First Experience with the NPseal®: A Novel Mechanically Powered Negative Pressure Dressing Applied to Colorectal Surgery Wounds.

Background: The use of prophylactic closed-incisional negative pressure wound therapy after colorectal procedures has been shown to reduce postoperative wound complications and surgical site infection. We present our experience with a novel, closed-incision, mechanically powered negative pressure (MP-NPD) dressing after colorectal procedures.

Methods: This was a prospective, single-center, single-arm observational study assessing patient reported and wound healing outcomes of colorectal surgical incisions dressed with a MP-NPD.

Pathologic Outcomes of Short-Course and Long-Course Radiotherapy for Locally Advanced Rectal Cancers Treated With Total Neoadjuvant Therapy.

Introduction: Total neoadjuvant therapy (TNT) for patients with locally advanced rectal cancer (LARC) is now the standard of care. Randomized trials suggest the use of short-course radiotherapy (SCRT) and long-course radiotherapy (LCRT) are oncologically equivalent.

Objective: To describe pathologic outcomes after surgical resections of patients receiving SCRT versus LCRT as part of TNT for LARC.

Complete mesocolic excision and extended lymphadenectomy: Where should we stand?

Debate regarding the risks and merits of complete mesocolic excision and extended lymphadenectomy is ongoing, particularly for right-sided colon cancers. In this article, we hope to provide a succinct yet encompassing review of the relevant literature. We posit that complete mesocolic excision with D3 dissection is indicated in select patients with colon cancers, particularly those distal to the cecum.

Inking outside the box: systematic review on the utility of tattooing lesions in rectal cancer.

Purpose: Endoscopic tattooing in rectal cancer is infrequently utilized for fear of tattoo ink obscuring anatomical planes, increasing the difficulty of surgical excision. Colon cancer tattooing has demonstrated increased lymph node yields and increased accuracy in establishing adequate margins. Rectal cancer tattooing may be especially helpful after neoadjuvant chemoradiation, where complete clinical responses could limit lesion identification and lymph node yields are typically less robust.

Endoscopy Reports for Rectosigmoid Tumors: Frequently Missing Key Information Needed for Surgical Planning.

Introduction: Endoscopy reports by gastroenterologists describing rectosigmoid tumors often are missing crucial data for surgical planning, leading to high rates of repeat exams before surgical decision-making. We hypothesize that there will be significant deficiencies in the endoscopic reporting of rectosigmoid lesions leading to high rates of repeat endoscopic examination at our institution.

Methods: Retrospective review from January 2016 to November 2019 included 188 patients with rectosigmoid lesions referred for surgery with an outside endoscopy report.

Prevalence of mesothelin expression in peritoneal disease from colorectal and appendiceal cancers.

Background: Mesothelin is a cell surface glycoprotein overexpressed in 28%-58% of colorectal cancer (CRC). We hypothesized that CRC mesothelin expression contributes to peritoneal spread and that it is selectively overexpressed in those with peritoneal metastasis versus distant metastasis.

Methods: This case-controlled study involved mesothelin immunohistochemistry staining of tumor specimens from patients with metastatic CRC/appendiceal cancers between 2017 and 2019.

Role of SUMO activating enzyme in cancer stem cell maintenance and self-renewal.

Cancer stem cells (CSCs) have key roles in treatment resistance, tumour metastasis and relapse. Using colorectal cancer (CC) cell lines, patient-derived xenograft (PDX) tissues and patient tissues, here we report that CC CSCs, which resist chemoradiation, have higher SUMO activating enzyme (E1) and global SUMOylation levels than non-CSCs. Knockdown of SUMO E1 or SUMO conjugating enzyme (E2) inhibits CC CSC maintenance and self-renewal, while overexpression of SUMO E1 or E2 increases CC cell stemness.

Alcohol fat clearing increases lymph node yield after surgery for colorectal cancer.

Lymph node (LN) yield is associated with oncologic outcome in patients who undergo surgery for colorectal adenocarcinoma (CRC). Standards to maximize LN yield have been initiated to enhance treatment of patients with CRC. This study evaluates the impact of a simple alcohol-based preparation protocol on LN yield.

TP53 and let-7a micro-RNA regulate K-Ras activity in HCT116 colorectal cancer cells.

Recent reports have indicated that KRAS and TP53 mutations predict response to therapy in colorectal cancer. However, little is known about the relationship between these two common genetic alterations. Micro-RNAs (miRNAs), a class of noncoding RNA implicated in cellular processes, have been increasingly linked to KRAS and TP53.

Mutations in specific codons of the KRAS oncogene are associated with variable resistance to neoadjuvant chemoradiation therapy in patients with rectal adenocarcinoma.

Background: Mutations in KRAS and TP53 are common in colorectal carcinogenesis and are associated with resistance to therapy. Rectal cancers carrying both mutations are less likely to respond to neoadjuvant chemoradiation therapy (CRT) compared with wild-type tumors. Codon-specific KRAS mutations are associated with variable resistance to targeted therapies, but their association with rectal cancer response to CRT remains unclear.

Distribution of residual cancer cells in the bowel wall after neoadjuvant chemoradiation in patients with rectal cancer.

Background: The standard treatment for locally advanced rectal cancer is preoperative chemoradiation and total mesorectal excision. After surgery, tumors are classified according to the depth of tumor invasion, nodal involvement, and tumor regression grade. However, these staging systems do not provide information about the distribution of residual cancer cells within the bowel wall.

Prognostic and predictive roles of KRAS mutation in colorectal cancer.

The RAS gene family is among the most studied and best characterized of the known cancer-related genes. Of the three human ras isoforms, KRAS is the most frequently altered gene, with mutations occurring in 17%-25% of all cancers. In particular, approximately 30%-40% of colon cancers harbor a KRAS mutation.

Gene polymorphisms predict toxicity to neoadjuvant therapy in patients with rectal cancer.

Background: Toxicity from neoadjuvant chemoradiation therapy (NT) increases morbidity and limits therapeutic efficacy in patients with rectal cancer. The objective of this study was to determine whether specific polymorphisms in genes associated with rectal cancer response to NT were correlated with NT-related toxicity.

Methods: One hundred thirty-two patients with locally advanced rectal cancer received NT followed by surgery.

Evaluation of lymphadenectomy in patients receiving neoadjuvant radiotherapy for rectal adenocarcinoma.

Background: Accurate pathologic staging has been shown to correlate with outcome in rectal cancer. Because the exact number of examined lymph nodes (LNs) may vary with preoperative therapies, our objective was to measure the impact of neoadjuvant radiation on LN number for rectal adenocarcinoma.

Methods: Patients who underwent curative-intent radical surgery for rectal adenocarcinoma in Los Angeles County (LAC) were identified from the Cancer Surveillance Program (CSP) of California (1988-2006).

Socioeconomic factors impact colon cancer outcomes in diverse patient populations.

Purpose: Cancer disparities among racial and ethnic groups are major public health concerns. Our objective was to examine the impact of socioeconomic status (SES) on survival of colon cancer patients within major racial and ethnic groups.

Methods: Patients with colon adenocarcinoma from Los Angeles County (LAC) were assessed.

Surgical complications and pathologic complete response after neoadjuvant chemoradiation in locally advanced rectal cancer.

Pathologic complete response (pCR) to neoadjuvant chemoradiation (CRT) in patients with rectal cancer is associated with improved prognosis, whereas postoperative surgical complications have been linked with poor oncologic outcomes. Our objective was to examine the association between postoperative complications and pCR. We analyzed 127 patients enrolled in a prospective multicenter study investigating rectal cancer response to CRT.

Molecular diagnosis of response to neoadjuvant chemoradiation therapy in patients with locally advanced rectal cancer.

Background: Pathologic complete response (pCR) to neoadjuvant chemoradiation (CRT) is an important prognostic factor in locally advanced rectal cancer. However, it is uncertain if histopathological techniques accurately detect pCR. We tested a novel molecular approach for detecting pCR and compared it with current histopathological approaches.