Pks-positive Escherichia coli in tumor tissue and surrounding normal mucosal tissue of colorectal cancer patients.

A significant association exists between the gut microbiome and colorectal carcinogenesis, as well as cancer progression. It has been reported that Escherichia coli (E. coli) containing polyketide synthetase (pks) island contribute to colorectal carcinogenesis by producing colibactin, a polyketide-peptide genotoxin. However, the functions of pks+ E. coli in initiation, proliferation, and metastasis of colorectal cancer (CRC) remain unclear. We investigated the clinical significance of pks+ E. coli to clarify its functions in CRC. This study included 413 patients with CRC. Pks+ E. coli of tumor tissue and normal mucosal tissue were quantified using droplet digital PCR. Pks+ E. coli was more abundant in Stages 0-I tumor tissue than in normal mucosal tissue or in Stages II-IV tumor tissue. High abundance of pks+ E. coli in tumor tissue was significantly associated with shallower tumor depth (hazard ratio [HR] = 5.0, 95% confidence interval [CI] = 2.3-11.3, p < 0.001) and absence of lymph node metastasis (HR = 3.0, 95% CI = 1.8-5.1, p < 0.001) in multivariable logistic analyses. Pks+ E. coli-low and -negative groups were significantly associated with shorter CRC-specific survival (HR = 6.4, 95% CI = 1.7-25.6, p = 0.005) and shorter relapse-free survival (HR = 3.1, 95% CI = 1.3-7.3, p = 0.01) compared to the pks+ E. coli-high group. Pks+ E. coli was abundant in Stages 0-I CRC and associated with CRC prognosis. These results suggest that pks+ E. coli might contribute to carcinogenesis of CRC but might not be associated with tumor progression.

Short- and long-term outcomes of surgical treatment for inguinal lymph node metastasis in rectal and anal canal adenocarcinoma.

AIM: The significance of lymphadenectomy and its indications in patients with inguinal lymph node metastasis (ILNM) of anorectal adenocarcinoma is unclear. This study aimed to clarify the surgical outcomes and prognostic factors of inguinal lymphadenectomy for ILNM. METHOD: This study included patients who underwent surgical resection for ILNM of rectal or anal canal adenocarcinoma with pathologically positive metastases between 1997 and 2011 at 20 participating centres in the Study Group for Inguinal Lymph Node Metastasis from Colorectal Cancer organized by the Japanese Society for Cancer of the Colon and Rectum. Clinicopathological characteristics and short- and long-term postoperative outcomes were retrospectively analysed. RESULTS: In total, 107 patients were included. The primary tumour was in the rectum in 57 patients (53.3%) and in the anal canal in 50 (46.7%). The median number of ILNMs was 2.34. Postoperative complications of Clavien-Dindo Grade III or higher were observed in five patients. The 5-year overall survival rate was 38.8%. Multivariate analysis identified undifferentiated histological type (P < 0.001), pathological venous invasion (P = 0.01) and pathological primary tumour depth T0-2 (P = 0.01) as independent prognostic factors for poor overall survival. CONCLUSION: The 5-year overall survival after inguinal lymph node dissection was acceptable, and it warrants consideration in more patients. Further larger-scale studies are needed in order to clarify the surgical indications.

The benefits of interval appendectomy and risk factors for nonoperative management failure in the therapeutic strategy for complicated appendicitis.

PURPOSE: Emergency surgery (ES) for complicated appendicitis (CA) is associated with high morbidity. Interval appendectomy (IA) decreases this rate; however, nonoperative management (NOM) is not always successful. Some patients require unplanned ES due to NOM failure (IA failure: IA-F). This study aimed to verify the benefits of IA and to evaluate the risk factors for NOM failure. METHODS: Patients diagnosed with CA who underwent surgery between January 2012 and December 2021 were included in this study. We compared the surgical outcomes of the ES group with those of the IA success (IA-S) and IA-F groups. We also analyzed 14 factors that predicted NOM failure. RESULTS: Among 302 patients, the rate of severe complications (Clavien-Dindo grade ≥ III) was significantly higher in the ES group (N = 165) than in the IA-S group (N = 102). The rates were equal between the ES (N = 165) and IA-F (N = 35) groups. NOM was successful in 110 patients and failed in 27. Lack of abscesses, comorbidities, high WBC count, and free air were independent risk factors for NOM failure. CONCLUSIONS: Considering the benefits of IA and the non-inferior surgical outcomes of IA-F compared to ES, IA is a good therapeutic strategy for CA. However, in patients exhibiting four independent risk factors for NOM failure, careful monitoring of unplanned ES is necessary.

Oncologic investigation of the interval from stent placement to surgery in patients with obstructive colorectal cancer.

PURPOSE: Self-expandable metallic stent (SEMS) placement is widely used as a bridge to surgery (BTS) procedure for obstructive colorectal cancer. However, evidence regarding the optimal interval between SEMS placement and elective surgery is lacking. METHODS: We retrospectively collected data from patients with BTS between January 2013 and October 2021. Inverse probability treatment-weighted propensity score analyses were used to compare short- and long-term outcomes between the short-interval (SI) and long-interval (LI) groups, using a cutoff of 20 days. RESULTS: In total, 138 patients were enrolled in this study (SI group, n = 63; LI group, n = 75). In the matched cohort, the patients' backgrounds were well balanced. The incidence of Clavien-Dindo grade ≥ II postoperative complications was not significantly different between the SI and LI groups (19.0% vs. 14.0%, P = 0.47). There were no significant differences between the SI and LI groups in the 3-year recurrence-free survival (68.0% vs. 76.4%, P = 0.73) or 3-year overall survival rates (86.0% vs. 90.6%, P = 0.72). CONCLUSIONS: A longer interval did not deteriorate the oncological outcomes. Individual perioperative management with an appropriate interval to improve the patient's condition is required to ensure safe surgery.

Significance of Adjuvant Chemotherapy for Obstructive Colorectal Cancer After Stent Placement: A Multicenter Retrospective Study.

BACKGROUND/AIM: To explore the survival benefit of adjuvant chemotherapy for obstructive colorectal cancer (OCRC) managed by self-expandable metallic stent (SEMS) placement as a bridge to surgery (BTS). PATIENTS AND METHODS: One hundred twenty-nine patients with pathological stage II/III OCRC who underwent BTS using a SEMS were included in this multicenter retrospective study. Patients were divided into the no-adjuvant chemotherapy group (No-Adj group) (n=52) and adjuvant chemotherapy group (Adj group) (n=77), and relapse-free survival (RFS) was compared. RESULTS: The No-Adj group had more fragile patient background factors, such as higher age, higher American Society of Anesthesiologists score, and lower preoperative albumin compared with the Adj group. The 3-year RFS rates for the overall cohort were significantly different between the No-Adj and Adj groups (56.4% and 78.5%, respectively; p=0.003). Significant RFS benefits of adjuvant chemotherapy were observed in both pathological stage II and III cancer. Characteristics of more advanced cancer, such as high carcinoembryonic antigen (CEA), pathological T4, and lymphovascular invasion, were associated with survival improvement by adjuvant chemotherapy. T4 and adjuvant chemotherapy were significantly associated with RFS in the multivariate Cox proportional analysis. CONCLUSION: To our knowledge, this is the first study to show a survival benefit of adjuvant chemotherapy in patients with OCRC undergoing BTS using a SEMS. Adjuvant chemotherapy is basically recommended regardless of the cancer stage and is strongly recommended with more advanced characteristics, such as high CEA, T4, and lymphovascular invasion.

Impact of resection for ovarian metastases from colorectal cancer and clinicopathologic analysis: A multicenter retrospective study in Japan.

Aim: The aim of this study was to clarify the significance of resection of ovarian metastases from colorectal cancer and to identify the clinicopathologic characteristics. Methods: In this multicenter retrospective study, we evaluated data on ovarian metastases from colorectal cancer obtained from patients at 20 centers in Japan between 2000 and 2014. We examined the impact of resection on the prognosis of patients with ovarian metastases and examined prognostic factors. Results: The study included 296 patients with ovarian metastasis. The 3-y overall survival rate was 68.6% for solitary ovarian metastases. In all cases of this cohort, the 3-y overall survival rates after curative resection, noncurative resection, and nonresection were 65.9%, 31.8%, and 6.1%, respectively (curative resection vs noncurative resection [P < 0.01] and noncurative resection vs nonresection [P < 0.01]). In the multivariate analysis of prognostic factors, tumor size of ovarian metastasis (P < 0.01), bilateral ovarian metastasis (P = 0.01), peritoneal metastasis (P < 0.01), pulmonary metastasis (P = 0.04), liver metastasis (P < 0.01), and remnant of ovarian metastasis (P < 0.01) were statistically significantly different. Conclusion: The prognosis after curative resection for solitary ovarian metastases was shown to be relatively favorable as Stage IV colorectal cancer. Resection of ovarian metastases, not only curative resection but also noncurative resection, confers a survival benefit. Prognostic factors were large ovarian metastases, bilateral ovarian metastases, the presence of extraovarian metastases, and remnant ovarian metastases.

Recent evidence for subcutaneous drains to prevent surgical site infections after abdominal surgery: A systematic review and meta-analysis.

BACKGROUND: Surgical site infections (SSIs) increase mortality, hospital stays, additional medical treatment, and medical costs. Subcutaneous drains prevent SSIs in gynecological and breast surgeries; however, their clinical impact in abdominal surgery remains unclear. AIM: To investigate whether subcutaneous drains were beneficial in abdominal surgery using a systematic review and meta-analysis. METHODS: The database search used PubMed, MEDLINE, and the Cochrane Library. The following inclusion criteria were set for the systematic review: (1) Randomized controlled trial studies comparing SSIs after abdominal surgery with or without subcutaneous drains; and (2) Studies that described clinical outcomes, such as SSIs, seroma formation, the length of hospital stays, and mortality. RESULTS: Eight studies were included in this meta-analysis. The rate of total SSIs was significantly lower in the drained group (54/771, 7.0%) than in the control group (89/759, 11.7%), particularly in gastrointestinal surgery. Furthermore, the rate of superficial SSIs was slightly lower in the drained group (31/517, 6.0%) than in the control group (49/521, 9.4%). No significant differences were observed in seroma formation between the groups. Hospital stays were shorter in the drained group than in the control group. CONCLUSION: Subcutaneous drains after abdominal surgery prevented SSIs and reduced hospital stays but did not significantly affect seroma formation. The timing of drain removal needs to be reconsidered in future studies.