Candidate driver genes in focal chromosomal aberrations of stage II colon cancer.

Chromosomal instable colorectal cancer is marked by specific large chromosomal copy number aberrations. Recently, focal aberrations of 3 Mb or smaller have been identified as a common phenomenon in cancer. Inherent to their limited size, these aberrations harbour one or few genes. The aim of this study was to identify recurrent focal chromosomal aberrations and their candidate driver genes in a well-defined series of stage II colon cancers and assess their potential clinical relevance. High-resolution DNA copy number profiles were obtained from 38 formalin-fixed, paraffin-embedded colon cancer samples with matched normal mucosa as a reference using array comparative genomic hybridization. In total, 81 focal chromosomal aberrations were identified that harboured 177 genes. Statistical validation of focal aberrations and identification of candidate driver genes were performed by enrichment analysis and mapping copy number and mutation data of colorectal, breast, and pancreatic cancer and glioblastomas to loci of focal aberrations in stage II colon cancer. This analysis demonstrated a significant overlap with previously identified focal amplifications in colorectal cancer, but not with cancers from other sites. In contrast, focal deletions seemed less tumour type-specific since they also showed significant overlap with focal deletions of other sites. Focal deletions detected were significantly enriched for cancer genes and genes frequently mutated in colorectal cancer. The mRNA expression of these genes was significantly correlated with DNA copy number status, supporting the relevance of focal aberrations. Loss of 5q34 and gain of 13q22.1 were identified as independent prognostic factors of survival in this series of patients. In conclusion, focal chromosomal copy number aberrations in stage II colon cancer are enriched in cancer genes that contribute to and drive the process of colorectal cancer development. DNA copy number status of these genes correlates with mRNA expression and some are associated with clinical outcome.

[A woman with a tumour in her lesser pelvis]. / Een vrouw met een tumor in het kleine bekken.

A 63-year-old postmenopausal woman was referred for a mass on MRI: a well-defined 13 cm hyperechoic mass with high fat content. Exploratory laparotomy revealed normal ovaries and an enlarged uterus; hysterectomy was performed. Histological examination found uterine lipoleiomyoma, a rare benign type of uterine myoma.

Small bowel obstruction caused by 18FDG-negative ileocecal metastasis of lobular breast carcinoma.

Breast carcinoma is the most frequently diagnosed cancer in women. In up to 30%, distant metastases will occur; however, ileocecal metastases are rare. Although there have been cases reported that demonstrate ileocecal metastases of breast carcinoma, PET/CT-negative cases have never been described. We present a patient with a small bowel obstruction, preoperatively complicated by pulmonary embolisms. The patient underwent placement of an inferior vena cava filter followed by hemicolectomy. Pathological examination revealed ileocecal lobular breast carcinoma metastases and adjacent peritoneal carcinomatosis, which had shown no intestinal 18FDG uptake 7 weeks prior to presentation. Subsequently, symptoms of metastases and the paraneoplastic syndrome progressed, and the patient was referred to the medical oncologist for palliative therapy. Although uncommon, physicians should be aware of potential presence of 18FDG-negative gastrointestinal metastases of breast cancer.

[Oxalate nephropathy due to malabsorption syndrome]. / Oxalaatnefropathie door malabsorptiesyndromen.

Enteric oxalate nephropathy is caused by hyperoxaluria. Factors which contribute to excessive oxalate absorption are an abundance of free fatty acids in the intestine due to malabsorption, changes in the microbiome, and bowel inflammation. We present two cases that illustrate different pathophysiological aspects of this disease. The first patient was a 70-year-old male who developed oxalate nephropathy through malabsorption caused by chronic pancreatitis. It is plausible that the oxalate nephropathy was set off by antibiotic treatment which influenced the microbiome. The second patient was a 63-year-old male who underwent a Roux-en-Y gastric bypass. The associated malabsorption resulted in oxalate nephropathy. Kidney biopsies from both patients showed typical oxalate crystals. Therapeutic regimens using calcium supplementation, steroids, and a low oxalate diet are rational treatments, which have proven to prevent deterioration of renal function in some patients.

Tumor stage in patients operated for rectal cancer: a comparison of the pre-operative MR and the resection specimen, with specific attention to the effect of neo-adjuvant radiotherapy.

BACKGROUND: Evaluate the preoperative TN stage with MR and the postoperative stage with histology. METHODS: Patients diagnosed with rectal cancer (2002-2015) and a pre-operative MR were included. A chart review was done. Pathology reports were evaluated for the post-operative tumor stage. Down staging was defined as a lower disease stage in the resection specimen compared with the pre-operative MR. Upgrading ("progression") was defined as a higher disease stage in the resection specimen. The study was approved by ethical committee of the Zaans Medisch Centrum. RESULTS: From 176 out of 231 operated patients a pre-operative MR was available for evaluation. 142 patients (80.7%) underwent neo-adjuvant treatment; the remainder 19.3% underwent immediate surgery. Neo-adjuvant therapy resulted in significant down staging. However, almost 14% of patients had a higher TN stage as determined by the pre-operative MR. In patients who underwent immediate surgery the percentage with "progression" was 30%. The number of patients with stage 1 and 2 were higher in the group not treated with neo-adjuvant therapy. There was no significant difference in tumor stage as determined by histological examination of the resection specimen. CONCLUSIONS: The diagnostic accuracy of the MR is not perfect. Underestimation as well as overestimation of the tumor occurred both in the patients treated with radiotherapy as well as those who underwent immediate operation. As such, MR results should be interpreted with caution when devising a treatment strategy.

Expression of the vascular endothelial cell protein C receptor in epithelial tumour cells.

The rat monoclonal antibody LMR-42 has previously been shown to react with an external epitope of a plasma membrane protein with a M(r) of approximately 55,000 that was upregulated in multidrug-resistant (MDR) tumour cells. Here, we report the isolation of the cDNA encoding the LMR-42 antigen from the MDR human fibrosarcoma cell line HT1080/DR4 and the lung cancer cell line GLC4/ADR by expression cloning. Sequence analysis showed that the LMR-42 antigen is identical to the endothelial cell protein C receptor (EPCR). Using the LMR-42 Mab for cytochemical analyses of a disease-oriented panel of 45 non-drug selected tumour cell lines of the National Cancer Institute (NCI), we found high EPCR expression in 47% of the primary tumour cell lines, including melanomas, renal- and colon carcinomas. In a small panel of human tumours, occasionally very high EPCR expression was detected in endothelial vessels, but expression in the tumour cells was a rare event. The functional significance of overexpression of EPCR on both primary and drug-selected tumour cells is still unclear. As the protein is related to MHC class I molecules and shares no characteristics with any of the currently known transporter proteins, EPCR is not expected to play a causal role in the resistant phenotype of the MDR tumour cells. Nevertheless, exposure of tumour cells to cytostatic drugs may frequently lead to EPCR overexpression. Since EPCR is known to play a pivotal role in preventing blood coagulation through binding of (activated) protein C, it might endow tumour cells, both of mesenchymal and epithelial derivations, with increased growth potential by local anti-coagulant activity.

The localisation of cancer in the sigmoid, rectum or rectosigmoid junction using endoscopy or radiology-What is the most accurate method?

INTRODUCTION: There is a difference in approach between colon and rectal cancer. AIM: EVALUATE THE METHODS OF LOCALISATION: endoscopy and radiology. MATERIALS AND METHODS: Patients with cancer in the sigmoid or rectum diagnosed with endoscopy, were included. Patients underwent additional radiological examinations. The resection specimen served as the gold standard. A tumour surrounded by serosa was considered a sigmoid cancer, surrounded by perirectal fat, than it was rectal cancer. If the frontal edge of the tumour showed serosa and the dorsal plane perirectal fat than the tumour was located in the "rectosigmoid". RESULTS: A total of 182 cancers were diagnosed. Of the 128 cancers with gold standard, endoscopy had the correct localisation in 112 (87.5%), and radiology in 114 (90.5%) cases. Concordance between both techniques was present in 80%. In 28 cases there was discordance. Radiology located 10 sigmoidal cancers wrongly in the rectum. One rectal cancer was placed in the sigmoid. In 16 cases the endoscopic localisation wrongly was the sigmoid. Sensitivity and specificity for endoscopy in sigmoidal cancer is 100% and 77% respectively, for rectal cancer 77% and 100%. Sensitivity of radiology for cancer in the sigmoid and rectum are 80% and 98% respectively. Specificity for both cancers is 98% and 80% respectively. CONCLUSIONS: The endoscopist and the radiologist should not be too overconfident with localisation of the tumour in cases of high rectal or low sigmoidal cancer.

MDR-1-overexpression in HT 29 colon cancer cells grown in SCID mice.

The multidrug-resistance 1 (MDR-1) P-glycoprotein (Pgp) is a transmembrane transporter system, which actively pumps cytotoxic drugs out of the cell. MDR-1 acquired in vitro differs from MDR-1 acquired in vivo, but has important consequences on the cellular phenotype and metastatic behavior. Here we report that the human colonic cancer cell line HT29 (MDR-1 negative) is more malignant than its MDR-1 overexpressing variant (HT29 MDR-1 positive). HT29 MDR-1 negative cells produce undifferentiated signet ring carcinomas when implanted subcutaneously into SCID mice, while HT29 MDR-1 positive cells form tumors with tubular structures, but without signet ring cells. Immunohistochemical proliferation marker analysis revealed that the MDR-1 positive cells proliferate much more slowly than the MDR-1 negative cells. MDR-1 overexpression results in a less differentiated phenotype at the cellular level (absence of mucin producing cells) but in a more differentiated phenotype at the tissue level (tubule formation). In addition, lectin binding patterns including that of Helix pomatia agglutinin (HPA), an indicator of metastatic potential, differed between the two cell lines. HT29 MDR-1 positive cells had less HPA binding sites than HT29 MDR-1 negative counterparts and metastasized less frequently in SCID mice. As slow proliferation, low degree of differentiation and multidrug-resistance is a hallmark of cancer stem cells and all were present in MDR-1 positive tumors, it is attractive to speculate that they represent a stem cell rich tumor. As shown by global gene expression analyses, genes involved, e.g. in cell adhesion, glycosylation and signal transduction, were deregulated in MDR-1 positive tumors compared to MDR-negative tumors. Overexpression of E-cadherin and carcinoembryonic antigen-related cell adhesion molecules 1 (CEACAM1) may provide clues to the mechanisms responsible for the reduced metastatic potential of MDR-1 overexpressing tumors. Since drug treatment shifted the cells towards a less metastatic phenotype in this in vivo model, it seems conceivable to achieve this using drug treatment also in a clinical situation.

Human soluble TRAIL/Apo2L induces apoptosis in a subpopulation of chemotherapy refractory nodal diffuse large B-cell lymphomas, determined by a highly sensitive in vitro apoptosis assay.

Resistance to chemotherapy in therapy-refractory diffuse large B-cell lymphomas (DLBCL) is related to inhibition of the intrinsic apoptosis pathway. Human soluble tumour necrosis factor (TNF)-related apoptosis-inducing ligand (hsTRAIL/Apo2L) induces apoptosis via the alternative, death-receptor mediated apoptosis pathway and might be an effective alternative form of therapy for these lymphomas. This study investigated whether hsTRAIL/Apo2L could actually induce apoptosis in isolated lymphoma cells of DLBCL biopsies of patients with chemotherapy-refractory DLBCL. Twelve out of a total of 22 DLBCL samples were sensitive to hsTRAIL/Apo2L. These sensitive lymphomas included seven clinically chemotherapy-refractory lymphomas. Furthermore, hsTRAIL/Apo2L induced apoptosis in DLBCL cells and in B-cell lines that showed high expression levels of inhibitors of the intrinsic apoptosis pathway: Bcl-2 and/or X-linked inhibitor of apoptosis (XIAP). hsTRAIL/Apo2L-sensitive lymphoma cells showed expression of the TRAIL receptors R1 and/or R2 and absence of R3 and R4. We conclude that hsTRAIL/Apo2L induced apoptosis in a subpopulation of chemotherapy-refractory nodal DLBCL and that disruption of the intrinsic apoptosis-mediated pathway and expression of Bcl-2 and XIAP did not confer resistance to hsTRAIL/Apo2L-induced apoptosis in DLBCL. Thus, based on our results, further exploration of hsTRAIL/Apo2L as an alternative treatment for patients with chemotherapy-refractory DLBCL should be considered.