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Dive into the research topics where Kimihiko Yanaoka is active.

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Featured researches published by Kimihiko Yanaoka.


Lancet Oncology | 2008

S-1 plus cisplatin versus S-1 alone for first-line treatment of advanced gastric cancer (SPIRITS trial): a phase III trial

Wasaburo Koizumi; Hiroyuki Narahara; Takuo Hara; Akinori Takagane; Toshikazu Akiya; Masakazu Takagi; Kosei Miyashita; Takashi Nishizaki; Osamu Kobayashi; Wataru Takiyama; Yasushi Toh; Takashi Nagaie; Seiichi Takagi; Yoshitaka Yamamura; Kimihiko Yanaoka; Hiroyuki Orita; Masahiro Takeuchi

BACKGROUND Phase I/II clinical trials of S-1 plus cisplatin for advanced gastric cancer have yielded good responses and the treatment was well tolerated. In this S-1 Plus cisplatin versus S-1 In RCT In the Treatment for Stomach cancer (SPIRITS) trial, we aimed to verify that overall survival was better in patients with advanced gastric cancer treated with S-1 plus cisplatin than with S-1 alone. METHODS In this phase III trial, chemotherapy-naive patients with advanced gastric cancer were enrolled between March 26, 2002, and Nov 30, 2004, at 38 centres in Japan, and randomly assigned to S-1 plus cisplatin or S-1 alone. In patients assigned to S-1 plus cisplatin, S-1 (40-60 mg depending on patients body surface area) was given orally, twice daily for 3 consecutive weeks, and 60 mg/m(2) cisplatin was given intravenously on day 8, followed by a 2-week rest period, within a 5-week cycle. Those assigned to S-1 alone received the same dose of S-1 twice daily for 4 consecutive weeks, followed by a 2-week rest period, within a 6-week cycle. The primary endpoint was overall survival. Secondary endpoints were progression-free survival, proportions of responders, and safety. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00150670. FINDINGS 305 patients were enrolled; seven patients were ineligible or withdrew consent, therefore, 148 patients were assigned to S-1 plus cisplatin and 150 patients were assigned to S-1 alone. Median overall survival was significantly longer in patients assigned to S-1 plus cisplatin (13.0 months [IQR 7.6-21.9]) than in those assigned to S-1 alone (11.0 months [5.6-19.8]; hazard ratio for death, 0.77; 95% CI 0.61-0.98; p=0.04). Progression-free survival was significantly longer in patients assigned to S-1 plus cisplatin than in those assigned to S-1 alone (median progression-free survival 6.0 months [3.3-12.9] vs 4.0 months [2.1-6.8]; p<0.0001). Additionally, of 87 patients assigned S-1 plus cisplatin who had target tumours, one patient had a complete response and 46 patients had partial responses, ie, a total of 54% (range 43-65). Of 106 patients assigned S-1 alone who had target tumours, one patient had a complete response and 32 had partial responses, ie, a total of 31% (23-41). We recorded more grade 3 or 4 adverse events including leucopenia, neutropenia, anaemia, nausea, and anorexia, in the group assigned to S-1 plus cisplatin than in the group assigned to S-1 alone. There were no treatment-related deaths in either group. INTERPRETATION S-1 plus cisplatin holds promise of becoming a standard first-line treatment for patients with advanced gastric cancer.


Clinical Cancer Research | 2006

High Levels of Aberrant DNA Methylation in Helicobacter pylori–Infected Gastric Mucosae and its Possible Association with Gastric Cancer Risk

Takao Maekita; Kazuyuki Nakazawa; Mami Mihara; Takeshi Nakajima; Kimihiko Yanaoka; Mikitaka Iguchi; Kenji Arii; Atsushi Kaneda; Tetsuya Tsukamoto; Masae Tatematsu; Gen Tamura; Daizo Saito; Takashi Sugimura; Masao Ichinose; Toshikazu Ushijima

Introduction: Risk prediction of gastric cancers is important to implement appropriate screening procedures. Although aberrant DNA methylation is deeply involved in gastric carcinogenesis, its induction by Helicobacter pylori, a strong gastric carcinogen, is unclear. Here, we analyzed the effect of H. pylori infection on the quantity of methylated DNA molecules in noncancerous gastric mucosae and examined its association with gastric cancer risk. Experimental Design: Gastric mucosae were collected from 154 healthy volunteers (56 H. pylori negative and 98 H. pylori positive) and 72 cases with differentiated-type gastric cancers (29 H. pylori negative and 43 H. pylori positive) by endoscopy. The numbers of DNA molecules methylated and unmethylated for eight regions of seven CpG islands (CGI) were quantified by quantitative PCR after bisulfite modification, and fractions of methylated molecules (methylation levels) were calculated. Results: Among healthy volunteers, methylation levels of all the eight regions were 5.4- to 303-fold higher in H. pylori positives than in H. pylori negatives (P < 0.0001). Methylation levels of the LOX, HAND1, and THBD promoter CGIs and p41ARC exonic CGI were as high as 7.4% or more in H. pylori–positive individuals. Among H. pylori–negative individuals, methylation levels of all the eight regions were 2.2- to 32-fold higher in gastric cancer cases than in age-matched healthy volunteers (P ≤ 0.01). Among H. pylori–positive individuals, methylation levels were highly variable, and that of only HAND1 was significantly increased in gastric cancer cases (1.4-fold, P = 0.02). Conclusions: It was indicated that H. pylori infection potently induces methylation of CGIs to various degrees. Methylation levels of specific CGIs seemed to reflect gastric cancer risk in H. pylori–negative individuals.


International Journal of Cancer | 2004

Progression of chronic atrophic gastritis associated with Helicobacter pylori infection increases risk of gastric cancer

Hiroshi Ohata; Shintaro Kitauchi; Noriko Yoshimura; Kouichi Mugitani; Masataka Iwane; Hideya Nakamura; Akiyoshi Yoshikawa; Kimihiko Yanaoka; Kenji Arii; Hideyuki Tamai; Yasuhito Shimizu; Tatsuya Takeshita; Osamu Mohara; Masao Ichinose

We conducted a longitudinal cohort study to determine the association of Helicobacter pylori infection and the progression of chronic atrophic gastritis (CAG) with gastric cancer. A cohort of 4,655 healthy asymptomatic subjects was followed for a mean period of 7.7 years. H. pylori infection was established by serum specific antibodies and the presence of CAG was confirmed by serum pepsinogen. During the follow‐up period, 45 gastric cancer cases were detected (incidence rate, 126/100,000 person‐years). A univariate analysis after adjustment for age showed that both H. pylori and CAG were significantly associated with gastric cancer. To clarify the interaction between H. pylori and CAG, an analysis stratified by H. pylori‐ and CAG–status was performed. No cancer developed in the H. pylori(−)/CAG(−) group during the study period. This supports the theory that it is quite rare for any type of gastric cancer to develop in an H. pylori‐free healthy stomach. With the progression of H. pylori‐induced gastritis, the risk of gastric cancer increased in a stepwise fashion from CAG‐free gastritis [H. pylori(+)/CAG(−) group] (HR=7.13, 95%CI=0.95‐53.33) to CAG [H. pylori(+)/CAG(+) group] (HR=14.85, 95%CI=1.96–107.7) and finally to severe CAG with extensive intestinal metaplasia [H. pylori(−)/CAG(+) group] (HR=61.85, 95%CI=5.6–682.64) in which loss of H. pylori from the stomach is observed. Therefore, it is probable that H. pylori alone is not directly associated with stomach carcinogenesis. Instead, H. pylori appears to influence stomach carcinogenesis through the development of CAG. The observed positive correlation between the extent of H. pylori‐induced gastritis and the development of cancer was strong, especially for the intestinal type. These results are compelling evidence that severe gastritis with extensive intestinal metaplasia is a major risk factor for gastric cancer, and they confirm the previously described model of stomach carcinogenesis: the gastritis‐metaplasia‐carcinoma sequence.


Journal of Ultrasound in Medicine | 2005

Contrast-Enhanced Ultrasonography in the Diagnosis of Solid Renal Tumors

Hideyuki Tamai; Yoshie Takiguchi; Masashi Oka; Naoki Shingaki; Shotaro Enomoto; Tatsuya Shiraki; Machi Furuta; Izumi Inoue; Mikitaka Iguchi; Kimihiko Yanaoka; Kenji Arii; Yasuhito Shimizu; Hiroya Nakata; Toshiaki Shinka; Tokio Sanke; Masao Ichinose

The purpose of this study was to evaluate the usefulness of contrast‐enhanced ultrasonography (CEUS) in the diagnosis of solid renal tumors.


International Journal of Cancer | 2009

Eradication of Helicobacter pylori prevents cancer development in subjects with mild gastric atrophy identified by serum pepsinogen levels

Kimihiko Yanaoka; Masashi Oka; Hiroshi Ohata; Noriko Yoshimura; Hisanobu Deguchi; Chizu Mukoubayashi; Shotaro Enomoto; Izumi Inoue; Mikitaka Iguchi; Takao Maekita; Kazuki Ueda; Hirotoshi Utsunomiya; Hideyuki Tamai; Mitsuhiro Fujishiro; Masataka Iwane; Tatsuya Takeshita; Osamu Mohara; Masao Ichinose

A longitudinal cohort study was conducted in Helicobactor pylori‐infected middle‐aged Japanese males to evaluate the preventive effects of H. pylori eradication on the development of gastric cancer according to the extent of chronic atrophic gastritis (CAG). The extent of CAG was monitored by baseline serum pepsinogen (PG) levels. We followed 3,656 subjects with persistent H. pylori infection and 473 subjects with successful H. pylori eradication for cancer development for a mean (SD) of 9.3 (0.7) years. Groups with and without extensive CAG were categorized based on PG test‐positive criteria to detect extensive CAG of PG I ≤ 70 ng/ml and PG I/II ratio ≤ 3.0. During the study period, 5 and 55 gastric cancers developed in H. pylori‐eradicated and the noneradicated subjects, respectively, indicating no significant reduction in cancer incidence after H. pylori eradication. Among the noneradicated subjects, 1,329 were PG test‐positive and 2,327 were PG test‐negative. Gastric cancer was confirmed in 30 and 25 subjects, respectively. Among subjects whose infection was eradicated, 155 were PG test‐positive and 318 were PG test‐negative. Of these subjects, gastric cancer was confirmed in 3 and 2 subjects, respectively. Significant reduction in cancer incidence after eradication was observed only in PG test‐negative subjects (p < 0.05; log‐rank test). The results of this study strongly indicate that cancer development after eradication depends on the presence of extensive CAG before eradication and that H. pylori eradication is beneficial to most PG test‐negative subjects with mild CAG as defined by the aforementioned criteria.


Cancer Epidemiology, Biomarkers & Prevention | 2008

Cancer High-Risk Subjects Identified by Serum Pepsinogen Tests: Outcomes after 10-Year Follow-up in Asymptomatic Middle-Aged Males

Kimihiko Yanaoka; Masashi Oka; Chizu Mukoubayashi; Noriko Yoshimura; Shotaro Enomoto; Mikitaka Iguchi; Hirohito Magari; Hirotoshi Utsunomiya; Hideyuki Tamai; Kenji Arii; Hiroshi Ohata; Mitsuhiro Fujishiro; Tatsuya Takeshita; Osamu Mohara; Masao Ichinose

Background: Gastric cancer screening using the pepsinogen filter test is receiving wide recognition in Japan owing to convenience, freedom from discomfort or risk, efficiency, and economy. Because the long-term outcomes of cancer development in extensive atrophic gastritis detected by pepsinogen test are unclear, test-positive and test-negative subjects were investigated in a longitudinal cohort study. Methods: Subjects comprised 5,209 middle-aged men with measured serum pepsinogen levels who were followed for 10 years. Cancer development based on “atrophy-positive” and “atrophy-negative” criteria used for cancer screening was investigated. Results: During the study, 63 cases of cancer developed in the cohort, representing an incidence rate of 125 per 100,000 person-years. Pepsinogen test screening using the most widely used atrophy-positive criterion (pepsinogen I, ≤70 ng/mL; pepsinogen I/II ratio, ≤3.0) displayed 58.7% sensitivity, 73.4% specificity, and 2.6% positive predictive value. Cancer incidence rate was 276 per 100,000 person-years for the atrophy-positive group and 70 per 100,000 person-years for the atrophy-negative group. Incidence rate was higher in groups fulfilling stricter positive criteria detecting more extensive atrophy, reaching 424 per 100,000 person-years. In addition, 9.2% of atrophy-negative subjects with pepsinogen I of >70 ng/mL and pepsinogen I/II ratio of ≤3.0 (reflecting putative inflammation-based high pepsinogen II level) are at high risk for cancer, particularly diffuse-type cancer, with a cancer incidence rate comparable with atrophy-positive subjects (216 per 100,000 person-years). Conclusion: Atrophy-positive subjects by pepsinogen filter test, particularly those fulfilling stricter criteria, and atrophy-negative subjects with low pepsinogen I/II ratio reflecting putative extensive active inflammation constitute populations at high risk for gastric cancer, requiring thorough endoscopic examination. (Cancer Epidemiol Biomarkers Prev 2008;17(4):838–45)


Biochemical and Biophysical Research Communications | 2009

Gastric acid reduction leads to an alteration in lower intestinal microflora

Takayuki Kanno; Takahiro Matsuki; Masashi Oka; Hirotoshi Utsunomiya; Ken-ichi Inada; Hirohito Magari; Izumi Inoue; Takao Maekita; Kazuki Ueda; Shotaro Enomoto; Mikitaka Iguchi; Kimihiko Yanaoka; Hideyuki Tamai; Shigeru Akimoto; Koji Nomoto; Ryuichiro Tanaka; Masao Ichinose

To clarify the alterations in lower intestinal microflora induced by gastric acid reduction, the dynamics of 12 major genera or groups of bacteria comprising the microflora in feces and colonic contents were examined by quantitative real-time PCR in proton pump inhibitor-treated rats and in asymptomatic human subjects with hypochlorhydria. In both rat and human experiments, most genera or groups of intestinal microflora (facultative and obligate anaerobes) proliferated by gastric acid reduction, and marked and significant increases in the Lactobacilli group and Veillonella, oropharyngeal bacteria, were observed. In rats, potent gastric acid inhibition led to a marked and significant increase of intestinal bacteria, including the Bacteroidesfragilis group, while Bifidobacterium, a beneficial bacterial species, remained at a constant level. These results strongly indicate that the gastric acid barrier not only controls the colonization and growth of oropharyngeal bacteria, but also regulates the population and composition of lower intestinal microflora.


Cancer Science | 2005

Gastric cancer screening of a high-risk population in Japan using serum pepsinogen and barium digital radiography

Hiroshi Ohata; Masashi Oka; Kimihiko Yanaoka; Yasuhito Shimizu; Chizu Mukoubayashi; Kouichi Mugitani; Masataka Iwane; Hideya Nakamura; Hideyuki Tamai; Kenji Arii; Hiroya Nakata; Noriko Yoshimura; Tetsuya Takeshita; Kazumasa Miki; Osamu Mohara; Masao Ichinose

With the aim of developing more efficient gastric cancer screening programs for use in Japan, we studied a new screening program that combines serum pepsinogen (PG) testing and barium digital radiography (DR). A total of 17 647 middle‐aged male subjects underwent workplace screening over a 7‐year period using a combination of PG testing and DR. This programs effectiveness, as well as other characteristics of the program, was analyzed. Forty‐nine cases of gastric cancer were detected (comprising 88% early cancer cases). The detection rate was 0.28%, and the positive predictive value was 0.85%. The PG test detected 63.3% of cases, DR detected 69.4% of cases, and both tests were positive in 32.7% of cancer cases. The two methods were almost equally effective, and were considerably more effective than conventional screening using photofluorography. Each screening method detected a distinct gastric cancer subgroup; the PG test efficiently detected asymptomatic small early cancer with intestinal type histology, while DR was efficient at detecting cancers with depressed or ulcerated morphology and diffuse type histology. The cost for the detection of a single cancer was much less than that for conventional screening. In fact, it is possible to further reduce the cost of detecting a single cancer to a cost comparable to that of surgically resecting a single gastric cancer. Thus, it is probable that a highly efficient gastric cancer screening system can be implemented by combining the two screening methods. Such a screening program would be beneficial in a population at high risk for gastric cancer. (Cancer Sci 2005; 96: 713 – 720)


International Journal of Cancer | 2008

Risk of gastric cancer in asymptomatic, middle-aged Japanese subjects based on serum pepsinogen and Helicobacter pylori antibody levels.

Kimihiko Yanaoka; Masashi Oka; Noriko Yoshimura; Chizu Mukoubayashi; Shotaro Enomoto; Mikitaka Iguchi; Hirohito Magari; Hirotoshi Utsunomiya; Hideyuki Tamai; Kenji Arii; Nobutake Yamamichi; Mitsuhiro Fujishiro; Tatsuya Takeshita; Osamu Mohara; Masao Ichinose

A total of 5,209 asymptomatic, middle‐aged subjects, whose serum pepsinogen (PG) and Helicobacter pylori antibody levels had been assessed, were followed for 10 years. Subjects with positive serum H. pylori antibodies (>50 U/mL) had an increased cancer risk (HR = 3.48, 95% CI = 1.26–9.64). Risk of gastric cancer increased as the antibody level increased; the H. pylori‐positive group with antibody levels >500 U/mL had the highest incidence rate (325/100,000 person‐years). Cancer development also increased with a reduced serum PG I level or a reduced PG I/II ratio; the risk was significantly elevated with serum PG I level ≤30 ng/mL (HR = 3.54, 95% CI = 1.95–6.40) or PG I/II ratio ≤3.0 (HR = 4.25, 95% CI = 2.47–7.32). Furthermore, the risk of diffuse‐type cancer increased as PG II level increased; it was significantly elevated with PG II level ≥30 ng/mL (HR = 3.81, 95% CI = 1.10–13.21). Using H. pylori antibody and PG levels, subgroups with an especially high or low cancer incidence rate could be identified. H. pylori‐negative or indeterminate subjects with low PG level (PG I ≤30 ng/mL or PG I/II ratio ≤2.0) or H. pylori‐positive subjects with antibody levels >500 U/mL and a low PG level were among the subgroups with a high cancer incidence rate (over 400/100,000 person‐years). In contrast, H. pylori‐negative subjects with a PG I level >70 ng/mL or a PG I/II ratio >3.0 had the lowest risk; none of these subjects developed cancer. Thus, serum PG levels and/or H. pylori antibody levels can be used to predict the risk of cancer in individuals with H. pylori‐related gastritis from the general population.


Helicobacter | 2001

Beneficial Effect of Helicobacter pylori Eradication in Dermatologic Diseases

Akiko Shiotani; Kazuhisa Okada; Kimihiko Yanaoka; Hidekazu Itoh; Shingo Nishioka; Mikihisa Sakurane; Masahiro Matsunaka

A relationship between skin diseases, particularly rosacea and chronic urticaria, and H. pylori infection has been suggested.

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Masao Ichinose

Wakayama Medical University

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Hideyuki Tamai

Wakayama Medical University

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Masashi Oka

Saitama Medical University

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Mikitaka Iguchi

Wakayama Medical University

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Izumi Inoue

Wakayama Medical University

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Takao Maekita

Wakayama Medical University

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Kenji Arii

Wakayama Medical University

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Hisanobu Deguchi

Wakayama Medical University

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Naoki Shingaki

Wakayama Medical University

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