A patient with colitis-associated cancer who developed clinically manifest Crohn's disease only after surgery.

BACKGROUND: Patients with prolonged inflammatory bowel disease have a greater risk of colorectal cancer, known as colitis-associated cancer. Here we describe an unusual case of colitis-associated cancer. CASE PRESENTATION: The subject is a 41-year-old male who has not presented digestive symptoms and has an appreciable medical history. He consulted a nearby doctor with left flank pain. A colonoscopy revealed a lateral spreading tumor (granular-type) in his descending colon. With a clinical diagnosis of cancer, D3 left hemicolectomy was performed and a small intestine stoma was constructed. The pathological diagnosis of the tumor was mucinous adenocarcinoma, pT4a(SE), pN2a, which was associated with dysplasia in the surface area. Post-operative ileus was prolonged and the endoscopic examination revealed longitudinal ulcers in the ileum. These ulcers responded quite well to the administration of infliximab, confirming the final diagnosis of Crohn's disease. Pathological re-examination revealed that the tumor was dysplasia-associated type, and another dysplasia was confirmed near the tumor. Furthermore, mural scars and sporadic lymphoid aggregates were noted in the colon tissues, which suggested pre-existing Crohn's disease. The patient died of peritoneal dissemination of cancer on day 207 after surgery. CONCLUSION: The present case was diagnosed as colitis-associated cancer with clinically latent Crohn's disease, who developed clinically manifest Crohn's disease only after surgery. Our review of literature revealed no cases comparable to ours.

Histological advantages of the tumor graft: a murine model involving transplantation of human pancreatic cancer tissue fragments.

OBJECTIVES: Experimental data based on cell line-derived xenograft models (cell xenograft) seldom reproduce the clinical situation, and therefore we demonstrated here the superiority of a murine model involving transplantation of human pancreatic cancer tissue fragments (tumor graft), focusing on the histological features and drug delivery characteristics. METHODS: Tumor pieces from 10 pancreatic cancer patients were transplanted into SCID (severe combined immunodeficient) mice. Histological characteristics of tumor grafts, including morphology, desmoplastic reaction, and vascularization, were compared with those of cell xenografts. Drug delivery was evaluated by quantifying the concentrations of injected drug, and the results were compared with its histological features. RESULTS: Eight of the 10 transplanted tumors successfully engrafted. Histological comparisons between tumor grafts and cell xenografts revealed the following: the amount of stroma was more (22.9% ± 11.8% vs 10.8% ± 5.4%; P < 0.05), vessel-cancer cell distance was longer (35.3 ± 39.0 vs 3.9 ± 3.1 µm; P < 0.001), and microvessel density was lower (6.8 ± 1.9 vs 10.8 ± 2.1 vessels/0.4 mm(2); P < 0.05) in tumor grafts. Drug concentrations in tumor grafts were lower than those in cell xenografts (3.3 ± 1.2 vs 6.0±0.2 µg/mL; P = 0.003), and the differences were correlated with the histological differences. CONCLUSIONS: Pancreatic tumor grafts better reproduce the histological nature of clinical cancer and thus provide a more realistic model that is applicable for pharmacokinetic studies.

Hyporesponsiveness to natural killer T-cell ligand alpha-galactosylceramide in cancer-bearing state mediated by CD11b+ Gr-1+ cells producing nitric oxide.

CD1d-restricted natural killer T (NKT) cells are a potential therapeutic target for cancer, for which several clinical trials have already been reported. NKT cells are specifically activated by a synthetic glycolipid, alpha-galactosylceramide (alpha-GalCer). However, it is known that, in human cancer patients, NKT cells express a degree of hyporesponsiveness to alpha-GalCer. In this study, we have examined the mechanism by which hyporesponsiveness to alpha-GalCer can be induced. In cancer-bearing mice, alpha-GalCer-induced NKT cell expansion, cytokine production, cytotoxicity, and antimetastatic effect in vivo were all significantly impaired. In fact, alpha-GalCer could eliminate metastatic disease in naive animals but failed to protect cancer-bearing mice. CD11b(+) Gr-1(+) cells were particularly increased in cancer-bearing mice and were necessary and sufficient for the suppression of the alpha-GalCer response in a nitric oxide-mediated fashion. Administration of a retinoic acid to cancer-bearing mice reduced the population of CD11b(+) Gr-1(+) cells and effectively restored alpha-GalCer-induced protection. These results show a novel feature of NKT cell function in cancer. Furthermore, our data suggest a new strategy to enhance NKT cell-mediated anticancer immune responses by suppressing CD11b(+) Gr-1(+) cell functions.

Tumor rejection by the poliovirus receptor family ligands of the DNAM-1 (CD226) receptor.

The poliovirus receptor CD155 and its family member CD112 (nectin-2) are the ligands for the activating cell-surface receptor DNAM-1 on CD8+ T cells and natural killer (NK) cells. Here, we demonstrate that, whereas the RMA tumor grew in syngeneic mice, DNAM-1 ligand-transduced RMA was rejected, in which CD8+ T cells and NK cells played an essential role. Importantly, CD8+ memory cytotoxic T cells to parental RMA were generated in these mice. We found that DNAM-1 was also expressed on CD8alpha+, rather than CD8alpha-, dendritic cells (DCs). Cross-linking DNAM-1 induced maturation of CD8alpha+ DCs. Antigen presentation by these stimulated DCs drove Th1 cells. Moreover, the rejection of DNAM-1 ligand-transduced RMA was canceled in CD4+ T-cell-depleted and major histocompatibility complex class II-deficient mice. Taken together, these results suggest that DNAM-1 ligands stimulate innate immunity by CD8alpha+ DCs as well as NK cells, which efficiently prime cell-mediated tumor-specific immunity.

[Induction of CPT-11 in a patient on hemodialysis with metastatic rectal cancer].

We report a case on hemodialysis with metastatic rectal cancer who was introduced to CPT-11. Although the expected pharmacokinetics was shown 24 hours post-dialysis with the infusion of dose-reduced CPT-11, grade 4 neutropenia was observed. Considering the chronic renal failure status with latent lower function of multiple organs, the dose escalation method was recommended while watching the pharmacokinetics. CPT-11 is not only the key compound for metastatic colorectal cancer, but is also effective with several other cancers. It is important for cancer patients with chronic renal failure that the feasibility and efficacy of CPT-11 should be determined by future study.