RNA expression of the molecular signature genes for metastasis in colorectal cancer

Colorectal cancer is an endemic disease in the Western world. Search for molecular signatures present in primary tumors that predict tumor metastasis potential has been proposed and in particular, a 17-gene molecular signature is associated with poor survival in breast cancer, prostate cancer, meduloblastoma and lymphoma in a recent study. Using quantitative real-time PCR assay (qPCR), our study observed tumor-normal differential RNA expression in 15 of these 17 genes in a cohort of 52 stage III colorectal cancer patients (all P0.05), two distinct groups among these genes were observed with Spearman correlation scores >0.6 (P0.05), but the recurrence group had more patients with mucinous tumors (9/12 vs. 7/25, P<0.05) and more lymph node involvement (median 7.2 vs. 2.5, P<0.05) compared to the non-recurrence group. Moreover, survival analysis revealed a significant difference in patient overall survival time between low and high tumor RNA levels for 1 of the 17 genes (PTTG1, P=0.024). Our qPCR validation study confirms the importance of most 17-gene molecular signature genes with differential RNA expression and suggests the relevance of PTTG1 for survival in colorectal cancers

Celecoxib pre-treatment in human colorectal adenocarcinoma patients is associated with gene expression alterations suggestive of diminished cellular proliferation

Cancer cells treated with the cyclooxygenase-2 inhibitor celecoxib show growth inhibition and induced apoptosis. This study was conducted to determine if the same processes are relevant to celecoxib’s effects on human colorectal adenocarcinomas treated in vivo. A cohort of 23 patients with primary colorectal adenocarcinomas was randomized to receive a 7-day course of celecoxib (400 mg b.i.d.) or no drug prior to surgical resection. Gene expression profiling was performed on resected adenocarcinomas from the cohort of patients. Using fold change (>1.5) and p-value (<0.05) cut-offs, 190 genes were differentially expressed between adenocarcinomas from patients receiving celecoxib and those that did not. The celecoxib pre-treated samples showed decreased expression levels in multiple genes involved in cellular lipid and glutathione metabolism; changes associated with diminished cellular proliferation. Celecoxib pre-treatment for 7 days in vivo is associated with alterations in colorectal adenocarcinoma gene expression which are suggestive of diminished cellular proliferation

Getting Started in Clinical Research

Clinical research is an important part of an academic surgery practice. To be successful, it is important to understand the multiple regularity committees and organizations that impact research. The author briefly reviews these groups and provides guidance on how to initiate and conduct research

Laparoscopy for Colon and Rectal Cancer

Laparoscopy has emerged as a useful tool in the surgical treatment of diseases of the colon and rectum. Specifically, in the application of colon cancer, a laparoscopic-assisted approach offers short-term benefits to patients while maintaining a long-term oncologic outcome. Hand-assisted laparoscopic surgery may help decrease operative times while preserving the benefits of laparoscopy. The literature on the use of laparoscopy for rectal cancer is still in its early stages. Limited data suggest short-term benefits without compromising oncologic outcome; however, data from large multicenter trials will clarify the role of laparoscopy in the treatment of rectal cancer. Robotic proctectomy is a novel technique that may offer considerable advantage and overcome some limitations laparoscopy creates while working in the confines of the pelvis. The improved magnification and visualization offered with the robot may also assist in preserving bladder and sexual function. Transanal endoscopic microsurgery (TEM) for the treatment of T1 rectal cancers with low-risk features appears to be safe. However, TEM has a significantly higher recurrence rate when used to treat invasive cancer. Endoluminal techniques and equipment are under development and could offer more minimally invasive approaches to the treatment of colon and rectal cancer. Credentialing and training of surgeons and teams involved in the use of laparoscopy is important prior to making these techniques ubiquitous

Colorectal Gastrointestinal Stromal Tumors: A Brief Review

Gastrointestinal stromal tumors (GISTs) are rare lesions that constitute the majority of mesenchymal tumors in the gastrointestinal tract. Within the colon and rectum, they represent 0.1% of all cancers. They can present with a variety of symptoms but are often asymptomatic. Although many lesions may be benign, up to half of patients develop recurrent disease within a few years. Almost all GISTs contain a mutation in the c-kit tyrosine kinase that leads to its constitutive activation and results in cell proliferation. This discovery has led to the immunostaining of the c-kit antigen (CD117) to distinguish GISTs from other malignancies. Radiologic examinations can be helpful in initial diagnosis and staging. Surgery is the best treatment for cure, but recent advances have led to the use of imatinib mesylate, a tyrosine kinase inhibitor, to treat metastatic or unresectable disease, or both. There are currently many clinical trials available to help treat GISTs

Receptive Field Organization in Ferret Primary Auditory Cortex: Spectral Orientation Columns

Abstract not available

Comparison of long-term follow up of laparoscopic versus open colectomy for transverse colon cancer.

Clinical Outcomes of Surgical Therapy (COST) was a landmark study demonstrating that laparoscopic-assisted colectomy had oncologic outcomes similar to those of open colectomy for colon cancer, but transverse colon cancers (TCCs) were excluded from that study. Oncologic results of a laparoscopic resection for TCC are unknown. This single-institution retrospective 3:1 case-matched review examined patients treated for TCC from January 1, 1996, to April 15, 2009. Laparoscopic colectomy (LC) and open colectomy (OC; extended right, extended left, and total abdominal) cases completed for Stage I to III adenocarcinoma of the transverse colon (hepatic flexure, transverse colon, and splenic flexure) were analyzed. Patients were matched for age, tumor location, and stage. Primary endpoints were overall survival and disease-free survival. Secondary endpoints were length of stay and pathologic parameters. One hundred and twenty-three OC cases were matched with 41 LC cases. There were four conversions (9.7%) in the LC group. Length of stay was reduced by 28% in the LC group (P = 0.02). Complication rate and severity were similar between the two groups (29% vs 24%; P = 0.68). Lymph node harvest was higher in the LC group than in the OC group (23.3 vs 18.6; P = 0.03). All pathologic margins were clear, and no local recurrence was found in either group. Five-year overall survival (61% vs 59%; P = 0.39) and disease-free survival (88% vs 82%; P = 0.23) were similar in the two groups. Short-term recovery was faster and lymph node harvest was improved in the LC group. Thus, laparoscopic management of TCC is a safe and feasible procedure