelioid subtype, and clinical stage I–III. Multivariate analysis demonstrated that patients who had radical surgery and systemic chemotherapy showed a longer survival, though this could be due to selection bias of patients.


Carcinogenesis | 2008

Aberrant promoter hypermethylation in serum DNA from patients with silicosis

Shigeki Umemura; Nobukazu Fujimoto; Akio Hiraki; Kenichi Gemba; Nagio Takigawa; Keiichi Fujiwara; Masanori Fujii; Hiroshi Umemura; Mamoru Satoh; Masahiro Tabata; Hiroshi Ueoka; Katsuyuki Kiura; Takumi Kishimoto; Mitsune Tanimoto

It is well established that patients with silicosis are at high risk for lung cancer; however, it is difficult to detect lung cancer by chest radiography during follow-up treatment of patients with silicosis because of preexisting diffuse pulmonary shadows. The purpose of this study is to evaluate the usefulness of detection of serum DNA methylation for early detection of lung cancer in silicosis. Serum samples from healthy controls (n = 20) and silicosis patients with (n = 11) and without (n = 67) lung cancer were tested for aberrant hypermethylation at the promoters of the DNA repair gene O(6)-methylguanine-DNA methyltransferase (MGMT), p16(INK4a), ras association domain family 1A (RASSF1A), the apoptosis-related gene death-associated protein kinase (DAPK) and retinoic acid receptor beta (RARbeta) by methylation-specific polymerase chain reaction. Aberrant promoter methylation in at least one of five tumor suppressor genes was detected more frequently in the serum DNA of silicosis patients with lung cancer than in that of patients without it (P = 0.006). Furthermore, the odds ratio of having lung cancer was 9.77 (P = 0.009) for those silicosis patients with methylation of at least one gene. Extended exposure to silica (>30 years) was correlated with an increased methylation frequency (P = 0.017); however, methylation status did not correlate with age, smoking history or radiographic findings of silicosis. These results suggest that testing for aberrant promoter methylation of tumor suppressor genes using serum DNA may facilitate early detection of lung cancer in patients with silicosis.


British Journal of Cancer | 2006

Second primary cancer in survivors following concurrent chemoradiation for locally advanced non-small-cell lung cancer

Nagio Takigawa; Katsuyuki Kiura; Yoshihiko Segawa; Y Watanabe; Haruhito Kamei; Tomonori Moritaka; Takuo Shibayama; Hiroshi Ueoka; Kenichi Gemba; Toshiro Yonei; Masahiro Tabata; Tetsu Shinkai; Shunkichi Hiraki; Mitsuhiro Takemoto; Susumu Kanazawa; Keitaro Matsuo; Mitsune Tanimoto

Long-term cancer survivors risk development of second primary cancers (SPC). Vigilant follow-up may be required. We report outcomes of 92 patients who underwent chemoradiation for unresectable stage III non-small-cell lung cancer, with a median follow-up of 8.9 years. The incidence of SPC was 2.4 per 100 patient-years (95% confidence interval: 1.0–4.9).

Collaboration


Dive into the Kenichi Gemba's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge