Masaaki Saito

Dr. Masaaki Saito


Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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25 June 2014 in BMC Cancer
Verified
Journal Article
Open access
PDF file
YMYuta Muto
Yuta Muto
TMTakafumi Maeda
Takafumi Maeda
KSKoichi Suzuki
Koichi Suzuki
TKTakaharu Kato
Takaharu Kato
FWFumiaki Watanabe
Fumiaki Watanabe
TRToshiki Rikiyama
Toshiki Rikiyama
Recent work led to recognize sessile serrated adenomas (SSA) as precursor to many of the sporadic colorectal cancers with microsatellite instability (MSI). However, comprehensive analyses of DNA methylation in SSA and MSI cancer have not been conducted.

24 October 2016 in World Journal of Surgical Oncology
Verified
Journal Article
Open access
PDF file
TKTakaharu Kato
Takaharu Kato
SASergio Alonso
Sergio Alonso
YMYuta Muto
Yuta Muto
HNHiroshi Noda
Hiroshi Noda
YMYasuyuki Miyakura
Yasuyuki Miyakura
TRToshiki Rikiyama
Toshiki Rikiyama
Incidence and clinical characteristics of synchronous colorectal cancer (sCRC) patients significantly vary among studies, likely due to differences in surveillance methodology. If remain undetected, sCRC can progress to more advanced stages seriously aggravating patient prognosis. We studied the incidence and clinicopathological characteristics of Japanese patients with sCRCs who underwent surgery for primary CRC and received exhaustive perioperative surveillance. We recruited 1005 patients with surgically resected CRCs between January 2007 and December 2011. The associations of clinical and pathological factors with sCRC development were assessed by univariate and multivariate logistic regression. Eighty-four patients (8.4 %) developed sCRCs, 16 of them (19.0 %) harboring three or more cancers. Companion sCRCs were smaller and earlier stage than the index lesion (P < 0.0001). In multivariate analysis, advanced age (odds ratio (OR) 1.03 per year; P = 0.009) and left colon tumor location (OR 1.78; P = 0.013) are associated with higher risk of sCRCs, particularly in females. Overall survival did not differ between solitary CRC and sCRC (P = 0.62). Our results highlight the importance of perioperative colonoscopy examination to ensure the absence of sCRCs that, being small and early staged, are more difficult to detect. The incidence of sCRC, and notably of triple or more sCRCs, was higher than previously recognized. Because they are also significantly higher than expected by merely stochastic accumulation of individual cancerous lesions, we suggest that the occurrence of many sCRC reflects a hitherto uncharacterized predisposition condition.

1 January 2014 in World Journal of Surgical Oncology
Verified
Journal Article
Open access
PDF file
MSMasaaki Saito
Masaaki Saito
HKHirokazu Kiyozaki
Hirokazu Kiyozaki
OTOsamu Takata
Osamu Takata
KSKoichi Suzuki
Koichi Suzuki
TRToshiki Rikiyama
Toshiki Rikiyama
The standard treatment for stage IV gastric cancer is chemotherapy, but outcomes remain poor. The effectiveness of induction chemotherapy followed by surgery in selected patients who had a good response to chemotherapy is unclear.

17 March 2016 in BMC Cancer
Verified
Journal Article
Open access
PDF file
MSMasaaki Saito
Masaaki Saito
HKHirokazu Kiyozaki
Hirokazu Kiyozaki
TOTamotu Obitsu
Tamotu Obitsu
HIHirofumi Imoto
Hirofumi Imoto
YTYusuke Taniyama
Yusuke Taniyama
TRToshiki Rikiyama
Toshiki Rikiyama
Systemic chemotherapy combined with steroids used as prophylactic antiemetics have been reported to induce immunosuppression. Further, herpes simplex virus-1 (HSV-1) infection has been reported to occur in patients with small cell carcinomas after chemoradiotherapy that includes brain irradiation. Here, we report a case of HSV-1 encephalitis that occurred in a patient undergoing chemoradiotherapy for advanced esophageal cancer. A 77-year-old woman received chemoradiotherapy (5-fluorouracil, 700 mg/m2; cisplatin, 70 mg/m2; and radiotherapy, 60 Gy in total) for stage III esophageal cancer. The total radiation dose was administered concurrently with the first two courses of chemotherapy, together with dexamethasone as a prophylactic antiemetic. Two days before completion of the fourth course of chemotherapy, the patient developed acute neurological symptoms of disorientation, clouding of consciousness, and fever. T2-weighted magnetic resonance imaging showed a high intensity area in the bilateral temporal lobes and insular cortex. Furthermore, DNA PCR testing of cerebrospinal fluid showed clear positivity for HSV-1 DNA, and the patient was diagnosed with herpetic encephalitis. Intravenous administration of acyclovir for 3 weeks led to gradual improvement of consciousness, and the patient was able to respond to verbal cues. In advanced esophageal cancer patients, standard treatment involves chemoradiotherapy and surgery. However, primary infection with or reactivation of endogenous latent HSV-1 in the brain cortex during chemoradiotherapy combined with administration of a steroid may compromise the benefits of treatment.

14 June 2011 in Gastric Cancer
Verified
Journal Article
Closed access
PDF file
MSMasaaki Saito
Masaaki Saito
HKHirokazu Kiyozaki
Hirokazu Kiyozaki
FCFumihiro Chiba
Fumihiro Chiba
OTOsamu Takata
Osamu Takata
TYTakayoshi Yoshida
Takayoshi Yoshida
FKFumio Konishi
Fumio Konishi

1 January 2020 in Journal of Surgical Case Reports
Verified
Journal Article
Open access
PDF file
IAIku Abe
Iku Abe
MSMasaaki Saito
Masaaki Saito
TITaro Ikeda
Taro Ikeda
RFRintaro Fukuda
Rintaro Fukuda
ATAkira Tanaka
Akira Tanaka
TRToshiki Rikiyama
Toshiki Rikiyama
We report a rare case of adult intussusception caused by an inverted Meckel’s diverticulum with ectopic pancreatic tissue. A 43-year-old woman was referred to our hospital with complaints of abdominal distention, intermittent abdominal pain and nausea that she experienced 3 months ago. Abdominal computed tomography scans demonstrated ileo-ileal intussusception that contained a tumor with fat density as the lead point. Laparoscopic-assisted partial resection of the small intestine was performed. The surgical specimen showed an elongated polypoid lesion invaginated into the intestinal tract indicating an inverted Meckel’s diverticulum. Pathological findings showed a true diverticulum that ran antimesentrically, with tall columnar epithelium, a mucous gland and an islet of Langerhans. The postoperative period was uneventful, and she was discharged on the ninth postoperative day.