廣 純一郎

OBJECTIVE: The risk factors for residual liver recurrence after resection of colorectal cancer liver metastases were analyzed separately for synchronous and metachronous metastases. METHODS: This retrospective study included 236 patients (139 with synchronous and 97 with metachronous lesions) who underwent initial surgery for colorectal cancer liver metastases from April 2010 to December 2021 at the Fujita Health University Hospital. We performed univariate and multivariate analyses of risk factors for recurrence based on clinical background. RESULTS: Univariate analysis of synchronous liver metastases identified three risk factors: positive lymph nodes (p = 0.018, HR = 2.067), ≥3 liver metastases (p < 0.001, HR = 2.382), and use of adjuvant chemotherapy (p = 0.013, HR = 0.560). Multivariate analysis identified the same three factors. For metachronous liver metastases, univariate and multivariate analysis identified ≥3 liver metastases as a risk factor (p = 0.002, HR = 2.988); however, use of adjuvant chemotherapy after hepatic resection was not associated with a lower risk of recurrence for metachronous lesions. Inverse probability of treatment weighting analysis of patients with these lesions with or without adjuvant chemotherapy after primary resection showed that patients with metachronous liver metastases who did not receive this treatment had fewer recurrences when adjuvant therapy was administered after subsequent liver resection, although the difference was not significant. Patients who received adjuvant chemotherapy after hepatic resection had less recurrence but less benefit from this treatment. CONCLUSION: Risk factors for liver recurrence after resection of synchronous liver metastases were positive lymph nodes, ≥3 liver metastases, and no postoperative adjuvant chemotherapy. Adjuvant chemotherapy is recommended after hepatic resection of synchronous liver metastases.

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.

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.

Obesity has been considered a risk factor for postoperative complications following colorectal cancer surgery. However, the usefulness of a combination of intracorporeal anastomosis and preoperative weight reduction for severely obese patients with colon cancer remains unclear. A 66-year-old man with a body mass index (BMI) of 43 kg/m2 presented with abdominal pain and iron deficiency anemia. Colonoscopy and computed tomography revealed advanced ascending colon cancer with regional lymph node metastasis and excessive abdominal fat. Preoperative diet-induced weight reduction was performed for severe obesity, which decreased his BMI to 39.7 kg/m2 after 1 month. Thereafter, curative resection was performed using intracorporeal anastomosis for reconstruction to achieve minimal colon and mesentery mobilization and a shorter incision. The patient was discharged from the hospital without complications. Laparoscopic right hemicolectomy combining intracorporeal anastomosis and preoperative weight reduction was extremely useful in the current patient with severe obesity and ascending colon cancer.

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.