Ulcerative colitis (UC) is a DNA damage-associated chronic inflammatory disease; the DNA double-strand break (DSB) repair pathway participates in UC-associated dysplasia/colitic cancer carcinogenesis. The DSB/interferon regulatory factor-1 (IRF-1) pathway can induce PD-L1 expression transcriptionally. However, the association of PD-L1/DSB/IRF-1 with sporadic colorectal cancer (SCRC), and UC-associated dysplasia/colitic cancer, remains elusive. Therefore, we investigated the significance of the PD-L1/DSB repair pathway using samples from 17 SCRC and 12 UC patients with rare UC-associated dysplasia/colitic cancer cases by immunohistochemical analysis. We compared PD-L1 expression between patients with SCRC and UC-associated dysplasia/colitic cancer and determined the association between PD-L1 and the CD8+ T-cell/DSB/IRF-1 axis in UC-associated dysplasia/colitic cancer. PD-L1 expression in UC and UC-associated dysplasia/colitic cancer was higher than in normal mucosa or SCRC, and in CD8-positive T lymphocytes in UC-associated dysplasia/colitic cancer than in SCRC. Moreover, PD-L1 upregulation was associated with γH2AX (DSB marker) and IRF-1 upregulation in UC-associated dysplasia/colitic cancer. IRF-1 upregulation was associated with γH2AX upregulation in UC-associated dysplasia/colitic cancer but not in SCRC. Multicolour immunofluorescence staining validated γH2AX/IRF-1/PD-L1 co-expression in colitic cancer tissue sections. Thus, immune cell-induced inflammation might activate the DSB/IRF-1 axis, potentially serving as the primary regulatory mechanism of PD-L1 expression in UC-associated carcinogenesis.
Background
No standard treatment for anorectal fistula cancer, such as multidisciplinary therapy, has been established due to the rarity of the disease. Herein, we investigated patients with cancer associated with anorectal fistula who underwent surgery to clarify the clinicopathological characteristics and to propose future perspectives for treatment strategies.
Case presentation
Seven patients with cancer associated with anorectal fistula who underwent rectal amputation in our institute were analyzed with regard to clinical characteristics, pathological findings, surgical results, and prognosis. Four cases had Crohn's disease as an underlying cause. All seven cases were diagnosed as advanced stage. Preoperative [18F]-fluoro-2-deoxy-d-glucose (FDG)-positron emission tomography/computed tomography (FDG-PET/CT) showed abnormal FDG accumulation in six cases including four mucinous adenocarcinomas. Three cases that received preoperative hyperthermo-chemoradiotherapy achieved pathological R0 resection. Postoperative recurrence was observed in four cases including three with Crohn's disease and one resulting in death.
Conclusions
Anorectal fistula cancer is rare and difficult to be diagnosed at early stages. Mucinous adenocarcinoma associated with anorectal fistula tends to exhibit abnormal FDG accumulation by FDG-PET/CT unlike common colorectal mucinous adenocarcinoma. Preoperative hyperthermo-chemoradiotherapy may be effective in obtaining pathological complete resection.
In this study, we describe a 60-year-old man with a giant retroperitoneal liposarcoma with multilocular cysts. He was admitted to our hospital because of a 5-month history of abdominal distention. Abdominal computed tomography revealed a giant lobulated cystic mass occupying the retroperitoneal space that contained partially solid fat components. Magnetic resonance imaging indicated that this complex mass exhibited a low signal intensity on a T1weighted image, whereas it exhibited a high and focally intermediate signal intensity on a T2weighted image. This patient was diagnosed with a mucinous type of retroperitoneal sarcoma, which was then resected. During surgery, the tumor was isolated from the retroperitoneum and other organs, but the detachment was required only because of fixation around the left external iliac artery. The histological diagnosis was a well-differentiated liposarcoma with multilocular cysts that contained old bloody, serous, and mucinous fluids, which are a rare phenomenon in liposarcoma. This case indicates that retroperitoneal liposarcoma should also be considered as a differential diagnosis of retroperitoneal cystic mass.
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