Masanobu Enomoto

Propensity Score Analysis of Regorafenib Versus Trifluridine/Tipiracil in Patients with Metastatic Colorectal Cancer Refractory to Standard Chemotherapy (REGOTAS): A Japanese Society for Cancer of the Colon and Rectum Multicenter Observational Study

This article compares the efficacy between regorafenib and trifluridine/tipiracil in patients with metastatic colorectal cancer refractory to standard chemotherapy, who had access to both drugs, to determine whether a further prospective comparative trial should be conducted.

Complete laparoscopic resection of the rectum using natural orifice specimen extraction

AIM To investigate how complete laparoscopic anterior resection with natural orifice specimen extraction (NOSE), as a novel minimally invasive surgery, compares to conventional laparoscopic surgery. METHODS Twenty patients who underwent complete laparoscopic anterior resection with NOSE and 50 patients who underwent laparoscopic assisted anterior resection by the conventional method between 2011 and 2012 were studied. Selection for complete laparoscopic anterior resection with NOSE was decided on the basis of tumor size, localization of the tumor, and body mass index. Outcomes related to surgery, including operation time, postoperative wound pain, hospital stay after surgery, the number of totally dissected lymph nodes, postoperative complications (suture failure and wound infection), and anal function, were reviewed retrospectively. Anal function was assessed at 3 and 6 mo after surgery using the Wexner fecal incontinence scoring system. RESULTS Complete laparoscopic resection with NOSE was performed to completion in all 20 patients. There was no patient emergency that required conversion to conventional laparoscopic surgery or open surgery. The comparison between complete laparoscopic resection with NOSE and conventional laparoscopic surgery showed no significant differences in the maximal diameter of the tumor, number of totally dissected lymph nodes, bleeding volume, mean operation time, time to start of oral ingestion, postoperative hospital stay, and postoperative complications. On the other hand, with regard to pain after epidural anesthesia, the total usage of analgesia in this novel surgical technique was 1.85 ± 1.8 times, whereas it was 5.89 ± 2.86 in conventional laparoscopic surgery (P < 0.001). The postoperative pain period was 1.9 ± 1.9 d in this novel surgical technique, whereas it was 3.43 ± 1.41 d in conventional laparoscopic surgery (P < 0.004). In complete laparoscopic surgery with NOSE, the mean postoperative follow-up period was 20 mo (range: 12-30 mo). Neither local recurrence nor remote metastasis was observed during the follow-up period. CONCLUSION Complete laparoscopic anterior resection using NOSE does not require any incision and has excellent cosmetic properties, with mitigated postoperative pain.

Analysis of Autonomic Nerve Preservation and Pouch Reconstruction Influencing Fragmentation of Defecation after Sphincter-Preserving Surgery for Rectal Cancer

Our questionnaire survey on defecation disorders after rectal cancer surgery revealed that 66.7% of postoperative patients were most annoyed with fragmentation of defecation. Therefore, we performed a change-over-time analysis on the relationship of fragmentation and factors including location of rectal cancer, surgical technique, anastomosis method, pouch reconstruction, extent of lymph node dissection, and degree of pelvic and colonic nerve preservation surrounding the superior mesenteric artery. The fragmentation decreased over time at the postoperative time points of 6 months, 2 and 5 years. A statistical analysis of factors influencing fragmentation revealed that location of cancer, reconstruction technique, anastomosis method and degree of pelvic nerve preservation were significant factors for the entire patient population and that colonic nerve preservation was a significant factor 5 years after surgery. Analysis of patients with lower rectal cancer only showed that in addition to surgical technique and anastomosis method, pouch reconstruction was effective and autonomic nerve preservation was effective 5 years after surgery. As a result, when the anastomotic site was closer to the anus, the frequency of fragmentation increased; we concluded that pouch reconstruction was an effective surgical technique and colonic nerve preservation was effective in the longer term.

Carcinosarcoma of the Sigmoid Colon: Report of a Case.

Our case was a 65-year-old male, with the chief complaints of diarrhea and abdominal distention. Three years earlier, the patient had undergone transcatheter arterial embolization and radiofrequency treatment based on a diagnosis of hepatocellular carcinoma due to hepatitis B by another doctor. In October 2007, the patient developed diarrhea and increased abdominal distention. In December, CT examination conducted by the previous doctor revealed a 20-cm tumor within the pelvis. The patient was diagnosed with sigmoid colon cancer based on barium enema examination using gastrografin, and was introduced to our hospital for treatment. He was diagnosed with low-differentiated carcinoma by biopsy of the colon during endoscopy and underwent sigmoidectomy based on a diagnosis of sigmoid colon cancer. The tumor had infiltrated the bladder, and a tumorectomy was conducted through partially combined resection. The tumor was a huge lesion occupying the inside of the lumen, and histopathological findings revealed that the tumor, the main part of which lay beneath the mucous membrane, had a transitional image composed of both spindle-shaped atypical cells and sarcomatoid shape. The result of immunostaining was CK7(+), CK20(–), AFP(–), and the patient was diagnosed as having carcinosarcoma of the colon. Carcinosarcoma of the colon is a malignant tumor with poor prognosis, and the mean survival period in past reports was approximately 6 months. The patient was treated with FOLFIRI+Bevacizumab therapy according to chemotherapy for colon cancer, but he was refractory to the therapy.

Urinary Polyamine Biomarker Panels with Machine-Learning Differentiated Colorectal Cancers, Benign Disease, and Healthy Controls

Colorectal cancer (CRC) is one of the most daunting diseases due to its increasing worldwide prevalence, which requires imperative development of minimally or non-invasive screening tests. Urinary polyamines have been reported as potential markers to detect CRC, and an accurate pattern recognition to differentiate CRC with early stage cases from healthy controls are needed. Here, we utilized liquid chromatography triple quadrupole mass spectrometry to profile seven kinds of polyamines, such as spermine and spermidine with their acetylated forms. Urinary samples from 201 CRCs and 31 non-CRCs revealed the N1,N12-diacetylspermine showing the highest area under the receiver operating characteristic curve (AUC), 0.794 (the 95% confidence interval (CI): 0.704–0.885, p < 0.0001), to differentiate CRC from the benign and healthy controls. Overall, 59 samples were analyzed to evaluate the reproducibility of quantified concentrations, acquired by collecting three times on three days each from each healthy control. We confirmed the stability of the observed quantified values. A machine learning method using combinations of polyamines showed a higher AUC value of 0.961 (95% CI: 0.937–0.984, p < 0.0001). Computational validations confirmed the generalization ability of the models. Taken together, polyamines and a machine-learning method showed potential as a screening tool of CRC.

Successful laparoscopic resection of a retroperitoneal schwannoma arising from the femoral nerve: A case report

We report on a 45‐year‐old man who presented with pain in the left leg, which he had had for 2 months. A contrast‐enhanced CT scan displayed a 25‐mm tumor in the lateral side of the left psoas muscle. For this suspected retroperitoneal tumor, we performed laparoscopic resection of the tumor, which was encapsulated by the funicular femoral nerve, using surgical scissors rather than a surgical energy device and preserved the normal fascicles wherever possible. Pathological examination indicated a benign ancient schwannoma arising from the femoral nerve. The patient was able to return to his job 3 weeks after surgery, and he has shown no evidence of recurrence. This was thought to be because of the use of surgical scissors, rather than a surgical energy device, combined with visual magnification. Therefore, the laparoscopic approach is an effective and minimally invasive option for the resection of femoral nerve schwannoma.

Preoperative evaluation of blood vessel anatomy using three-dimensional computed tomography for laparoscopic surgery of transverse colon cancer

This study describes the efficacy of the evaluation of blood vessel anatomy by 3-dimensional computed tomography (3D-CT) for laparoscopic surgery for transverse colon cancer (TCC). A total of 102 p...