Differential analysis of microbiomes in mucus and tissues obtained from colorectal cancer patients.

The outer mucus layer of the colorectal epithelium is easily removable and colonized by commensal microbiota, while the inner mucus layer is firmly attached to the epithelium and devoid of bacteria. Although the specific bacteria penetrating the inner mucus layer can contact epithelial cells and trigger cancer development, most studies ignore the degree of mucus adhesion at sampling. Therefore, we evaluated whether bacteria adhering to tissues could be identified by removing the outer mucus layer. Our 16S rRNA gene sequencing analysis of 18 surgical specimens of human colorectal cancer revealed that Sutterella (P = 0.045) and Enterobacteriaceae (P = 0.045) were significantly enriched in the mucus covering the mucosa relative to the mucosa. Rikenellaceae (P = 0.026) was significantly enriched in the mucus covering cancer tissues compared with those same cancer tissues. Ruminococcaceae (P = 0.015), Enterobacteriaceae (P = 0.030), and Erysipelotrichaceae (P = 0.028) were significantly enriched in the mucus covering the mucosa compared with the mucus covering cancers. Fusobacterium (P = 0.038) was significantly enriched in the mucus covering cancers compared with the mucus covering the mucosa. Comparing the microbiomes of mucus and tissues with mucus removed may facilitate identifying bacteria that genuinely invade tissues and affect tumorigenesis.

Establishment of the menthol test as a clinical evaluation method for oxaliplatin-induced neuropathy.

Objectives: To determine whether the tongue menthol test, which measures the cold sensation detection threshold (CDT) of the tongue, used before and after oxaliplatin administration is an objective evaluation method for oxaliplatin-induced peripheral neuropathy (OPN). Methods: The tongue menthol test was administered to patients both before and after undergoing chemotherapy containing oxaliplatin for colorectal cancer. The tongue menthol test was conducted by applying a menthol solution (a selective agonist of transient receptor potential cation channel subfamily M member 8 [TRPM8]) to the tongue and measuring the CDT. Results: The mean CDT before the first dose of oxaliplatin was 0.34% (0.005%-1%; n=38), and the mean CDT after the first dose was 0.32% (0.005%-1%; n=38). The CDT appeared to decrease after the first dose, but this difference was not significant. In patients who received five courses of oxaliplatin, changes in CDT values were compared before and after the five courses. In patients with Neurotoxicity Criteria of Debiopharm (DEB-NTC) grade 2 neuropathy, the pre-oxaliplatin administration CDT was compared between before grade exacerbation and when exacerbation occurred, and was found to decline when grade exacerbation occurred. Moreover, when the CDTs before and after administration were compared before grade exacerbation, there was a significant decrease in CDT after administration (P=0.04). Conclusions: By performing a menthol test in oxaliplatin-treated patients, it may be possible to objectively predict the exacerbation of peripheral neuropathy at an early stage.

[Clinical Study of Inguinal Lymph Node Metastasis in Anal Canal Adenocarcinoma].

We reviewed clinical records of 73 cases with anal canal adenocarcinoma who underwent bilateral inguinal lymph node (ILN)dissection. Eleven patients with positive ILN metastasis(ILNM)were compared with 62 patients with negative ILNM in clinicopathological items and treatment outcomes to evaluate the effectiveness of ILN dissection. Positive ILNM were older, higher preoperative serum levels of CEA and CA19-9, more frequencies of undifferentiated carcinoma, T4b and severe lymphatic invasion than negative ILNM. And the number of mesorectal and lateral node metastasis were significantly more in positive ILNM than negative ILNM. Although the frequency of curability A surgery was significantly less in positive ILNM (63.6%)than negative ILNM(93.5%), there were no significant differences in recurrence rate and prognosis between positive ILNM and negative ILNM in Stage Ⅲ cancer. Recurrence in ILN occurred significantly more in positive ILNM (2 cases) than in negative ILNM(0 case)as initial recurrent site. And recurrence in pelvic local site occurred significantly more in positive ILNM(4 cases)than in negative ILNM(6 cases). Although there was no significant difference in oncological outcome in Stage Ⅲ anal canal adenocarcinoma, ILN recurrence and pelvic local recurrence should be cared for positive ILNM in postoperative follow-up.

Robotic Surgery for Rectal Cancer: Operative Technique and Review of the Literature.

The number of patients undergoing robotic surgery for rectal cancer has rapidly increased in Japan, since the government approved the procedure for national insurance coverage in April 2018. Robotic surgery has the potential to overcome some limitations of laparoscopic surgery, especially in the narrow pelvis, providing a three-dimensional view, articulated instruments, and a stable camera platform. Although meta-analyses and randomized controlled trials have failed to demonstrate the superiority of robotic surgery over laparoscopic surgery with respect to the short-term clinical outcomes, the published findings suggest that robotic surgery may be potentially beneficial for patients who are obese, male, or patients undergoing sphincter-preserving surgery for rectal cancer. The safety and feasibility of robotic surgery for lateral lymph node dissection, the standard procedure for locally advanced lower rectal cancer in Japan, have been demonstrated in some retrospective studies. However, additional prospective, randomized trials are required to determine the actual benefits of robotic surgery to ameliorate the urogenital and oncological outcomes. The cost of this approach is a long-standing principal concern. A literature search showed that the cost of robotic surgery for rectal cancer was 1.3-2.5 times higher per patient than that for the laparoscopic approach. We herein describe our surgical technique using a da Vinci Surgical System (S/Si/Xi) with 10 years of experience in performing robotic surgery. We also review current evidence regarding short-term clinical and long-term oncological outcomes, lateral lymph node dissection, and the cost of the procedure.