T cell neoepitope discovery in colorectal cancer by high throughput profiling of somatic mutations in expressed genes.

OBJECTIVE: Patient-specific (unique) tumour antigens, encoded by somatically mutated cancer genes, generate neoepitopes that are implicated in the induction of tumour-controlling T cell responses. Recent advancements in massive DNA sequencing combined with robust T cell epitope predictions have allowed their systematic identification in several malignancies. DESIGN: We undertook the identification of unique neoepitopes in colorectal cancers (CRCs) by using high-throughput sequencing of cDNAs expressed by standard cancer cell cultures, and by related cancer stem/initiating cells (CSCs) cultures, coupled with a reverse immunology approach not requiring human leukocyte antigen (HLA) allele-specific epitope predictions. RESULTS: Several unique mutated antigens of CRC, shared by standard cancer and related CSC cultures, were identified by this strategy. CD8+ and CD4+ T cells, either autologous to the patient or derived from HLA-matched healthy donors, were readily expanded in vitro by peptides spanning different cancer mutations and specifically recognised differentiated cancer cells and CSC cultures, expressing the mutations. Neoepitope-specific CD8+ T cell frequency was also increased in a patient, compared with healthy donors, supporting the occurrence of clonal expansion in vivo. CONCLUSIONS: These results provide a proof-of-concept approach for the identification of unique neoepitopes that are immunogenic in patients with CRC and can also target T cells against the most aggressive CSC component.

Cancer-initiating cells from colorectal cancer patients escape from T cell-mediated immunosurveillance in vitro through membrane-bound IL-4.

Cancer-initiating cells (CICs) that are responsible for tumor initiation, propagation, and resistance to standard therapies have been isolated from human solid tumors, including colorectal cancer (CRC). The aim of this study was to obtain an immunological profile of CRC-derived CICs and to identify CIC-associated target molecules for T cell immunotherapy. We have isolated cells with CIC properties along with their putative non-CIC autologous counterparts from human primary CRC tissues. These CICs have been shown to display "tumor-initiating/stemness" properties, including the expression of CIC-associated markers (e.g., CD44, CD24, ALDH-1, EpCAM, Lgr5), multipotency, and tumorigenicity following injection in immunodeficient mice. The immune profile of these cells was assessed by phenotype analysis and by in vitro stimulation of PBMCs with CICs as a source of Ags. CICs, compared with non-CIC counterparts, showed weak immunogenicity. This feature correlated with the expression of high levels of immunomodulatory molecules, such as IL-4, and with CIC-mediated inhibitory activity for anti-tumor T cell responses. CIC-associated IL-4 was found to be responsible for this negative function, which requires cell-to-cell contact with T lymphocytes and which is impaired by blocking IL-4 signaling. In addition, the CRC-associated Ag COA-1 was found to be expressed by CICs and to represent, in an autologous setting, a target molecule for anti-tumor T cells. Our study provides relevant information that may contribute to designing new immunotherapy protocols to target CICs in CRC patients.

A Rare Case of Small Bowel Obstruction due to Migration of a Percutaneous Biliary Stent.

Biliary endoprostheses are widely used in the treatment of biliary lithiasis, malignant and benign strictures, and occasionally in long-lasting biliary fistulas. They can be placed endoscopically during endoscopic retrograde cholangiopancreatography and radiologically (percutaneous) when the endoscopic route is not feasible. Complications associated with the endoscopic placement of biliary endoprostheses are well described in the literature, with migration being the most common. Intestinal obstruction is a rare complication associated with the migration of these devices. There are no reports in the literature of this complication occurring after percutaneous placement. We present a case of a patient who arrived at the emergency department with ileal obstruction secondary to the migration and concurrent embedding of a covered stent placed radiologically to treat a biliary leak after surgery. The patient underwent diagnostic laparoscopic and ileal resection, revealing a lithiasic concretion at the tip of the stent, causing the small bowel obstruction.

Effect of prednisolone on local and systemic response in laparoscopic vs. open colon surgery: a randomized, double-blind, placebo-controlled trial.

PURPOSE: This study was designed to assess whether preoperative, short-term, intravenously administered high doses of methylprednisolone (30 mg/kg 90 minutes before surgery) influence local and systemic biohumoral responses in patients undergoing laparoscopic or open resection of colon cancer. METHODS: Fifty-two patients who were candidates for curative colon resection were randomly assigned to laparoscopic or open surgery and, in a double-blind design, assigned to receive methylprednisolone (n = 26) or placebo (n = 26). Pulmonary function, postoperative pain, C-reactive protein, interleukins 6 and 8, and tumor necrosis factor alpha were analyzed, as was patient outcome. RESULTS: The steroid and placebo groups were well balanced for preoperative variables, as were the subgroups of patients who underwent laparoscopic (methylprednisolone, n = 13; placebo, n = 13) and open surgery (methylprednisolone, n = 13; placebo, n = 13). No adverse events related to steroid administration occurred. In the methylprednisolone groups, significant improvement in pulmonary performance (P = 0.01), pain control (P = 0.001), and length of stay (P = 0.03) were observed independent of the surgical technique. No differences in morbidity or anastomotic leak rate were observed among groups. CONCLUSION: Preoperative administration of methylprednisolone in colon cancer patients may improve pulmonary performance and postoperative pain, and shorten length of stay regardless of the surgical technique used (laparoscopy, open colon resection).

Laparoscopic incisional and ventral hernia repair without sutures: a single-center experience with 200 cases.

BACKGROUND: Laparoscopic incisional and ventral herniorraphy (LIVH), using a mesh, has gained recognition as an effective method and is associated with lower complication and recurrence. Controversies in the operative technique still exist about biomaterial, method of fixation, and overlap of the mesh over the defect. The aim of this study was to evaluate the outcomes achieved with LIVH in 200 consecutive patients treated in a single hospital, using fixation of the mesh with only tacks. Results of the first 100 (group A) and the last 100 (group B) operations were also compared. METHODS: From 2003 through 2007, 200 patients underwent LIVH. Overlap of the mesh was 3-5 cm. The mesh was secured with tacks alone, with the "double crown" technique. In group B, adhesiolysis was performed, avoiding high energies. RESULTS: Mean ventral defect was 107.5 (+/- 95.4) cm2. The recurrent ventral hernia rate was 20%, and the conversion rate was 2.5%. Mean operative time was 77.5 (+/- 33.9) minutes. Mean mesh dimension was 326.4 (+/- 166.8) cm2. The overall morbidity rate was 10.5%. Bowel injuries were 5 (2.5 %). Minor complications were 8.0%. Median postoperative hospital stay was 3 days. Recurrence rate was 3.5%, with a mean follow-up of 22.5 months. Chronic pain was 1%. No difference was seen between groups A and B regarding minor complications, whereas a significant difference was found regarding enterotomies (5 vs. 0; P = 0.024) and recurrences (6 vs. 1; P = 0.056). CONCLUSIONS: Fixation of the mesh with the sole use of tacks was demonstrated to be safe and effective. Avoiding high energies, no case of enterotomy occurred.

Short and long-term outcomes of laparoscopic colectomy in obese patients.

AIM: To investigate the impact of laparoscopic colectomy on short and long-term outcomes in obese patients with colorectal diseases. METHODS: A total of 98 obese (body mass index > 30 kg/m(2)) patients who underwent laparoscopic (LPS) right or left colectomy over a 10 year period were identified from a prospective institutionally approved database and manually matched to obese patients who underwent open colectomy. Controls were selected to match for body mass index, site of primary disease, American Society of Anesthesiologists score, and year of surgery (± 3 year). The parameters analyzed included age, gender, comorbid conditions, American Society of Anaesthesiologists class, diagnosis, procedure, and duration of operation, operative blood loss, and amount of homologous blood transfused. Conversion rate, intra and postoperative complications as were as reoperation rate, 30 d and long-term morbidity rate were also analyzed. For continuous variables, the Student's t test was used for normally distributed data the Mann-Whitney U test for non-normally distributed data. The Pearson's χ(2) tests, or the Fisher exact test as appropriate, were used for proportions. RESULTS: Conversion to open surgery was necessary in 13 of 98 patients (13.3%). In the LPS group, operative time was 29 min longer and blood loss was 78 mL lower when compared to open colectomy (P = 0.03, P = 0.0001, respectively). Overall morbidity, anastomotic leak and readmission rate did not significantly differ between the two groups. A trend toward a reduction of wound complications was observed in the LPS when compared to open group (P = 0.09). In the LPS group, an earlier recovery of bowel function (P = 0.001) and a shorter length of stay (P = 0.03) were observed. After a median follow-up of 62 (range 12-132) mo 23 patients in the LPS group and 38 in the open group experienced long-term complications (LPS vs open, P = 0.03). Incisional hernia resulted to be the most frequent long-term complication with a significantly higher occurrence in the open group when compared to the laparoscopic one (P = 0.03). CONCLUSION: Laparoscopic colectomy in obese patients is safe, does not jeopardize postoperative complications and resulted in lower incidence of long-term complications when compared with open cases.