Endoscopic self-expanding metal stents for acute colonic obstruction.

The current study presents our experience with the introduction of self-expanding metal stents (SEMS) and assesses success rate, clinical outcomes, and complications. We conducted a historical cohort study reviewing endoscopic SEMS insertions between 2000 and 2010. Overall, 51 patients underwent stent insertion: 38 with an emergent procedure and 13 with a semielective procedure. SEMS was inserted in 27 men and 24 women with a mean age of 68.9 years. Colonic malignancy was the cause of obstruction in all patients. The tumors were localized in the rectosigmoid in 33 (64.7%), in the left colon in 16 (31.4%), and in the right colon in two cases (3.9%). Endoscopic SEMS insertion was technically successful in 68.4 per cent of patients in an emergency and in 84.6 per cent of patients in a semielective setting. Successful stent insertion allowed a "bridge to surgery" in 23 and palliative care in 14 patients. Stent migration occurred in three, obstruction in two, and bowel perforation in three cases. Nineteen patients in the emergent group underwent a subsequent successful semielective colonic resection within 8.1 days (range, 2 to 30 days) of stent insertion. There were two cases (11.1%) of major and four cases (22.2%) of minor postoperative complications in this series. No anastomotic leaks were observed. Mean postoperative hospitalization was 10.1 days (range, 5 to 45 days). Endoscopic stent insertion is a relatively simple procedure providing an effective first-line treatment for relief of symptoms of acute malignant colorectal obstruction, preventing acute perforation, and serving either as a preoperative procedure (allowing lower morbidity semielective surgery) or as palliative care.

Diamond shaped optical fiber delivery system.

BACKGROUND: Optical fibers are generally used with a flat cut end. The adaptation of a coaxial exit of a refrigerated gas near the distal tip of the optical fiber cools the tissue where the laser beam is applied and reduces the injury of thermal effects on biological tissue. MATERIALS AND METHODS: We have changed the flat end geometry of the fiber's end to a pyramidal end shape (named: Diamond tip). In this project we have evaluated the new shape of the fiber's end using laboratory tests and in real conditions. We have examined the emission pattern in the air and in water as well as its performance in surgery. RESULTS: With the new shape better results were obtained: higher power density, more utilizations of the same fiber (after sterilization) resulting in economical savings. The diamond tip is characterized by greater mechanical resistance then conical tip delivery systems. The greater resistance of the Diamond tip prevents optical fiber breakage during surgery. The delivered system can be reshaped by a trained hospital physician and reused. Our experience shows that delivery systems intended by the producer to one use only can be converted, by reshaping their tips, to highly performing delivery systems, which can be reused many times. In addition less power was needed, with less tissue penetration. The thermal effect was minimized and higher mechanical resistance was achieved, which allowed reusing the fiber more than six times. The special structure of the faces of the optical fiber diamond tip eased its sliding. CONCLUSION: The Diamond tip is superior to other fiber end tips by having minimal thermal effects, higher mechanical resistance and by being reused many times.

Prediction potential of IR-micro spectroscopy for colon cancer relapse.

This study aimed to determine the potential of IR-spectroscopy to diagnose abnormality in histologically normal resection margins for predicting relapse in colon cancer patients. The present study evaluates potential abnormal crypt proliferation in histologically normal resection margins. Resection margins of 10 colon cancer patients (adenocarcinoma) (27 biopsies in all), found completely normal by standard histology were re-evaluated. Fourier transform infrared microscopy (FTIR-MSP) was performed on the longitudinal sections of the crypt, and spectral data collected from the base, middle and top portion of crypts. Absorbance in the region 900-1185 cm(-1) arising from carbohydrates and nucleic acids was found to be the most effective variate for such evaluation. In total 225 crypts were classified after assessing the levels of abnormality observed by the above technique. The abnormal biopsies detected using the above optical method was correlated with a relapse in the patient's history. Patients who had a relapse had at least one abnormal biopsy (crypt) based on the present methodology. Among the patients, the only case without a relapse was also the case where no abnormal crypts were found in any biopsies from the resection margins. The agreement between the biopsy status, as determined by the optical methodology, and the relapse of colonic malignancy based on the patients' medical files, establishes the translational nature of FTIR-MSP for medical purposes and hints at future clinical evaluation of the biopsies using this technique to determine more precisely the zone of excision during anastomosis.

A similar cell-specific pattern of HOXA methylation in normal and in cancer tissues.

HOX genes are developmental genes that determine anterior-posterior embryonic pattern and govern the process of differentiation. Inappropriate expression of HOX genes has been implicated in developmental abnormalities and hematopoietic malignancies. In addition, HOX genes silencing by DNA methylation has been reported in cancers and related to disease aggressiveness and outcome. On the other hand, accumulating evidence suggests that epigenetic changes at HOX genes are linked to normal development and differentiation. To better understand the relationship between HOXA methylation and cancer, we analyzed the methylation pattern of HOXA genes in human primary breast and colon carcinomas, normal tissues, and normal white blood cells. Genome-wide methylation arrays of breast cancers and white blood cells demonstrated similar methylation patterns. Quantitative methylation analysis of seven representative HOXA genes revealed various levels of methylation in both normal tissues and cancers. Analysis of epithelial-enriched normal breast tissue and stroma indicated that the stroma was the major origin of HOXA methylation. Furthermore, in selected dense breast cancers, minimal increase in methylation of several HOXA genes did not correlate with the predominance of malignant epithelial cells in these tumors. Our results suggest that methylation of the HOXA cluster may be a normal developmental and cell type specific process rather than a cancer specific mechanism.

Mantle cell lymphoma in a tubular adenoma: unusual presentation with synchronous colonic carcinoma.

An 80-year-old man underwent sigmoidectomy for adenocarcinoma. Six months later, after a near-syncope incident, pancytopenia was detected in the absence of occult blood in the stools. A bone marrow biopsy showed malignant lymphoma, suggestive of mantle cell lymphoma (MCL). Colonoscopy at this time revealed 3 colonic tubular adenomas. Reassessment of the histology of the colonic polyps and appropriate immunohistochemical stains showed that the lamina propria of one of the tubular adenomas was infiltrated by MCL. Reexamination of the sections taken at the time of the original sigmoidectomy showed MCL in 2 of the regional lymph nodes removed at that time, but no evidence of lymphoma in the colon was found. To our knowledge, this is the fifth reported case of synchronous occurrence of intestinal MCL and colonic carcinoma and the first report of MCL presenting in a tubular adenoma of the colon.

Tomato lycopene extract supplementation decreases insulin-like growth factor-I levels in colon cancer patients.

Epidemiological studies have shown that high serum levels of insulin-like growth factor-I are associated with an increased risk of colon and other types of cancer. The aim of this study was to determine whether short intervention with dietary tomato lycopene extract will affect serum levels of the insulin-like growth factor system components in colon cancer patients. The study had a double-blind, randomized, placebo-controlled design. Colon cancer patients (n=56), candidates for colectomy, were recruited from the local community a few days to a few weeks before surgery. Personal and medical data were recorded. Plasma concentrations of insulin-like growth factor-I and II and insulin-like growth factor-I-binding protein-3 were assayed by routine laboratory methods. Lycopene was assayed by high-performance liquid chromatography. Plasma lycopene levels increased by twofold after supplementation with tomato lycopene extract. In the placebo-treated group, there was a small nonsignificant increase in lycopene plasma levels. The plasma concentration of insulin-like growth factor-I decreased significantly by about 25% after tomato lycopene extract supplementation as compared with the placebo-treated group (P<0.05). No significant change was observed in insulin-like growth factor-I-binding protein-3 or insulin-like growth factor-II, whereas the insulin-like growth factor-I/insulin-like growth factor-I-binding protein-3 molar ratio decreased significantly (P<0.05). Given that high plasma levels of insulin-like growth factor-I have been suggested as a risk factor for various types of cancer including colon cancer, the results support our suggestion that tomato lycopene extract has a role in the prevention of colon and possibly other types of cancer.

Colitis cystica profunda and solitary rectal ulcer syndrome-polypoid variant: Two confusing clinical conditions.

Colitis cystica profunda and solitary rectal ulcer syndrome-polyoid variant are related chronic benign disorders with characteristic histological features. However, the clinical and endoscopic settings are confusing and misleading, suggesting other rectal conditions. We report a case of colitis cystica profunda and solitary rectal ulcer syndrome-polypoid variant that was misdiagnosed initially as an ulcerative proctitis. Since an occult malignancy could not be ruled out by superficial biopsies, the mass was removed by full-thickness transanal excision.

Combined multimodal approach to the treatment of metastatic anal carcinoma: report of a case and review of the literature.

BACKGROUND: We report on a patient with squamous cell anal carcinoma and liver metastases, who underwent multimodal treatment for cure, consisting of repeated partial hepatectomy in combination with chemoradiotherapy. PATIENTS AND METHODS: A 54-year-old woman presented with squamous cell anal carcinoma and liver metastases. She was treated with a combination of chemoradiotherapy for the primary tumor and then underwent surgery for liver metastases. 2 and 5 years after presentation, the patient underwent repeated partial hepatectomies for recurrent liver disease. At present, 5 months after completing therapy and 71 months after the initial diagnosis, she is in good health with no evidence of disease. RESULTS: Repeated partial hepatectomy led to prolonged survival in a patient with squamous cell anal carcinoma metastatic to the liver. CONCLUSIONS: This is the first report of aggressive partial hepatectomy for recurrent liver metastases resulting from anal cancer. Based on our experience, we suggest that in selected patients repeated hepatectomy should be part of an aggressive multimodal treatment program with curative intent.

Modulation of transcriptional activity by antioxidant carotenoids.

It is widely accepted that diet changes are a powerful means to prevent cancer. The possible involvement of transcriptional activity in the anticancer activity of carotenoids will be the focus of this review. Carotenoids function as potent antioxidants, and this is clearly a major mechanism of their action. In addition carotenoids action involves interference in several pathways related to cancer cell proliferation and includes changes in the expression of many proteins participating in these processes such as connexins, phase II enzymes, cyclins, cyclin-dependent kinases and their inhibitors. These changes in protein expression suggest that the initial effect involves modulation of transcription by ligand-activated nuclear receptors or by other transcription factors. It is feasible to suggest that carotenoids and their oxidized derivatives interact with a network of transcription systems that are activated by different ligands at low affinity and specificity and that this activation leads to the synergistic inhibition of cell growth.