[Retrospective Analysis of Treatment Strategies for Local Recurrence following Radical Resection of Rectal Cancer].

We report the findings from a retrospective study to determine the optimum treatment strategy for local recurrence following radical resection of rectal cancer. In our department, among all 430 patients that underwent radical resection of rectal cancer from 2012 to 2018, there were 28 patients that developed local recurrence. Of those patients, 12 underwent surgical treatment(Op group)and 16 did not(N-Op group). In the Op group, 8 patients underwent radical resection, of which 2 patients remained recurrence-free, and the other 6 patients developed recurrence. In the N-Op group, 6 patients were treated with systemic chemotherapy alone, a further 6 patients had palliative irradiation in addition to systemic chemotherapy, and the other 4 selected best supportive care(2 patients were treated with palliative irradiation). In the 8 patients who had palliative irradiation, 7 showed a decrease in numerical rating scale(NRS)after irradiation. The adverse events of palliative irradiation were scrotal dermatitis in 1 patient and perianal inflammation in another 3 patients. Our surgical results for local recurrence of rectal cancer in our department were worse in terms of recurrence rate, so these findings suggest that the preoperative surgical strategy could be reviewed, as well as the actual surgical methods such as the optimal circumferential resection margin. Palliative irradiation was found to be useful for pain control. However, the occurrence of adverse events remains a concern.

Identification of DNA Repair-related Genes as Biomarkers Reflecting MSI, TMB, and TIL in Colorectal Cancer.

BACKGROUND/AIM: There are no established biomarkers for immune checkpoint inhibitors (ICI) in colorectal cancer (CRC) with microsatellite stability (MSS) or proficient mismatch repair (pMMR). Therefore, this study aimed to identify biomarkers for ICI benefit in patients with pMMR by analyzing the down-regulated DNA repair-related genes involved in highly immunogenic and immune responses, and comparing their expression levels and clinical features. MATERIALS AND METHODS: Mismatch repair (MMR), tumor-infiltrating lymphocytes (TIL), and tumor mutation burden (TMB) were evaluated in 13 CRC cases and mRNA expression levels of 95 DNA repair-related genes were measured. DNA repair-related genes with reduced mRNA expression in the high immunogenicity and high immune response groups were identified. Then, the mRNA expression levels of the identified DNA repair-related genes were measured in 135 patients with CRC. Hierarchical cluster analysis was performed using the mRNA expression levels to compare the clinicopathological characteristics of each cluster. RESULTS: ATR, LIG4, and RAD52 mRNA levels were significantly down-regulated in the high immunogenicity group. GADD45B, SMUG1, and XRCC6 mRNA levels were significantly down-regulated in the high immune response group. Cases in the cluster with reduced mRNA expression of the six genes were pMMR cases. CD8 mRNA expression level was higher in this cluster than in the other clusters. CONCLUSION: Decreased mRNA expression levels of ATR, LIG4, RAD52, GADD45B, SMUG1, and XRCC6 genes were associated with high cytotoxic T cell and TMB levels, suggesting that these genes could serve as biomarkers for ICI efficacy in pMMR cases.

Factors associated with the need for long-term total parenteral nutrition in survivors of acute superior mesenteric artery occlusion.

BACKGROUND: Acute superior mesenteric artery (SMA) occlusion is an uncommon condition associated with high mortality. If extensive bowel resection is performed for patients with acute SMA occlusion and the patient survives, long-term total parenteral nutrition (TPN) may be needed due to short bowel syndrome. This study examined factors associated with the need for long-term TPN after the treatment of acute SMA occlusion. METHODS: We retrospectively analyzed 78 patients with acute SMA occlusion. Patients were abstracted from a Japanese database from institutions with at least 10 patients with acute SMA occlusive disease from January 2015 through December 2020 RESULTS: Among the initial cohort there were 41/78 survivors. Of these, 14/41 (34%) required permanent TPN who were compared with those who did not require long-term TPN (27/41, 66%). Compared to patients in the non-TPN group, those in the TPN group had significantly shorter remaining small intestine (90.7 cm vs. 218 cm, P<0.01), more patients with time from onset to intervention >6 hours (P=0.02), pneumatosis intestinalis on enhanced computed tomography scan (P=0.04), ascites (Odds Ratio 11.6, P<0.01), and a positive smaller superior mesenteric vein sign (P= 0.03). These were considered significant risk factors for needing long-term TPN. Age, gender, underlying disease, presence of peritoneal sign, presence of shock requiring vasopressors, site of obstruction (proximal vs. distal), and initial treatment (surgery vs. interventional radiology vs. thrombolytic therapy) were not significantly different between the two groups. Long-term TPN was significantly associated with longer hospital stay (52 vs. 35 days, P=0.04). Multivariate analysis identified the presence of ascites as an independent risk factor for needing long-term TPN. CONCLUSION: The need for permanent TPN after treatment of acute SMA occlusion is significantly associated with longer hospital stay, longer time to intervention, and characteristic imaging findings (pneumatosis intestinalis, ascites, Smaller SMV sign). Ascites is an independent risk factor. LEVEL OF EVIDENCE: III.

Mesenteric Myxofibrosarcoma: A Case Report.

Myxofibrosarcoma is a soft tissue sarcoma that occurs in elderly patients. Primary myxofibrosarcoma rarely arises in the mesentery; this is the fourth known case of myxofibrosarcoma presenting as a mesenteric tumor. A 62-year-old male with a mesenteric myxofibrosarcoma presented with an abdominal mass; his symptoms were frequent urination and a sense of abdominal pressure. He was admitted for further examination. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a mesenteric lesion. The preoperative diagnosis was a suspected malignant myxoid tumor. We performed a curative resection with wide margins. The histopathological and immunohistochemical findings confirmed that the tumor was mesenteric myxofibrosarcoma. The postoperative course was uneventful, and there have been no signs of relapse for three years to date after surgery. It is difficult to make a definitive diagnosis of mesenteric myxofibrosarcoma using only CT or MRI. However, when the preoperative findings suggest a malignant mesenteric tumor, then the best practice is resection with sufficient margins.