Objective: Skeletal muscle loss (sarcopenia) is a prognostic factor in patients undergoing gastrointestinal surgery. However, the influence of muscle quality on prognosis remains unclear. We retrospectively examined preoperative skeletal muscle quantity and quality impact on survival of elderly patients undergoing curative resection of colorectal cancer. Methods: We examined data from 142 patients aged ≥75 years who underwent curative resection of colorectal cancer between 2007 and 2012. We determined the size and quality of skeletal muscles, represented by the psoas muscle mass index (PMI) and intramuscular adipose tissue content (IMAC), respectively, using a preoperative computed tomography image. Overall survival (OS) and relapse-free survival (RFS) rates were determined according to values of PMI, IMAC, and other prognostic factors. Results: OS and RFS rates in patients with low PMI were lower than those in patients with normal PMI. The OS and RFS rates in patients with high IMAC were also lower than those in patients with normal IMAC. PMI and IMAC were independent prognostic factors for OS (hazard ratio [HR], 3.81, and 3.04, respectively); IMAC was an independent factor for RFS (hazard ratio [HR], 3.03). Conclusion: Preoperative sarcopenia, indicating low quality and size of skeletal muscle, predicts mortality after curative resection of colorectal cancer in the elderly.

Objectives: Colorectal laterally spreading tumors (LSTs) are widely recognized owing to their structural characteristics. This study aims to clarify the histopathological characteristics of large colorectal LSTs according to growth pattern. Methods: We studied 297 colorectal LSTs measuring ≥20 mm in diameter. The LSTs were classified into four types: granular homogenous type (LST-G-H), granular nodular mixed type (LST-G-M), non-granular flat elevated type (LST-NG-F), and non-granular pseudo-depressed type (LST-NG-PD). Retrospectively collected data were examined to compare the histopathological characteristics of LSTs according to the growth pattern. Results: LST-G-M lesions (142 lesions) were most common, followed by LST-NG-F (74 lesions), LST-G-H (61 lesions), and LST-NG-PD (20 lesions). The mean tumor diameter of LST-G lesions (38.5 ± 17.2 mm) was significantly greater than that of LST-NG lesions (26.3 ± 7.0 mm, P < 0.001). In particular, 45% of LST-G-M lesions were ≥40 mm in diameter. Adenomas accounted for 54% of LST-G-H lesions compared with only 10% of LST-NG-PD lesions. Pathological T1 carcinomas accounted for 55% of LST-NG-PD lesions and were not found among LST-G-H lesions. Conclusions: The biological malignancy of colorectal LSTs differs considerably depending on the growth pattern even among large lesions and therefore should be considered when selecting treatment regimens.

Objectives: The purpose of this study was to investigate whether the symptoms of fecal incontinence (FI) or anal sphincter dysfunction are improved by daikenchuto (DKT). Methods: This is a retrospective observational study that analyzes the effects of DKT. The study was conducted at Kunimoto Hospital. Patients who visited the hospital from January 2012 to December 2016 due to symptoms of FI with a certain degree of chronic constipation and who took DKT were enrolled. The drug to be evaluated was "Tsumura Daikenchuto Extract Granules for Ethical Use (TJ-100) " manufactured by Tsumura & Co., Tokyo, Japan. The primary outcome measures were changes in the scores of the Cleveland Clinic Incontinence Score (CCIS) and Constipation Scoring System (CSS) before and after the administration of DKT. Results: A total of 157 patients were enrolled. On the CCIS, "leakage of solid stool," "leakage of liquid stool," "pad use," and "total score" were significantly improved. On the contrary, on the CSS, the score of "type of assistance" was significantly improved after the administration of DKT, but no significant difference was found in the total score. On the Bristol Stool Form Scale, the administration of DKT showed a tendency to normalize stool consistency. Maximum resting anal pressure and maximum squeeze anal pressure significantly increased after the administration of DKT. No side effects caused by DKT were observed during the study. Conclusions: DKT appears to be a safe and useful agent for the management of FI in patients with defecation disorders and internal anal sphincter dysfunction.

Objectives: Left colic artery preserving lymph node dissection around the inferior mesenteric artery (IMA) is a standard procedure for rectal cancer surgery. Although the IMA sheath is a well-known structure, to our knowledge, there are no reports describing its microanatomy from an oncological point of view; therefore, there is no consensus on how to handle the sheath for accurate lymph node dissection around IMA. We aimed to investigate the components of the IMA sheath pathologically, focusing particularly on the presence of lymph nodes (LNs) and lymphatic ducts (LDs). Methods: We evaluated rectal and sigmoid cancer specimens resected with high-tie technique in our institute in April 2017-April 2018. The specimens were collected consecutively, without any selection. In the resected specimens, the entire anatomical structure of IMA was investigated. We defined the IMA sheath as the tissues located between the surface of the IMA adventitia and collagenous layers connecting the outermost nerve fibers. The microanatomy around the IMA was examined using H&E staining, and LDs were identified using D2-40 immunohistochemistry. Results: Twenty patients were enrolled. No LNs were observed within the sheath in any of the cases. However, there were a significant number of LDs (11.08 ± 3.35) within the sheath. Conclusions: Our anatomical definition of IMA sheath was feasible and objectively possible. These microanatomical results partially support the surgical concept of left colic artery preserving lymph node dissection around the IMA. It may be difficult to remove all lymphatic ducts without removing the IMA itself.

Objectives: To determine whether primary tumor location is an independent prognostic factor in stage IV colon cancer, focusing on its relationship with chemotherapy and/or sex. Methods: We retrospectively analyzed clinicopathological data from 255 patients with stage IV colon cancer from two treatment eras according to the year of starting multidrug combination chemotherapy: period A was from 1985 to 2005 and period B from 2006 to 2013. Propensity score matching (1:1) was performed to assess overall survival (OS). Results: Right-sided colon cancer tended to be more common in elderly females with large-sized tumors, exhibiting mucinous histology or peritoneal dissemination. After propensity score matching, 130 patients were identified. There was no difference in OS between left-sided and right-sided tumors in either period A or B. The prognosis of patients receiving chemotherapy in either period was superior to that of those without chemotherapy. Better outcome of chemotherapy was seen only in female left-sided patients from both periods (p < 0.05). By multivariate analysis, liver metastasis, peritoneal dissemination, and chemotherapy were found to be independent risk factors in period A, whereas only liver metastasis and chemotherapy were the independent factors in period B. Conclusions: Primary tumor location is not an independent prognostic factor, but seems to be a chemotherapy effect modifier.